Genetic Diversity and Population Structure of Helianthemum ordosicum (Cistaceae) in west Ordos's national nature reserve revealed by ISSR markers
【摘要】：In this study, we analyzed the genetic diversity and population structure of 4 Helianthemum ordosicum populations in west Ordos national nature reserve of Inner Mongolia using the inter-simple sequence repeat (ISSR) markers. The results were as follows: Twenty Polymorphic ISSR primers amplified 246 DNA fragments, of which 211 (86.3%) showed polymorphisms among the populations. The percentage of polymorphic bands at the population level ranged from 72.1% to 94.3%, with an average of 83.1%. Nei's and Shannon's information index were 0.247 and 0.318, respectively, at the population level, both index were 0.306 and 0.461, respectively, at the species level. Moreover, the Analysis of Molecular Variance(AMOVA) showed that 46.67% of the total genetic diversity was among populations ; the index of genetic differentiation (G st =0.4320) from software POPGENE indicated that 43.20 % of molecular variation was among populations, which was similar to the result of AMOVA . Habitat fragmentation could result in lower gene flow among the populations(N m =0.658), and relatively lower gene flow might be one of important factors influencing the genetic structure of the species.Based on the genetic distance, Neighbor-joining cluster analysis shows that the Mt. Zhuozi and Qianligou populations grouped together firstly, and then clustered with Qipanjing populations, which were clustered finally with Aerbasi population, Mantel test showed that there was no correlation between genetic and geographic distances. The present analysis reveals that 4 populations of H.songaricum Schrenk in west Ordos national nature reserve of Inner Mongoliahave high genetic diversity and high genetic differentiation, Qianlishan and Qipanjing populations should be given priority for conservation, because both had the highest genetic diversity among all the four populations investigated.