基于nrDNA ITS序列的浙江沿海引种秋茄树群体遗传多样性评估

Genetic Diversity of Introduced Populations of Kandelia obovate in Coastal Zhejiang Province Based on nrDNA ITS Sequences

采用核糖体nrDNA ITS序列分析技术对浙江台州沿海秋茄树的3个驯化地(三门,临海和温岭)和4个种源地(椒江,玉环,温州龙港,福建龙海)共10个居群100个个体的遗传多样性进行分析比较。结果表明:获得ITS序列总长度为342 bp,在物种水平上共检测到3个分离位点数,定义5个单倍型(h),单倍型多样性(Hd)为0.135±0.046,平均核苷酸差异(k)为0.17475,核苷酸多样性(π)为0.00051±0.0019。3个驯化地遗传多样性排序为:三门>临海>温岭,4个种源地的遗传多样性排序为:椒江>玉环>龙海>龙港。就区域尺度而言,引种秋茄树居群总体的遗传多样性和遗传分化水平较低,且随纬度升高而增大,其耐寒性亦相应地增强,这可能是由长期人工引种驯化下的部分居群适应性分化产生的。三门、椒江种源可作为台州沿海地区未来推广应用秋茄树的优良来源。

The rDNA ITS sequence analysis was used to compare the genetic diversity of 100 individuals in ten Kandelia obovate populations from three domesticated sites(Sanmen,Linhai and Wenling)and four provenance sites(Jiaojiang,Yuhuan,Wenzhou Longgang and Fujian Longhai).The results showed that the total lengths of ITS sequence were 342 bp.At the species level,three isolated sites were detected and five haplotypes were identified,with the haplotype diversity(Hd),the average number of nucleotide differences(k)and the nucleotide diversity(π)of 0.135±0.046,0.17475,and 0.00051±0.0019,respectively.The sequence of genetic diversity in the three introduced sites was ranked Sanmen>Linhai>Wenling.Meanwhile,the genetic diversity of the four provenances was ranked Jiaojiang>Yuhuan>Longhai>Longgang.On a regional scale,the genetic diversity and differentiation level of the introduced K.obovate population was relatively low,which were increased with the increase of latitude,and its cold resistance was enhanced accordingly.This might be caused by the adaptive differentiation of some populations after long-term artificial introduction and domestication.Sanmen and Jiaojiang provenances could be used as excellent sources for promoting and applying K.obovate in coastal areas of Taizhou in the future.