中国珍稀濒危特有蕨类植物--云贵水韭的遗传多样性

采用随机扩增的多态性DNA（RAPD）方法对云贵水韭现存于贵州平坝境内的惟一的自然居群46个样晶进行厂DNA多态性分析．从60个随机引物中l筛选出12个有效引物，共产生95条DNA片段，其巾59条具有遗传多忿性，多态化点百分率（PPB）为62．1％．与其他蕨类植物相比，云贵水韭居群内存仵较高水平的遗传多样性，较高水甲的遗传多样性，一方面可能足由丁遗传变异长期积累的结果，同时也可能是近期生境的破坏还没有较严晕地到使其遗传多样性丧失．随符居群规模的减小，云贵水韭的遗传多样性将会逐渐丧失，建议用现存于平坝居群的云贵水北材料对其居群进行了恢复重建．

Genetic Diversity in Isoetes yunguiensis, a Rare and Endangered Endemic Fern in China

Isoetes yunguiensis is an endangered and endemic fern in China.Field survey indicated that only one population and no more than 50 individuals were left in the wild.The genetic variation of 46 individuals form the population remaining at Pingba(Guizhou province) was assessed by RAPD fingerprinting.Twelve primers were screened from sixty ten-bp arbitrary primers,and a total of 95 DNA fragments were scored,62.1% of these were polymorphic loci,which indicated that high level of genetic variation existed in the natural population.The accumulation of genetic variation in history and the genetic diversity has less been effected by the current destroys of habitat may responsible for the high level of genetic diversity remaining in the I.yunguiensis population.With decreasing of population size,the genetic diversity will be lost gradually.We suggest that materials from the extant population were available for re-establishment of the populations.