Successes and Ii m itations

Paulden F. Knowles, Professor, Agronomy and Range Science, Davis

sinceits beginning, the University of Cali- fornia has been actively involved, directly or indirectly, in traditional plant breeding pro- grams, including germplasm collection and evaluation, development of genetic stocks for use in plant breeding programs, development of finished varieties, new crop development, and training of plant breeders. Such plant breeding is actually a form of genetic en- gineering. It involves management of genes and their carriers, the chromosomes. Germplasm collection University personnel have been plant ex- plorers, searching areas where crop plants or- iginated or where their wild relatives exist to bring back to the United States stocks that very often provided characteristics to im- prove our plants (see CaliforniaAgriculture, September 1977). Germplasm collections have been made for established crops, such as grapes, strawbemes, and safflower; crops es- tablished elsewhere but not yet grown in Cali- fornia, such as rapeseed and amaranths; and wild species not yet domesticated, including wild sunflower, guayule, and jojoba. Development of genetic stocks and finished cultivars University researchers have provided ge- netic stocks, which in turn have been used to improve cultivars being developed by both public and private agencies. Often these have involved transfers of characteristics from related wild species. Examples of genetic stocks are: OTomatoes with disease resistance OSafflower (from the wild Carthamus ox- yacantha of the Middle East) resistant to rust OYellow-dwarf-resistant barley obtained from introductions from Ethiopia OShort-stemmed high-yielding types of rice obtained by using mutagens. This important activity of the University will be advanced by genetic engineering. The University’s role in development of finished cultivars has yielded economic bene- fits to agriculture far in excess of all the costs

6 CALIFORNIA AGRICULTURE. AUGUST 1982 Plant breeding trials with gua- yule, a potential source of rubber, by I? F. Knowles may yield economic benefits well above research costs. of U.C. agricultural research. years, in large measure because of the Univer- peratures. Its seed oil, chemically similar to Today, 75 to 80 percent of the barley crop sity breeding program, production of pro- that of the endangered sperm whale, has in California is grown to U.C.-developed cul- cessed tomatoes has quadrupled. many uses (see California Agriculture, Au- tivars, which have resulted in yield increases A U.C. grape breeding program began gust 1979). of up to 48 percent during the last 15 years. yielding new cultivars in 1946. Since then a Other potential new crops being investi- About 80 percent of the strawberry acreage steady flow of cultivars has been released for gated by the University are sesame and mus- in California is planted to cultivars developed all facets of the grape industry including rai- tards as a source of oil and protein, amaranths by the University of California. The new cul- sin varieties, red and white wine varieties, and and triticale as a source of carbohydrate and tivars with high yields and excellent quality an array of table varieties. Improvements in protein, and guayule as a source of rubber. have expanded the area of production and table grapes include seedlessness, earliness, Not the least of the University’s contribu- permit year-round production of fruit. storage ability, and bright red color. Disease, tions to plant breeding has been the training Virtually all the California asparagus acre- nematode, and insect resistance has been in- of plant breeders through formal courses, age has been planted to University cultivars corporated into new varieties, in some cases textbooks on plant breeding, and research or for 40 years. The latest in a series of seven cul- through interspecific hybridization. apprentice-type experience under the gui- tivars is F, hybrid UC 157, renowned for its UC-1 was the first commercial variety of dance of a plant breeder. The training has fo- high yields of uniform, superior spears and safflower with high levels of oleic acid, in- cused on both basic and applied aspects of tolerance to fusarium wilt. stead of linoleic acid, in the seed oil. Chemi- plant breeding, and graduates serve agricul- The University has been deeply involved in cally, the oil is like olive oil. It is an example ture throughout the world. melon breeding since the 1920s. The most re- of using a single gene to provide a new oil cent developments are short-internode bush crop. Trends cultivars of honeydew and crenshaw types, A new area of research where the Univer- At one time much of the plant breeding which are easier to harvest and better adapted sity has provided leadership is the development was supported financially from state and fed- to the home garden. of dwarf cultivars of peaches and nectarines. eral sources. This support was justified, be- The male-sterile variant in the onion culti- Such dwarf varieties have short internodes, cause society as a whole benefited from the var Italian Red was discovered in the 1920s, which reduces woody growth, yet have the programs. In recent years, with declining and the first studies on its inheritance were same number of leaves, flowers, and fruits as support from public agencies, breeding pro- made by the University. This discovery led to normal trees. The result is precocious bearing grams have derived much of their financial development of the hybrid onion industry of many fruits per unit length of stem: if support from commodity groups. and served as a model for the use of cytoster- 1,000 trees are planted per acre instead of the Where private companies have assumed a iles in other crops. usual 100, yield is doubled. The dwarfing major role in breeding improved varieties, the U.C. cultivars have had a profound effect gene is being transferred to almonds, where it University has often shifted its emphasis on the tomato industry for six decades. Some is expected that the increased yield, compared from development of finished varieties to de- steps in cultivar development were: improved with that of normal trees, will be greater than velopment of germplasm and to the study of selections of cultivar Santa Clara! cultivar in peaches. breeding systems. It has sought to have its Pearson with bush habit and high yields; VF breeding programs complementary to, and 6 and VF 9 with resistance to fusarium and New crop development not competitive with, those in the private sec- verticillium wilts; VF 36 with improved fruit The University’s research program on saf- tor. In some cases the University has assumed setting; VFN 8 and VFN 14 with resistance to flower, initiated in 1947, was the necessary very long-range, high-risk objectives in plant nematodes; and VF 145 and 13L in 1954, and first step to commercial development of saf- breeding. more recently UC 134 and UC 82, which are flower beginning in California in 1950. Tests Training will continue to be an important adapted to completely mechanical harvest be- were conducted both at Davis and in the coun- role of the University. As in the past, the cause of their compact plant type, concen- ties under the supervision of farm advisors. trend will be towards a better understanding trated fruit ripening, and fruit characteristics. In large part because of the University’s re- of fundamentals rather than the practice of Because of their superiority, the latter four search, jojoba, a shrub of the Sonoran Des- plant breeding. It will deal with the behavior varieties occupy most of the California acre- ert, is now grown on nearly 16,000 acres in and management of genes and chromo- age and have increased production to 5 to 7 the United States. Jojoba performs well with somes, with basic physiological processes, million tons per year, accounting for 75 to 85 low amounts of irrigation water, low soil fer- and with the interactions of crop plants with percent of U.S. production. Over the last 40 tility, high salinity, and a broad range of tem- pathogens and insect pests.

CALIFORNIA AGRICULTURE, AUGUST 1982 7