Development of EST-SSR Markers and Population Genetic Analysis of Hemsleya zhejiangensis , an Endangered Species Endemic to Eastern China

Hemsleya zhejiangensis C.Z. Zhang (Cucurbitaceae) is a rare and endangered plant species endemic to eastern China and is listed as a key protected species in Zhejiang Province. However, owing to the lack of genomic information and efficient molecular markers, the genetic diversity and population structure of this species remain unknown. In this study, we conducted transcriptome sequencing and de novo assembly of two H. zhejiangensis individuals to develop expressed sequence tag-simple sequence repeat (EST-SSR) markers. Using CandiSSR software, 345 candidate polymorphic EST-SSRs were identified. Twenty EST-SSRs were developed for illustrating the genetic diversity and structure of the four populations of H. zhejiangensis . The populations of ZX (Taishun, Zhejiang) and WYL (Taishun, Zhejiang) have the closest kinship, whereas the populations from WYS (Mount Wuyi, Fujian) showed the farthest kinship with all populations from Zhejiang, suggesting that geographic isolation may significantly impede gene exchange and reduce the genetic diversity of this species. The availability of genomic resource will facilitate subsequent population genetic analyses and molecular breeding, which will be of great significance in formulating strategies for the conservation and utilization of H. zhejiangensis .