木榄属3种红树植物的遗传变异和亲缘关系分析

用随机扩增多态性DNA(RAPD)和inter-简单重复序列(ISSR)分子标记技术对木榄属(Bruguiera)3种红树木榄(Bruguiera gynmorrhiza)、海莲(B．serangula)、尖瓣海莲(B．serangula var．rhynchopetala)进行遗传亲缘关系研究。12个RAPD引物和10个ISSR引物分别扩增出240和191条带，多态位点百分率分别为38．75％和52．88％，ISSR检测到的多态位点率高于RAPD。运用Nei指数法计算木榄-海莲、木榄-尖瓣海莲、海莲-尖瓣海莲之间的遗传距离．RAPD分析结果为0．47、0．36、0．29，ISSR分析结果为0．62、0．4l、0．32。同时运用UPGMA统计法进行聚类分析，结果显示，海莲和尖瓣海莲聚为一组，木揽单独一组。结合宏观形态和等位酶资料，作者把尖瓣海莲确定为海莲的变种。

Genetic variation and relationship of 3 Bruguiera species by RAPD and ISSR

Randomamplified polymorphic DNA(RAPD)and inter-simple sequence repeat(ISSR)methods were applied to detectgenetic variation and relationship of3mangrove species of Bruguiera(Bruguiera gymnorrhiza,B.sexangul,B.sexangula var.rhynchopetala).12RAPD and10ISSR primers generated240and191bands,of which91and101were polymorphic,respectively.Percentages of polymorphic bands of RAPD and ISSRwere38.75%and52.88%.Comparison of the two marker systems shows that ISSR was better than RAPD in terms of reproducibility and ability of detecting genetic polymorphism.It was found that the average genetic distance among different3mangrove species of Bruguiera by RAPD and ISSR were0.37and0.45,respectively.Based on UPGMA cluster analysis,it showed that Bruguiera sexangula and B.sexangula var.rhynchopetala were classified into same group,while Bruguiera gymnorrhiza in an other group.Comparing withthe results of morphology and allozyme by other reports,B.sexangula var.rhynchopetala could be regarded as a variety of Bruguiera sexangula.