【摘要】 利用RAPD分子标记对濒危植物华木莲(SinomanglietiaglaucaZ.X.YuetQ.Y.Zheng)的19个天然群体进行遗传多样性分析,13条引物共扩增出171个位点,平均每条引物13.2个,其中多态性位点91个,占总位点数的53.22%。分析结果表明:华木莲居群在遗传距离为0.205处可分为三大类,玉金山居群为一类,模式标本树周围居群为一类,模式标本树对面山上的其余居群为一类。19个居群之间的遗传相似性指数介于0.7000～0.9389之间,遗传距离值介于0.0931～0.3808之间,平均观察等位基因数与平均有效等位基因数分别为1.5444和1.3134,平均基因多样度和平均Shannon信息指数分别为0.1847和0.2782。华木莲自然居群的遗传多样性水平低于一般物种,与其它濒危植物相比,低于观光木、北美鹅掌楸及鹅掌楸,高于版纳青梅,可能与水杉相当而高于银杉。其居群间的分化可能主要受环境因子选择和基因流阻隔的影响,生境破坏严重与其自身的生物生态学特性可能是导致华木莲陷入濒危状态的主要原因。应对华木莲现有生境进行保护,并通过人工促进天然更新,扩大现有居群,提高遗传多样性,并开展迁地保护。更多还原

【Abstract】 After analysis on genetic diversity of 19 populations of endangered Sinomanglietia glauca Z. X. Yu et Q. Y. Zheng by Random Amplified Polymorphic DNA(RAPD), a total of 171 sites are detected by 13 primers, 91 of which are polymorphic(53.22%). The UPGMA analysis indicates that 19 populations of S. glauca can be divided into three groups at the point of genetic distance 0.205:the populations in Yujing Mountain, the populations around the type specimen tree, the populations in the mountain opposite to the type specimen tree. And the similarity indexes vary from 0.7000 to 0.9389, the genetic distances range from 0.0931 to 0.3808, the average value of observed number of alleles, effective number of alleles, Nei’s gene diversity, Shannon’s information index are 1.5444, 1.3134, 0.1847 and 0.2782 respectively. The genetic diversity of natural population of S. glauca is lower than those of ordinary plants. Compared with other endangered plants, the genetic diversity of natural population of S. glauca is lower than those of Tsoongiodendron odorum, Liriodendron tulipifera and L. chinense, higher than those of Vatica guangxiensis and Cathaya argyrophylla, and approximates to that of Metasequoia glyptostroboides. The genetic differentiation may be mainly caused by environmental choice and gene flow isolation, and serious destroyed environment and its own bioecologic characteristics are probably the main reasons for it’s endangered position. It is important to protect the existing environment, enlarge the existing population and improve the genetic diversity through artificial measures promoting regeneration, and carry out ex-situ conservation.更多还原