江西野生寒兰居群遗传结构与遗传多样性研究  

Study on Population Genetic Structure and Genetic Diversity of Cymbidium kanran from Jiangxi Province

作　　者：谢慧敏 张威 罗火林[1,2] 杨柏云 熊冬金[1] XIE Huimin;ZHANG Wei;LUO Huolin;YANG Boyun;XIONG Dongjin(School of Life Science, Nanchang University, Nanchang 330031, China;Key Laboratory of Plant Resources in Jiangxi Province, Nanchang 330031, China)

机构地区：[1]南昌大学生命科学学院,南昌330031 [2]江西省植物资源重点实验室,南昌330031

出　　处：《西北植物学报》2020年第5期785-794,共10页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31260485);江西省科技支撑计划(20122BBF60059);南昌大学研究生创新专项(CX2018104)。

摘　　要：该研究采用叶绿体基因组片段(petB-petD)和核基因组ITS序列,对分布于江西的寒兰17个自然居群的252个体进行遗传结构与遗传多样性分析,以明确江西野生寒兰遗传多样性水平与居群遗传结构特征,为探寻江西寒兰资源数量锐减以及保护提供理论依据。结果表明:(1)nrDNA ITS序列长度652~658 bp,总变异位点140处,变异位点百分率为21.3%~21.5%,(G+C)含量为58.9%~67.1%。cpDNA序列长度522~529 bp,有变异位点9处,变异位点百分率为1.70%~1.72%,(G+C)含量为32.9%~33.7%。(2)分子方差分析(AMOVA)表明,种群内的遗传变异大于种群间变异,cpDNA片段居群间的遗传变异为40.76%,居群内为59.24%;ITS居群间的遗传变异为28.96%,居群内为71.04%;基因流(Nm)较大,cpDNA片段Nm为1.2265;ITS Nm为0.7267。(3)ITS和cpDNA数据失配分析和中性检验均表明江西寒兰野生居群在历史近期经历了扩张事件,nrDNA ITS序列较叶绿体序列进化较快,变异速率也较快。Genetic structure and genetic diversity 252 individuals in 17 natural populations of Cymbidium kanran distributed in Jiangxi Province were studied by using chloroplast genome fragment(petb-petd)and nuclear genome ITS sequence.It provide some suggestions for the analysis of the reason of the decrease in the number of wild C.kanran in Jiangxi Province and the protection and rational utilization of wild cold orchid resources.The results showed that:(1)there were a total of 652-658 bp of nrDNA ITS sequences,with 140 variable loci,the percentage of variation loci was 21.3%to 21.5%,and the content of(G+C)was 58.9%to 67.1%.The sequence length of cpDNA was 522-529 bp,with 9 variable loci,the percentage of mutation sites was 1.70%-1.72%,and the content of(G+C)was 32.9%to 33.7%.(2)Molecular analysis of variance(AMOVA)showed that the genetic variation within populations was greater than that between populations,the genetic variation of cpDNA was 40.76%among population and 59.24%within population the genetic variation of ITS was 28.96%among population and 71.04%within population;While gene flow was high,cpDNA:Nm=1.2265;ITS:Nm=0.7267.(3)Through the mismatch analysis of ITS and cpDNA data,it is shown that the wild population of Cymbidium kanran Makino has experienced an expansion event recently.ITS sequence of nrDNA evolved faster and mutated faster than chloroplast DNA sequence.

关 键 词：寒兰 ITS CPDNA 遗传结构 遗传多样性 

分 类 号：Q346.5[生物学—遗传学] Q789