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 <rf StoekhCIlnr in I ?6"? e nd the Secsnd Werlri Consuitstiern or: F*rest .1'rve SreeetirrlS ut V\teshingfr:m, ff"{.i". in I $SS. Tits ("lnrrrritte* on f:oresf i'r*al ln"iprr.:venr*nt *{ the; Soeiefy erf &me,rir-ein f'tire:ti:rs undsr'[c::r$r the prepeirsfi;;r ** nrcnu:cripts fc,r Nsrilr Arr:er:csn lpeci**s. SUMMARY ABSTRACT 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 rang- ing 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 ta 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. 2 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.