Genetic diversity and genetic structure of a rare and endangered species Semiliquidambar cathayensis Hung T. Chang

Genetic diversity and genetic structure of Semiliquidambar cathayensis Hung T. Chang were analyzed using 15 EST-SSR primers. Results revealed that its genetic diversity was high (H_e=0.816), and that genetic variation mainly existed within populations (76.63%), although the genetic differentiation coefficient among different regions was slightly high (F_st=0.176). The 17 populations could be divided into seven gene banks. We found that the genetic background was complex and the gene heterozygosity was high. However, the genetic structure of the populations were unstable, and four populations (40%) experienced bottleneck events. We showed that S. cathayensis maintained relatively rich genetic variation and had high evolutionary potential. Habitat fragmentation and its endangerment caused by breeding system and human disturbance might be the main causes for the formation of the current geographical distribution pattern and population genetic structure.