Genetics of Western White Pine R

of WESTERN wH':- PINE

wo-t 2 CONTENTS

Page Page SUMMARY ABSTRACT ___-___ iii Crossability - - 9 II{TRODUCTIOI{ 1 D e I eteri o u s R *; ";"* e-;; ;;t Paleobotanical and Present Range --- I Other Genes -- 10 Speciation 3 Variation in Natural Stands 10 Habitats -, 3 Monoterpenes -----*- 10 Grorvth 4 Grorvth 10 SE}iTIAL REPRODUCTION - 4 Insect Resistance 11 Chromosomes 4 Induced Mutation 11 Flowering 4 Blister Rust Resistance ____ 11 Cone and Seed Bearing ____,*_ 5 Physiology of Resistance ______Lz Poilen Storage o IMPROVEMENT PROGRAM 13 AS}JXUAL REPRODUCTION 6 Ilooting Breeding for Blister Rust Resistance, 18 G Tandem Griifting 7 Selection for Blister Rust, Resistance and Growth Rate ______18 G]Ii{ETICS AND BREBDII.{G 7 ?axonomy 7 LITERATURE CITED

Issued December 1g?1 This pu[:licotisn is or:u irr E :;eiies cr'r thsj genelits rr$ irnp:orf*nt fslrert fr*as *i i{elrth Aiireric*: beirrg pub!ilhed by the Fsn*:si Servirs, tr.5. E*p;:rti::errl tlf drgriculfur*, in co*percf ion .n*ith the $ce ie iy slf Anr*riasn F+resters. Development oi ihi,: seris:s is in **earcl ",vilh fhe resofufi$ffis of the Wt> rld C.un:ulfurtiorr cn F*r*sl {}*rra:?ics ernd Tre"e lmprovement

More than 20 years of investigation on the P. monticola appears to be noncrossable with inheritance of white pine blister tust (Cronar- P. balfouriana and P. aristata of Subsection tium ribicola) disease resistance, growth, and Batf ourianae,but with at least three species of other features of the paleobotany, flowering, Subsection Cembrae, sound seed of unverified seed yield, and inbreeding of western white hybridity have been produced repeatedly. With- pine (Pinus monticola) are summarized. in Subsection Strobi, repeated crossings with Megafossil collections indicate that the pro- six other species have been successful, but re- genitor of P. monticola (the fossil species P. peated crossings with P. armandii and P. lurn- wheeleri) has been present in and around the bertianct have failed. Thus there is good pros- present distribution of P. monticola since the pect for obtaining white pine blister rust early Pliocene to mid-Eocene eras, and that the resistance-genes from resistant Eurasian spe- species has withdrawn into four western North cies like P. cem,bra, P. sibiricu, P. koruiensis, P. American subpopulations. Special signiflcance griffithii. and P. peuce. Growth of individual is placed upon three megafossil cone collections hybrids varies widely depending on the partic- from eastern Siberia, authoritatively identified ular parental combinations. as P. monticola,. These collections indicate that The genetic load of P. monti,cola includes P. monticolo has had opportunity for gene- deleterious recessive genes for albinism, dwarf- exchange with other Asiatic white pines that ing, curly needles, and a variety of chlorophyll have evolved near the gene-center for C. deficiencies. Monoterpenes are under strong ribicola. genetic control. Variation in growth associated P. monttcola is monoecious, precociously fe- with elevation of seed source appears to occur, male as early as age 7 and remaining so through especially at the extreme upper and lower ele- age 20. Under wide spacing in a cultivated, vations. Heritability of height growth is low (5 irrigated, and fertilized seed orchard, grafts to 30 percent) ; heritability of blister rust re- produced nine cones per tree 12 years after sistance is high (65* percent). Four races of grafting; in a comparable arboretum seedlings C. ri,bicola characterized by foliage lesion types produced 4[ cones at age 11, and 20 cones at are recognized, and several recessive and domi- age 18. Anthesis ( A- ) and rneceptivity ( 9 ) are nant resistance-genes are either recognized or simultaneous, with ample overlap for self- hypothesized. pollination. Long-term average yields for 25- Relative abundance and variety of white pine to 70-year-old trees are 28 cones; seed produced blister rust resistance factors present in P. by these cones include 104 filled seed per wind- monticola strengthens the hypothesis that P. pollinated cone, 88 filled seed per controlled monticola and, C. ribicolu have made contact cross-pollinated cone and.47 filled seed per self- in the past, or that gene-exchange has occurred pollinated cone. Yields vary greatly between between P. mont'icola and resistant Asiatic mother itrees, localities, and seed years. Selfing white pines. Breeding for blister rust resistance results in lower cone and seed yields, and a is eminently possible. A first-stage program for growth reduction percent of 30 to 40 below that mass-producing partially resistant F, seed is of outcrossed progenies. seedling-seed orchard planting Needle bundles and cuttings from young trees now in the can be rooted with fair to good success. Green- stages; a second-stage program has been house grafting is highly successful, but in started for the purpose of further improving northern Idaho field grafting meets with scant and stabilizing the level of resistance and to success. incorporate improvement of growth.

ilt Genetics of Western White Pine R. T. Binghom, R. J. Hoff, ond R. J. Steinhoff ' INTRODUCTION Western white pine (Pittus monticola Dougl.) of six of the megafossil localities (Axelrod is among the prized conifers native to the west- 1966a; Evernden and James 1964) place their ern United States. Its stately, clean-boled form age at 10.7 million years (early Pliocene) (fig. 1), its soft, white, easily machined and through 55 million years (mid-Eocene). Radio- valuable lumber, its ability to reproduce itself carbon and other dating techniques place the naturally, its relatively rapid and long-con- age of bog pollens at from 2,000 to 18,000+ tinued growth, and its occupancy of sites often years (Hansen 1942c; 1947a; 1967). not favorable for other commercial conifers all have combined to make this species a favorite of the forest manager throughout the species' range. Now the introduced, epidemic white pine blister rust disease (pathogen Cronarti,um ri.bi,- cola J.C. Fisch. ex Rabenh.) has rendered man- agement of western white pine uneconomical over all but the southern part of its California- Sierra Nevada Mountain distribution. Thus, for the last 20 years, forest geneticists have been preoccupied largely with the survival trait (blister rust resistance) for this species. Im- provement of other western white pine qualities is also underway.

Poleobotonicql ond Present Ronge

The Cenozoic era progenitors of P. monticola Dougl., represented by four- to five-needled fascicles, winged seeds, and occasionally by cone fossils have been grouped under one wide ranging and morphologically variable fossil species, P'i,nu.s uheeleri Cockerell, by Chaney and Axel- rod (1959) ; this species also may include the progenitors of Pi,nus albicaulis Engelm., Pinus aristuta Engelm., Pirtus flexilis James, Pi,nus Iambertiano Dougl., and Pitrus stt'obiformi,s Engelm. or P'inus strobus var. chiapensis Mar- tinez (the soft or white pine classification of Critchfield and Little (1966) is followed). Dis- tribution of these megafossils along with that of fossil and bog pollens and the pertinent refer- ences are shown in figure 2. Potassium-Argon dates determined for the fossil-bearing stratum 'n.*"r""fr Plant Geneticists. USDA Forest Service, Intermountain Forest and Range Experiment Station, Ogden, Utah 84401; stationed in Moscow, Idaho, at the Figure l,-An overmature western white pine (age 300*' Forestry Sciences Laboratory, maintained in cooperation iieight 185 feet, diameter 52 inches), growing on the with the University of Idaho. Kaniksu National Forest, northern Idaho. Genetics of western white pine--figure 2. --Bingham, Hoff & Steinhoff WO Forest Service Research Paper

I I BRITISH COLUMSIA ALEERTA I sasxaTcHEwaN I I I

29-lo MONTANA

X^a^ / tr-- _ ,x X a 16@/ 67 \89 l oREGoN I &44 xorr X - - / | oaHo wYoutilG x -XO3',l-- X or- -l------I I -- X I I Xrp, I NEVADA I ------J- I I UTAH ORADO e' I I I eao/t|,8, {2 7- etnus MoN!!9LA iit"., I X ISOLATED OCCURRENCE h\, I

o MEGAFossTL (p wxeeuent)J W, I OCCURRENCE "r. ---l----___L CALIFORNIA C FOSSIL POLLEI'I OCCURRENCE

O POSTGLACIAL BOG POLLEN oCcURRENcE JLl ARIZONA NEY / YExICo

l/ ueolrossrl occuRREilcEs TNcLUDE THosE oF ALL sp€crEs coilsroEREo syNoflyrrous wrrx prNus !!EE!E_E! cocKERELL, By cHAt{Ey alo AX€LROO. I959. CON'€YPORARY RAilGE tS THAT OF MAP 6. CRITCHFIELO AND LITTLE, I966.

-3-l NUMBER AccoMpAilyrilG MEGAFosstL oR poLLEr{ occuRRENcE to€r{TrFrEs rHe AUTHoRrry FoR THE occuRREitc€ , As sHowt 8Y CORRESPOIDING I{U"BER IN LITERATURE CITED. 'HE Figure 2.-Past and present range of Pinus monticofa Dougl.

I There are reports of P. monticola (not P. strobif ormfs, both of which often have needles wheeleri) megafossils from four different lo- of this length. calities in northeastern and eastern Siberia In any event, P. monticolo seems to have (Hopkins, MacNeil, Merklin, and others. 1965; withdrawn into four major gene centers that Vashkovsky 1959; Sukachev 1910; and Krish- are now more or less isolated. This is shown by tofovich 1941). The first three of these reports Map 6 of Critchfield and Little (1966) and in are based upon cones-the first two on sectioned figure 2 which is an adaptation of that map. cones (thus on seeds with wings, or their traces, The four subpopulations (Inland Empire, Cas- on adaxial surfaces of cone scales, along with cade Mountains-Vancouver Island, Siskiyou cone morphology),, and the third, according to Mountains, and Sierra Nevadas) appear to have Mirov (1967), on cone and branch material been isolated for at least several thousand years, "preserved so well in frozen strata that it was and possibly much longer. Latitudinal spread identified without any difficulty as P. monti,- of the species is relatively great, ,,Ter- almost 171/2". coll,." These megafossils are dated merely The southernmost outlier of P. monticola is tiary" (Mirov 1967), or late Pliocene to early probably in Onion Valley north of Siretta Peak, Pleistocene., n These Siberian megafossils seem California and the northernmost near Quesnel to be correctly identified and thus lead to the Lake, B. C. (Can Dep. Resources and Develop. following alternative hypotheses : ( 1) that 1950). progenitors of P. monticolo crossed the Bering No range-wide study of genetic variation has I,and Bridge (probably eastward, Mirov 196Zi yet been undertaken; however, in view of the from Siberia and retreated southward in North geographic, climatic, topographic, and edaphic America before the evolution of the blister rust diversity of the present major population cen- fungus; (2) that the pine and rust met some- ters, plus outliers, interpopulation variation can where in northeast Asia, but that the rust was be expected to be great. somehow incapable of following the pine in its retreat to North America; or (B) that the pine and rust were present simultaneously in north- Speciotion east Asia yet never met, the pine, via pollen,-Asian having exchanged genes A study of Maps 5 through 8 in Critchfield with resistant (1966) gives pines so that carried and Little also rise to speculation it away some resistance concerning natural hybridization genes in its retreat across andlor intro- the Bridge. gression of P. monticola with other North - Considering North American megafossil and American white pines. P. monticola is isolated fossil pollen occurrences, it would seem that the by more than 1,000 miles from P. strobus Ll, present range of P. monticolu is very similar with which, however, it remains quite crossable. to its range during the Pliocene. However, the But at some localities (extreme southeastern species never quite regained the range it occu- British Columbia, Blue Mountains of north- pied prior to glaciation; for the molt part it eastern Oregon, and in the central and southern failed to repopulate the now dry areas at the Sierra Nevadas of California) P. monttcola oc- fringes of the present range. The occurrence of curs close to crossable P. flerili,s and we may P. wheeleri fossils at Florissant, Colorado (the presume a limited but continuing gene ex- type locality, Cockerell 1g0g) is somewhat dim_ change. P. monticola and P. albicaulzs are sym- cult to reconcile with the distribution of most patric over an even greater portion of their of the other fossils attributed to that fossil ranges. Although these latter species appear to species; it is also difficult to reconcile this oc- cross only with difficulty, there exist even more currence with the present range of p, monticola. possibilities for gene exchange. P. Iamberti,ana The type specimen, however, has needles which is another western North American white pine are exceptionally long (12f cm.) in respect to with a partly sympatric range, but it has proved other collections of P. wheeleri, or for that to be noncrossable with P. monticola (see sec- matter to present-day P. monticola. Thus, there tion on crossability, page 9). is a possibility it might be a progenitor of the present-day P. strobus var. chiapensis, or p. Hobitots p. Over most of its range (fig. Z), P. monti.cola 'Personal communication, A. Vashkovsky, 1g6g, is fire-perpetuated, through Dr. David M. Hopkins. seral, and frequently is a 3 pioneer species. In the north (Inland Empire Personal communication, Dr. David M, Hopkins, 1968; A. P. Vashkovsky, 1968, through Dr. Hopkins. 'p""*."f communication, W. B. Critchfield, 1g62. and Vancouver Island-Puget Sound area) it layan white pine). At an age of 1 year the ranges over a broad elevational belt from 1,000 nursery seedlings average only 3 to 5 cm. in to 6,000 feet in the Inland Empire, and from height (Squillace and Bingham 1954) ; they sea level to 5,000 feet on the Pacific Coast average 5 to 10 cm. at age 2 (Squillace and (Wellner 1962). To the south, in the Cascades Bingham 1958a). Transplants in three north- and Sierra Nevadas, however, it is often nar- ern Idaho field plots ranged from: 11 to 17 cm. rowly belted between Douglas-fir-ln,'ssfgrn in height at age 3 (Bingham, Squillace, and hemlock and Pacific silver fir forest-cover types Patton 1956; Squillace and Bingham 1958a) ; (Society of American Foresters 1954) at 5,000 17 to25 cm. at age 4 (Squillace, Bingham, Nam- to 7,500 feet in southern Oregon, between koong, and others. 1967); and they averaged Douglas-fir-rilTssfsrn hemlock and red fir types 57 cm. in height at age 9.' Il natural stands at 6,000 to 7,500 feet in the northern Sierras of P. monticola does not commence rapid height California, and between ponderosa pine, sugar growth until about age 15, although rapid pine, fir-Jeffrey pine types at 8,500 to l-0,000 growth may begin as early as age 10 under feet in the southern Sierras of California' Even wide spacing in cultivated, watered, and fer- though P. monticola is narrowly belted in the tilized plantations (Bingham 1967). Thereafter southern part of its range, the species displays height grorvth continues at 1 to 3 feet per year, aggressiveness and tenacity in this transition often for more than 100 years on the better zone between mid- and high-elevation types. sites. Maximum heights of 220 to 240 feet, and Climatically, on the north, stream-bottom diameters (d.b.h.) of 81 to 84 inches are re- types persist although they may receive as little corded (Anonymous 1956; Otter 1933), prob- as 25 inches of annual precipitation. In areas ably for 400- to S00-year-old veterans. where 35 to 40 inches of precipitation is re- Another characteristic of western white pine ceived, the distribution of P. monticola is gen- grorvth that contributes to the difficulty of its eral. On western Vancouver Island P. monti'- establishment in plantations and arboreta, es- cota grows in 110-inch precipitation areas pecially outside its natural range, is its youth- (Wellner 1962). Growing seasons on the north ful sensitivity to winter injury. Where nursery range from less than 70 to more than 225 days seedlings are not under deep snow or otherwise (Wellner 1962), and an elevationally associated protected from frost-heaving and exposure to variation in growing season length of as much drying winter winds, they may be killed out- as 40 to 80 days may occur between stands only right, and transplants up to 10 years of age a few miles apart. Little is known about soil may be almost completely defoliated. requirements of P. monticolu; however, in Added to these problems is another one con- northern Idaho best growth occurs on deep, cerning seed dormancy. Early fall sowing (Oc- well drained, medium to fine textured soils over- tober), or long periods of stratification (90 to lying a variety of parent materials (Wellner 120 days) help to overcome seed coat and em- 1962) . bryonic dormancies but even these treatments often fail to assure good germination.' Growth For successful greenhouse manipulation of potted seedlings, at least 14 weeks of chilling at Early height growth of P. monticola is very 40" F. is r;quired before seedlings will resume slow, unlike that of its near relatives P. strobus normal growth (Steinhoff and Hoff in prepara- and, Pi.nus griffithii, McClell. (blue pine or llima- tion).

SEXUA.L REPRODUCTION

Chromosomes griffi,thii. R. J. Hoff' Iater confirmed the number n : 12. Saylor and Smith (1966) studied chromo- Flowering some behavior in P. m.onticola, showing the typical number (n: 12) of chromosomes and P. monticola is monoecious. Like many pines relatively minor meiotic irregularities in the it is precociously female; in a northern Idaho species or in its hybrids with P. strobtts and P. arboretum it produces female strobili as early

4 as age ? (Bingham 1967). Righter (1939) also firmly fixed. On a single area, over the 6 years, reported female strobili in this species at age 7 periods for maximum anthesis varied as much at a Placerville, California, arboretum, and as 3 weeks; timing of anthesis was closely asso- Olson (1932) observed mature cones in the field ciated with average May and June tempera- in northern Idaho at age 10. P. monticola te- tures. Generally, P. monti,cola is synacmous, i.e., mains predominantly "female" through age 20 there is no phenological barrier to selfing. or more; in a Moscow, Idaho, arboretum during One convenient feature of P. monti'cola a humper "flowering" year, at age 15-18 years, "flowering" is that unpollinated female strobili 90 percent of the trees produced female strobili in sausage-casing bags may remain receptive but only 10 percent produced male strobili for as long as 10 days to 2 weeks. After remain- (Bingham 1967). ing receptive for this period, unpollinated stro- Five years of cultural treatments with young bili may abort and dehisce within another week. ancl with reproductively mature trees in the Data are lacking on fertilization in P. monti- field (watering, fertilizing, and cultivating) cola,but if the process is like that in P. strobus, had little effect on strobilus production. Neither it takes place in June, about 1 year after polli- did grafting 6-year-old seedling scions on re- nation (Ferguson 1904), and the maturing, productively rnature stocks induce earlier or second-year female strobili then elongate rapid- heavier flowering in young plants (Barnes and Iy, reaching full size by mid-July. Bingham 1963). I{owever, wide spacing of 5- to 7-year-old transplants and continued culti- Cone ond Seed Beoring vation and irrigation with filtered and proc- essed sewage effiuent gave good results in a Large P. monticolo cones ranging from 20 Moscow, Idaho, arboretum. Female strobili to 25 cm. in length have the potential for bear- borne annually on 11- to 18-year-old trees in- ing more than 300 seeds, of which more than creased from 4.5 per tree in 1964 to 20.2 per 225 filled seeds have been known to develop tree in 1967, and filled seed per cone ranged under wind pollination. Records over an 18- from 60 to 136 (Bingham 1967). Meanwhile, in year period on more than 25,300 cones from a grafted seed orchard at Sandpoint, Idaho, up 380 25- to ?0-year-old trees at 13 localities in to 8 years after grafting on 5-year-old stocks, northern Idaho and northwestern Montana strobili per scion averaged less than one; 12 gave the cone and seed yields shown in table 1 years after grafting, cones per scion averaged (Bingham and Rehfeldt 1970). 9.2.5 Exact time of production of female cone Tnsl,n l.-Cone and seed bearing i.n l1otmg P. initials is unknown in P. monticola, but ap- Monticola trees parently, like those of P. strob'zrs, they are not visible until April or later in the year Type of cones Total trees when they are pollinated (Ferguson 1904; or seeds Average Maximum observed Stephens 7962). Stephens (7962) did find dif- Number ferentiated male strobili of P. strobus by mid- Mature cones per tree 400+ November, but none at the end of August. Filled seed per cone: Bingham and Squillace (1957) summarized Wind-pollinated cones 104 226 L72 time of anthesis and maximum ovulate stro- Controlled cross- bilus receptivity for a 6-year period on a num- pollinated cones 88 222 329 ber of P. m,onticolo trees in northern Idaho as Self-pollinated cones 47 161 202 follows: Hoilow seed per cone: Wind-pollinated cones Aaerage date Controlled cross- Eleaation (feet) Anthesis g Strobilus receptiaity pollinated cones 13 209 58 209 2,700 - 3,300 Jrne 27 June 29 Self-pollinated cones 5000 July 8 July 7 Throughout this elevational range, for the 6 Good first-year female strobilus ("flower") years observed, earliest pollen release was June crops occur ohce every 3 to 4 years, with the 10; latest was July 12. The earliest receptive major cycle being 4 years. Autoregression tech- female strobili were found June 10; latest were niques involving flowers of the four previous found July 14. Certain individual trees in the seasons accounted for 47 percent of the varia- same area were consistently early or late, and tion in current-season flower crops. Similar the sequence of flowering between areas was regressions extended to moisture stress (which integrates temperature and precipitation) tlur- (Barnes, Bingham, and Schenk 1962; Schenk ing June to mid-September inclicated that and Goyer 1967). warm, dry "stress" periotls in the eitrly sum- Seifirrg rtl P. rnontlcolo prodnces lower yields mers of the 2 years prior to flolver emergence of sound seeds, higher yields of hollow seed, favored flor,ver production; on the other hancl, anti slorver grou'ing seedlings. On the a.lerirge, stresses in the l:rte slinmer of the year pt'ior tcr the production of filled seed in self-pollin:rted emergence, or cluling the period of emergence, con€s averages only 55 percent of the yieic[ in depressed flower prorlnction (Iiehfeldt, Stage, controllerl cro.qs-pollin:rtecl cones ; furthermore, and Bingham ln prep:rration). hollorv sered f ieids at'e nrore than 2.5 times as Mother trees, localities, and years in u'hich gi'cat in the seifecl as in the cro-qsed cones (table the cones wele born signilicantly affect yielcls 1). Selfed seedlings shos' a depression in height of cones and seeds. Individual mother trees vary glo',r'th that seems to incre:lse up to about :tge among themselves, but from yeur to year are 10, then it levels oIf to zL grorvth rate that is only consistent in their capacitl, to bear cones olr set 60 to 70 percent that of seedlings from out- seed. To illustrate this variation, total annual crossecl progenies of the salne parent trees seed-setting capacity for fir'e 1s11,-yieldinH trees (Binghanr arrcl Squillace 1955; Squillace and (average 20 cones per tree) obseLved 5 to 8 Ringham 1958b; Rarnes 1964). years wa-q 4,250 {iiled seerl ; fior five }righ-yield- A selectir.e feltilization mechanism cliscrimi- ing trees (average 77 cones pel ti'ce) observed nating agtiinst self pollen, r,vhen in competition 5 to 15 years, the capacity was 55,600 filled seed rvith outtross pollern, is probatrlS e{Iective in re- (Bingham and Rehfeldt 1970). I)i1l'erent locali- cltrcirrg ntrtural selfing in P. tnotttfu:ola. Some ties, seed years, and mother'-tree microsites con- u'estel'n ri'hitc pines lvere fonnd tcl be highly found the preceding results ; thus. it is imlro:riii- serlt-feltile, but the majority rvere essentially ble to prescribe extent of gcnetic controi on cor)e seli'-sterile. Tlris, along with lorver selfed seed and seed bearing. yields arrcl lorver slrrvival of selfed seedlings, Squillace (1967) str.rdicd the var:iability in leri to ther conclusion that very small propor- length of cones frcm five trees llhere ntean tions of the seed proclucecl by rvind pollination cone iength ranged from 17 to 21 irm. IIe found in mr"rlticlone seed olchards u'ould be seif s that cones from a single tree varied as mnch (Bingham nr1{ -Squillace 1955; B:rrnes, Bing- as 12 cm. in length, aithough the maximr-rm dif- hanr, ancl Squillace 1962). ference in average cone length betr.veen trees \\ras only 13 cm. He also founci that strobili on Pollen Storoge upper branches on the south and rvest sirles of the tree produced yielcls higher of heavier seed. Air dried pcllens stored at 0" to 5" F. in a The largest P. montic:oln cone ever seen hele household deepfreeze unit retain for 3 years or u'as almost 36 cm. long, ancl the smallest rvas more their ability to set usefui quantities of less than 5 cm. long. sonncl seed. Callahnm nncl Steinhoff (1966) Cone and seed insects, especially Cortoplt- shorved only 20 percent reduction in seed-setting tlt ot' t t s lt r.t t tt i t, ol rt r: Hopk., E ut: o s tn tt r e s cis s tL t ia t tu ability of 3-year-stored vs. fresh pollens, and Hein., and Diot'yctriu abietellcr (D. and S.), Bingham nnd \Vise (1968) later confirmed cause partial to almost complete failures of cone these results, showing about 50 percent filled crops in otherrn'ise poor to filir crolr years seed yields for 3-year-old pollens.

ASEXUAL REPRODUCTION

Qooting cent)." These cuttings u,'ere collected during March, treatecl rvith rooting hormones, and Cr-rttings from r,vestern rvhite pine trees rrore planted in P:rlouse silt loam soil : peat moss : than 4 to 5 years old trt'e difllcuit to root.. De- sand, or in pure sand. spite this handicap, Deuber (7942) obtained 11 Needle bundles taken from 2-year-old western rootecl cuttings from a total of 196 taken from u'hite pine seecllings have been rooted success- a 56-year-olcl tree; however, he later reported lully (HofI anci Mcl)onald 1968; McDonald and no success with 120 cuttings frcm a 45-year-old Hofl 1969). These needle bundles were collectecl tree. Cuttings firom 3-year-old seedlitrgs have tluring FebrLrary or etrrly March, and were (1) been rooted with fair success (20 to BOf per- treated -uvith rcoting horrnones or left untreated

6 and (2) placed in washed river sand or a mix- such as observed in older grafts of southern ture of this sand with peat moss and forest soil percent. Hanover concluded that this was due (1 :1 :1). Highest rooting success (81 percent) to an early incompatibility, possibly associated was with a treatment of rooting hormones and with the vigor of ortets. Latent incompatibility a foresb soil : peat moss : sand culture medium. In pines and Douglas-fir (Pseud,otsuga menzies'ii one experiment involving 318 budded needle (Mirb.) Franco) recently also has been observed bundles (Hoff and McDonald 1968) 45 of the in P. monticola grafts, 12 years after graft- bundles rooted and eight of these produced ing.' shoot growth. Subsequent growth of grafts has ranged between good (Bingham 1966) on northern Idaho field plots to fair or poor in a Moscow arbore- Grofting tum.5 Growth records at a grafted seed orchard at Sandpoint, Idaho (Bingham, Hanover, Hart- P. motfticolcl is relatively easy to propagate man, and others. 1963), show that within 3 by grafting at all ages (Bingham 1966; Barnes years after grafting most grafts were develop- and Bingham 1963). Several types of grafts ing into normal upright trees. have been used with good success including Although root grafting has been commonly bottle, whip-and-tongue, side, approach, and reported for most forest species, there are only wedge grafts. Early spring grafting prior to a few reports of root grafts for western white flushing is most successful, and yet scions col- pine: C. D. Leapharts; Rigg and Harrar 1931; lected during early winter and stored in a McMinn 1955. This is probably due lack grafted to a freezer nearly as well as those collected of reporting and not to a lack of observation. fresh. Furthermore, scions taken from a variety Two natural intertree branch-to-stem grafts in places graft of in the tree crown with equal P. monticola, one of these grafts involving a success (Hanover 1962). Tltu,ia plicata Donn, have been observed by C. Grafting conducted under greenhouse con- A. Wellner.6 ditions, including high humidity control, con- Interspecies grafting of P. montfcolo scions sistently gives the best results (85 to 95 per- on other white pine rootstocks has been gen- cent success in securing unions and new growth erally successful. R. T. Bingham and A. E. on scions), whereas the success of field grafting Squillace' successfully grafted P. monticola on varies depending upon weather conditions. On P. strobus and on western white pine inter- the West Coast, and in some interior valleys of species hybrid rcotstocks (P. monticola X P. the Inland Empire, grafting success has been strobus and P. monticola X P. griffi.thii,). Dr. good-probably because of high humidity dur- J. W. Duffield,? successfully grafte d P. monticol,a ing and after grafting. But in the hotter, drier on P. lambertiana, P. griffitllii and, Pinus aAa- regions of the Inland Empire such as at Moscow cahuite Ehrenb. rootstocks; also, he successful- and Sandpoint, Idaho, field grafting is a chancy ly grafted P. monticolo on the P. monti,cola X P. operation. Success is only 30 percent, or less, strobus hybriC rootstock. And Bingham and even when a plastic bag with an aluminum foil Squillace' attempted interspecies grafts with covering is used over the graft. P. monticolo scions on Pinus ponderosa Laws., There may be clonal differences in ability to Pinus contorta Dougl., Picea engelmann'i'i graft (Hanover 1962). Two hundred and fifty Parry, Pseudotsttga menziesii, and the inter- greenhouse grafts were made for each of 13 species hybrid Pinus contorta X Pi.nus bank- ortets. Four months after grafting, survival siarm, Lamb. A few grafts of all of these latter rates ranged from 97 down to 55 percent; but combinations made weak unions and remained after two seasons in a greenhouse and one in alive 4 to 5 months, but thereafter all scions the field, survival rates ranged from 83 to 13 died during the winter.

GENETICS AND BREEDING Toxonomy and 1924) placement of the species in Section Haplorylon, Subsection Cembra, Group Strobi,. P. monticoJcr (according to Critchfield and Thus, P. m,onti,cola belongs among the flve- Little 1966) has been placed in Subgenus " Personal communication, J.968. Strobtts, Section Strobus, Subsection Strobi, o Personal communication, 1968. This r:lassification is equivalent to Shaw's (1914 ' Personal communication. 1951, Tasl,r 2.-summary of hybridization efforts within portions of the Sub- genus Strobus Section Stroubus of the Genus Pirrus.L

LI Table 2,--Su@ry of hybrldlzatloo efforts ulthln porti@s of the Subgeuue Strobs Sectloo 9g!g of the Cenus PlN.

Subsectlod on.tBRAB 6l P. cepbra L. tl q5l "tol 3. PuElIa TI Regel r,l "ll P. slblrlca 9l Du Tour !l _ .21 _91 P. kolalensls ql -sr66l-E-ZG. ;l ;l P. albicaulis tJ-2-a U-1-a u-l-a t-z -rnllTil- 1.4 4 3 3,4,10 ol .rl ql Subsection STROBI xl ol ill ..jl P. f;.ex11is F-I F-I F-I F.I U-2-a Janes j,4,10 4 3 3,4, 10 9l .-ll P. strobiformis H-l -a €l -rnEETfrl- 4 El !l !t .il 6t fl P. arundil t-1 F-l U-l-a €l !l -rrii$l- 3 310 3,4 4, r0 10 ol LI P, eyacahulte:' F-l H-1 -b bl 6l Ehrenb. t0 4 l0 !l ol jt dI P. laobertlana H-Z-e E-J-a ! -I .AI ttSJrtO 1odlil- 3 IO l0 4, l0 IO Z,+,tO 2ltl iU g. Paslflora 3l 'al Zucc, 3, 10 3,4 3,4 10 3, 10 tl Sieb. & ol F-1 F-1 ll-1-a EI !' Peuce $11 Grlseb. I l,t0 3,4 10 l0

o -'{ Ffl rLl { r-r E- Z-a F-l H-l-e H-l-O H-2-a EI 10 3, 10 3 l{cClell. IO 33 3, 410 l0 11| jl ;l 3l P. stlobus L. u-2-b r-1 H-2-a F-l lt-2-b lr-2 -b H-2-a H-l-b ;l 1,10 1,8 IO 5, l0 l0 9, 10 3,5,10 3,5,8 , 10 1 ,3,5, 10 3,5, 10 EI P. nontlcole U-l-a U-2-a U-1-a H-t-e r-z H-2-c B-Z-C h-J-C H-J-C D"EI:- 2 2,10 2 2,6 4,19! 2,4,ro 2,4,tO 2,3,10 2,3 ,6 3, 10 2,3,5,10

! ftrls table ls edapred frml,frtght (f959). It lncludes h1s lnfotuatlon throuSh that date, plus dev infometlotr (footnoted) obtalned froo the se@ and additlonal statlons through 1968. 1/ F = f"rlu.", U = utrcertaln--sound seed or seedlings produced bu, ,rlalg not yet authentlcated, H = hybllds verlfied' 1 = less than 20 crosseg attempted, 2 = 2O-50 crosses atleopted, .l = oote than 50 crosseg ettebPted. a=lessthanlfllledseedpercone,b-1-5ftlledseedspercone,c=norethao5fllledseedsPercone. 1 n *.." lefer to the foll@ln8 !efelences: I. C. E. Ahlgren, 1967, personal co@nlcatlon. 2. Table 3, this paper. 3. tl, Helmburger, 1967, personal comnlcatlon. 4. Bleedlng lecord fil.es, lnst. Forest Genetlcs, PlacewLlle, Ca11f. 5. H. B. Krtebel, 1967, Personal [email protected]. 5. Little and Rlghte!, 1965. 7. Righrer 6nd Duffield, 1951. 8, I{. Saho, 1968, personal co@n{catlon. 9. E. J. Schrelner 1967, p€rsonal co@nlcatlon. 10. Wrlght' 1959. 3 Sone of the reports lrstlng P. ayacahulte probably refer to varlety EggllplsIg whlch ls sFon)eous ltEh P. stroblfomis, I orlgtnally reported as H tn Hrl8ht, 1959. !/ o.tgtr"1ly reported as P. oontlcole x P. ayacahulte. needled white pines having deciduous needle able with P. monticola.s ln the Subsection Cem- sheaths, unarmed, terminal cone-scale umbos, brae and. Strobi pines, however, crossability is with cones that open and liberate the seed, and fair to good, as shown in table 2. with seeds having either well-developed or P. monticola has proved to be easily crossable rudimentary wings. with six of the other nine important white Critchfield and Little (1966), whom we fol- pines of Subsection Strobi, including the mod- low, list 14 species in the Subsection Strobi.We erately resistant P. peuce and the highly re- will consider here only 10 of these Subsection sistant P. griffi.thia. Failure to produce the P. Strobi species which are those having a sub- monticola X P. armandii hybrid has been dis- stantial botanical range and with which inter- appointing, since the southeastern Asian P. species hybridization has been attempted more armundii is probably the world's most blister than a few times. In addition, we will consider rust resistant white pine. Conversely, probable five white pines in Subsection Cembrae and two success of inter-Subsection crosses between P. in Subsection Balf ourianae. monticola and moderately to highly resistant P. cembra and P. koraiensis encourages the re- Crossobility sistance breeder. More than 180 controlled pollinations at- From the taxonomic standpoint crossability tempting to produce interspecies hybrids be- of P. monticola witb all species of the Subgenus tween P. monticola and, other white pines in Strobus would be of interest. But from the prac- Subsections Strobi, Cembrae, and Bulf ourianae tical, tree improvement standpoint, its cross- have been made by the Intermountain Forest ability with those species in Section Strobus, or and Range Experiment Station, Moscow, Idaho, in Section Parrya, Subsection Balfourianae as part of the project for investigation of blister (i.e., the five-needled white pines), is of great- rust resistance. Results of these crossings are est interest for improving blister rust resist- outlined in table 3; they confirm the general ance or other qualities of P. monticoln. findings on crossability shown in table 2. Unfortunately, the Subsection Balfourianae 'U"polUrhed data: USDA Forest Service, Institute pines (Pizr,us balf ouriana Grev. and Balf. and of Forest Genetics, Placerville, California, and the In- P. aristata), both of which are moderately re- termountain Forest and Range Experiment Station, sistant to blister rust, appear not to be cross- Moscow, Idaho.

TAeLr 3.-Pinus monticola interspecies hybrids attempted 1950-1968

Number ol Total Average I Number of Total number crosses number of Total Total parent I Pollen difrerent number cones producing filled seed lnumber o1 rumber ol crosses strobili collected d filled per maturel fiIled seed seediings attempted pollinated extracted seed cone I all crosses produced

Section STROBUS Subsection CEMBRAE P. albicaulis 5 It)D I12 o 0.5 74 0' P. cembra 7 t2l o7 5 1- 73 o P. koruiensis 19 44L 286 5 trace 10 Subsection STEOBI P. armandii 1A 344 90 2 trace z', 0 P. flerilis 26 680 428 .)i 19.9 5,168 2,000-r P. Iambertiana 5 t52 105 2 trace 3' not sown P. paruiflora IJ QNA 269 13 31.4 9,790 445 P. peuce 20 467 ona 20 17.0 5,t54 700 + P, strobus .JO 585 327 32 18.9 4,645 2,000-c P. griffitllii 28 oro 271 8 0.9 568 L75'+ Section PARRYA Subsection B A LF O U RI AN AE P. aristata 7 O'A 161 1 trace 22 0 P. balfouriana o 2r2 t82 1 trace r"0

'Seed collected in 1968-not yet planted. 2 Possibly resulting ftom contaminating P. monticola pollens accidentally getting into pollination bags. Deleterious Recessive Genes ond Other iind reslrlts have been rather restricted. The first tr,vo nlirsery and field te sts ( 191-r2 and Genes 1953) for rr,rst resistance \yere also nsetl to get Several single recessive genes are recognized an early idea of height gror,vth potential of the in P. monticola self-pollinated progenies. Among selected trees. At the end of 1 year's gror.vth in 150 trees represented by 31 progenies, we recog- the nursely, the correlation betu'een periodic nize the following: 15 carriers albino annnal gror,vth ol the indiviclual parents and of an grorvth gene; another 10 or more trees carrying chloro- height of their seecllings u,as found to phyll-deficiency genes (deficient seedlings be 0.30 ; in a second experiment the next year this correlation r,v:rs 0.84 (Squillace and Bing- show various shades of yellow-green foliage) ; one or two trees having a curly-foliage gene; ham 1954). In fr"rrther studies of the heritabil- juvenile gro'uvth and at least one tree having a dwarling gene. ity of rate of the same seed- Selfed progenies of five or more trees conttrin lings in flekl plots (Squillace, Bingham, Nam- chlorophyll-deficient types r.l'here segregation koong, and others. 1967), averrige heritability fourth-year is not clearly in a 3:1 ratio, and one selfed of height increment \vas approx- progeny that contains a very low proportion of im;rtely 6.6 percent. It r.vas predicted that pos- types having green cotyledons but albino epi- sible genetic gain, basecl on several combina- cotyls. One tree carries the aibino, the curly- ti

t2 IMPROVEMENT PROGRAM

Breeding for Blister Rust Resistonce resistant stock only onto sites within the pertinent zones. Because resistance to blister rust is the most important trait for P. monticola in the Inland Empire (northeastern Washington, northern Tondem Selection for Blister Rust Idaho, northwestern Montana and south-central British Columbia), and in coastal British Co- Resistonce ond Growth Rote lumbia, Washington, Oregon, northern and program California, work on other traits largely has A "second-stage" selection aimed at been held in abeyance awaiting results of re- obtaining more highly resistant, possibly rust race buffered, and faster growing materials is sistance testing. just getting Now appears that testing candidates for underway in northern Idaho. The it job genetic g.c.a. in respect to resistance (i.e., test crossing first of greatly expanding the base phenotypically resistant candidates and arti- of phenotypically resistant candidate trees was ficially inoculating test cross progenies), fol- commenced in 1967. Almost 2,700 new candi- goal lowed by remating of the best 25 percent of the date trees out of a of 2,800 have been lo- g.c.a.-trees, artificially inoculating these prog- cated in 1967 through 1969. enies, and planting their surviving Fr seedlings Now that the second stage base has been se- so they will cross in seed orchards will give lected, plans call for: (1) more meaningful, two-step gains perhaps producing up to 50 per- genecological classification of candidates ac- cent resistant F, planting stock. cording to habitat types and/or aspect and ele- This is the practical "first-stage" program vation to further preclude planting maladapta- now underway in northern Idaho and in the tion; and (2) dual selection among 500- to 800- western Washington and Oregon Cascade candidate groups in perhaps four to six ecologi- Mountain populations of P. monticola. In north- cal zones for both resistance and growth rate. ern Idaho, first-stage orchards of resistant Fr The same or higher levels of resistance, along seedlings will be planted beginning in 1971. with 5 to 10f percent increase in growth rate Significant production of resistant F, seedlings is anticipated from this second-stage work. is anticipated by about 1985. Plans to control Mixed pollen crosses (Bingham 1968), im- problems arising from elevational variation in- provement of inoculation methods, and securing clude remating g.c.a.-trees only from within the higher progeny test efficiency are applied breed- same elevational zones, and thereafter planting ing objectives for the future.

LITERATURE CITED

Anonymous. (3) Axelrod, D. I. 1956. These are the champs. Part II. Amer. 1966b. The Eocene Copper Basin flora of Forests 62:33-40, northeastern Nevada. Univ. Calif. Pub. (1)to 4*ut"o., o. t. Geol. Sci. 59: 1-83. 1956. Mio-Pliocene floras from west-central (4\ Ting. Nevada. Univ. Calif . Pub. GeoI. Sci. 33: , and W. S. t_322. 1960. Late Piiocene floras east of the Sierra (2) Nevada. Univ. Calif. Pub. Geol. Sci. 39: 1962. A Pliocene Sequoiadendron forest from 1_1 18. western Nevada. Univ. Calif. Pub. GeoL Barnes, B. V. Sci. 39: 195-268. 1964. Self- and cross-pollination of western white pine: a comparison of height 1966a. Potassium-Argon ages of some west- growth of progeny. USDA Forest Serv. ern Tertiary floras. Amer. J. Sci, 264: Res. Note INT-22, 3 p. 497-506.

1967. Phenotypic variation associated with loNumbers in parentheses identify authorities for elevation in western white nine. Forest megafossil and fossil pollen occurrences of figure 2, Sci. 13: 357-364.

I Barnes, B, V., and R. T. Bingham. Bingham, R. T., and A. E. Squillace. 1962, Juvenile performance of hybrids be- 1955. Self-compatability and effects of self- tween western and eastern white pine, fertility in western white pine. Forest USDA Forest Serv., Intermountain For- Sci. 1: 121-129. est and Range Exp. Sta. Res. Note 104, and 7p. 1957, Phenology and other features of the and flowering of pines, with special reference 1963. Flower induction. and stimulation in to Pinus- monticola Dougl. USDA Forest western white pine. USDA Forest Serv. Serv., Intermountain Forest and Range Res. -Pap. INT-2, 10 p. Exp. Sta. Res. Pap. 53, 26 p. and J. A. Schenk. and R. F. Patton. 1962. Insect-caused loss to western white pine 1956. Vigor, disease resistance, and field per- cones. USDA Forest Serv., Intermoun- formance in juvenile progenies of the hy- tain Forest & Range Exp. Sta. Res. Note brid, Pinus monticola Dougl. X Pinue 702,7 p. strobus L. Ztschr, f. Forstgenet, u. Forst- and A. E. Squillace. pflanzenzuch. 5 : L04-112, 1962. Selective fertilization in Pinus monti- and J. W. Wright. cola Dottgl. II. Results of additional tests. 1960. Breeding blister rust resistant western Silvae Genet. 11: 103-111. white pine. II. First results of progeny to, Becker, H. F. tests including preliminary estimates of 1961. Oligocene plants from the Upper Ruby heritability and rate of improvement. River Basin, southwestern Montana. Silvae Genet. 9: 33-41. Geol. Soc. Amer. Memoir 82,127 p. and K. C. Wise. (6) Berry, E. W. 1968. Western white pine cones pollinated 1929. A revision of the flora of the Latah with 1- to 3-year-old pollens give good formation, U,S, Geol. Surv. Prof. Pan. seed yields. USDA Forest Serv. Res. Note 154-H: 225-264. INT-81, 3 p. Bingham, R. T. (7) Brown, R. W. 1966. Breeding blister rust resistant western 1937. Additions to some fossil floras of the white pine. III. Comparative performance western United States. U.S. Geol. Surv. of clonal and seedling lines from rust- Prof. Pap. 186-J: 163-186. free selections. Silvae Genet. 15: 160-164. Buchholz, J. T. 1945. Embryological aspects of hybird vigor in 1967. Possibilities for production of blister pines. Science 702: 135-L42. rust resistant tree seed in the Moscow Callaham, R.2., and, R. J. Steinhoff. Research Arboretum. USDA Forest 1966. Pine pollens frozen five years produce Serv., Intermountain Forest and Range seed. P. 94-101 in, Second Forest Genet. Exp. Sta. Office Rep. August 28, 18 p. Workshop. Proc., USDA Forest Serv. Res. Pap. NC-6, 110 p. 1968. Breeding blister rust resistant western Canada Department Resources and Development, white pine. IV. Mixed pollen crosses for 1950. Native trees of Canada. 4th Ed. Can. appraisal of general combining ability. Dep. Resources and Develop., Forest. Br. Silvae Genet. 17: 133-188. Bull. 61, 293 p. J. W. Hanover, H. J. Hartman, and Chaney, R. W., and D. I. Axelrod. Q, W. Larson. 1959. Miocene floras of the Columbia Plateau, 1963. Western white pine experimental Part 2, Systematic considerations. Car- seed orchard established. J. Forest. 61: negie Inst. Wash. Pub. 617: L35-237. 300_301. (8) Cockerell, T. D. A. R. J. Olson, W. A. Becker, and M. A. 1908. Fossil flora of Florissant, Colorado. Marsden. Bull. Amer. Mus. Natur. Hist. 24: 71- 1969, Breeding blister rust resistant western 1 10. white pine. V. Estimates of heritability, Critchfield, W. B., and E. L. Little, Jr. combining ability, and genetic advance 1966. Geographic distribution of the pines based on tester matings. Silvae Genet. of the world. USDA Forest Serv. Misc. 18:28-38. Pub. 991, 97 p. and G. E. Rehfeldt. Deuber, C, G. 1970. Cone and seed yields in young western 1942. Ihe vegetative propagation of eastern white pines. USDA Forest Serv., Res. white pine and other five-needle pines, Pap. INT-79, 12p. J. Arnold Arb. 23: 198-215.

f (e) Dorf, E. of Pinus nzonticola resistant and suscep- 1938. A late Tertiary flora from southwestern tible to CronarthLm ribicola. Physiol. Idaho. Carnegie Inst. Wash. Pub. 476 Plant. 19: 554 562. (II): 73-124. Duffield, J. W., and F. I. Righter. 1966b. Pollination of western white pine with 1953. Annotated list of pine hybrids made at water suspensions of pollen-a technique the Institute of Forest Genetics. USDA -and- for chemical mutagen treatments. Forest Forest Serv., Calif . Forest and Range Sci. 12: 372-373. Exp. Sta., Forest Res. Note 86, 9 p. (10) Hansen, H. P. Evernden, J. F., and G. T. James. 1938. Postglacial forest succession and cli- 1964. Potassium-Argon dates and the Tertiary mate in the Puget Sound region. Ecology floras of North America. Amer. J. Sci. l9: 528-542. 262: 915-974. (11) _ F'erguson, M. C. 1939a. Paleoecology of a central Washington 1904. Contributions to the knowledge of the bog. Ecology 20: 563-568. life history of PitLtrs with special refer- (12) ___ ence to sporogenesis, the development of 1939b. Pollen analysis of a bog in northern the gametophytes, and fertilization. Idaho. Amer. J. Bot. 26:225-228. Wash. Acad. Sci. Proc. 6: 1-202. (13) _ Gerhold. H. D.. and R. L. Soles. 1939c. Polien :rnalysis of a bog near Spokane, 1967. Weevil attacks on caged seedlings of Washington. Bu1l. Torrey Bot. Club 66: three white pine species. P. 51-59 itt, 14th .'1< 99n Northeastern Forest Tree Impr. Conf . (14) _ Proc., 91 p. 1940a. Paleoecology of a montane peat bog at Hanover, J. W. Bonaparte Lake, Washington. Northwest 1962. Clonal variation in western rvhite pine. Sci. 14: 60-69. L Graftability. USDA Forest Serv., In- (15) _ termountain Forest and Range Exp. Sta. 1940b, Paleoecology of two peat bogs in south- Res. Note 101-, 4 p. western British Columbia' Amer' J. Bot' 27: 1.44-749. 1963a. Comparative biochemistry and physi- (16) ology of western white pine (Pinus mon- 1941a. A pollen study of post-Pleistocene lake ticola Dougl.) resistant and susceptible sediments in the Upper Sonoran life zone to infecticn by the blister rust fungus of Washington. Amer. J. Sci. 239: 503- (Cronartium ribicola Fischer). Ph.D. 522. Thesis, Wash. State Univ., 166 p. ( 17) 1941b. Further pollen studies of post-Pleisto- 1963b. New developments in breeding western cene bogs in the Puget Lowland of Wash- white pine. II. Biochemistry of rust re- ington. BuIl. Torrey Bot. CIub 68: 133* sistance. P.77*78 rrz, Forest Genet. Work- 148. shop Proc. Southern Forest Tree Impr. (18) Comm. Pub.22,97 p. 1941c. Paleoecology of a bog in the spruce- hemlock clin-rax of the Olympic Peninsula. 1965. Effect of the chemical mutagen ethyl Amer. Midland Natur' 25: 290-297. methanesulfonate on western white pine. (1e) _ Silvae Genet. 14: 23*26. 1941d. Paleoecology of a montane bog near Lake Wcnatchee, Washington. Northwest 1966a. Genetics of terpenes. I. Gene control of bcl. -tD: D'J-t]J, monoterpene levels in t'tnus rtonticola (20) __ Dougl. Heredity 2I: 73-84. 1941e. Paleoecology of a peat deposit in rvest central Oregon. Amer. J' Bot. 28: 206- 1966b. Inheritance of 3-carene concentration 2r2. in Pinus monticola. Forest Sci. 12: 447- (21) _ 450. 1942a. A' pollen study of a montane peat de- and B. V. Barnes. posit near Mount Adams, Washington. 1963. Heritability of height growth in year- Lloydia 5: 305-313' old western white pine. P.7I-76 irz, For- t19\ est Genet. Workshop Proc., Southern For- lg42b. A pollen study of iake sediments in the est Tree Impr. Comrl . Pub. 22, 97 p. lower Willamette Valiey of western and R. J. Hoff. Oregon. 8u11. Torrey Bot. Club 69: 262' 1966a. A comparison of phenolic constituents 280.

l5 l (23) Hansen, H. P. Heimburger, C" 7942c. "Ihe influence of volcanic eruptions 1958. Forest tree breeding and genetics in upon post-Pliocene forest succession in Canada. p. 41-49 in, Gen. Soc. Can. Froc. centrai OreEon. Amer. J. Bot. 29: 214-219. 3, 83 p. (24) _ Hoff, R. J. 1943a. A polien study of two bogs on Orcas 1968. Comparative physiology cf Pil:rs m'attti,* Island, of the San Juan Islands, lYash- cola Dougl. resistant :rtrd suscr:ptibir: ington. 8u11. Torrey Bot. Clitb 70: 236- to CroncLrtittm ribicola J. C. l'is;r:h, ex oAe Rabenh. Ph,D. Thesis, Wash. State Univ. (25't 76 p" 1943b. Paleoecology of a bog in east central Washington. Northwest Sci. 17: 35-40" 19?0. Inhibitory compcrunds of Pinus ritt'tt.t,i' (26t _ cola Dougl. resistant ancl si.rsceptibie to - 1943c, Post-Pleistocene forest succession in Cronartium ribicola J. C, Fisch. ex Ra- northern Idaho. Amer. Midland Natur' benh. Can. J. Bot. 48: 37tr-376. 30:796-803. and G. I. McDonaid. (27\ _ 1968. Rooting of needle fascicles from western 1944. Postglacial vegetation of easterrr white pine seedlings, USDA Forest Sen', Washington. Northwest Sci. 18: 79-87. Res. Note INT-80, 6 p. (28) _ Hopkins, D. M., F. S. MacNeil, R. tr " Merklin, 1946. Postglacial forest succession and climate and O. M. Petlov. 1965, Quaternary in the Oregon Cascades. Amer. J. Sci. correlation across Bering Strait" Science 244: 710-734. 14?:110?-1114. (29\ __ (36) Hoxie, L. R. 1947a. Climate versus fire and soil as factors 1965. The Sparta Flora from Baker Counly, in postglacial forest succession in the Oregon. Northwest Sci. 39: 26-35. Puget Sound Lowland of Washington. (37) Knowlton, I'. H. Amer. J. Sci.245: 265*286. 1900. Fcssil plants associatcrl with the l:r-,'as (30) _ of the Cascade Range, P. 36-64 ur., lI.Sl. 1947b. Postglacial forest succession, climate, Geol. Surv. Annu. Rep. 20 (Ft.3). 595 p. and chronology in the Pacific Northwest. (38) __ Amer. Phil. Soc. Trans. 3?: 1-130. 1926. Flora of the Lat:rh formation oli Spo. (31) __ kane, Washington, and Coerur d'Aiene, 1947c. Postglacial vegetation of the northern Idaho" 11.S. Geoi. Surv. Prof " F;rp" 14fi: Great Basin. Amer. J. Bot. 3tr: 164-1?1, 1 7-8 1. (32) _ Krishtofovich, A. N. 1948. Postglacial forests of the Glacier Na- 1941. Prodomus florae fossilis. Pnleontologi:r tional Park region. Ecclogy 29: 146-152. S.S.S.R. (Paleontology of the tJ'S.S'R.) (33) _ Vo1. Xli. Suppiement Akad" lJatrk S.S.S.R. Paleontology Inst. 494 p" 1950. Pollen analysis of three bogs on Van- (39) LaMotte, R. S. couver Island. Canada. J. Ecol. 50: 270- 1936. The Upper Cedarville Flora of north- 276. western Nevada and adjacent Caiifornia. (34) _ Carnegie Inst. Wash. Pub. 455(V): 5?- 1955. Postglacial forests in south central and r42. central British Columbia. Amer, J. Sci. (40) Lesquereux, L. 253: 640-658. 1B?4. The lignitic formation and its fossil flora" P. 363-425 ia, U. S. Geoi. 8'. Geog. 1967. Chronology of postglacial pollen profiles Surv. of the Territories Arinu. Rcp. 18?3 in the Pacific Northwest. Rev. Paleobot. (Part II). 718 p. & Palynol. 4: 103-106. /41 \ (35) and J. H. Macklin. 1878. Contributions to the fossiii flora cf the 1940. A further study of interglacial peat We stern Territories. Palt 2, the Te'rti:rry from Washington. Bull. Torrey Bot. Club flora. U.S. Geol. Surv" of the Territori.es -, 67: I3l-142. Itep., VoI. 7 (Part 2). 366 p. Heimburger, C. Little, E. L., Jr., and F. I. llighter 1953. The breeding of white pine (Pinus 1965. Botanical descriptions of forty ar.'tifirrial strobus L.) in Canada, Abstr,, p. 307 in, pine hybrids. USDA Forest Ser:.". Tech. Int. Congr. Rot. Proc. ?,899 p, BulI. 1345,47 p.

t6 l McDonald. G. I.. and R. J. Hoff. Riker. A. J,. and R. F. Patton. 1969. Effect of rooting mediums and hormone 1954. Breeding of Pinus strobus for quality application on rooting of western white and resistance to blister rust. Univ. Wisc. pine needle fascicles. USDA Forest Serv., Forest. Res. Note 12, 2 p. Res. Note INT-101. 6 n. Saylor, L. C., and B. W. Smith. McMinn, R. G. 1966. Meiotic irregularity in species and in- 1955. Studies on the root systems of health;' terspecific hybrids of Pinus, Amer, J. and pole blight affected white pine (Pirzzzs Bot. 53: 453-468. monticola Dougl.). Interim Report, Forest Schenk, J. A., and R. A. Goyer. Biology Laboratory, Victoria, B. C. Can. 1967. Cone and see,:l insects of western white Dep. Agr. Sci. Serv., Forest Biol, Div, pine in northern ldaho: Distribution and mimeo, 31 p. seed losscs in relation to stand densitv, (42) MacGinitie, H. D. J. Forest. 65: 186-187. 1953. Fossil plants of the Florissant beds, Schiitt. P.. and R. J. Hoff. Colorado. Carnegie Inst. Wash. Pub. 1969. Foliage dry matter of Pinus monticola; 599: 198 n. its variability with environment and blis- Mirov, N. T. ter rust resistance. USDA Forest Serv. l-967. The genus Pinzs.. New York, Ronaid Res. Note INT-102. 6 n. Press, 602 p. Shavr, G. R. 1914. The genus Pinzrs. Arnold Arb. Pub. 5. Olson, D. S. 96 n. 1932. Germinative capacity of seed produced from young trees. J. Forest. 30: 8?1. 1924, Notes on the genus Pfzz.rs. J. Arnold Otter, F. L. Arb.5: 225-227. 1933. Idaho's record trees. Univ. Idaho Forest. (44) Smith, H. V. 15: 37-39. 1941. A Mic,cene flora from Thorn Creek, Patton, R. F. Idaho. Amer. Midland Natur. 25: 473- 1961. The effect of age upon susceptibility of 522. eastern white pine to infection by Cron- Society of American Foresters. artium ribicola. Phytopatholoey 5l: 429- 1954. Forest cover types of North America 434. (exclusive of Mexico). Soc. Amer. Forest. and A. J. Riker. Comm. on Forest Types Rep,, 67 p. 1966. Lessons from nursery and field testing Squillace, A. E. of eastern white pine selections and 1957. Variations in cone properties, seed yield progenies for resistance to blister rust. and seed weight in western white pine P. 403-414 zrz, Gerhold, H. D., et al. when pollination is controlled. Mont. (Eds.), Breeding pest-resistant trees, Ox- State Univ. Sch. Forest. Bull. 5, 16 p. ford, Pergamon Press. 505 p. and R. T. Bingham. (43) Penhallow. D. P. 1954. Breeding for improved growth rate and 1908, Report on Tertiary plants of British timber quality in western white pine. J. Columbia. Can. Dep. Mines, Geol, Surv. Forest. 52: 656-661. Br. Pub. 1013, 167 p. and Rigg, G. B., and E. S, Haruar. 1958a. Localized ecotypic variation in western 1931. The root systems of trees growing in white pine. Forest Sci. 4: 20-34. sphagnum. Amer. J. Bot. 18: 391-397. Squillace, A. E.,- and R. T. Bingham. Righter, F. L 1958b. Selective fertilization in Pimzrs monti- 1939. Early flower production among the colo. Dougl. I. Preliminary results. Silvae pines. J. Forest. 37: 935-938. Genet. 7: 188-196. G. Namkoong, and H. F. 1945. The relationship of seed size and seed- Robinson. ling size to inherent vigor. J. Forest. 1967. Heritability for juvenile growth rate 43:131-137. and expected gain from selection in west- and J. W. Duffield. ern white pine. Silvae Genet. 16: 1-6. 1951, Interspecies hybrids in pines. A sum- Stephens, G. R,, Jr. mary of interspecific crossings in the 1962. Initiation of strobiii primordia in Pinus genus Pirzzrs made at the Institute of strobus L. P. 41-43 in, 9th Northeastern Forest Genetics. J. Hered. 42: 75-80. Forest Tree Impr. Conf. Proc., 74 p,

t7 Sukachev, V. N, Lcmonsov Univ. Moscow, Geol. Faculty 1910. Nekotoryia dannyia k dolednikovoi flore and Museum of General Geography, Mos- severa sibiri. (New derta on the pre- conv. 559 P. glacial flora of the north of Siberia). Wcllner, C. A. Akad. Nauk Geologicheskii mesei irneni 1962. Silvics of u'estern white pine. USDA Petra velikago Trudy 4: 55-62. Forest Serv., Intermountain Forest and Vashkovsky, A. P. Range Exp. Sta., Misc. Pub. 26, 24 p. 1959. A brief essay of vegetation, climate, \Yright, J. W. and Quaternary chronology on the Upper 1959. Specics hybridization in the white pines. Kolyma and the Upper Indigirka Rivers Folest Sci. 5: 210-222. and on the northern coast of the Okhotsk Sea. P. 510-555 irr, N[arkov, K. K. and and W. J. Gabriel. A. J. Popov (Eds.), Lednikov'y Period na 1959. Possibilities of breeding rveevil-resistant territorii Europeiskoi Chasti S.S.S.R. i - white pine strains. USDA Forest Serv., Sibiri. (Ice age in the European section Northeastern Forest Exp. Sta., Sta. Pap. of the U.S.S.R. and in Siberia.) State 115, 35 p.

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