海桑属红树植物遗传多样性和引种关系研究
Analysis on genetic diversity of mangrove species of Sonneratia and relationship to plant introduction
Abstract
[中文文摘]以海南东寨港红树林自然保护区内无瓣海桑 (Sonneratiaapetala)、海南海桑(S hainanensis)、拟海桑 (S paracaseolaris)、杯萼海桑 (S abla)、大叶海桑(S ovata)、海桑 (S caseolaris)等 6种海桑属红树植物为材料 ,对15个有效引物进行RAPD分析 ,共扩增出512条带 ,其中多态性条带为297,占总扩增条带的58.01% .Nei指数法分析和UPGMA统计分析表明 ,6种海桑属红树植物分为A ,B ,C 3个组 ,平均遗传距离为0.38.A组包括无瓣海桑、海南海桑、大叶海桑、怀萼海桑 ,其中无瓣海桑、海南海桑、大叶海桑处于同一个亚组 .B组包括拟海桑 .C组包括海桑 .对海南和福建无瓣海桑种群进行RAPD分析 .对Shannon表型多样性指数统计结果表明 ,福建种群为0.669,海南种群为0.671 ,各种群遗传变异较大 ,这与无瓣海桑种群广泛的适应性相一致 .对种群间的Shannon表型多样性指数分析表明 ,种群内的遗传变异占整个遗传变异的93.3% ,而种群间的遗传变异仅占6.7% .这表明无瓣海桑种群的大部分遗传变异存在于种群内,而种群间的遗传变异较小. 由此可见,无瓣海桑基因组丰富的多样性,是使其由海南成功引种到福建的重要因素. 同时探讨了与无瓣海桑遗传距离较近的海南海桑(0.132) 和大叶海桑(0.126) ,作为海桑属红树植物进一步由海南向福建引种的可能性.[英文文摘]RAPD markers were used to assess the relationships among 6 species of Sonneratia in the National Mangrove Nature Reserve of Dongzhai Harbor in Hainan by using the 15 effective 10- oligonucleotide arbitrary primers,a total of 512 DNA bands were amplified,among which 297 (58. 01%)were polymorphic. Based on UPGMA cluster analysis of 512 DNA bands amplified by the thirty primers,a DNA molecular dendrogram was established, which divided 6 species of Sonneratia into three main groups. Group A included 4 species : Sonneratia apetala , S . hainanensis , S . abla , S . ovata , and Group B : S . paracasedaris and Group C: S . caseolaris only contained one species respectively. Group A could be divided into two subgroups , Al : Sonneratia apetala , S .hainanensis , S . ovata and A2 : S . abla ; two populations of Sonneratia apetala , which were from Hainan and Fujian (introduced from Hainan) respectively ,were compared by RAPDs. The phenotypic frequencies detected with the 15 primers were calculated and used to estimate diversity ( H) within sub2populations. Fujian sub-population exhibited 01669 and Hainan exhibited 0.671 variability. Shannon’s index of phenotypic diversity was then used to partition the diversity were within and between sub-populations components. An assessment of the proportion of diversity present within sub2populations , Hpop/ Hsp = 0.1933 ,compared with that between sub-populations , ( Hsp -Hpop) / Hsp = 0.067 ,indicates that ,on average ,most of the diversity (93.3 %) is detected within sub-populations ; while only 6.7 %between populations. The plant introduction of S . hainanensis and S . ovata , which have the
nearer genetic distance with Sonneratia apetala ,is also disscussed.