Abstract: Twenty-six mutants were obtained from the 5-year plantation of the seeds of Stylosanthes guianensis (Aubl.) Sw.cv.’Reyan No.2’ which were carried into outer space by a recoverable satellite in 1996.The genetic diversity of the 26 mutant lines and the contral varieties(S.guianensis cv.Reyan No.2 and S.guianensis cv.Reyan No.5) was analyzed by RAPD using 11 primers from 50 random primers.There were 53 polymorphic DNA bands(68.8%) among the 77 DNA bands amplified by RAPD.The average number of polymorphic DNA bands per primer was 4.8,and the range of genetic distance among these lines varied from 0.056 to 0.509 as assessed by Nei’s 72.A DNA molecular tree diagram was established base on UPGMA analysis by NTSYS software and the 28 materials of S.guianensis were classified into five groups according to a standard of similarity coefficient at 0.77 in the dendrogram.

Key words: Stylosanthes guianensis (Aubl.) Sw.’Reyan No.2’, Space-flight breeding, RAPD, Genetic diversity, Cluster analysis

摘要： 以返回式卫星搭载的‘热研2号’柱花草(Stylosanthes guianensis (Aubl.) Sw.)种子为材料,经过5年地面种植和选择,获得26个变异株系。利用RAPD分子标记技术对26个变异株系和2个对照‘热研2号’与‘热研5号’柱花草进行遗传多样性研究。从50个随机引物中筛选出11个,共扩增出77条带,其中53条为多态性带,占68.8%,平均每个引物扩增出多态性带4.8条;采用Nei72方法计算出不同材料间的遗传距离,其变化范围为0.056~0.509;利用NTSYS软件进行非加权组法(UPGMA)聚类分析,建立‘热研2号’柱花草太空育种后代材料间的分子系统树状图;并以相似系数0.77为标准,将28份材料分为5类。

关键词: 热研2号柱花草, 太空育种, RAPD, 遗传多样性, 聚类分析