Genetic Diversity Of Microsatellites (SSRs) For Seedling Seed Orchard Of Masson's Pine(Pinus Massoniana L.)

Seed orchard is the most important population of seed production and improvement, which construct the bridge of breeding between the forest breeding and seed production. The genetic diversity of its offspring will directly affect the stability and adaptability of the artificial population.A seedling seed orchard of masson's pine in Baisha Forestry Farm, Fujian Province was studied by microsatellite (SSR) markers. And the single tree's genetic quality of the seed orchard in directions was also analyzed. Comparison of the genetic diversity among the improvement course of masson's pine was made and then discussed the strategies to manage seed orchards. The results were as follows:1. Ten polymorphic SSR primers were selected from 152 primers developed in P. taeda, P. radiate, P. sylvestris, P. cembra, et al. The number of alleles per locus varied from 4 to 10, and the total polymorphic alleles in all loci were 64 and 6.4 on average.2. Parentage population and the progeny population showed a high genetic diversity. The analysis compared between the progeny and parentage populations showed that: the mean alleles, the effective number of alleles (Ne), the Shannon's diversity index (I), mean expected heterozygosity (He), the Nei diversity (Nei) and the gene flow (Nm) of progeny which were 6.4, 2.2377, 1.0146, 0.5291, 0.5285 and 4.6049 were all higher than the parentage's 4.20, 1.9947, 0.8804, 0.6842, 0.4906 and 1.5814 respectively, expect the mean observed heterozygosity (Ho) of progeny (0.6728) which was little lower than the parentage's 0.0.6842. Those all showed relatively high level of gene flow among families and minished the genetic differentiation between families. So we could see that the progenies of this seed orchard keeped a higher level of genetic diversity.3. The single tree's genetic quality of the seed orchard in directions was also analyzed, and it concluded that the west, north and south of the trees had a high genetic quality, and then was the east. This was related with the location and the environment of the single tree.4. The analysis of the genetic distance of the progeny and parentage populations showed that it correlated with the geographical location. Although the parenthood had a little influence on the progeny population, the result showed that the genetic distance of all the families of the progeny population had some difference with that of the parentage. It concluded that the collocation of single tree of every family was reasonable, which basically avoid the inbreeding depression.