兰花蕉的遗传多样性研究

Study on Genetic Diversity of Orchidantha chinensis (Lowiaceae)

摘要:

采用简单重复序列区间(ISSR，Inter-Simple Sequence Repeat)分子标记技术，对采自广东省的濒危植物兰花蕉(Orchidantha chinensis T.L.Wu)的7个居群137个个体进行遗传变异分析。用10个ISSR引物共扩增出清晰谱带101条，其中58条具有多态性，总多态位点百分率为57.43％。居群水平相对较低，多态位点百分率在6.93％-35.64％之间，平均为18.24％。经POPGENE1.31数据处理，结果表明：在物种水平上Nei基因多样性为0.125±0.1686：Shannon信息指数为0.2000±0.2429；Nei基因分化系数为0.5481，表明54.81％的遗传变异分布在居群间，45.19％的遗传变异分布在居群内。物种居群间的遗传一致度在0.8855—0.9511之间。我们认为红花潭是其最适合生境，建议在此建立自然保护区：鉴于兰花蕉居群间出现了一定程度的分化，为最大限度地保护兰花蕉的遗传多样性，建议在自然居群间进行相互移栽，以提高群体间的基因交流。

Abstract:

Inter-simple sequence repeats 0SSR)marker was used to analyze the genetic diversity and diferentiation of 137 individuals within and among 7 populations of Orchidantha chinensis，an endan gered species，in Guangdong Province．Ten ISSR primers generated 101 bands，ofwhich 58(57.43％)were polymorphic．ISSR diversity within the population was lower than that among the populations(at species level：P=57.43％，H=0.1254，I=0.2000；at population level：P=18.24％，H=0.057，I=0.0876)．Based on Nei’s G_ST value calculated by POPGENE1．3 1，gene diversity within populations was 0.1 254±0.1686．Shannon information index was 0.2000±0.2429．Variation coeficient among populations was O.5481, and that within population was O.4519．The ranger ofgentic identity among populations was from 0.8855 to 0.9511. Based on the gene diversity inform ation available for Orchidantha, two management strategies are proposed．A conservation area is suggested to be established in Honghuatan(HHT) where is considered to be an optimal habitat for O.chinensis growth．And because ofthe diferentiation among the populations， cross transplan tation is suggested in order to enhan ce the gene flow among the populations． By this means，the genetic diversity resources of the species could be preserved to the greatest extent.