蓝碧海峡澄黄滨珊瑚群体遗传多样性

Genetic structure of ITS gene sequence of Porites lutea populations in Lembeh Strait

通过对印度尼西亚蓝碧海峡3个澄黄滨珊瑚(Porites lutea)地理群体(YM、YN、YS)的79个样本核糖体RNA转录单元内间隔区ITS基因(包括ITS1区和ITS2区)片段进行克隆、测序,探讨澄黄滨珊瑚的群体遗传多样性和遗传分化.结果表明:79条序列共获得63个单倍型,3个群体呈现出高的单倍型多样性(Hd=0.991 56)和高的核苷酸多样性(Pi=0.026 81).Tajima'D检验、Fu's Fs检验和岐点分布检验(mismatch analysis)推测种群经历了群体扩张事件.单倍型邻接关系树和单倍型网络图表明澄黄滨珊瑚群体没有明显的地理谱系结构.分子方差分析(AMOVA)表明群体间遗传变异占1.22%,群体内遗传变异占98.78%.群体间固定指数(Fst)的绝对值为0.012 2,表明群体间遗传分化较弱.各群体间的基因流值均大于4,说明澄黄滨珊瑚在当地群体间随机交配,基因交流十分充沛,各珊瑚群体间没有地理隔离,可以互相作为造礁珊瑚修复用的来源补充地.

The ribosomal RNA internal transcribed spacer（ ITS） of three geographical population of Porites lutea was cloned and sequenced to discuss population difference and genetic differentiation. We got 63 haplotype from 79 sequence and find higher haplotype diversity（ Hd= 0. 991 56） and nucleotide diversity（ Pi= 0. 026 81）. Tajima＇D test、Fu＇s Fstest and mismatch analysis disclosed that the populations of Porites lutea had ever experienced population expansion. Neighbour-joining tree and median-joining network generated from haplotype data set displayed no apparent lineage clades association with sampling locations. An analysis of molecular variance（ AMOVA） showed that variance among populations accounted for 1. 22%,while within populations accounted for 98. 78%. The absolute values of fixation index among populations（ Fst= 0. 012 2） suggested that there was week genetic differentiationfor pairwise populations. Gene flow between populations were greater than 4 which indicated that there were random mating at the local P. lutea populations and the gene flow was very abundant which showed no geographic isolation from each other and could be complementarily sources for local coral reef restoration.