濒危植物连香树遗传多样性研究

以我国特有的濒危被子植物连香树为材料，采用RAPD标记对分布于浙江、安徽、湖南、湖北、四川、陕西、河南的11 个天然居群进行了检测。以20个引物共扩增出691条DNA片段，其中多态性条带328条，占总条带数的475 %。AMOVA分析表明，连香树的基因分化系数为0479 7，居群内变异占总变异的5203 %。由Nei基因分化系数估计的基因流仅为0542 4，表明居群间基因交流困难。UPGMA聚类分析表明，安徽歙县居群与河南济源居群的关系最远。遗传漂变等因素可能是连香树目前遗传结构的主要成因。保护现有生境、通过培育实生苗并扩大繁殖栽培的范围是目前对连香树比较好的保护措施。

Study on the genetic diversity of an endangered plant Cercidiphyllum japonicum

Random amplified polymorphic DNA(RAPD) markers were used to measure the genetic diversity of Cercidiphyllum japonicum,an endangered plant in China.The experiment was implemented among 11 natural populations from Zhejiang,Anhui,Hunan,Hubei,Sichuan,Shannxi and Henan of C.japonicum.A total of 691 DNA fragments were amplified from 20 RAPD primers,of which 328 were polymorphic,account for 47.5 % of all bands.AMOVA was used to determine the variation within and among populations.Results indicated that the variation among populations was 0.479 7 and that within populations was 52.03%.The gene flow was 0.542 4 based on the Nei gene differentiation index indicated that the gene intercourse was difficult among populations.Results of UPGMA cluster analysis indicated that the genetic distance between the population of Shexian Anhui and Jiyuan Henan was the largest among populations.Genetic drift might have enhanced genetic differentiation within populations.In order to protect the species,preserving the habitat and breeding the seedlings to expand the species were suggested.