海桑属红树植物遗传多样性和引种关系研究

以海南东寨港红树林自然保护区内无瓣海桑(Sonneratia apetala)、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,C3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.

Analysis on genetic diversity of mangrove species of Sonneratia and relationship to plant introduction

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 sub populations. Fujian sub population exhibited 0 669 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 sub populations, H pop / H sp =0 933,compared with that between sub populations,( H sp - H pop )/ H sp =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.