湖北野生天麻的遗传分化及栽培天麻种质评价

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1、湖北野生天麻的遗传分化及栽培天麻种质评价**吴会芳李作洲黄宏文(中国科学院武汉植物园，武汉430074)摘要：采用7条1SSR引物对天麻(Gastrodiaelata)8个自然居群和6个人工栽培居群共483个样本的居群遗传多样性进行了初步检测,共检测出清晰、重复性好的DNA带77条,其屮64条为多态性带，总多态位点百分比PPB23.12%。遗传多样性分析结果表明：天麻自然屈群的遗传多样性参数分别为：多态位点百分比PPB=59.09%,冇效等位基因数Ac=1.29,Nei's遗传多样度H=0.176,Shannonys多态信息

2、指数1=0.270,明显高于人工栽培居群(PPB=35.71%,Ae=1.16,H=0.100,1=0.155),揭示出栽培居群存在明显的遗传基础狭窄和遗传均质性问题oUPGMA聚类分析表明，自然居群与栽培居群存在明显的分化而分别聚为两大类群。自然居群间基因分化系数GST=0.255&与AMOVA分析所揭示的居群间遗传变异量占总变异的27.25%的结果相近，自然屈群间亦存在一定程度的遗传分化；居群间基因流(Nm)为1.4547,相对较弱，可能对H然居群的遗传分化有一定影响。自然居群聚类结果显示出一定程度的地理区域聚类趋势，但

3、Mantel检验表明自然居群间遗传距离与地理距离并不存在显著相关(r=0.1669,P=0.2110),揭示出天麻自然居群的分化现状可能是其生活史特性、地理隔离与人为破坏综合作用的结果。栽培居样的遗传均质化趋势，揭示了引种驯化的瓶颈效应和长期无性繁育所导致的遗传多样性丧失，也反映出栽培犬麻种质的遗传基础狭窄。而栽培居群与白然居群间存在着明显的遗传分化,反映天麻栽培居群与自然居群间可能冇在基因流的阻断。关键in

4、:Gastrodiaelata,白然居群，栽培居群,ISSR,遗传多样性，居群遗传分化Geneticdifferen

5、tiationamongnaturalpopulationsofGastrodiadata(Orchidaceae)inHubeiandgermplasmassessmentofthecultivatedpopulationsHuifangWu,ZuozhouLi,HongwenHuangWuhanBotanicalGarden,ChineseAcademyofSciences,Wuhan430074Abstract:Gastrodiadata(Orchidaccac)isarareandendangeredmedicina

6、lplant.SevenISSRprimerswereusedtoexaminepopulationgeneticparametersof483samplesacrosseightnaturalpopulationsandsixcultivatedpopulationsofG.elata.Thesevenprimersamplifiedatotalof77unambiguousandreproduciblebands,amongwhich64bandswerepolymorphicandthepercentageofpol

7、ymorphiclociwasPPB=83.12%.Theresultsshowedthatgeneticvariationinthenaturalpopulationswassignificantlyhigherthanthatinthecultivatedpopulations(PPB=59.09%vs.PPB=35.71%,A=1.29vs.A=1.16,H=0.176vs.H=0.100andeeShannon's1=0.270vs.1=().155),suggestingthatthecultivatedpopul

8、ationsarenarrowlygcnctic-bascdandgeneticallyuniform.UPGMAclusteranalysisshowedthatnaturalpopulationsandcultivatedpopulationsweredistinc什yseparatedintotwogroups・Coefficientofgeneticdifferentiationamongeightnaturalpopulationswas0.2558(GST)whichwaswellinaccordancewit

9、htheresultbyAMOVAanalysis(27.25%ofthetotalgeneticvariationresidedamongpopulations),indicatingthatnaturalpopulationsweregeneticallydifferentiate