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份样本中扩增该衍生序列,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样性与变异。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0.011,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。

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

Objective] This study aimed to analyze the genetic structure of eight populations of Spartina alterniflora in China at the nuclear DNA level.Method] The EH277045-derived sequences were amplified from 75 samples in 8 populations and directly sequenced.Nucleotide diversity,haplotype diversity,the mean value of Nei’s genetic distance,genetic differentiation index FST and other genetic parameters were calculated to estimate the genetic diversity and genetic differentiation of S.alterniflora populations in China.Result] 75 samples were divided into 25 haplotypes by 28 polymorphic sites.Relatively high nucleotide diversity(π=0.011) and haplotype diversity(Hd=0.794) were detected.The mean value of Nei’s genetic distance and genetic differentiation index FST among eight populations were 0.056 and 0.222,respectively,the Nei’s genetic distance ranged from 0.000 to 0.189 and FST ranged from 0.000 to 0.444 between each pair of the eight populations.AMOVA result revealed that 79% and 21% of the total genetic variation was partitioned within and among S.alterniflora populations,respectively.Conclusion] At the nuclear DNA level,there were a relatively high level of genetic diversity and a relatively low level of genetic differentiation among S.alterniflora populations in China,and the genetic diversity existed mainly within rather than among populations.