关键词: 永瓣藤, 克隆植物, 遗传多样性, ISSR

Abstract:

Monimopetalum chinense is a rare and endangered clonal plant endemic to China,which is limited to a small area from north Jiangxi to south Anhui and southeast Hubei.In the present study,population genetic diversity of M.chinense was investigated using inter-simple sequence repeat(ISSR)markers.Ten ISSR primers were used to amplify 190 individuals of 10 natural populations in the whole distribution region,39.2%of which being polymorphic.The Shannon diversity index(H_o)ranged from 0.045 to 0.101,with an average of 0.083 at the population level(H_pop)and 0.183 at the species level(H_sp).The results indicated that the level of genetic variation at the species level or at the population level was all lower than that of most clonal plants.Moreover,the genetic differential index(G_ST= 0.567 2)based on POPGENE indicated that 56.72% of molecular variation was among populations,and the results revealed a strong genetic differentiation among populations in M.chinense.Such factors as population fragmentation due to the geologic change and vegetation damage,small population size hindering gene flow,and the reproductive type of self-pollination may have contributed to the population genetic variation of this species.The results also show that the genetic distance is related to the geographical distance among populations in M.chinense.

Key words: Monimopetalum chinense, clonal plant, genetic diversity, ISSR