Genetic diversity of Chimonanthus grammatus populations determined with inter-simple sequence repeats (ISSR) analysis: Implications for conservation

Abstract

Chimonanthus grammatus is an endangered and national-protected medicinal plant species with highly restricted geographical distribution and disjunctly locates in the border area of Anyuan and Huichang county of Jiangxi province, China. In this study, inter-simple sequence repeats (ISSR) markers were used to analyzed genetic diversity of seven populations of C. grammatus, collected from the area of Anyuan (4 populations) and Huichang (3 population) county of Jiangxi province, China. Our results showed that ten primers produced 74 discernible bands (39 polymorphic), with a low genetic diversity at species level percentages of polymorphic bands (PPB = 52.7%, H = 0.157, I = 0.241) and at population level (PPB = 35.7%,H = 0.119, I = 0.177). A high population differentiation (Gst = 0.249) was detected among seven populations and significant association were found between genetic and geographical distances (r = 0.712, p < 0.001), suggesting that gene flow was restricted geographically. Analysis of molecular variance (AMOVA) also revealed that 26.4% of the ISSR variation resided among populations, while 73.6% resided within populations, and 21.8% of the ISSR variation resided among Anyuan and Huichang groups, while 78.2% resided within groups. Factors, such as gene flow, genetic drift and evolutionary history, might have important influence on genetic structure and diversity of C. grammatus populations. An understanding of the genetic diversity and population structure of C. grammatus can provide insight into the conservation and management of this species.   Key words: Chimonanthus grammatus, genetic diversity, inter-simple sequence repeats (ISSR), conservation.