根据EH277045衍生序列变异分析中国互花米草种群的遗传结构

目的]在核DNA水平根据DNA序列变异分析我国沿海8个互花米草种群的遗传结构。方法]根据互花米草EST序列EH277045的序列信息设计引物，在8个种群共75份样本中扩增该序列，采取直接测序的方法，比较序列差异，计算多种遗传参数，分析中国互花米草种群的遗传多棹性与变异。结果]共得到28个多态位点，将75份样本分为25种单倍型，核苷酸多样性为0．01l，单倍型多样性为0．794；种群间基因分化系数Gst，为0．163，遗传分化指数Fst，为0．222；AMOVA分析揭示79％的遗传差异来源于种群内，21％的遗传差异来源于种群间。结论]我国互花米草种群遗传多样性水平高，种群间遗传分化较低，遗传多样性主要存在于种群内。

Genetic Structure of Spartina alterniflora Populations in China Based on EH277045-derived Sequence

Objective] To examine the genetic structure of eight S.alterniflora populations in China at the nuclear DNA level.Method] The EH277045-derived sequences of seventy-five samples in eight populations were amplified and direct sequenced,and sequence differences were compared,to calculate many kinds of genetic parameters and analyze genetic diversity and differentiation of these populations.Results] A total of twenty-five haplotypes,which were distinguished by twenty-eight polymorphic sites,were discovered,and the diversity of nucleotide and haplotype were 0.011 and 0.794,respectively,the divergence index G_ST of gene among populations was 0.163,the genetic differentiation index F_ST was 0.222;AMOVA analysis revealed that 21% of the total genetic variation was partitioned among populations.Conclusion] At the nuclear DNA level,a relatively high level of genetic diversity and low level of genetic differentiation among S.alterniflora population and the genetic difference of the species existed mainly within population in China.