【摘要】 基于探讨桑属植物种群间遗传变异规律 ,采用显性分子标记RAPD技术 ,对我国桑树现行分类的 15个种、4个变种及近缘属的 4 8份供试材料进行了桑属种群的遗传结构分析。结果表明 :桑树具有丰富的遗传多样性 ,多态位点百分率为 78 95 % ;Nei′s基因多样性指数 (h)与Shannon多样性指数 (I)具有相同的群体遗传多样性评价结果 ,即种群组成差异越大 ,h与I指数越大 ,桑属种群的h指数为 0 1893,I指数为 0 30 91;桑属种群总基因流值Nm<1(0 5 2 2 0 ) ,基因分化系数Gst为 0 4 75 3;AMOVA分析表明种群内的变异百分率为 72 6 5 % ,种群内的变异大于种群间 ;UPGMA聚类结果与基因流值、基因分化系数有密切的关系更多还原

【Abstract】 Genetic structure variance is an adaptability variation through the nature selection and human being impact for long time. China is one of the origins ground of the mulberry tree. There are a large amount of species, variants, varieties and transitional types by selection of nature and persons for long time. In this paper, 48 materials including 15 species, 4 variants and allied genera were carried out by analysis of genetic structure variance using dominate molecular maker RAPD. The mean proportion of polymorphic loci (PPL) of Morus spp. is 78.95% at population level, indicating abundance genetic diversity existing in populations of mulberry tree. There is an alike result for genetic diversity evaluating, that is to say, the more difference in population, the more greater the Nei′s gene index(h) and Shannon diversity index(I). The h and I are 0.189 3 and 0.309 1 respectively, gene flow value (Nm) and gene differentiation value (Gst) 0.522 0 and 0.475 3 respectively in Morus ssp. The proportion of variance within populations by analysis of molecular variance (AMOVA) was 72.65, indicating variance mostly existing within populations. The results of UPGMA are close relationship with gene flow and gene diversity.更多还原