【摘要】 采用随机扩增多态DNA(RAPD)分子标记方法,对大王马先蒿(PedicularisrexL.)分布在云南中甸、丽江、大理、武定和昆明的5个居群(其中中甸居群有3个亚居群)的遗传多样性和遗传结构进行了研究。结果表明,大王马先蒿居群具有较高的遗传多样性,多态位点百分率P、Shannon表型多样性指数I和Nei的基因多样性指数h分别为82.0%、0.361和0.240,遗传多样性水平与居群的地理分布范围相关;大王马先蒿居群间的遗传变异较高,遗传变异主要发生在居群之间,而不是居群内部;居群间遗传分化系数Gst为0.747,遗传分化明显,居群间基因交流较少。居群间的遗传距离与居群间的相对地理距离具有一定的相关性。对云南西北部中甸居群的3个亚居群的遗传多样性分析表明,居群的遗传多样性水平与海拔高度有一定的相关性。居群间遗传变异较高可能是由于大王马先蒿为短命多年生植物,繁育系统为混交型,且自交占较大比例等原因造成的。更多还原

【Abstract】 Genetic variation of five populations (one of which with three subpopulations) of Pedicularis rex L.in Yunnan were examined by using 14 random amplified polymorphic DNA (RAPD) primers.The results showed that the overall genetic variability of P.rex was high.The percentage of polymorphic loci ( P ) was 82.0%,i.e.,132 polymorphic loci out of a total of 161 loci.The Shannon’s Index ( I ) and the Nei’s Index ( h ) were 0.361 and 0.240,respectively.Genetic diversity among the populations was higher than that within a population.The genetic variability occurred mainly among the populations.The genetic variation was related to the geographic distribution of the populations,i.e.distant population having larger genetic divergence.The populations of Zhongdian and Lijiang in northwestern Yunnan in high altitude had greater levels of genetic diversity than that of central Yunnan.According to Nei’s Gst (0.747) calculated,the gene differentiation among the populations was conspicuous,indicating low gene flow among the populations.A separate analysis of the three subpopulations of P.rex from Zhongdian county,northwestern Yunnan revealed that higher genetic diversity was found in high-altituded subpopulations.It was suggested that P.rex ,being a short-lived perennial species with mixed breeding system,could be mainly self-pollinated.更多还原