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作 者 ：张云香，胡灏禹，何兴金*

期 刊 ：西北植物学报 2013年 6期 页码：1098~1105

关键词：距瓣尾囊草；遗传多样性；ISSR；

Keywords:Urophysa rockii Ulbrich, genetic diversity, ISSR,

摘 要 ：利用ISSR分子标记，对狭域分布在四川省江油涪江上游区段的毛茛科濒危植物距瓣尾囊草(Urophysa rockii Ulbrich)现存4个居群的遗传多样性进行了研究。结果显示：（1）14个引物共检测到121条清晰的谱带，其中多样性条带118条；距瓣尾囊草在物种水平上遗传多样性较高，多态位点百分率（PPB）为97.86%，Nei’s基因多样度指数（H）为0.306 9，Shannon’s多样性信息指数（H_sp）为0.466 3；在居群水平上遗传多样性相对偏低，PPB为63.22%，H为0.196 2，Shannon多样性信息指数（H_pop）为0.271 1。（2）3种方法分析显示，居群间遗传分化较低，AMOVA、G_st和(H_sp-H_pop)/H_sp分别为0.341 2、0.295 2和0.42，据此推测距瓣尾囊草繁育系统以异交为主。（3）经Mantel检验，居群间的遗传距离与地理距离之间存在正相关关系（r=0.742 4，P=0.089 0）。研究表明，人类活动的干扰和生境的片断化是导致距瓣尾囊草濒危现状的主要原因，建议对距瓣尾囊草全部居群的全部个体予以及时地就地保护；因遗传变异主要存在于居群内的个体间，故迁地保护时应在各居群内大量采样，以达到最大限度保存距瓣尾囊草遗传多样性的目的。

Abstract:The endangered species,Urophysa rockii Ulbr.(Ranunculaceae),is endemic to China,with only approximately 2000 individuals confined in the upper reaches of the Fujiang River in Jiangyou City.ISSR PCR (14 primers) was used to assess the genetic variability within and among four extant populations of this species.(1)The results revealed a high level of genetic diversity of U.rockii at species level:percentage of polymorphic loci PPB=97.86%;Nei’s gene diversity (H) 0.306 9;Shannon’s information index (H_sp) 0.466 3.However,there existed little lower genetic variation at population level:PPB=63.22%,H=0.196 2,and Shannon’s information index (H_pop)=0.271 1.(2)A low level of genetic differentiation among populations was detected in U.rockii (0.341 2,0.295 2 and 0.42 for AMOVE,Nei’s genetic coefficient of differentiation (G_st) and Shannon’s diversity index),which may result from out-breeding.(3)There was a significant correlation between genetic and geographic distance among the populations studied.The results indicated that the influence of human activity and habitat fragment may play a prominent role in creating this species’ current endangered status.Based on these results,strategies are proposed for the genetic conservation and management of U.rockii.

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