Genetic diversity of second generation-parental germplasm of masson pine revealed by SSR markers and establishment of a core germplasm collection

Twenty SSR markers were used to evaluate the genetic diversity of 304 s-generation parentals of masson pine (Pinus massoniana Lamb.), which was collected from eight locations in China. The average polymorphism information content value (0.892) and Shannon's information index value (2.87) indicated high genetic diversity. Analysis of molecular variance revealed that most of the genetic variations occurred within geographic locations (99.82%), resulting in high gene flow (Nm = 1.351). Germplasm of timber utilization (13.51) had a significantly more average number of effective alleles than germplasm of rosin utilization (10.30). Genetic diversity estimates for germplasm between locations and utilization were similar. Genetic structure analysis and cluster analysis showed three clusters. Genotypes revealed a high level of admixture between the gene pool within locations and utilization germplasms. A core collection of 104 individuals contained 100% alleles identified in the initial 304 accessions.