Genetic diversity and population structure in Castanopsis fissa revealed by analyses of sequence-related amplified polymorphism (SRAP) markers

Improved understanding of the genetic structure and genetic variation patterns in natural populations is an essential element of breeding programs that focus on forest species. Castanopsis fissa is an important, fast-growing evergreen species in southern China, where it is used for reforestation. We sampled 28 different C. fissa populations from three provinces in southern China and investigated their genetic variation and genetic relationship through an analysis of sequence-related amplified polymorphism (SRAP) markers. We acquired 236 electrophoretic bands from the 241 individuals analyzed by SRAP; 195 bands were polymorphic. Analysis of molecular variance (AMOVA) detected significant genetic variation within and among the populations; genetic variation among populations was smaller than variation within populations (p < 0.001). The 28 populations of C. fissa were classified into three types by STRUCTURE analysis. The clustering by the unweighted pair group method of arithmetic averages (UPGMA) procedure divided the 28 populations into four groups that corresponded to the output of a principal coordinate analysis (PCoA). Improved understanding of the population structure and population genetic diversity of C. fissa will be an essential element of programs that aim to genetically improve and breed the species. Our information on the population structure and genetic diversity of C. fissa in three provinces in southern China will enable future development of a theoretical scientific foundation for genetically improving and breeding this species.