Genetic Variation And Selection Of Resin Traits In Pinus Elliottii

For breeding fine varieties of Pinus elliottii with high yield and quality resin，theannual resin yield of113half-sib families were determined,the heritability of family andindividual of3yields (the basic yield ability, the potential yield ability, and the actualannual yield) were estimated. And the turpentine composition of20families wereanalysed to estimate the heritability of family and individual of6qualities (turpentine,a-pinene, camphene, β-pinene, dipentene, myrcene). The families and individuals withhigh resin yield were choosed taking the breeding value of3yields as a standard, thecontents and components of turpentine of the individuals was evaluated synthetically, andthe individuals with high quality resin were selected on the basis of high yield. The mainresults as below:(1) The resin yield traits had a relatively high family heritability (0.7416-0.9081)and a medium individual heritability (0.3041-0.5639) and the high genetic effect.Similarly, the resin quality traits had a medium family heritability (0.3402-0.5713) and amedium individual heritability (0.2112-0.4773).The β-pinene had the highest familyheritability and individual heritability, higher genetic variation coefficient and selectionefficiency.(2) According to breeding value of three resin yield traits in families and individuals,there were22families and186individuals selected as high resin yield, their actualgenetic gain was44.93%and46.97%. According to breeding value of turpentine,93highquality individuals were selected by selection-rate of50%, the real genetic gain ofturpentine was0.2%based on high yield. According to the comprehensive selectionindex of the contents and components of turpentine and the selection-rate of50%,93high yield of individuals was selected, and the real genetic gain of turpentine, a-pinene,camphene,β-pinene, dipentene and myrcene was0.2%,-0.57%,8.71%,2.24%,15.67%and2.21%separately. The36individuals that their breeding value of resin yield traitsand turpentine and comprehensive selection index rank at the top were the good breedingmaterials with highest yield and best quality and would be selected as the core breedinggroups of the second generation seed orchard.the186individuals would be selected asmain breeding goups.(3) In the course of cutting, with the increasing of the moths, the resin yield was onthe rise, was lowest in May and highest in September, the resinosis stop after October.There was a high correlation and significant regression relation of resin yield betweenmonths’(June, July, August) and year’, and it was a best regression equation in July(Y=4.7377X+1.5525, r2=0.9507) and in August (Y=4.8882X+0.9462, r2=0.9325)respectively. The resinosis start and the resin yield was unstable in May. The resin yieldin September and October was higher but had a low correlation with annunal total resinyield. Therefore, cutting resin on the suitable months (July, August) could estimateannunal yield well on the basis of reduced workloads.