基于RAPD标记的丽江云杉遗传多样性及谱系地理  

Genetic Variation and Phylogeography of Picea likiangensis Inferred from RAPD Markers

作　　者：彭晓莉[1,2] 吴旺泽[3] 

机构地区：[1]合肥工业大学生物与食品科学学院,合肥230009 [2]兰州大学干旱与草地生态学重点实验室,兰州730000 [3]安徽省农业科学院作物研究所,合肥230031

出　　处：《植物研究》2011年第4期436-442,共7页Bulletin of Botanical Research

基　　金：合肥工业大学博士专项基金(113-036405);国家自然科学基金项目(3043056)

摘　　要：由于青藏高于独特的地理环境,第四纪冰期反复的退缩和扩展对目前该地区生物物种的地理分布及居群结构产生重要的影响。本文对这一地区特有分布物种丽江云杉(Picea likiangnsis)3个变种丽江云杉变种(var.liki-angensis)、川西云杉变种(var.rubescens)和林芝云杉变种(var.linzhiensis)共11个种群228个个体进行RAPD分析,研究其遗传多样性及谱系地理。结果表明,该种具有较高的总体遗传多样性,多态位点达85.42%;然而在群体水平上却保持了相对低的多态性,种群间差异不显著,种群平均多态条带百分率为62.31%,Nei's平均遗传多样性指数(HE)为0.250,Shannon's多样性指数(Hpop)从0.267到0.421 1。Nei's基因多样性(GST=0.256)和AMOVE分析(Phist=0.236)表明,群体间有较高的遗传分化,群体间基因流有限(Nm=1.453 2),远远低于已报道的其它松科植物。UPGMA聚类分析表明3个形态上分离的变种没有单个聚成一枝,形成单系群。本研究认为,在第四纪冰期丽江云杉这一种在南部可能存在至少3个不同的避难所,北边和西边的居群应该是南方避难所里的居群经过不同的回迁路线而产生的,有可能是由于种内亚种间的反复杂交造成了目前的种群分布模式。The geographical isolations in the Qinghai-Tibetan Plateau region were suggested to have played an important role in the high diversification of plants occurring there.It remains elusive whether this mechanism had also contributed to the morphological differentiation and the following speciation of the wind-pollinated conifers.In this study,we investigated the within-specific diversity and phylogenetic relationships of different variants within Picea likiangensis,a dominant forest species in this region based on random amplify polymorphism（RAPD） markers.Our results suggested that this species has a high overall genetic diversity with mean percentage of polymorphic loci at p=85.42%.Consistent with the initial expectation,a high level of genetic differentiation among populations was detected based on Nei＇s genetic diversity（Gst=0.256） and AMOVA analysis（Phist=0.236）.However,gene flow among populations are limited（Nm=1.4532）,far lower than reported for other conifers with the wide distribution ranges from the other regions.Three morphological variants respectively in the south,the north and the west show no corresponding clusters according to UPGMA analyses.However,this clustering pattern further suggests multiple origins of the north variants from the south one.It is a probable scenario if considering that more than one of refugia probably existed for this species in the south during the glacial stages and that the postglacial recolonizations from different refugia toward the north occurred.The intra-specific morphological differentiation in this species might reflect the ecological adaptation to the current environmental gradients.

关 键 词：丽江云杉 遗传多样性 RAPD 谱系地理 

分 类 号：S718.46[农业科学—林学]