老芒麦和垂穗披碱草rDNA-ITS序列分析

分析了老芒麦和垂穗披碱草rDNA-ITS序列,为这两个种的鉴别提供分子指纹图谱,为系统发育提供分子生物学依据。结果表明,22份材料的ITS、ITS1、5.8S、ITS2序列长度均相同,依次为604bp、222bp、164bp、218bp,GC含量依次为62.25%～63.08%,62.16%～63.06%,59.76%,64.22%～65.60%。除5.8S外,碱基位点都有不同程度的变化,一些变异位点有明显的种性变异规律,可作为老芒麦和垂穗披碱草种质DNA指纹特异鉴别位点。7个ITS序列的同源性98.7%～99.8%,遗传分歧0.2～1.3,具有保守性,为非近期分化类群。系统发育分析表明不同来源地的同种材料,差异主要表现在DNA变化快慢及碱基替换数,但相同的种归为一类,进一步反映了种内的遗传稳定性。

Analysis on rDNA-ITS Sequence of Elymus sibiricus and E.nutans

It will provide useful information for germplasm DNA fingerprint identification, phylogeny by using ITS sequences analysis of Elymus sibiricus and E.nutans. The results show length of ITS, ITS1, 5.8S and ITS2 are identity, and they are 604bp, 222bp, 164bp and 218bp in order, and G C content are 62.25-63.08%, 62.16-63.06%, 59.76%, 64.22-65.60% in order. Except for 5.8S, base sites have some vary, some variable sites are species-specific and can be used as DNA molecular markers of Elymus sibiricus and E.nutans. Percent identity of the seven ITS squences is 98.7%-99.8%, divergence is 0.2-1.3, they have conservation, and not recent differentiated groups. Phylogenetic analysis indicates that different sources of the same species, speed of DNA changes and the number of base subsititue are different, but the same species belongs to group together, and reflects the intraspecific genetic stability in further.