Genetic Diversity among Breeding Parents of Schima superba Revealed by SSR

Schima superba is a representative, widely distributed species of broadleaf tree found in the subtropical forests of southern China. It valued commercially for its timber and ecology using. We used SSR molecular technique to investigate the genetic diversity and structure of S. superba, which would formulate the breeding strategy and provide insight for selecting breeding parents. 14 pairs of SSR primers were selected and 133 individuals came from 15 provenances were conducted in this experiment. The results showed that 86 polymorphic loci with alleles ranged from 2 to 11 were detected. The observed number of alleles, number of effect alleles, observed heterozygosity, Shannon information index and Nei's gene diversity were 6.14, 3.23, 0.572 0, 1.224 7 and 0.599 0 respectively. The breeding parents of S. superba held higher genetic diversity and the genetic diversity in Jian'ou of Fujian Province was highest, but it was lowest in Suichang of Zhejiang Province. The genetic difference was large among the individuals of the breeding parents of S. superba. The genetic distance was ranged from 0.023 3 to 1.633 8 with the average value of 0.606 7. Shannon's index of breeding parents was significantly negative with the latitudes of the seed sources (r=-0.516 2, p=0.048 9). The UPGMA cluster analysis showed that 133 individuals clustered into three groups and the third group could be divided into 4 sub-groups. It is important to consider the origin of the trees when selected the parents for hybridization.