七筋菇自然种群间的遗传变异及其多倍体起源

Genetic diversity of Clintonia udensis Trautv.et Mey. populations and the origin of C. udensis Trautv.et Mey. polyploid were examined by using 15 ISSR primers. The results showed that the overall genetic diversity of C. udensis Trautv.et Mey. populations was high, and the higher genetic diversity was related to the geographic distribution of populations and its evolution history. The percentage of polymorphic loci (P), Shannon information index (I) and Nei’s gene diversity index (h) were 98.8%, 0.5638 and 0.3833, respectively. Genetic variation among the populations was higher than that within populations, and the genetic variability occurred mainly among the populations. According to Nei’s GST (0.6944) calculated, the gene differentiation among the populations was conspicuous, indicating low gene flow among the populations (Nm ＝0.2200). By the Mantel Test, it found that there was no significantly relationship between genetic distance and geographical distance. Itself biological character, biggish geography isolation, limited gene flow and genetic drift might lead to the higher genetic variation among the populations. And there was speculated to be polytopic of the polyploid origin of C. udensis Trautv.et Mey., it was an active area of the C. udensis Trautv.et Mey. polyploid origin from the Shannxi south to Himalayas.