地理隔离对西南藏区山杨居群遗传结构影响的SRAP分析  

SRAP Analysis on the Effect of Geographic Isolation on Population Genetic Structure of Populus davidiana in Tibetan-inhabited Regions in Southwest China

作　　者：何承忠[1,2,3] 李佳蔓[1,2] 员涛[1,2] 纵丹[1,2] 周安佩[1,2] 欧光龙[2] 尹五元[2,3] 

机构地区：[1]云南省高校林木遗传改良与繁育重点实验室,西南林业大学,云南昆明650224 [2]西南地区生物多样性保育国家林业局重点实验室,西南林业大学,云南昆明650224 [3]西南山地森林资源保护与利用省部共建教育部重点实验室,西南林业大学,云南昆明650224

出　　处：《林业科学研究》2015年第2期152-157,共6页Forest Research

基　　金：国家林业公益性行业专项基金项目(201104076);国家自然科学基金项目(31360184);云南省教育厅基金项目(2014J99);云南省中青年学术与技术带头人后备人才培养基金项目(2012HB021)

摘　　要：采用SRAP分子标记技术,对分布于我国西南3个藏族地区山杨9个居群130个个体进行了遗传结构分析。结果表明,筛选出的7对引物组合共检测到多态性条带(AP)99条,多态性条带百分比(PPB)为59.28%。采用POPGENE软件分析,山杨9个居群平均多态位点百分率(PPB)为33.80%,Nei’s基因多样性指数(H)和Shannon’s信息指数(I)分别为0.130 9和0.213 7,较东北地区山杨具有偏低的遗传多样性。遗传分化系数Gst=0.325 5,表明遗传变异主要存在于居群内个体间。地理距离与遗传距离之间具有弱相关关系(r=0.349,P=94.5%),山脉阻隔效应是导致西南藏族地区山杨居群间遗传分化的主要因素。UPGMA聚类表明,甘孜地区4个居群与迪庆地区的维西居群具有较近的亲缘关系,迪庆地区的德钦、香格里拉居群和昌都地区2个居群的遗传相似度较高。基于西南藏族地区山杨遗传结构分析,建议实施就地保护的同时,建立山杨种质资源库,促进不同居群间的基因交流。130 individuals of 9 Populus davidiana populations collected from 3 Tibetan-inhabited regions in southwest China were examined by sequence-related amplified polymorphism （SRAP） markers to determine the genetic struc- ture. 99 polymorphic loci were obtained from the 9 populations using 7 selected primers, and its percentage was 59.28%. As analyzed by POPGENE soft, the average percentage of polymorphic loci （PPB =33.80% ）, Nei＇s genetic diversity （H ＂-O. 130 9 ） and Shannon＇ s information index （I--0. 213 7 ） indicated that P. davidiana dis- tributed in Tibetan-inhabited regions in Southwest China held a lower level of genetic diversity than that of P. david- iana distributed in Northeast China. The coefficient gene differentiation （Gst） was 0.325 5, indicating more varia- tion existed in the individuals of the populations. A weak correlation was found between geographic distance and genetic distance （r = 0. 349 ,P = 94.5% ）, which indicated that the mountain barriers strongly influenced genetic differentiation among populations. Unweighted pair-group method with arithmetical averages cluster analyses （UPG- MA） revealed that the Weixi population from Diqing region had grouped with the four populations from Ganzi region, while the Deqin and Xianggelila population from Diqing region had grouped with the two populations from Changdu region. According to the analysis on genetic structure of P. davidiana populations, it is proposed that natural population should be protected in situ, and the germplasm resources should be constructed to enhence the gene flow.

关 键 词：山杨 SRAP标记 地理隔离 遗传多样性 遗传结构 

分 类 号：S718.46[农业科学—林学]