100 years of breeding

Cereal

Fiber

Forage

Fruit

Germplasm

Nuts

Oilseed

Ornamental

Vegetable

Plant Breeding Academy

Research and Information Centers

Plant Breeding Program COLLEGE OF AGRICULTURAL AND ENVIRONMENTAL SCIENCES Office of the Dean COLLEGE OF AGRICULTURAL AND ENVIRONMENTAL SCIENCES AOffice ofnote the Dean from the editor

ummarizing 100 years of history not only California, but the United Sin plant breeding at UC Davis is States and in many cases the world, a formidable task. As a land-grant to enjoy fresh produce throughout university, UC Davis has played the year. This publication captures a major role in developing and the impact that UC Davis has had managing many of the more than on developing crops through plant 350 plant commodities now grown breeding over the last century and in California. The diversity of crops just as importantly, highlights the ranges across vegetables, fruits, nuts, people who have made this possible. grains, forages, ornamentals and turf. ! In the early 1900s the focus was on a few grain crops, and has expanded considerably since that time. The application of plant breeding and training of breeders at UC Davis Allen Van Deynze focused on the unique and diverse (530) 754-6444 California environment, allowing [email protected]

Table of contents Peach, processing 20 Vegetable Strawberry 22 Artichoke 36 Dean’s address 3 Prune and plum 24 Carrot 37 Celery 38 Cereal Germplasm Garlic 39 Oat 4 Foundation Seed Program 25 Grain legumes 40 Other Triticeae 5 Foundation Plant Services 26 Lettuce 42 Rice 6 C.M. Rick Tomato Potato 44 Wheat 8 Genetics Resource Center 27 Sweet potato 45 Barley 10 Tomato 46 Nuts Onion 48 Fiber Almond 28 Pepper 48 Cotton 11 Walnut 30 Pistachio 32 Miscellaneous Forage Plant Breeding Academy 49 Alfalfa 12 Oilseed Research and Information Clover, Berseem 14 Safflower 33 Centers 50 Plant Breeding Program 51 Fruit Ornamental Acknowlegements 51 Cherry 15 Arboretum All-Stars 34 Melon 15 Buffalograss, turf 35 Grape: table and wine 16 Fig 18 Rootstocks for stone fruit 19

2 UC Davis Plant Breeding Program Dean’s address In support of plant breeding

lant breeding at the University Our strawberry program provided Pof California, Davis, has been a the germplasm for 60 percent of priority since the beginning days of the world’s strawberries; more the campus. It was recognized early than 80 percent of the strawberries on that a program in production produced in North America are agriculture, which included from UC Davis varieties. The alfalfa plant breeding, was necessary for breeding program recently released California farmers to thrive. In 1906, varieties with the single-known the University Farm — now the source of resistance to whiteflies. UC Davis campus — was established As leaders in virus treatment as part of the UC Berkeley campus. technology, UC Davis maintains By then, plant breeding was clean seed stock of many of the already well underway. In 1870, a genetic resources for the world, selection was made for the almond including tomatoes, strawberries, variety Nonpareil that would remain grapes, cherries, peaches, the primary female almond variety plums, pistachios, almonds, for the next 100 years. Wheat sweet potatoes, and roses. improvement programs began at These are but a sample of the UC Davis in 1904, with selections established and transformed by the many accomplishments of the from Spanish introductions. wild tomato germplasm collections thousands of plant breeders and Both of these programs remain made by Charlie Rick; these students who have been affiliated internationally recognized today. collections are still maintained on with UC Davis. Our campus Our researchers are now using campus and used in international continues to evolve in training breeding techniques that were not breeding programs. The tomato- plant breeders with the recent even imaginable 100 years ago. processing industry in California introduction of the Plant Breeding Key breeding developments came about as a result of the joint Academy. It is only fitting that have come from UC Davis that development of tomatoes that its inaugural class graduated on can be mechanically harvested this centennial anniversary. UC Davis researchers and the tomato harvester — both Researchers at UC Davis remain were landmark research areas committed to plant breeding and remain committed at UC Davis in the 1950s. working with the agricultural and to plant breeding The basis of much of the plant food industries to enhance the breeding and plant genetics economic vitality of agriculture and working with the research in California is rooted and improve the health and quality agricultural and food at UC Davis. Robert Allard spent of life for Californians and people four decades (1940s–1970s) throughout the world. UC Davis has industries to enhance developing our understanding progressed markedly from its early the economic vitality of the recombination of genes, University Farm days to its current quantitative genetics, and gene position as a premier international of agriculture. interactions with the environment. research university — our plant Clonal selections of grapes were breeding programs reflect our rich have changed and improved many made at UC Davis by Harold Olmo heritage and our commitment to agricultural crops. Male-sterile in the 1950s and ’60s that resulted food and agriculture in California. lines were discovered in carrot in the success of the Chardonnay and onion, thereby establishing grape as a California crop — Neal Van Alfen their hybrid-seed industries. Chardonnay grapes are now grown Dean, College of Agricultural The tomato industry was on nearly 100,000 acres in the U.S. and Environmental Sciences

UC Davis Plant Breeding Program 3 Cereal

Oat Avena sativa L. As top breeders, sowing our oats

at ranks just behind wheat, Obarley, and rice in cereal pro- Cal Qualset and duction in California, and is grown UC oat varieties. primarily for hay, secondarily for grain, and rarely for human con- sumption. UC Davis has been active in its development since the 1930s. Oat production in California ini- tially was derived from introduced landraces, such as California Red, Coastblack, Fulghum, and Kanota. UC Davis released a mass-selection purified stock source of California Red in 1937 which became the pri- mary source of all subsequent pro- duction of that variety in California. Early oat breeding at Davis con- sisted primarily of screening lines for adaptation as well as pest and Coit Suneson, a USDA breeder Calvin Qualset has led oat breed- pathogen resistances and releasing located at UC Davis, bred several ing at UC Davis since 1968, focus- promising lines. For example, West- oat varieties — Indio in the 1950s, ing on expanding genetic diversity; dale was released in 1942 by the Ag- selected from crosses that included breeding and distributing oat vari- ricultural Experiment Station (AES) Fulghum and Palestine in their par- eties with disease resistance, good at Davis after screening showed it entage, and Curt (1958), the first agronomic traits, and high grain and had resistance to a stem rust which short-statured cereal crop released in forage yield; and building a system of was impacting Central Coast oat the U.S. He also exploited hybrids of seed multiplication and distribution production. Another example is Pal- cultivated oat varieties with wild oat, to ensure new varieties are widely estine, distributed in the late 1940s and released Sierra (1961), Rapida available to California growers. In by the AES for its drought resistance. (1966), and Montezuma (1968). 1994, Qualset released Pert and Bates-89. By 1997, Pert had become the major variety planted in the state. Other varieties from this program Decade Variety Breeder have recently been released: UC 113, 2000s UC 113, UC 125, UC 128, Qualset UC 125, UC 128, UC 129, UC130, UC 129, UC 130, UC 132, UC 132, UC 142, and UC 148. UC 142, and UC 148 1990s Pert, Bates 89 Qualset Early researchers: W.W. Mackie, G.W. Hendry. Breeders: G.A. Wie- 1960s Rapida, Sierra, Montezuma Suneson be, USDA (1920s–1934), C.A. 1950s Indio, Curt Suneson Suneson, USDA-Dept. of Agronomy/ 1940s Ventura, Palestine, Westdale Suneson Agronomy and Range Science (1936–1968), C.O. Qualset, Dept. 1920s Kanota, Fulghum introductions of Agronomy and Range Science/ 1910s California Red, Coastblack landraces Plant Sciences (1968–present).

4 UC Davis Plant Breeding Program Cereal

Other Triticeae Donald Kirby in the triticale and wheat plots at the Tule Varieties Lake field station. put to good use

he grass-family tribe Triticeae T consists of the cereal crop species of wheat, barley, rye, triticale, and many wild species often used as gene sources for crop improvement. UC Davis breeders have focused on rye and triticale and interspecific hybrids between crops and wild Triticeae species. Triticale is a relatively new crop, Coit Suneson, USDA-UC Davis, or distorted seeds. The goal was a produced by hybridizing wheat and worked from the 1940s into the seed crop that did not need annual rye and chemically doubling the 1960s to develop a perennial wheat. replanting. Commercial success chromosome number of the hybrid. He created a bulk population of was never achieved, but it was Triticale has a place as feed and for progeny from crosses between five released as a bulk population (CAS human consumption as flour and different wheat varieties, which 10180) and has found some use for in whisky. Research at UC Davis has are annual, and two species of feeding game birds during winters. centered on reducing height and wheatgrass, which are perennial. lodging tendency and increasing The population was sometimes Breeders: C.A. Suneson, USDA-ARS/ fertility and grain quality. Calvin supplemented by additional crosses, Dept. of Agronomy (1936–1965), Qualset, a UC Davis professor of with the mechanical removal C.O. Qualset, Dept. of Agronomy agronomy and breeder, released of plants expressing undesired, and Range Science (1967–1994). three spring triticales: the dwarf primitive traits such as fragile stems variety UC-38 in 1973, Siskiyou in 1978, and Juan in 1984. Rye (Secale cereale L.) is an out- crossing species, unlike the other Other Triticeae cereals Triticeae crops which are self-pol- linating, and is a very minor crop Decade Variety Breeder in California. Merced, named and 1980s Juan (triticale) Qualset released in 1947, is a population 1970s UC-90 (dwarf rye population), Qualset derived from a landrace. It has been UC-38 (dwarf triticale), used widely as a forage grass and re- Siskiyou (triticale) cently as a cover crop. UC-90 was a 1960s CAS 10180 Suneson dwarf winter rye released by Qualset (perennial wheat population) in 1973, used primarily as a par- ent in triticale production with the 1940s Merced (rye population) landrace goal of short-statured triticale lines.

UC Davis Plant Breeding Program 5 Cereal

Stakeholders tour a rice field at the California Rice Field Day held each year in August at the Rice Experiment Station in Biggs, Calif.

Rice Oryza sativus L. Cooperation makes for nice rice

he rice industry in California and other disciplinary research. and Foundation Seed at UC Davis Tdistinguishes itself from the The California Rice Research to ensure the availability of pure, rest of the United States by growing Board (RRB) funds the program weed-free, high-quality seed. short-, medium-, and specialty-grain through a grower-voted check-off A large interdisciplinary team of rice destined for local and Japonica- system based on production. scientists from UC Davis and the type rice markets. The success UC Cooperative Extension county of the California rice industry is UC Davis contributes programs continually evaluates based on the close collaboration of Before any new rice variety is new integrated strategies for the industry breeding program at released, it must be evaluated under sustainable rice production. These the Rice Experiment Station (RES) real-world growing conditions over include research on integrated pest in Biggs, a USDA rice genetics several years to ensure stability of management to control filamentous program at UC Davis, and the UC traits relative to current reference algae, armyworm, rice water weevil, Cooperative Extension (UCCE) varieties. At least sixteen preliminary and tadpole shrimp in rice fields. rice variety evaluation program. and advanced breeding-line trials are On-farm experiments show how An important objective is to conducted annually by UCCE across nitrogen management needs to address the breadth of industry the California rice-growing region. be modified as weed control and research needs, including support Foundation seed of California water management practices take of UC and USDA research, public rice varieties is produced on new directions. Rice variety by providing land, resources, in a cooperative program between improvement combines techniques and management for genetic, the California Cooperative Rice in molecular biology with knowledge agronomic, weed, insect, disease, Research Foundation (CCRRF), of conventional plant breeding

6 UC Davis Plant Breeding Program Cereal methods to tap new sources of disease resistance. Research is being conducted to optimize management and harvest conditions to maximize rice yield and quality, including investigation of milling methods. For example, recent studies show that moisture content of rice and milling at controlled temperatures affect milling yield. The results of this work are shared with growers through annual rice field days, UCCE county grower meetings, websites, and information bulletins. Importantly, the research conducted at UC Davis in cooperation with the breeding The breeding program program has trained dozens of students who will continue to From 1918 to 1970, California grew primarily only three tall-, short- and advance the California rice industry. medium-grain varieties — Caloro, Colusa, and Calrose — with average Approximately one-fourth of the yields of about 5,500 pounds per acre. An accelerated breeding program global rice crop is grown in rain- was initiated in 1969 and funded by growers through a marketing order by fed, lowland plots that are prone the California Rice Research Board. By 1972, more than 95 percent of Cali- to unpredictable seasonal flooding fornia’s rice acreage was planted to improved semi-dwarf rice varieties. resulting in annual yield losses estimated at more than $1 billion. Since 2000, California rice yields have averaged 7,900 pounds per acre. A research team lead by Pamela The 42 rice varieties released since 1969 include very early- to late-maturing Ronald has identified a gene that short-, medium-, and long-grain types (all major U.S. market classes), and confers submergence tolerance to specialty types such as waxy (sweet), premium medium and short grains, aro- rice while maintaining high yields. matic, basmati, and low-amylose rice. Development of submergence- tolerant varieties for commercial Recent advances include development of Calrose medium grains resistant to production in Laos, Bangladesh, one of the most important diseases in rice, Blast. Calamylow-201 is a newly and India is now underway. It is released premium-quality short grain that has been introduced for use in expected to increase food security chilled or frozen rice products popular in Japan. for 70 million of the world’s poorest people, and may reduce In 1969, every effort was made to develop rice varieties in the shortest pos- yield losses from weeds in areas sible time. Initial crosses were made in the greenhouse, often during the win- like the United States where rice ter months. Goals were short stature, lodging resistance, earliness, and grain is seeded in flooded fields. quality. Research on insects and diseases was already being coordinated with UC Davis. Howard Carnahan joined the California Cooperative Rice Breeders: Howard Carnahan, Research Foundation in November 1969 as director of plant breeding. Kent McKenzie, Virgilio Andaya, Farman Jodari, Carl Johnson, Today, Kent McKenzie is the station director who directs four plant breeders, Jacob Lage, and S.T. Tseng. a pathologist, and support staff. The plant breeding program at the Rice Ex- Breeding Support: Neil Rutger, David periment Station is designed to develop rice varieties of all grain types and Mackill, Jim Hill, Thomas Tai, market classes with high and stable grain yields and quality that will sustain Albert Fischer, Jeffrey Oster, Jack the profitability of rice with minimum adverse environmental impact. It focuses Williams, Carl Wick, Steve Scardaci, on agronomic traits, disease and pest resistance, yield, and kernel quality. Chris Greer, and Luis Espino.

UC Davis Plant Breeding Program 7 Cereal

Wheat (bread) Triticum aestivum L. Wheat (durum) Triticum durum L. Wheat that’s worth its weight ver the past 100 years, UC ODavis has played a central role Jorge Dubcovsky in developing varieties of both bread selects wheat lines. wheat and durum wheat, meeting the challenges of California markets and environments. As important as the varieties released from UC Davis have been to California’s wheat production, equally vital have been the research, development, and verification of breeding practices: backcross breeding, bulk-pedigree breeding, and, most recently, marker-assisted selection, a highly efficient means to genetic gain. Just 10 years after the Gold Rush, California became prominent in the United States for wheat production. By 1890, California ranked second in the nation for wheat production. In cooperation with the USDA, experi- ments to improve wheat varieties and cultural practices began at the By 1890, California the international wheat improve- University of California in 1904. ment program based in Mexico Prior to that, yield had been about ranked second (CIMMYT), the bulk-pedigree 0.1 tons per acre and the varieties in the nation for method became the predominant grown were landraces descended breeding practice at UC Davis. All of from Spanish introductions and wheat production. the UC Davis bread-wheat variet- others introduced in the early years ies released from the 1960s through after statehood. Initial yield increases There was some hybridization and the 1990s had CIMMYT parentage. were due primarily to improved selection from both the progeny of In addition, in response to the cultural practices and introduced these crosses and from landraces. In stripe rust outbreak in California varieties, but by 1940, improved 1922, the first backcrosses, driven in 1960–1961, resistant CIMMYT varieties accounted for most of by the goal of transferring specific varieties were screened for adapt- the higher yield — then about 25 new characteristics to established ability to California growing re- percent greater than at the turn of varieties, were undertaken. Dur- gions and released. The first du- the century. Improvement objec- ing this period, crossing between rum wheat released in California tives included enhanced disease and varieties with selection of new types (Modoc, in 1975) was also the insect resistance. Today, yield can from the progeny (pedigree method) first public short-statured durum average 2.5 to 3.5 tons per acre. was also practiced. However, by the wheat bred in the United States. Prevalent breeding practices have end of the decade and for the next In the late 1990s to date, there changed over time. Prior to 1922, few decades, backcrossing became has been a resurgence in the use of the emphasis was on bringing in the primary breeding practice. backcrossing, driven primarily by the varieties from elsewhere and testing Beginning in the 1960s, in paral- availability of molecular markers for them under California conditions. lel and often in cooperation with specific traits (i.e., marker-assisted

8 UC Davis Plant Breeding Program Cereal

Bread wheat Decade Variety Breeder 2000s Clear White (HWS), Lassik (HRS), Patwin (HRS) Dubcovsky 1990s Kern (HRS) Qualset, Dubcovsky 1980s Serra (HRS), Yolo (HRS), Tadinia (HRS), Qualset Phoenix (HWW) 1970s Anza (HRS), Portola (HRS), Tanori 71 (HRS), Qualset Yecora Rojo (HRS), Shasta (HRS) 1960s Lerma Rojo (SRS), Nainari 60 (HRS), Schaller, selection or MAS). Marker-assisted Yaqui 50 (HRS), Chapingo 53 (HRS), Williams, selection speeds up the breeding pro- Yaqui 54 (HRS), Lerma Rojo 64 (SRS), Qualset cess because researchers can identify Pitic 62 (HRS), Sonora 64 (HRS), Suneson desirable traits with markers which Siete Cerros 66 (HWS), INIA 66 (HRS), are either the genes themselves or INIA 66R (HRS), Big Club 60 (SWS) DNA which is very closely linked. 1950s Poso 48 (SWS), Ramona 50 (HWS), Briggs, Since 2000, UC Davis has provid- Red Baart 52 (HRS), Onas 53 (SWS), Schaller, ed leadership of a national consor- Baart 54 (HWS), White Federation 54 (SWS), Suneson tium to implement forward-breeding MAS strategies in public wheat- White Federation 57 (SWS) breeding programs. UC Davis cloned 1940s Big Club 40 (SWS), Poso 41 (SWS), Briggs, the first important agronomic genes Ramona 41 (HWS), Bunyip 41 (SWS), Schaller, regulating wheat flowering time Awnless Baart (HWS), Escondido 41 (SWS), Suneson and grain protein content. Patwin, Onas 41 (SWS), Federation 41 (SWS), a hard white spring wheat released Awned Onas (SWS), Poso 42 (SWS), from UC Davis in 2006, was one of Big Club 43 (SWS), Poso 44 (SWS), the first wheat varieties in the United Ramona 44 (HWS), Baart 46 (HWS) States to be produced by MAS. Lassik, a hard red spring wheat, 1930s Poso (SWS), Ramona (HWS), Briggs, followed and included the pyramid- Baart 35 (HWS), Big Club 37 (SWS), Suneson ing of six favorable genes by MAS. Pacific Bluestem 37 (HWS), Sonora 37 (SWS), White Federation 38 (SWS), Early researchers: G.W. Hendry, Baart 38 (HWS) W.W. Mackie, B.A. Madson, and 1920s Onas (SWS), Escondido (SWS) Wiebe, V.H. Florell, USDA. Breeders: G.A. Hendry Wiebe, USDA (1920s–1934); C.A. Suneson, USDA-ARS/Dept. of 1910s Baart (HWS), White Federation (SWS), Wiebe, Agronomy (1936–1965); F.N. Briggs, Federation (SWS), Bunyip (SWS) Florell Dept. of Agronomy (1930–1952); HWS=hard white spring, HRS=hard red spring, HWW=hard white winter, SRS=soft red spring, SWS=soft white spring. C.W. Schaller, Dept. of Agronomy Durum wheat (1946–1961); J.C. Williams, Dept. of Agronomy (1961–1965); C.O. Year Variety Breeder Qualset, Dept. of Agronomy and 2005 Desert King Dubcovsky Range Science (1967–1994); and Jorge Dubcovsky, Dept. of 1985 Altar 84 Qualset Agronomy and Range Science/ 1975 Modoc Qualset Plant Sciences (1995 to present).

UC Davis Plant Breeding Program 9 cereal

Barley Hordeum vulgare L. Decade Variety Breeder 2000s UC 933, UC 937, UC 960, Gallagher High-yield Ishi, Tamalpais 1990s UC 969 Puri, Gallagher 1980s UC 337, UC 476, UC 603, UC 828 Schaller, Puri crops, free 1970s Sutter, UC 566, CM 72, Atlas 74, Schaller, Worker, Prato, UC Signal, Wocus 71 Puri 1960s UCD 27, UCD 1520, Harland, Schaller, Suneson of disease Grande, Briggs, Numar, CM 67, Atlas 57, Atlas 68, Blanco Mariout, Firlbecks III arley has been an important crop Bin California since the Spanish 1950s Atlas 54 Briggs, Schaller, Mission period, more than 200 years Suneson ago. UC Davis had a significant role 1940s Atlas 46, Rojo, Arivat Briggs, Schaller, in improving barley yield and disease Suneson resistance beginning about 100 years 1920s Atlas, Vaughn, Hero, Sacramento Wiebe, Hendry, ago. Barley yields in California were Florell, Mackie typically about 0.6 tons per acre in 1910s California Mariout, Winter Tennessee, Madson, Hendry, the early 1900s, but current yields California 4000 Florell can be as high as 3.5 tons per acre. The earliest plantings were from landraces introduced by the Span- ish for both malting barley and feed resistance was bred into new va- grain. Initial improvement came from rieties by university breeders. selections with increased uniformity, Varieties for particular niche mar- special adaptations (such as disease kets are also now being pursued by resistance), and slightly higher yields Lynn Gallagher’s barley breeding pro- from the earlier landraces and intro- gram. Targets include hooded forage ductions. In the 1920s, researchers barley, short-growing-cycle varieties at the university began backcross- for low-moisture environments, na- ing — repeatedly crossing a hybrid ked or hull-less varieties for human with one of its parents — and for the consumption, and malting varieties. next several decades, this consti- tuted the primary practice for barley Early researchers: G.W. Hendry; W.W. improvement. By 1940, average yield Mackie; B.A. Madson; V.H. Florell, had increased about 25 percent. feed barleys. By the mid-1980s, USDA. Breeders: G.A. Wiebe, USDA, During this period, crossing about 80 percent of the barley 1920s–1934; C.A. Suneson, USDA- between breeding lines with selec- grown in California consisted of ARS/Dept. of Agronomy, 1936–1965; tion of new types from the progeny varieties that had been developed F.N. Briggs, Dept. of Agronomy, (pedigree method) also began. A since 1946 in the UC Davis breed- 1930–1952; G.F. Worker, Jr., Imperi- bulk-pedigree method is now used ing program of Charles Schaller. al Valley Field Station, 1940s–1980s; and the most common cross after As pathogens keep evolving, the C.W. Schaller, Dept. of Agronomy/ the single cross is the three-way development of disease-resistant Agronomy and Range Science, 1946– cross using the best parent crossed varieties has been a continuing chal- 1985, Y.P. Puri, Tulelake Field Sta- back to the progeny of a cross. lenge for breeders. For example, in tion/Dept. of Agronomy and Range The main objective for barley the late 1990s, a race of stripe rust Science, 1962–1992; L.W. Gallagher, improvement has been to develop caused statewide losses in barley Dept. of Agronomy and Range Sci- disease-free, high-grain-yielding production. As in the past, genetic ence/Plant Sciences, 1993 to present.

10 UC Davis Plant Breeding Program Fiber

Cotton Gossypium hirsutum L. and G. barbadense L. A crop with high-fiber quality

he U.S. Department of management principles still used TAgriculture (USDA), University today. Work on mechanical pickers of California, and private parties in the 1940s, in cooperation with began joint experimentation with the USDA, helped the industry cotton in the San Joaquin Valley move toward commercialization and nearby Southern California and more widespread adoption districts starting as early as the of mechanical pickers. 1870s, but more widespread efforts UC research improved the began around 1910, with field understanding of dominant tests of Upland and Acala types in pests and beneficial insects, and Kern County, Los Angeles County, provided guidelines for economic Imperial County, and at the Kearney management practices important Vineyard Station in Fresno County. to sustainable cotton production. Field trials also included multiple Cooperative Extension specialists Sacramento Valley sites from were instrumental in extensive field 1910 to about 1920. In 1922, the evaluations in the 1980s to establish U.S. Cotton Research Station was that large-scale Pima production established in Shafter by the USDA Cotton Cooperative Extension specialist — over 50 percent of the California Robert Hutmacher This station, now called the Shafter crop today — could be successful Research and Extension Center, management practices, insect in the San Joaquin Valley, opening is currently owned and managed and weed management practices, the way to new opportunities by the University of California. and pathology work useful to with a different cotton species. Over the years, UC scientists, both breeders and agronomists in Since the 1940s, the UC campus- and county-based, have making selections suitable for Cooperative Extension specialist been instrumental in identifying field situations and market needs. assigned to cotton has been located agronomic practices important Their work with irrigation and at the Shafter station to better to cotton yield and quality, best fertility helped establish crop coordinate efforts among the USDA, university, and industry. The variety testing program for approved Acala and Pima varieties jointly run by A few cotton researchers through the years the University of California and the San Joaquin Valley Cotton Board Decade researchers has also been coordinated at the 1870–1910 Hilgard, Coit, and Packard Shafter Research and Extension Center for many decades. 1920s Beckett and Dunshee In recent years, multiple 1930s–1940s Veihmeyer, Adams, and Brown UC Davis researchers specializing in 1940s–1950s Fairbanks, Hoover, Smith, Bassett, Leigh, Stern, aspects of molecular biology have continued work to advance cotton and Van den Bosch genetics through efforts including 1950s–present George, Stromberg, Johnson, McCutcheon, Black, identification of DNA markers Kerby, Hake, Vargas, Weir, Goodell, Godfrey, potentially useful in breeding and Zelinski, Roberts, Munk, Wright, Keeley, Travis, Rains, development of information to better Jernstedt, Ball, Van Deynze, Wilkins, and Hutmacher define control of diverse factors such as disease resistance and fiber quality.

UC Davis Plant Breeding Program 11 Forage

Alfalfa Medicago sativa L. Higher yield, pest resistance

lfalfa was introduced to A California by Mexican missionaries about the time of the Gold Rush. Early introductions have been traced to two different types known as Chilean and Peruvian that were brought to South America by Spanish explorers during the 16th century. These types were adopted by farmers and were widely grown throughout the southwestern United States for nearly 100 years. During this time, seed of these genetically unimproved types was produced and shared among growers within regions. Ernest H. Stanford initiated the University of California alfalfa breeding program following California produces one-third of the U.S. alfalfa seed. World War II. The first variety released was California Common and a very wide adaptation to 49 and possessed resistance to different climatic zones. alfalfa dwarf (Pierce’s disease). In 1977, Larry Teuber joined the Caliverde was released in 1951, breeding program, emphasizing adding resistance to bacterial wilt, development of insect and disease common leaf spot, pseudopeziza resistance, breeding methodologies, leaf spot, and downy mildew, and and breeding for increased seed demonstrating the use of backcross production. His studies on seedling breeding in cross-pollinated species. development and fall dormancy That same year, Stanford published contributed significantly to cultural a seminal paper confirming practices, optimizing planting date autotetraploid inheritance in to maximize forage yield. Highline alfalfa, with four copies of each was released in 1997 with increased chromosome instead of the two irrigated southwest desert. Lehman pest resistance and hay yields that that are found in diploids. and Stanford released UC Salton, are 110 percent of CUF 101. Caliverde was subsequently UC Cargo, CUF 101, and UC UC-Impalo-WF was released improved by adding resistance Cibola. CUF 101 was released to in 2000 in response to another to spotted alfalfa aphid, stem address a serious new problem new pest, the Bemisia whitefly. nematode, and foliar diseases. in California alfalfa production This variety was the first alfalfa This resulted in the release of — the blue alfalfa aphid. species to exhibit resistance Caliverde 65 as one of the first CUF 101 was first available to to this devestatng pest. multiple pest-resistant varieties. growers in the fall of 1977 and it was The UC Davis alfalfa breeding William F. Lehman joined the the most successful alfalfa variety program has also released over 50 program in 1958. He focused on ever released; it is still grown on elite breeding lines that have contrib- improving non-dormant varieties significant acreage worldwide. It uted significantly to many varieties adapted to production in the has a broad array of pest resistances released by private plant breeders.

12 UC Davis Plant Breeding Program Forage

Table: University of California Alfalfa Variety Releases

Cultivar Year seed Breeder Cooperating Fall Resistance Comments first agencies dormancy characteristics available

California Com- 1949 Stanford Calif. Ag. Exp. Sta. 7 Alfalfa dwarf First UC alfalfa mon 49 cultivar

Caliverde 1951 Stanford, Calif. Ag. Exp. Sta. 7 Bacterial wilt, pseudo- Demonstration of Houston peziza leaf spot resistance, backcross breed- downy mildew ing in cross-polli- nated species

Moapa 1957 Smith USDA/ARS, 8 Spotted alfalfa aphid resis- Introduction of Nev. Ag. Exp. Sta., tance races Ent-A and B very non-dormant Ariz. Ag. Exp. Sta., African germ- Calif. Ag. Exp. Sta. plasm

Caliverde 65 1966 Stanford Calif. Ag. Exp. Sta. 7 Spotted alfalfa aphid, First multiple pest- stem nematode, and foliar resistant cultivar leaf disease resistance to Caliverde

Moapa 69 1971 Hunt, USDA/ARS, 8 Spotted alfalfa aphid Introduction of Peaden, Nev. Ag. Exp. Sta., resistance races Ent-A, very non-dormant Lehman, Calif. Ag. Exp. Sta. C, E, and F Indian germplasm Stanford

UC Salton 1973 Lehman, Calif. Ag. Exp. Sta. 9 Phytophthora root rot, Stanford, spotted alfalfa aphid resis- Erwin tance, especially Ent-F

UC Cargo 1975 Lehman, Calif. Ag. Exp. Sta., 9 Higher in resistance than Stanford, USDA/ARS UC Salton, and spotted Erwin, alfalfa aphid resistance, Nielson race Ent H

CUF 101 1977 Lehman, Calif. Ag. Exp. Sta., 9 Blue alfalfa aphid First blue-aphid Nielson, USDA/ARS resistance and very non- resistant cultivar, Marble, dormant and very non- Stanford dormant

UC Cibola 1984 Lehman, Calif. Ag. Exp. Sta. 9 Nematode resistance Ede, Marble, Nielson, Radewald

Highline 1997 Teuber, Calif. Ag. Exp. Sta. 9 Multiple pest resistance; First UC cultivar Gibbs, High yield to receive Plant Taggard, Variety Protection Phillips, Lehman

UC-Impalo-WF 2000 Teuber, Calif. Ag. Exp. Sta. 9 Multiple pest resistance; First cultivar with Taggard, Resistance to Bemisia Bemisia whitefly Gibbs whitefly resistance

UC Davis Plant Breeding Program 13 Forage

Berseem Clover Trifolium alexandrinum L. Known for its water-use efficiency

erseem clover, or Egyptian B clover, is an annual clover that is well adapted to warm regions of California. It was introduced into California in the early 20th century. Breeding by UC Davis scientists began in the 1980s due to the need for nitrogen-fixing cover crops and rotational forage crops. Bill Williams, a professor of agronomy whose career spanned six decades, tested many berseem clover lines for adaptation and disease and insect resistance. He worked closely with Walter Graves, a UC Cooperative Extension farm advisor, and UC Davis scientists Dan Putnam, Bob Gilbertson, Ivan Buddenhagen, and Larry Teuber. Some original southern-adapted varieties (like Bigbee) were not appropriate for California, so Multicut and later Joe Burton were released in the late 1980s and 1990s. Multicut provided a significant improvement in yield efficiently fix nitrogen from the air. previous varieties. over Bigbee and other lines, yielding Joe Burton berseem has Working with Cooperative Exten- 15 to 25 percent more in trials. Joe significantly greater virus resistance sion farm advisors Rachael Long and Burton berseem was named after than Multicut or Bigbee, and Mick Canevari, the team discovered during the 1990s that berseem clover is an excellent candidate for over- Berseem clover is an excellent candidate for seeding into old alfalfa stands and for mixtures with grasses such as oats or overseeding into old alfalfa stands and for mixtures ryegrass as an annual forage option, with grasses such as oats or ryegrass as an annual resulting in better yields in winter and higher water-use efficiency. forage option, resulting in better yields in winter Berseem remains a minor crop in and higher water-use efficiency. California, grown primarily in the desert and Central Valley regions. However, berseem could have the head of research for the Nitragin both Joe Burton and Multicut are increased applications due to the Company (of Milwaukee, now significantly higher yielding than need for water-use efficient forage EMD Biosciences) who isolated the earlier lines. Both Multicut and Joe crops of high forage quality, or as a original strain of Rhizobium inoculant Burton appear nearly completely cover crop in California’s complex for berseem that allows it to resistant to alfalfa weevil than cropping systems.

14 UC Davis Plant Breeding Program Fruit

Cherry Prunus avium L. Brooks helped expand production

C Davis has a history of sweet Brooks matures about four days Ucherry breeding dating back earlier than Bing and produces fewer to 1934. Perhaps the program’s double fruits when grown in the greatest success was the release southern San Joaquin Valley. As a in 1984 of Brooks, a large, sweet, result, commercial cherry production firm variety that matures earlier could move to the warmer areas of and produces fewer double fruits the valley where earlier fruit could than Bing, the industry standard. be produced. This has allowed In 1964, UC Davis breeders Reid California cherry growers to take Brooks and William Griggs released advantage of excellent markets five new varieties — Mona, Jubilee, for fruit produced earlier than Berryessa, Bada, and Larian — the anywhere else in the United States. latter of which is still grown today. Coral Champagne is another Paul Hansche was hired to UC variety popular with cherry continue the breeding program growers. It was never officially in the 1960s, but after several Hansche’s crosses, and one variety released but growers like it because, rounds of crosses, the program was — Brooks — showed promise. It like Brooks, Coral Champagne discontinued in the early 1970s was released in 1984 and had a cherries are sweet and firm, due to lack of funding. UC Davis major impact on the future of sweet they mature early, and seldom researchers continued to evaluate cherry production in California. produce two fruits on one stem.

Melon Cucumis melo L. Breeding for disease resistance

C Davis, through the efforts of breeding lines that were used by Uvegetable crops specialist Frank others to develop improved varieties Zink, contributed significantly to in the 1970s and 1980s. the melon industry in California. Among Zink’s releases were melon As early as the late 1940s, bush breeding lines UC SR-91, Zink worked on defining the UC Top Mark Bush, UC Perlita “melon virus complex,” which Bush, UC Honeydew Bush, and has been updated since then UC Crenshaw Bush. He developed but still plagues the industry. and released UC Honeyloupe, In the 1960s, Zink turned his an orange-fleshed honeydew efforts toward developing improved melon, a forerunner to the many 1980s, Zink and UC Cooperative melon varieties for the industry. specialty melons available to the Extension specialist Doug Gubler He released varieties of several industry and to consumers today. released three fusarium-wilt- melons (cantaloupe, honeydew, Disease resistance was always resistant breeding lines, UC PMR crenshaw, and honeyloupe) that an important component of melon 45 Fom-e, UC Top Mark Fom- were industry standards and/or breeding at UC Davis. In the 1, and UC Top Mark Fom-3.

UC Davis Plant Breeding Program 15 Fruit

Redglobe and Chardonnay grapes

Grape Vitis vinifera L. Whether wine or table, we deliver

ou can taste the impact of two rootstocks. His most widely Wild grapevines that he brought Ythe UC Davis grape breeding planted varieties are the table back from Afghanistan in the 1940s program every time you sip a glass grapes Redglobe, Ruby Seedless, were grown in UC Davis vineyards, of Chardonnay or eat a Redglobe and Perlette; the winegrape Ruby and cuttings from some have recently grape. And that’s only the beginning. Cabernet; and the juice grape been sent back to Afghanistan Starting with Harold Olmo’s first Rubired. Olmo developed varieties where they had become extinct. crosses in 1934 and continuing that would grow and ripen at As he accumulated grape today with Andy Walker at the various times and under different germplasm for his breeding efforts, helm, winegrape and table-grape environmental conditions, a Olmo noticed the tremendous breeding have had a rich and development that greatly expanded morphological and enological productive history at UC Davis. California’s agricultural industry. diversity within winegrape varieties. Olmo released more than 30 Throughout his career, Olmo He was one of the creators of what is grape varieties during his 33-year traveled the world in search of rare now recognized as the most effective career at UC Davis, including 20 or endangered grapevines, returning means of improving winegrape table grapes, nine wine grapes, and with cuttings to study and propagate. varieties — clonal selection.

16 UC Davis Plant Breeding Program Fruit

Chardonnay was an uncommon their resistance to a viral These rootstocks were bred to resist and unproductive variety when disease called fanleaf degeneration. aggressive complexes of nematodes, Olmo began practicing clonal One of these two rootstocks, microscopic root-feeding parasitic selection on it (using clones that O39-16, is used in many California worms that can dramatically Louis Martini had collected.) vineyards in the Rutherford area of impede grapevine growth. These Today, largely because of his clonal Napa Valley, the Alexander Valley efforts are primarily funded by selection focused on improving and Healdsburg regions of Sonoma the California Grape Rootstock fruit quality and productivity, County, across the northern Improvement Commission. Chardonnay is the most popular San Joaquin Valley, and beyond. Breeding efforts continue winegrape in the United States, planted on almost 100,000 acres. Many of Olmo’s winegrapes play Breeding efforts continue toward developing an important role in California and internationally. His most popular rootstocks with better fanleaf degeneration winegrape is Ruby Cabernet, which resistance and tolerance to drought and salinity, he designed to increase crop yield and produce more acidic juice, increasing problems as water becomes less available and could be grown in California’s due to population pressure and climate change. warm San Joaquin Valley. One of his varieties, Rubired, was initially released as a winegrape, Grape breeding at UC Davis toward developing rootstocks but in fact created a new grape continues to thrive under the with better resistance to the product category — red concentrate. direction of Andrew Walker. disease fanleaf degeneration and Rubired is a red-juiced variety His work focuses on rootstocks tolerance to drought and salinity, (most grapes have clear juice; the for soilborne pest resistance increasing problems as water color in wine comes from the skins) and the development of fruiting becomes less available due to that is very productive and is now varieties resistant to Pierce’s population pressure, environmental used to produce a concentrated disease. Funding comes from the needs, and climate change. source of red sugar used in food California Department of Food and Walker and his team also work products from juice to candy. Agriculture Pierce’s Disease Board. to develop winegrapes and table The two rootstocks Olmo released The Walker breeding program grapes resistant to powdery mildew, were selected by his colleagues Lloyd released its first five rootstocks in a fungal disease responsible for Lider and Austin Goheen because of 2008 — GRN1 through GRN5. the vast majority of the pesticides used on grapes. As demands increase for organically grown produce, grape growers will likely Did you know? reduce their fungicide use. Since it is not possible to Cabernet Sauvignon is actually the hybrid offspring of Sauvignon Blanc grow vinifera winegrapes and and Cabernet Franc. table grapes without regular and 16 fine-winegrape varieties, including Chardonnay, are the direct frequent fungicide applications, descendants of the classic Pinot variety and Gouais (goo-WAY) Blanc, breeders are beginning to focus a variety considered so mediocre that it is no longer planted in France. on hybrid types that will grow without fungicides. The adoption The famous California Zinfandel, imported in the 1850s, was traced of these grapes will require higher back to a vine named Crijenak Kastelanski found on a small island off quality and greater marketing the coast of Croatia. and promotion, but still, growers will likely soon look to hybrid UC Davis geneticist Carol Meredith used DNA fingerprinting and varieties — and to the resources historical records to trace the origin of these California favorites. UC Davis continues to provide.

UC Davis Plant Breeding Program 17 Fruit

Fig Ficus carica L. Starring role in emerging market

mong tree fruit crops, figs are A distinguished by having the largest number and widest range of naturally occurring varieties. It is therefore no surprise that figs have a long history of breeding. A sustained fig improvement program was maintained by the University of California, Riverside, from 1928–1980s by Ira Condit and William Storey. Their objective was a drying fig withCalimyrna quality without the need for caprification (artificial pollination with wild fig), and with a small ostiole, or opening. Caprification and a large ostiole are major factors in insect infestation and fungal- disease development in figs. At UC Davis, James Doyle maintained the germplasm and crosses made by Condit and Storey until the fig breeding program was revived in 1989. Since then, Doyle and Louise Ferguson made crosses and produced the open- release Sierra and patented Sequoia common fig cultivars. Sierra is suitable for dry fig and Sequoia produce a large second insect infestation and the fungal production and both are good crop with large- to medium- diseases that are transmitted by fresh figs. They have yellow-green size fruit and maintain fruit size insects. The fruit flavor and quality skin and reddish-amber pulp. well into the fall, in contrast to of both are as good or better This skin color is competitive the small late-season fruit size of than all four of the previously established varieties listed here The increase in plantings and fresh-market sales of with the exception of Calimyrna. The increase in plantings and these new varieties demonstrates that both these figs fresh-market sales of these new will play a major role in the fresh fig industry which varieties demonstrates that both these figs will play a major role continues to grow in California. in the fresh fig industry which continues to grow in California. with the yellow-green Calimyrna Mission and Kadota figs and the and Kadota, and complements absence of fruit on Calimyrna. the violet-black California Brown The ostiole of Sierra and Sequoia Turkey and Mission figs. Sierra figs is very tight, reducing potential

18 UC Davis Plant Breeding Program Fruit

Rootstocks for stone fruit Controlling size, vigor

or more than 75 years, UC Davis Fhas been involved in testing UC Controller 5 reduces and identifying superior rootstocks tree size to aid in for stone fruits. Early research pruning and picking. focused on selecting seedlings of various species for graft/rootstock compatibility and tree vigor, along with resistance and tolerance to the insect pests, diseases, and soil conditions specific to California. In the 1930s, Leonard Day was instrumental in identifying Myrobalan 29C and Marianna 2624 plum rootstocks as being particularly suitable for plum and prune culture. He also noted the compatibility of Marianna 2624 with apricots and selected almond cultivars. An extension of the initial work with Marianna rootstocks resulted in the 1998 release of M40 rootstock by Claron Hesse, Robert Fenton, and James Doyle. This Marianna rootstock has performance characteristics similar to Marianna 2624 but is much less prone to developing adventitious stems from root suckers. Other work by Carl Hansen, Dale Kester, and Tom Gradziel identified several selections of peach-almond hybrid rootstocks as imparting high vigor and yields to almond trees, and the Hansen and Nickels rootstocks were released for almonds. More recent research on root- stocks for stone fruits has focused on decreasing tree vigor and size of peach and nectarine trees in an at- researchers (David Ramming, Several promising new selections tempt to reduce labor costs associ- Ted DeJong, James Doyle, and from research more recently ated with ladder-work, such as prun- Scott Johnson) resulted in the initiated by Fred Bliss (formerly ing, fruit thinning, and harvesting. release of two new size-controlling with UC Davis) and Ali Almehdi Recently a collaborative effort rootstocks for peach and nectarine are currently being tested. between USDA-ARS and UC Davis (Controller 5 and Controller 9).

UC Davis Plant Breeding Program 19 Fruit

Stakeholders evaluate the quality of a new peach variety and share their feedback with Tom Gradziel (center).

Processing Peach Prunus persica L. Dependent on public breeders

bout half of the 2 billion processing-peach breeding has with G.L. Philps of what was then Apounds of peaches produced not been profitable in the private the UC Berkeley research farm at annually in the U.S. are processing sector. It has therefore fallen Davis, remain heavily planted today peaches grown almost entirely in on public breeders to develop and have been used as parents California’s Central Valley. The varieties for this important and in many recent varieties. Initial lower price paid for processing predominantly family-farm industry. selection was for local adaptation, peaches requires a consistently From its beginning in the early uniform fruit size, shape, and higher production of marketable 1900s, the processing-peach golden-yellow flesh color, as fruit for a variety to be commercially industry in California has depended well as a continuous sequence viable. Growers are understandably on varieties developed by public of ripening periods to supply reluctant to aggressively plant programs and on grower selections canneries throughout the summer. new, largely unproven varieties. of seedling trees often derived Breeding of Clingstone peach Consequently, unlike with the from public varieties. Carson, varieties continued in the 1950s relatively high-priced fresh-market Carolyn, and Corona, developed under L.D. Davis, whose program peaches where new varieties meet in the 1930s and 1940s by W.F. was notable for its incorporation changing consumer preferences, Wight of the USDA in collaboration of germplasm to improve fruit

20 UC Davis Plant Breeding Program Fruit flavor and canning quality, as well as its thoroughness and continued emphasis on high productivity. Three of his varieties, Klampt, Tufts, and Andross, were not released until after his retirement in 1964. All three remain commercially planted today. Evaluation of Davis’ breeding selections continued under Clarion Hesse (1970–1979), Andrew Kuniyuki (1979–1984), and Jim Beutel (1979–1987), resulting in the release in the mid-1980s of Ross, Dr. Davis, Dee-Six, and Riegels. Ross and Dr. Davis have become the industry standards for productivity and quality and remain the most heavily planted processing- season variety which could be held and cultivated almond. Progress peach varieties in California. in cold storage up to eight weeks towards mechanically harvestable The importance of Ross to the and still maintain good canning varieties includes the identification industry was further enhanced with quality (to buffer the increasingly in wild and domestic germplasm the release by Bill Tsuji, Ted DeJong, erratic raw product supplies to the of sources of improved harvest and and Jim Doyle in 1990 of Late Ross, postharvest fruit integrity, single a late-maturing bud sport (a bud or The California pass harvestability, and modified shoot having a natural mutation) tree structure, size, and bearing of Ross which extended its harvest Clingstone Peach habit. Modified tree structure and season by one to two weeks. Marketing Board also size is also being pursued by DeJong In 1988, the program was through various size-controlling continued and expanded under supports a permanent rootstocks. Molecular markers for Tom Gradziel with funding from endowment for the these traits are being pursued in the California Clingstone Peach collaboration with Carlos Crisosto. Marketing Board, California UC Davis peach Molecular-based research has processors, and the UC Agricultural transformed breeding program Experiment Station. Immediate breeding program. funding, with about half of current objectives were to replace the funds coming from competitive historically important and canneries during this period). grants and the remainder from the extensively planted Dixon, Andross, Goodwin (2001) combines Clingstone Peach Marketing Board, Halford, and Starn varieties improved case yields — in processors, and UC Agricultural because of their deteriorating particular, freedom from red Experiment Station funds. The processing quality along with rapid pit staining and associated pit California Clingstone Peach development of varieties with fragmentation — with improved Marketing Board also supports a improved pest resistance, ability disease resistance. Lilleland (2002) permanent endowment for the to be mechanically harvested, combines high fruit quality with UC Davis peach breeding program. and ease of orchard maintenance freedom from red pit staining and Integration of advanced field- (to counter the dramatic losses associated pit fragmentation. and lab-based technologies into in labor during this period). Sources of resistance to flower applied variety breeding has made In 1992, Hesse was released blight, fruit rot, leaf curl, mildew, UC Davis an international center as a high case yield and high and green peach aphid have been for peach genetic research with phytonutrient (pro-vitamin A) identified in closely relatedPrunus collaborations among scientists replacement for Starn. Rizzi was also species, including wild peach in the U.S., Europe, Canada, and released as a high case yield, mid- species, wild almond species, Central and South America.

UC Davis Plant Breeding Program 21 Fruit

Strawberry Fragaria x ananassa Duch. The bulk of the world’s supply

mprovement in the production California has become the dominant starts with 100–150 controlled I efficiency and product quality producer of both fresh and processed crosses among selected parents for of any agricultural commodity strawberry fruit in the world, each production location, chosen results from the development of providing varieties for greater than based on a variety of production superior production environments 87 percent of the strawberries and horticultural traits. Initial and the breeding of varieties consumed in North America. evaluations are performed on the specifically adapted to these superior Varieties developed by this program basis of seedling performance, environments. Mainly due to such produce approximately 60 percent with primary populations of developments at the University of of the strawberry fruit worldwide. 8,000–12,000 seedlings established California, lead initially by Harold at both UC South Coast and Thomas and Earl Goldsmith, later The Process UC Davis field stations. by Royce Bringhurst and Victor Improved strawberry varieties Approximately 300 genotypes Voth, and for the last 22 years result from recurrent breeding, (breeding lines) are retained from by Doug Shaw and Kirk Larson, testing, and selection. Each cycle each primary seedling population,

22 UC Davis Plant Breeding Program Fruit with subsequent evaluation of these selections based on plots of runner plants tested with planting treatments that simulate commercial conditions. Selections that are retained after initial screening are then tested using relevant cultural manipulations, and information is obtained about the cultural conditions that will optimize performance for each advanced selection. At present, all advanced selections are tested for a large number of pest tolerances. Specific Objectives The University of California program has released 56 strawberry varieties since its beginning in the 1930s. The standards required for success in a California strawberry variety have changed substantially during the past 75 years, due in Doug Shaw describes breeding trials at the Watsonville, Calif., research farm. part from the past success of the breeding program (Table 1). shelf life, and flavor), and resistance The Future or tolerance to important insects Target traits for new varieties At present, the rate of progress for and pathogens. New varieties must include improved production all measurable traits is approximately double historical averages. Through careful management of genetic The University of California program has released resources and proper application 56 strawberry varieties since the 1930s. of genetic principles, the likelihood of continued progress for this program has been preserved. attributes (yield, production pattern, fruit size, and ease of meet minimum standards for all of harvest), superior quality for both the above traits and meet the specific fresh and processing markets (fruit needs of the California industry and appearance, color, shipping quality, similar environments worldwide.

Table 1. Improvement of strawberries in the UC breeding program

Cultivar Plant Fruit yield Appearance Fruit size Fruit firmness release date diameter (g/plant) score (g/fruit) (N) (cm) (1-5, 5=best)

1945–1966 18.40±0.63 595±42 2.29±0.06 14.9±0.4 2.45±0.12

1993–2004 22.86±0.49 1,429±61 3.38±0.08 24.8±0.7 4.56±0.12

UC Davis Plant Breeding Program 23 Fruit

Prune and Plum Prunus domestica L. Producing larger, tastier treats

prune is simply a dried Aplum. UC Davis has released three promising prune varieties since its prune breeding program got underway in 1985. In 1985, the California prune industry asked UC researchers Ted DeJong and James Doyle to start a traditional prune breeding program to try to develop new varieties that could extend the harvest season for the California prune industry. At that time the industry consisted of about 80,000 acres of a single variety — Improved French. A year later, DeJong and Doyle started a program and two varieties have since been released for the dried prune industry — Sutter in 2000 and Muir Beauty in 2004. Both of Muir Beauty was released to the dried prune industry in 2004. these varieties produce fruit that is larger, tastier, and earlier maturing that have an interesting array of (by 7 to 14 days) than Improved fruit color, flavor, and quality French. Substantial acreage of characteristics. External fruit colors Sutter has been planted and interest range from yellow and pink to in Muir Beauty is growing. completely blue or purple, and A third variety derived from dried flavors have hints of apricot, this program, Tulare Giant, cherry, and even cognac. Several produces a very large fruit and was new varieties are expected to be released specifically for the fresh released in the next few years.

External fruit colors range from yellow and pink Extension county advisor position to completely blue or purple, and dried flavors and is now co-managing the program with DeJong, while Sarah have hints of apricot, cherry, and even cognac. Bradley has taken over day-to- Several new varieties are expected to be released day operations of the program. This program receives substantial in the next few years. support from the California Dried Plum/Prune Board and many market. It is currently the most Doyle retired from the university growers are routinely involved in popular fresh-market European in 2000, the same year Carolyn evaluating advanced selections. plum grown in California. DeBuse became involved with the The project is currently evaluating prune breeding program. In 2007, more than 80 advanced selections DeBuse took a UC Cooperative

24 UC Davis Plant Breeding Program Germplasm

Foundation Seed Program Maintaining pure seed supplies

n 1937, the UC Davis Department Iof Agronomy was home to active breeding programs on wheat and barley. Breeding programs on other crops (common beans, alfalfa, safflower, sunflower, etc.) soon followed. The vast majority of new varieties were developed by scientists working in Agricultural Experiment Stations or the USDA. Responsibility for maintaining and increasing seed of new varieties was associated solely with the breeding program, so the department institutionalized that role. Frank Parsons was hired in 1937 to establish this program. In 1939, the Federal Seed Act was passed, followed soon thereafter by the California Seed Law — both designed to regulate seed labeling. These important pieces of legislation were critical to the University of California Foundation Seed Program (FSP) and the separate development of the California Crop Improvement Association (CCIA). Both of these programs grew out of the Department of Agronomy and were directed by Parsons for the next 40 years. The Foundation Seed Program is now an organized service unit at UC Davis. Its mission is to 1) Grow, increase, and maintain seed of cultivars developed by the University of California and other The Foundation Seed Program warehouse at UC Davis public plant breeders, 2) Maintain genetic purity of these cultivars, meet anticipated demand. All UC Davis is a CCIA-approved and and 3) Ensure that certified seed production must conform to the certified-organic seed-conditioning of cultivars in the program’s standards of the Association of facility. It contains a conditioning charge is available to the public. Official Seed Certifying Agencies plant with specialized equipment for Foundation seed is produced (AOSCA) and the California Crop sorting seed based on size, shape, from basic seed stocks (breeder Improvement Association. density, and color. The facility is seed) initially supplied by the The seed conditioning and specifically designed for handling plant breeder, sufficient to warehousing facility located at high-quality, low-volume seed stocks.

UC Davis Plant Breeding Program 25 Germplasm

Foundation Plant Services Healthy stock, new varieties

hough its name has changed Tsince its inception in 1958, the mission of the Foundation Plant Services (FPS) center at UC Davis has remained the same — to provide researchers and industry with healthy, true-to- variety planting stock of many horticultural crops. As a result, the California grape and tree industries have benefited by the introduction of better scion and rootstock varieties from around the world. However, too often as new plant selections were introduced to California, new pests and diseases appeared as well. These pests were often spread unwittingly through careless propagation and viticultural techniques. Because planting virus-free stock is an effective way to control many of these diseases, much of FPS’ effort has focused on detection and elimination of virus diseases. Plant pathologists from UC Davis and USDA-ARS stationed Researcher Josh Chase making a grape meristem tip culture. in Davis are international leaders in grape virus-disease detection, By 1995, FPS crops potted plants added in 2003. identification, and treatment. FPS now offers laboratory testing UC Davis viticulturists and included grapes, many services for plant pathogens, DNA pomologists provide expertise to fruit and nut trees, tests to determine cultivar identity, ensure the FPS grape collection and custom services for grape represents the great diversity of strawberries, sweet importation and virus therapy. horticultural plant materials needed potatoes, and roses, UC Davis provides two faculty by a vital and ever-changing industry. positions to Foundation Plant In July 1958, two programs — with additional cuttings, Services, as well as a prime location the California Grape Certification on campus for propagation and Association and the virus-free cherry seeds, and potted plants testing of plant materials. Beyond stock program — were combined added in 2003. that, FPS is self-supporting, mostly into FPS. Its goal was to maintain by nursery growers, and continues and distribute virus-tested cherry to play a key role in distributing new and grape stock. Over the years, fruit and nut trees, strawberries, crop varieties and healthy planting other crops were added. By 1995, sweet potatoes, and roses, with stocks throughout the world. FPS crops included grapes, many additional cuttings, seeds, and

26 UC Davis Plant Breeding Program Germplasm

C.M. Rick Tomato Genetics Resource Center Improving production worldwide

he tomato, a major vegetable Tcrop in California, is an example of the many cultivated plants that suffer from a shortage of genetic variation. Throughout its history of migrations and domestication, the tomato lost a great deal of its original genetic diversity. As a consequence, tomato breeding progressed slowly and yields remained low until 1940 when the first high-level disease resistance was reported. Since then, great strides have been made in tomato improvement, roughly in proportion to the utilization of exotic germplasm (landraces, wild forms of the cultivated species, and other exclusively wild species). In California, yields of processing tomatoes have increased a spectacular five-fold since the 1940s. The C.M. Rick Tomato Genetics Roger Chetelat, director of the Tomato Genetics Resource Center, collects seed of wild Resource Center (TGRC) is a seed tomatoes in the Atacama Desert of Chile. repository of mutants, genetic stocks, and related wild species of resistance of 44 major tomato stocks are available nowhere else in tomato. The TGRC was founded by diseases, at least 20 insect pests, the world. TGRC accessions are used the late Charles Rick as a byproduct improved fruit traits, tolerances to by investigators for a wide variety of of his tomato genetics research at stresses such as drought and salinity, research and breeding on tomato. UC Davis. The TGRC has grown and other useful traits. Rick made Director Roger Chetelat and into a national and international 17 major collecting expeditions to his team continue to broaden the genetic diversity accessible for tomato improvement, and to The wild species of tomato in the repository are study biological processes relevant to biodiversity conservation, the source of resistance of 44 major tomato diseases, domestication, and plant breeding. at least 20 insect pests, improved fruit traits, The TGRC is supported in part by federal grants, the California Tomato tolerances to stresses such as drought and salinity, Research Institute, UC Davis, and and other useful traits. an endowment fund. To learn more, visit http://tgrc.ucdavis.edu. repository of over 3,600 lines collect tomato populations, many developed at UC Davis and beyond. of which have since been extirpated The wild species of tomato in in the wild. The majority of the the repository are the source of tomato’s mutants and chromosomal

UC Davis Plant Breeding Program 27 Nuts

Almond Prunus amygdalus L. Pollination discovery started it all

lmonds are one of the most It was there, in the late 1870s, that pollinator varieties and honey bee A successful crops grown in nurseryman A.T. Hatch selected pollinators to transfer compatible California today. With annual the variety Nonpareil, which, pollen between otherwise self- production over 1.25 billion pounds because of its good kernel quality sterile varieties. From that time on, and a value well over $2 billion, and high productivity, would most breeding efforts have focused almonds are the nation’s largest become the industry standard. on developing pollinator varieties specialty-crop export and California’s Frequent crop failures were with good commercial quality to top agricultural export. The common until the 1920s when the provide pollen for the late, mid-, birthplace of the modern California classic work of W.P. Tufts and G.V. and in particular, early bloom of (and western U.S.) almond industry Philp at the Agricultural Experiment the dominant Nonpareil variety. could be considered Suisun, located Station showed almond to be From 1923 to 1948, almond between UC Berkeley and Davis. self-incompatible, requiring both breeding at UC Davis was a joint

28 UC Davis Plant Breeding Program Nuts venture between Milo Wood of the approximately that of the original inter-species breeding platform USDA and Arthur Davey of the seedling Nonpareil tree. This work offers rich opportunities for both Agricultural Experiment Station. led directly to the rehabilitation basic and applied genetic research Their work resulted in the release and continued commercial viability in the areas of gene mapping, gene of the widely planted, early- of the Nonpareil and Carmel, discovery, and trait dissection. flowering pollinatorsJordanollo , which currently make up over Gradziel’s team has released two Harpereil, and Davey, which 50 percent of the total acreage partially self-compatible varieties eventually failed due primarily of almonds in California. — Winters and Sweetheart. to their susceptibility to disease Kester also developed a series of Winters provides excellent bloom and pests, thus demonstrating the interspecific crosses between almond overlap with the early to mid- need for improved resistance. and related species, including peach, Nonpareil bloom. This also provided Dale Kester took over the UC as potential rootstocks and sources exceptional yields without the need almond breeding program in 1948. of new germplasm. The Hansen for its own early-bloom pollinator. He targeted the development of and Nickels hybrid rootstocks, Sweetheart combines the self- more locally adapted pollinator which exploited the hybrid vigor compatibility and high kernel oil varieties including Solano and Padre, which continue to have wide plantings. Kester also released The next generation of advanced almond selections the specialty-market varieties Kaperiel and Milow, developed to that combine self-fruitfulness with a wider array of supply high-quality, small-kernel resistance, and quality and productivity genes from almonds required by the candy industry for chocolate bars, etc. multiple species sources, are currently undergoing The industry faced a serious regional grower testing. challenge at that time with the deterioration of the major varieties, particularly Nonpareil, from of the interspecies (almond x quality genes from peach with local virus contamination and a poorly peach) cross, were bred to promote adaptation and insect resistance understood genetic aging disorder, rapid tree growth in orchard from almond. The next generation now known as noninfectious bud- replant situations and almond of advanced almond selections that failure (BF). In response, Kester’s production on marginal soils. combine self-fruitfulness with a program helped pioneer the In the early 1990s, Thomas wider array of resistance, and quality development of clean-stock programs Gradziel took over the almond and productivity genes from multiple for supplying the nursery industry breeding program. Using and species sources, are currently with virus-free plant propagation expanding the interspecies gene pool undergoing regional grower testing. material as foundation stock. developed by Kester, the current The continuing integration of Kester then applied this program continues to focus on advanced field- and lab-based experience in vegetative clone developing pollinator varieties with technologies towards the goal deterioration to the bud- improved resistance to diseases and of applied cultivar breeding has failure problem, perceiving it insect pests with support from the made the UC Davis program to be associated with the aging/ Almond Board of California and the an international center for deterioration of a critical gene Agricultural Experiment Station. almond genetic research. function rather that resulting from Climate change and the related virus/viroid contamination. His insect pollinator collapse, however, ingenious and now classic solution have imposed the concurrent need was to exploit the time-capsule effect to rapidly transform almond from a of very early developed dormant self-sterile to a self-fruitful crop. The buds at the base of Nonpareil trees development and early utilization of (which could be over one hundred molecular markers, in collaboration years old), which he showed to with Abhaya Dandekar, has allowed be suspended in genetic age to accelerated breeding progress. The

UC Davis Plant Breeding Program 29 Nuts

A ripe walnut, ready for harvest.

Walnut Juglans regia L. Chandler transforms the industry

hen a grower plants a walnut 1948. Chandler gave California breeding program was to increase Wtree, it is most likely a product growers what they needed to the yield of high-quality walnuts. of the UC Davis walnut breeding succeed — a highly prolific tree Yield is closely related to the number program. Virtually all of the walnut that produces leaves mid-season of female flowers produced. Serr varieties sold in California nurseries after most of the rains and freezing and Forde identified a unique are UC Davis varieties. One variety temperatures have passed, and flowering type in which flowering — Chandler — accounts for 90 produces nuts with the light-golden buds were produced not just percent of all nursery sales of walnut. kernels that consumers love. terminally but along a branch. The California produces 99 percent Forde and his colleague first genotype (variety or clone) of the walnuts grown in the Eugene Serr started the UC Davis exhibiting this trait was Payne, United States, and is the second- walnut breeding program using which became an outstanding largest walnut-producing country selected parents and controlled parent that conferred the lateral in the world, behind China. pollinations. The breeding program fruiting to many of its progeny. Chandler was patented in 1979 is still active, now under the Serr and Forde released ten by Harold Forde, who co-created direction of Gale McGranahan. varieties in 1968. The varieties Vina, the walnut-breeding program in The goal of the Serr/Forde Serr, and Chico stood out. Vina,

30 UC Davis Plant Breeding Program Nuts Growers now look to UC Davis to solve Chandler’s one major problem: it is too popular. It harvests late in the season, and with the dominance of Chandler, processors are challenged by an end-of-the-season glut.

Forde. Livermore has a bright- red kernel bred from a darker- Eugene Serr (front left, holding the branch) helped start the walnut breeding program at purple germplasm introduction. UC Davis in 1948. Sexton, Gillet, and Forde are mid-season cultivars that have Chandler. These were the control- high yields, jumbo light-colored pollinated grandchildren of Payne. kernels, and low susceptibility to Sunland had a lovely plump nut, walnut blight. They also do not but the tree was almost too vigorous have a seed coat shrivel, which and the kernel color was sometimes can be a problem with Chandler. too dark. Howard is still a cultivar “Forde is potentially the new of interest, making up about eight Chandler,” says Chuck Leslie, percent of nursery sales. Chandler, staff research associate with however, took over the industry. McGranahan’s breeding program. Growers now look to UC Davis The Walnut Marketing Board to solve Chandler’s one major has endowed the program, which problem: it is too popular. It is working to develop early- harvests late in the season, and harvesting cultivars with all the with the dominance of Chandler, attributes of Forde and Chandler. processors are challenged by Field trials of promising early an end-of-the-season glut. selections are underway. McGranahan has released two cultivars from crosses made by Serr and Forde. These are Cisco, a suitable pollinator for Chandler, and Tulare, which was released Virtually all the walnut varieties sold after 20 years of evaluation. Tulare in California nurseries are UC Davis varietes. is very precocious in bearing fruit and harvests mid-season, which has high yields but average but does not have Chandler’s kernel quality, is still planted today. light-colored kernels which have In 1978, just before he retired, become the industry standard. Forde patented three new walnut UC Davis’ latest varieties include varieties — Sunland, Howard, and Livermore, Sexton, Gillet, and

UC Davis Plant Breeding Program 31 Nuts

Pistachio Pistacia vera L. Protecting a $500 million crop

istachio is the third most Pimportant nut crop produced in California (behind almonds and walnuts) with more than 112,000 acres in production and another 60,000 acres planted but not yet producing. The California crop is worth more than $500 million annually but suffers from a classic case of genetic vulnerability. More than 99 percent of pistachios grown in California are produced from a single female cultivar, Kerman, pollinated by a single male cultivar, Peters. Under such conditions, an unknown disease or insect could potentially destroy the entire crop. In 1989, a breeding program was initiated by Dan Parfitt in the pomology department at UC Davis and Joseph Maranto, Machines now assist in harvesting pistachios, the third most important nut crop grown in a UC Cooperative Extension California. county advisor stationed in Kern County. After Maranto retired, flower earlier and perform better alternate bearing than Kerman. Craig Kallsen replaced him as than Kerman under low chilling Both cultivars have a more farm advisor and continued on conditions. Both have significantly uniform maturity than Kerman, with this project (funded by the higher percentages of split nuts (a which suffers from irregular California Pistachio Commission desirable consumer characteristic) maturation, requiring multiple from 1989 to 2000.) Based on and marketable yield, and they harvests. Lost Hills also has a superior performance in replicated ripen a few weeks earlier than larger nut than Kerman, but a higher percentage of loose shells More than 99 percent of pistachios grown (the kernel separates from the shells during processing). in California are produced from a single female An early-flowering male cultivar cultivar, Kerman, pollinated by a single male was selected to serve as the pollinator for Golden Hills and Lost cultivar, Peters. Under such conditions, Hills. Randy blooms about one week an unknown disease or insect could potentially earlier than Peters and does not appear to be affected by low-chill destroy the entire crop. winters. Pollen viability is much higher than for Peters and once trials, two female cultivars, Golden Kerman. Extension of the harvest shed, the pollen is more durable. Hills and Lost Hills, and one male season permits more efficient use The release of these new cultivars cultivar, Randy, were released. of labor and equipment. Golden should help protect the pistachio The new female cultivars Hills shows decreased tendency for industry from genetic vulnerability.

32 UC Davis Plant Breeding Program oilseed

Safflower Carthamus tinctorius L. Recognizing a crop’s potential

afflower has been grown S commercially in California since 1949, thanks to the late Paul Knowles, a longtime UC Davis professor and researcher known as the “Father of California Safflower.” Knowles recognized the potential of safflower as a new crop for California in the late 1940s. Over his 35-year career at UC Davis, he worked to introduce the crop to California growers, develop appropriate cultural practices, and screen available variants for California conditions. He broadened the accessible gene pool by organizing and carrying out germplasm collection missions to 18 countries and conducted genetic and breeding studies. In the late 1950s and mid-1960s, Safflower in commercial production near Davis. Knowles traveled more than 32,000 miles with his wife and son across high oleic oil variant. The resulting red-flowered, spineless type for use North Africa, the Middle East, and varieties enhanced the safflower oil in dried flower arrangements, and South Asia, gathering germplasm market in the health-food industry. UC-1 (1965), the first commercial of wild and domesticated safflower Safflower is used primarily as variety with high oleic oil content. species, an effort which produced an oilseed crop but is also grown A.L. Urie and Knowles released most of the accessions now in the for seed meal for livestock and Oleic Leed in 1974, having USDA world safflower collection. as a saffron substitute. There are bred the high oleic trait into an established variety, Leed.

Over his 35-year career at UC Davis, Paul Knowles Breeders: P.F. Knowles, Dept. of worked to introduce safflower to California growers, Agronomy/Agronomy and Range Science, 1947-1982; A.L. Urie, develop appropriate cultural practices, and screen USDA-Dept. of Agronomy and available variants for California conditions. Range Science, 1970s-1980s.

Knowles and his students and two types of oil produced from colleagues researched the genetic and different varieties of safflower: high chemical properties of the species linoleic oil (polyunsaturated) and and sought genetic resistance to high oleic oil (monounsaturated, pests. They characterized a mutant similar to olive oil). from an accession from the Ganges Notable varieties released by delta in India that produced the Knowles were UC-26 (1959), a

UC Davis Plant Breeding Program 33 Ornamental

Arboretum All-Stars Plants for eco-friendly gardening

n California, half of the water, Ifertilizers, and pesticides used in homes and businesses goes onto landscapes. These chemicals are often over-applied by home garden- ers, and the excess contaminates soil or is flushed into waterways. To make it easier for gardeners to choose plants appropriate for California’s Mediterranean climate, UC Davis Arboretum staff identified and tested 50 tough, reliable plants to include in the All-Stars program. These plants are easy to grow, do not need a lot of water, have few problems with pests, and have outstanding garden qualities. Many of them are California-native or Mediterranean plants, and most provide food or habitats for native birds and insect pollinators. These plants can be found on the Storer garden, UC Davis Arboretum website (arboretum.ucdavis.edu) and at the Arboretum gardens, each with a photo of the plant in bloom, a list of its outstanding features, and information on how to grow it. Also on the website, viewers can look for plants that meet specific criteria — for example, plants that grow in shade, have white flowers in June, or attract hummingbirds. Although, not widely available Mexican tulip poppy for retail, the Arboretum is work- ing with the UC Davis California ticulture in California. Using these Center for Urban Horticulture to “green” plants can help reduce water develop partnerships with wholesale and energy use in the landscape, re- and retail nurseries in California duce carbon emissions from power to make the All-Stars available for equipment, reduce chemical runoff, home landscapes. Fifty additional and support native pollinators. It’s outstanding plants will be added to an easy way for home gardeners to the All-Stars roster in late 2008. help mitigate the effects of global The Arboretum All-Stars program climate change, and to benefit the is only one facet of the Arboretum’s long-term environmental, social, mission to promote sustainable hor- and economic health of the planet. Heuchera “Lilian’s Pink”

34 UC Davis Plant Breeding Program Ornamental Buffalograss Buchloe dactyloides (Nutt) Engelm. Taking advantage of the wild

uffalograss is a fine-leaved native Bturfgrass species that has become popular for low-maintenance lawns in the midwest and southwest states. Buffalograss is so named because it was a primary food source of the American buffalo, found across the Great Plains into the Mexican region and in most of Texas. Being a native grass, it survives in many tough areas, is drought resistant, low growing, fine in texture, and survives in hot and cool temperatures. Recognizing that the turfgrass industry has limited variation, Lin Wu, UC Davis, collected buffalograss germplasm over a wide range of geographic areas from Central Mexico to the North American short-grass plains. With extensive genetic variation in ploidy (chromosome number) levels, morphological and physiological traits have been found within and between germplasm collections. As a result, Wu released four winter dormancy, spring turf and compete with weeds, yet it is varieties of buffalograss; three quality, drought tolerance, low a low-maintenance turfgrass and were vegetatively propagated maintenance requirements, and grows only 4 to 8 inches tall. A female varieties through mass improved turf performance. drought-tolerant turfgrass such as UC Verde offers a bright future for both home lawns and golf courses So named because it was a primary food source in water-conscious California. of the American buffalo, buffalograss survives Wu also released the first commercial diploid seed-propagated in many tough areas, is drought resistant, buffalograss, UCHL-1, which low growing, fine in texture, and survives is characterized by drought resistance, low growth, and an in hot and cool temperatures. extended winter green color. selection. HiLite 15 and HiLite UC Verde (2002) is widely used 25 were released in 1994. They today, especially on the coastal were distinguished by their fine regions of California and lower valley texture, high turf density, rapid of Arizona. It is well known for its stolon spreading rate, competitive ability to stay green throughout growth, short height, improved the growing season, spread rapidly,

UC Davis Plant Breeding Program 35 Vegetable

Artichoke Cynara scolymus L. Thornless beauties, year-round

he world has become Taccustomed to having fresh fruits and vegetables year-round and the artichoke is no exception. Artichokes are available even in the winter, when 70 percent of the crop is grown in California. Perennial globe artichokes are grown along California’s central coast and managed by cutting plants back to deliver fruit in spring, summer, and fall. Winter annual production from seeded varieties in California was limited due to poor quality and yields until the mid-1990s. After 12 years of plant breeding and research, Wayne Schrader and Keith Mayberry, UC Cooperative Extension farm advisors, developed a widely adapted artichoke, Imperial Star, which is currently grown as a seed- propagated variety in Southern California, the Central Coast, and the Central Valley. It is also grown in and six additional years of selection several other states and countries. work focused on uniformity, Imperial Star is a thornless globe yield, and absence of thorns. artichoke with distinctive bract Imperial Star showed broad glossiness. It was derived from a climatic adaptability and marketable

Imperial Star showed broad climatic adaptability and marketable yields three to four times higher than other varieties when it was developed, especially in winter production. segregating line obtained from the USDA. Selection was for earliness, yields three to four times higher than absence of thorns, uniformity, yield other varieties when it was developed, potential, bud appearance (glossiness, especially during winter production. shape, and color), and the rate at Imperial Star is still one of the most which bracts spread open with widely grown varieties today. increasing maturity. Mass selections were conducted for four generations Artichokes in bloom

36 UC Davis Plant Breeding Program Vegetable

Carrot Daucus carota L. Two seasons are better than one

C Davis has been involved in Ucarrot breeding for over 50 years — from the development of open-pollinated varieties to hybrids, and the selection of the long, slender types now used for “baby” carrots. Over 85 percent of the nation’s $300,000 carrot industry is grown in California. The vast majority of varieties are hybrids developed by private companies — primarily, the long, thin Imperator fresh-market types. The UC Davis program began in the early 1950s by Ted Welch in collaboration with Clint Petersen (USDA, later University of Wisconsin). By breeding carrots in the Midwest and in California’s Imperial Valley, selections can be made two seasons per year in the field, resulting in rapid Carrot seed production improvement and stable varieties. Initially, the focus was to increase The hybrid industry yield. Welch and E.L. Grimball changed the industry by selecting a resulted in significant plant with brown anthers that was increases in yield and male-sterile but produced seed. This resulted in significant increases in uniformity of carrots. yield and uniformity of carrots and Growers eventually enabled the creation of the hybrid industry. More and more, growers adopted these more eventually adopted these more improving carotene content and expensive but highly expensive but highly profitable resistance to root diseases. By the varieties. The focus then turned 1980s, the program was energized profitable varieties. to developing breeding parents to by the burgeoning baby carrot license for hybrids with disease market which demands a long, thin Since the inception of the UC Davis/ resistance and high quality such uniform type that can be shaped USDA program, vitamin A in carrots as sweetness, taste, and crunch. into the popular snack forms. has doubled, and dozens of inbred In the mid-1960s, Vince Rubatzky Since the mid-1990s, Joe Nunez, lines, breeding populations, and joined the program and continued a UC Cooperative Extension hybrid varieties have been released. the joint venture and bi-seasonal farm advisor in Kern County, has breeding program with the USDA, continued the program with a focus now managed by Phil Simon in on resistance to nematodes and Wisconsin. Breeding focused on specialty types high in antioxidants.

UC Davis Plant Breeding Program 37 Vegetable

Celery Apium graveolens L. Adapting to evolving conditions

alifornia produces 50 to 60 Cpercent of the total celery in the U.S. About 25,000 acres of celery are harvested each year in California, with a value of approximately $182 million. UC Davis is one of the few institutions in the world working on celery breeding and genetics. In 1977, Thomas Orton founded a celery breeding and genetics program at UC Davis after finding celeriac accessions resistant to fusarium yellows. In 1983, Carlos Quiros took over the program which produced its first fusarium-resistant line, UC1, in 1984. UC1 has served as the foundation material for further selection and release of the first commercial fusarium- resistant varieties developed by the seed industry. Quiros and his team later released eight advanced lines, including industry for further development. Since its inception in 1976, UC8, UC10, UC390S, and UC862 The program is developing molecular the California Celery Research which have been the most popular markers and a genetic map useful Advisory Board has supported for further improvement by seed for marker-assisted selection. With UC Davis’ celery breeding research. companies. In 1994, the program its broad germplasm base and The program continues to adapt produced the fusarium-resistant comprehensive genetic information, and solve present and future Promise, derived from UC10 after the celery genetics program at problems faced by the celery growers, such as leafminers and About 25,000 acres of celery are harvested other insect pests and diseases. each year in California, with a value of approximately $182 million. UC Davis is one of the few institutions in the world working on celery breeding and genetics. backcrossing it to T.U. 52-75. UC Davis allows California growers The breeding program has also to continue to grow celery in produced celery lines with multiple fusarium-infested soil with most of disease and insect resistance which the existing resistant varieties derived have been released to the seed from UC Davis’ resistant lines.

38 UC Davis Plant Breeding Program Vegetable

Garlic Allium sativum L. The sweet smell of collaboration

ollaboration between UC Davis Cbreeders and the California garlic industry has contributed to the success of the annual Gilroy Garlic Festival, which attracts over 130,000 people each year and offers specialties like garlic shrimp and garlic-flavored ice cream. California grows over 85 percent of the commercial garlic in the U.S. Garlic is primarily a vegetatively propagated crop — a commercial- scale breeding program is still in its infancy. Pollination and seed set, requirements of true breeding to make genetic gain, is difficult and rarely occurs naturally in garlic. In the 1940s, UC Davis researchers identified two clones, an early-maturing processing type and a late-maturing fresh-market type that set seed. These clones, or varieties, still account for 75 percent of the garlic grown in California today. Viruses are a major limitation to high yields of garlic in California and around the world. In the 1970s, Bob Shepherd, a UC Davis researcher, developed a method to eliminate viruses in garlic plants using meristem tissue culture. UC Davis Cooperative Extension specialists Ron Voss and Dennis Hall subsequently showed that yield can be increased by at least 30 percent in some varieties using virus-free seed garlic. With the California garlic industry adopting the technology, average yields increased from 6 tons per acre to 10 tons per acre. Garlic drying at the UC Davis Student Farm. UC Davis conducted a garlic selection and testing program for 15 characterizing these accessions for research has supported a USDA years, until 2004, evaluating over ability to form true seed, quality program that is continuing the work. 300 accessions from the USDA and traits, disease resistance, and international germplasm banks, environmental adaptability. This

UC Davis Plant Breeding Program 39 Vegetable

Grain legumes The principles of plant breeding

rain legume varieties have The father of the internationally UC pathologists, entomologists, Gbeen developed for many recognized UC Davis legume and nematologists, along with decades by UC Davis plant breeders breeding program was Francis the grain legume genetics and to meet the need for well-adapted Smith, who was succeeded by several evolution research of Paul Gepts. rotation crops in many and varied bean breeders, most recently Steve In 1946, Robert Allard was cropping systems throughout the Temple. Many UC pest management hired at UC Davis. He began his Central Valley and the California researchers, UC Cooperative work by backcrossing mainly coast. Most commercial legume Extension county advisors, and disease-resistance genes in lima production today utilizes more than growers have participated actively bean (Phaseolus limensis L.). 15 UC Davis public varieties, with in UC Davis grain legume varietal Allard expanded the germplasm a smaller but significant acreage development. The UC Davis diversity for breeding with a of foundation and certified seed of breeding program has also benefited germplasm exploration trip to private and non-UC public varieties. substantially from cooperation with Latin America. He released several

40 UC Davis Plant Breeding Program Vegetable bean varieties in the 1950s, including the cultivar Mackie. Allard developed the theory on gene interactions and recombination by studying variation in color of beans and later protein and DNA markers. This, along with studies on quantitative genetics in wheat and barley, led to many advances in our understanding of plant Trait development and deployment has emphasized seed and canning quality. breeding; Allard documented this in his 1960 publication, “Principles of Plant Breeding.” This book still is one of the most comprehensive Bean cutting equipment books on plant breeding. Research at UC Davis focused on large and baby lima blackeye cowpea (Vigna unguiculata L.), and an assortment of Phaseolus vulgaris L. common bean classes. A large number of varieties have been released in all of these classes and grain types. Trait development and deployment has emphasized seed and canning quality, as well as host plant resistance to root knot nematode, lygus bug feeding damage, and to diseases (especially aphid-vectored viruses and soil pathogens). The most significant recent releases feature resistance to bean common mosaic virus, root knot nematodes, fusarium yellows, and lygus bug. Germplasm for these traits was obtained from One of the initial grain legumes UC Davis focused on was the cowpea. U.S. and international breeding and genetics programs. yielded primary responsibility (Cicer arietinum L.) breeding. This Beginning in the early 1990s, for blackeye improvement to testing and selection work on a shift from public to marketing UC Riverside breeders, and began winter legumes (chickpea, and to order support of breeding activities a regular germplasm exchange and a lesser extent grain lupin, Lupinus occurred, primarily due to UC testing program with USDA/ARS polyphyllus L.), has led to the release budget constraints. UC Davis also (Pullman, Wash.) for chickpea of ascochyta-resistant varieties.

UC Davis Plant Breeding Program 41 Vegetable

Lettuce Lactuca sativa L. Decreasing disease with genetics

ettuce ranks as one of the top Lten most-valuable crops in the U.S. with an annual value of over $2 billion, 80 percent of which is grown in California. Lettuce is often grown over large areas, making it vulnerable to a variety of diseases. While chemi- cal controls are available for some diseases, their ecological impact, regulations, and costs make them less desirable than genetic resistance. Therefore, the development of germ- plasm with resistance to the most im- portant lettuce diseases in California has been a major priority for lettuce breeding at UC Davis and elsewhere. The UC Davis lettuce breeding tor pathogen variability and assess Calmar’s downy-mildew resistant program was started in 1942 by the efficacy of new resistances. gene was eventually overcome by Ted Welch in collaboration with The program also emphasizes evolving types of the pathogen, and the USDA. This program empha- determination of the genetic basis of the needs of the lettuce shipping in- sized identifying genes conferring resistance to these diseases and the dustry changed. Calmar and its sister disease resistance, particularly to identification of DNA (molecular) lines were used at UC Davis and else- downy mildew, and incorporating markers for marker-assisted selec- where to develop new varieties that them into crisphead horticultural tion of genes for disease resistance retained the quality and field per- types suitable for California. Since and other agriculturally important formance but also met new industry 1982, the program has been con- traits. As in humans, DNA can be needs. In 1975, Ed Ryder from the tinued by Richard Michelmore, and used to track the forms (alleles) of USDA released Salinas, which had the number of diseases targeted genes in plants. Determination of Calmar in its parentage and replaced has increased, notably to include the global genetic architecture of Calmar as the most commonly culti- corky root, which was becoming disease resistance in lettuce and vated crisphead lettuce type. Salinas a major problem in the 1980s. the development of an ultra-high- and its relatives remain the predomi- In the late 1990s, the program was density genetic map are underway. nant type planted in California today. expanded to include breeding for Initially, a series of breeding mate- Since 1982, the UC Davis pro- improvement of leafy horticultural rials was developed and released to gram has focused on the release of types in response to an industry the seed industry and lettuce growers advanced breeding material with shift to leafy varieties such as ro- in the late 1950s. In 1960, the pro- new disease-resistance genes rather maine. The program now includes gram released its first and highly suc- than the release of varieties. Twenty- breeding for resistance to downy cessful variety, Calmar. Because of its nine breeding lines carrying several mildew, corky root, lettuce mosaic genetic resist­ance to downy mildew, novel sources of resistance for let- virus, anthracnose, verticillium, and tip burn resistance, vigor, size, and tuce downy mildew and combina- fusarium. The program involves ex- wide adaptability, Calmar became the tions of other resistance genes have tensive germplasm screens to identify dominant variety in the Salinas Val- been released thus far (see Table new sources of resistance as well as ley for fifteen years. Ten other variet- 1). Resistance to corky root was surveys of pathogen populations, ies were released by the program but shown to be determined by a single particularly downy mildew, to moni- none proved as successful as Calmar. recessive gene, cor, which greatly

42 UC Davis Plant Breeding Program Vegetable accelerated the breeding of resis- now been identified and molecular Lettuce Research Board. The USDA tance to this disease; the majority of markers have been identified for and National Science Foundation commercial varieties now contain them providing a wealth of genes have also contributed to the program this gene and the disease is rarely for future lettuce improvement. by supporting classical and molecu- problematic. Numerous additional The breeding program has been lar genetics of lettuce and the devel- lettuce disease-resistance genes have funded primarily by the California opment of molecular breeding tools.

Table1: Historical events in the lettuce breeding program at UC Davis.

Decade Principal Events Investigator

1940s Ted Welch Initiation of the lettuce breeding program.

1950s Ted Welch Programs started for resistance to diseases, including lettuce downy mildew (LDM), lettuce mosaic virus, and big vein, as well as to peach aphid, an insect pest.

1960s Ted Welch Release of Calmar, a large, vigorous head lettuce cultivar of the Great Lakes type.

1970s Ted Welch Head lettuce releases: Calicel, Calrey, Calrico.

1980s Ted Welch Head lettuce releases: Alamo, Anza, Laguna, Ramona, Rita, Vega, and Vista.

Richard Techniques established for transformation mediated by Agrobacterium tumefaciens Michelmore and genetic mapping of lettuce with DNA markers.

Detection of Ridomil insensitivity in lettuce downy mildew.

1990s Richard Bulked segregant analysis developed for rapid mapping of resistance genes. Michelmore Head lettuce releases: breeding lines UC201, UC204, UC205, UC206, UC207, UC209, and UC210 containing resistance to LDM and corky root.

Head lettuce releases: breeding lines UC9602, UC9606, UC9607, UC9608, UC9612, UC9614, and UC9652 containing novel sources of resistance to LDM and corky root, anthracnose, and LMV. 2000s Richard Leafy lettuce breeding program initiated. Michelmore Head lettuce releases: breeding lines UC02100, UC02101, UC02102, UC02103, UC02104, UC02105 and UC02106 containing novel sources of resistance to LDM and various combinations of other resistant genes.

Comparative genomics program initiated.

Dm3 LDM resistance gene cloned.

Head lettuce releases: breeding lines UC07107, UC07108, UC07109, and UC07110 containing novel sources of resistance to LDM.

Leafy lettuce releases: breeding lines UC07100, UC07103, and UC07105 containing novel sources of resistance to LDM.

UC Davis Plant Breeding Program 43 Vegetable

Potato Solanum tuberosum L. Developing bulk of state’s varieties

lthough California is not dustry. Seedlings were selected under Several new varieties were A a major potato producer, the California environment and for released including Cal White, a UC Davis researchers have developed California markets. Almost every long white potato with smooth potatoes that perform well in potato variety grown for pro- skin and high yield that replaced California. The UC Davis potato cessing or for the fresh market White Rose. Focusing on fresh variety development and testing in California was developed market and chipping, red potato program was initiated in the 1940s or introduced through this varieties — like CalRed — were by Glen Davis. The focus was on UC collaborative program. released. The fresh-market Russet fresh-market, long white potatoes Although only five or six Norkotah was introduced, as well as at a time when the variety White species of potato are grown the high-yielding, low-sugar content Rose, selected in the1890s, was still commercially worldwide, a variety, Atlantic, that replaced the predominantly grown in California. wide range of characteristics are famous Kennebec for chipping. In the 1970s, UC Davis Coopera- available in other Solanum species In the 1990s, several spe- tive Extension specialist Ron Voss that can be introduced into the cialty varieties were also selected organized a potato collaborative commercial species. These include and introduced from private and variety development and testing pro- disease resistance, colored flesh, public programs. These varieties gram that included breeders from the and other characteristics. New include colored-flesh lines such USDA and several land-grant univer- selections were tested and licensed, Inka Gold, high in anthocyanin sities. The program was coordinated broadening the spectrum of and antioxidants, developed by with and funded by the potato in- potatoes available for California. UC Davis geneticist Carlos Quiros.

44 UC Davis Plant Breeding Program Vegetable

Sweet potato Ipomoea battatas L. Clean seeds, healthy stocks

ontrary to its name, the sweet Cpotato is not in the same family as potatoes. It is in the same family (Convolvulaceae) and genus (Ipomoea) as morning glory. UC Davis began its sweet potato breeding program in the 1950s. Jack Hanna released UC779 (“yam” or “Jewel” type; i.e., moist flesh) that was grown exclusively in California in the 1960s through the 1980s for canning due to its sweetness and high yield. Garnet, a red-skinned, orange-flesh (Puerto Rico and “yam”) type, was released to the industry in the late 1960s. The variety Hanna Sweet, a dry white/yellow-fleshed (“Jersey” or “sweet potato”) type sweet potato, was released in the early 1980s for fresh market and is still grown today. A collaborative variety testing program, coordinated in California by the UC Cooperative Extension county advisor in Merced County, has resulted in several new varieties since then. Perhaps the most significant contribution by UC Davis to the sweet potato industry was the development of a clean-seed program and the maintenance of disease-free seed stocks. UC Davis researchers developed the methodology for clean, disease-free seed stock for clonally propagated plants. Shoots from sweet potato are heat-sterilized to eradicate disease, then grown and propagated using tissue culture. These shoots are then transplanted The Jewel type sweet potato, UC7799, was grown exclusively for 20 years in California. and observed in nurseries for genetic stability and disease. Only plants that Services facility on the UC Davis are “true to type” and disease-free campus for sweet potato and many are carried forward to release as seed other clonally propagated crops. stock for California. Deborah Golino manages the Foundation Plant

UC Davis Plant Breeding Program 45 Vegetable

California produces the majority of world’s processing tomatoes.

Tomato Solanum lycopersicum L. New technology leads to boom

rom the 1940s through the the economically important Vegetable Crops and released F1980s, UC Davis plant breeder nematode-resistance gene, Mi, for commercial use beginning in and plant pathologist Paul G. Smith into cultivated tomato, which led the early 1960s. Prior to that, all contributed to the development of to its identification. This trait is tomatoes were picked by hand, varieties of cherry tomatoes, such still widely used in commercial requiring considerable labor in as Royal Red Cherry and Short cultivars. Indeed, it is the only such the fields. Foreseeing a need for Red Cherry. Smith was perhaps gene available to growers today. machine-harvested tomatoes, Hanna the first person to successfully The first tomato varieties designed began a breeding program in the late hybridize cultivated tomato with the specifically for machine harvest 1940s. His foresight was based on wild relative Solanum peruvianum. were bred by Gordie (Jack) Hanna experience with other crops, such as He consequently transferred in the UC Davis Department of sugar beets, in which labor shortages

46 UC Davis Plant Breeding Program Vegetable had also led to mechanized harvest. In 1964, the Bracero Program, which brought large numbers of farm workers into the U.S. to pick tomatoes and other crops, was terminated by Congress. The resulting labor shortage in California meant that the canning companies could not be assured a steady supply of tomatoes, causing some companies to consider relocating out of the state. Fortunately, the California tomato industry was rescued by two UC Davis inventions: a tomato harvester and suitable tomato varieties. The harvesting machine was created by Coby Lorenzen in the UC Davis Department of Agricultural Engineering. Later The tomato harvester is a UC Davis innovation. it was commercialized by the Blackwelder company. Hanna’s The coordinated varieties had to not only stand up to machine picking, but also development of the meet the requirements of growers and canners. As prototypes of the tomato harvester and harvester were developed, they were tomato varieties led to tested on fields of Hanna’s tomatoes. These tomatoes had been selected a great expansion of for desirable characteristics such the processing tomato as firm fruit, high soluble solids, heavy fruit set during a narrow industry in California. window of time (necessary because Today, the state machine harvest was a once-over, destructive process), compact vines, produces 95 percent good field-holding capacity, etc. of the national and In addition, Hanna introduced resistance to some diseases prevalent nearly 50 percent of in California, such as fusarium and the world’s supply of verticillium wilts, as well as the ability to set fruit under the high canning tomatoes. summer temperatures common in Jack Hanna was instrumental in the Central Valley. This led to the developing tomatoes that can be California. Today, the state produces mechanically harvested. release of tomato varieties such 95 percent of the national and as VF145, the first variety bred nearly 50 percent of the world’s specifically for machine harvest, supply of canning tomatoes. and later VF13L and VFN8. The coordinated development of the tomato harvester and tomato varieties led to a great expansion of the processing tomato industry in

UC Davis Plant Breeding Program 47 Vegetable

Onion Allium cepa L. The mother of all onions

ost new onion varieties today Mare developed by international private companies. In California, the largest onion-producing state in the U.S., approximately 60 percent of the acreage is grown for dehydration processing and 40 percent for fresh market. Henry Jones, a UC Davis researcher, began breeding onions as early as the 1920s, focusing on fresh-market types. Jones changed the onion industry in 1925 by discovering a male-sterile Italian Red plant in the UC Davis onion breeding plots. The development, distribution, and use of this male- sterility enabled the production of hybrid onions resulting in rility was the basis of all hybrid on- onions such as CalRed, from which increased yields and uniformity. ions for many decades. In the 1950s, Fresno Red and Stockton Red The UC Davis source of male ste- Glen Davis released several red were selected and still grown today.

Pepper Capsicum spp. Array of colors is in the genes

epper breeding at UC Davis was published research on Capsicum Pactive from the 1940s to the spp. taxonomy and described a 1980s, led by Paul G. Smith, a plant new species of pepper from Peru. pathologist, breeder, and former He also was an authority on the member of the UC Davis Department crossing relationships (sexual of Vegetable Crops. Smith released compatibility) of Capsicum species. bell pepper varieties including Smith and his colleagues also Caloro, a yellow wax type pepper, studied the inheritance of fruit color and Summer Sunshine, a yellow in peppers, and developed a model bell type. He identified a source of on how the diversity of colors is resistance to phytophthora root rot controlled at the genetic level. disease (Phytophthora capsici) still widely used in commercial varieties. In addition to his contributions in plant pathology and breeding, Smith

48 UC Davis Plant Breeding Program Miscellaneous

The Plant Breeding Academy Meeting demand for breeders

C Davis is developing Uinnovative programs to teach modern plant breeders. There is a worldwide shortage of skilled plant breeders due to both an increasing demand and a decreasing number of active public breeding programs. Furthermore, the skills required for public breeding are becoming divergent from those demanded by the private global seed businesses. In direct response to industry con- cerns, the UC Davis Seed Biotech- nology Center developed the Plant Breeding Academy (PBA). The course provides an opportunity for compa- nies to invest in advanced training for dedicated personnel who are involved in breeding programs. The two-year program provides formal instruction in genetics, statistics, and plant-breeding theory. The course Inaugural class and instructors for the Plant Breeding Academy, 2006-2008. schedule allows students to main- tain their working positions while America, and from as far away as Course curricula extend to all enrolled. The goal is for academy Hong Kong, to attend six one-week issues involved in plant breeding graduates to be able to work as inde- sessions over the two-year course. from genetics, statistics, trait pendent plant breeders or to direct The UC Davis certificate course selection, population development, regional plant-breeding programs consists of lectures, field trips, resistance breeding, genotype by upon completion of the course. discussions, homework, and a environment interactions, and The first class (Class I) of the comprehensive final project for biotechnology, to finishing varieties and seed production. Class I The goal is for academy graduates to be able completed the course in June 2008, and 23 new students from around to work as independent plant breeders or the world are enrolled in Class II, beginning in September 2008. to direct regional plant-breeding programs Visit http://pba.ucdavis.edu for upon completion of the course. more information.

Plant Breeding Academy began which students design a breeding instruction in September 2006 with program. The primary course 15 students. Most were already instructors are Doug Shaw and breeding assistants with practical Larry Teuber from UC Davis and knowledge in plant breeding but not Todd Wehner from North Carolina the theory behind it. They travelled State University, all internationally from various locations in North recognized plant breeders.

UC Davis Plant Breeding Program 49 Miscellaneous

Research and Information Centers

Agronomy Research Seed Biotechnology Center About RICs: and Information Center Kent Bradford, Academic Director; The RICs listed are coordinated AgRIC provides information on Mike Campbell, Executive by the Department of Plant California agronomic crops, Director; Susan DiTomaso, Sciences at UC Davis. including alfalfa, winter cereals, Manager of Outreach Chris van Kessel, Chair, corn, cotton, dry edible legumes, The SBC is a focal point for Department of Plant Sciences rice, safflower, sugarbeet, interaction between the seed sunflower, and specialty crops. Ted DeJong, Vice Chair, industry and the research and Department of Plant Sciences educational resources of the California Rangelands Extension and Outreach UC Davis. It coordinates research Research and Louise Ferguson, that interests the seed industry and Information Center RIC Coordinator provides continuing education in Mel George, Director; Janice seed biology and technology. Sue DiTomaso, Manager Corner, Program Representative of Outreach. For info, contact Vegetable Research The CRRIC develops research [email protected] and Information Center and extension education initiatives or (530) 754-7333. and fosters collaboration Tim Hartz, Director; Gale Perez, between California rangeland Find us online: Program Representative researchers and educators. rics.ucdavis.edu VRIC’s mission is to foster research, collect and disseminate information Environmental relevant to consumers, growers, Horticulture Research Fruit and Nut Research and processors in the California and Information Center and Information Center vegetable industry, and serve as Heiner Lieth, Director; Judy Louise Ferguson, Director; Judy a leading source of research and Sams, Program Representative Sams and Penny Stockdale, information for the vegetable industry. EHRIC is a resource created Program Representatives for research-based information Weed Research and The Fruit and Nut RIC aids in the Information Center on issues facing the horticulture coordination and dissemination of industry in California. EHRIC UC research-based information, and Joe DiTomaso, Director; Gale acts as an umbrella organization statewide research and extension Perez, Program Representative coordinating activities of the Turf, activities related to fruit and nut crops. WeedRIC fosters research in Landscape, Urban Horticulture, weed management and facilitates and Floriculture and Nursery Postharvest Technology distribution of associated knowledge workgroups within the UC system. Research and for the benefit of agriculture and for Information Center the preservation of natural resources. Jim Thompson, Academic Director; Jim Gorny, Executive Director; Mary Reed, Program Representative The Postharvest RIC provides relevant information and programs to California growers, shippers, marketers, carriers, distributors, retailers, processors, and consumers of fresh horticultural crops.

50 UC Davis Plant Breeding Program Plant Breeding programs

Academic Departments Department of Plant Sciences Department of Viticulture and Enology Graduate Group in Horticulture (530) 752-1703 (530) 752-0380 and Agronomy www.plantsciences.ucdavis.edu wineserver.ucdavis.edu (530)752-7738, ggha.ucdavis.edu

Centers, Institutes, and Programs Agricultural Sustainability Institute Foundation Plant Services (530) 752-3915 (530) 752-3590 www.asi.ucdavis.edu fpms.ucdavis.edu

California Center for Urban Horticulture Foundation Seed Program (530) 752-6642 (530) 752-2461 ccuh.ucdavis.edu fsp.ucdavis.edu

California Crop Improvement Association Genomics Facility (530) 752-0544 (530) 754-6616 ccia.ucdavis.edu www.cgf.ucdavis.edu

C.M. Rick Tomato Genetics Resource Center Ralph M. Parsons Foundation Plant Transformation Facility (530) 754-6059 (530) 752-3766 tgrc.ucdavis.edu ucdptf.ucdavis.edu

Acknowledgements

The College of Agricultural and Environmental Sciences would like to thank Allen Van Deynze for leading the production and editing of this publication, Diane Nelson for primary editing, Ann Filmer for copy editing, Eric Rohr for design and layout, and Michael Parrella for initiating the project and moving it forward. The college also thanks the contributors for their help in researching and writing the text for each of the sections. Contributors William Biasi David Fujino Kirk Larson Oswaldo Ochoa Larry Teuber Melissa Borel Lynn Gallagher Belinda Martineau Daniel Putnam Allen Van Deynze Diane Cary Catherine Glaeser James McCreight Calvin Qualset Ronald Voss Roger Chetelat Deborah Golino Gale McGranahan Carlos Quiros Paul Vossen Theodore DeJong Thomas Gradziel Patrick McGuire Vincent Rubatzky Andrew Walker Susan DiTomaso James Harding Kent McKenzie Charles Schaller Lin Wu Jorge Dubcovsky James Hill Richard Michelmore Douglas Shaw Louise Ferguson Robert Hutmacher Eugene Miyao Steven Temple

Photographers Jack Kelly Clark Carl Jones Robyn Rominger Beverly Ferguson Jeanette Martins Larry Teuber Ann Filmer Diane Nelson Allen Van Deynze

UC Davis Plant Breeding Program 51 COLLEGE OF AGRICULTURAL AND ENVIRONMENTAL SCIENCES Office of the Dean This publication was produced by:

Dean’s office Neal K. Van Alfen, Dean Michael P. Parrella, Associate Dean for Agricultural Sciences

150 Mrak Hall (530) 752-0108 www.caes.ucdavis.edu department of plant sciences Chris van Kessel, Chair

1210 Plant and Environmental Sciences (530) 752-1703 www.plantsciences.ucdavis.edu

Seed biotechnology center Kent J. Bradford, Academic Director Michael Campbell, Executive Director

Plant Reproductive Biology (530) 754-SEED (7333) sbc.ucdavis.edu

For additional information and to view this publication online, visit www.plantsciences.ucdavis.edu/plantbreeding

The University of California does not discriminate in any of its policies, procedures, or practices. The university is an affirmative action/equal opportunity employer.