基于matK基因和ITS序列的江苏地方豆类植物的亲缘关系研究

Phylogenetic relationship among local legumes in Jiangsu Province based on analyses of matK gene and ITS sequence

[目的]为探究江苏地方豆类植物之间的亲缘关系,从分子水平上对14种豆科植物进行了深入分析,旨在为后续豆类植物的种质创新和遗传改良提供理论依据。[方法]对14种豆类植物的mat K基因和ITS序列的扩增片段进行PCR产物直接测序,并结合Gen Bank数据库中的大豆(Glycine max)、菜豆(Phaseolus vulgaris)、红小豆(Vigna angularis)和绿豆(Vigna radiata)4种豆类植物基因组序列,利用Clustal W、MEGA 6.0、Bio Edit软件对这18种材料的mat K基因和ITS序列分别进行比对和分析,并以百脉根(Lotus corniculatus)为外类群,分别构建系统进化树并计算分化时间。[结果]18种豆类植物的mat K基因序列长度为750 bp,其中变异位点数为85,信息位点数为82,遗传距离的范围为0~0.099。ITS序列长度为795 bp,其中变异位点数为260,信息位点数为242,遗传距离的范围为0~0.292。以百脉根为外类群,用mat K基因序列和ITS序列分别构建的进化树显示,18种豆类植物可分为3组,即红小豆和绿豆分为一组,菜豆和大豆分别聚为一组。分化时间结果表明,大豆与菜豆的分化时间为19.02百万年前,菜豆与红小豆的分化时间为13.50百万年前,绿豆与红小豆的分化时间为2.94百万年前。[结论]序列分析和系统进化树的结果与形态学的特征基本一致,表明mat K基因和ITS序列可用于豆类植物属间亲缘关系分析。

[ Objectives] Genetic relationships among 14 legumes were analyzed under the molecular level,in order to provide a theo- retical basis for the germplasm innovation and genetic improvement in legumes. [ Methods ] We sequenced the matK gene and ITS sequence of 14 Jiangsu local varieties of legumes collected by our laboratory and another four legumes （ Glycine max, Phaseolus vulgaris ,Vigna angularis and Vigna radiata）from GenBank. Then we compared and analyzed the mark gene and ITS sequences of 18 legumes by Clustal W,MEGA 6.0 and BioEdit. A phylogenetie tree was constructed and the divergence time was also calculated by using Lotus corniculatus as outgroup. [ Results] The resuhs showed that the length of matK gene in 18 legumes was 750 bp after alignment, including 85 variable sites and 82 informative sites with the genetic distance that ranged from 0 to 0.099. The length of ITS sequence was 795 bp after alignment,including 260 variable sites and 242 informative sites with the genetic distance that ranged from 0 to 0.292. The phylogenetic tree constructed by marK gene and ITS sequence showed that 18 legumes were divided into three groups, Vigna angularis and Vigna radiate were grouped to one branch, Glycine max and Phaseolus vulgaris were grouped into the other two branches, respectively. The estimated divergence times were 19.02 million years ago（ Glycine max vs Phaseolus vtdgaris ） , 13.50 million years ago（ Phaseolus vulgaris vs Vigna angularis）and 2.94 million years ago（ Vigna radiate vs Vigna angularis）for the three respective groups. [ Conclusions ] Sequence analyses and results from phylogenetic tree were consistent with the morphologic identification in these legumes, which suggested that both matK gene and ITS sequence could be used for phylogenetie analysis among species in local legumes.