草木樨在汞胁迫下的遗传分化研究(英文)

Genetic Differentiation among Melilotus officinalis Seedlings Exposed to Mercury

以草木樨(Melilotus officinalis)种子为研究对象,将其暴露于0、20、40和60mg·L-1浓度的氯化汞中进行萌发,并对存活的幼苗利用水平淀粉凝胶电泳进行等位酶分析。结果表明,草木樨在Me和Pgi基因座具有多态性,其平均的等位基因数为3.0基因座-1,杂合性为0.332-0.342,草木樨符合种群遗传研究的条件。Roger's遗传距离聚类分析表明草木樨在对照组和汞暴露存活个体组间存在明显的遗传距离分化。草木樨的某些基因型极有可能对汞污染存抗性作用,汞暴露通过定向选择导致遗传分化。研究表明,野化的草木樨是在黄土高原地区进行矿区植物修复的理想潜在物种。

To examine the genotypic responses of forage grass species to acute exposure to mercury chloride（HgCl2）,Melilotus officinalis seed was selected for germinating in concentrations of 0,20,40 and 60 mg·L-1 HgCl2.Polymeric allozyme genotypes of seedlings were tested using horizontal starch gel electrophoresis.The allozyme analysis showed high polymorphism at PGI and ME with the mean allele frequency of 3.0 and the mean observed heterozygosity of 0.332-0.342 for M.officinalis,suggesting the suitability of the species for allozyme analysis on genetic adaptations.The cluster analysis using Roger＇s genetic distance showed remarkable deviation between the surviving individuals and the control group.This indicates that certain genotypes of Melilotus officinalis may be more resistant to acute HgCl2 under laboratory conditions.The genetic differentiations are observed via directional selection process.The richness in genetic variation in wild Melilotus officinalis makes it being a potentially promising species in soil remediation in mining areas in loess plateau.