基于ITS2和rbcL序列石斛属植物的鉴定

Identification of Dendrobium by ITS2 and rbcL Sequence

为选育优质石斛品种和开发利用高效药用石斛资源,利用形态学分类法和DNA条形码技术对采集到的石斛样品进行鉴定,并对样品ITS2序列二级结构进行分析。结果表明:样品形态与石斛属植物特征相似。以ITS2序列构建系统发育树,样品GX07与Dendrobium loddigesii,YN08与Dendrobium officinale位于同一位置,其二级结构也基本一致,螺旋区和茎环等结构均无明显区别。基于rbcL序列构建的系统发育树没有达到很好的分辨效果,石斛属种间遗传距离最大为0.028。表明ITS2比rbcL更适合石斛属种间物种鉴定,并且其二级结构具有一定的辅助作用。

To breed high-quality varieties and develop resources of Dendrobium,the collected samples were identified by morphological determination and DNA barcoding method,and the ITS2 secondary structure was predicted and analyzed.The results showed the morphology of the samples was similar to that of the genus Dendrobium.The phylogenetic tree based on ITS2 sequence showed that GX07 and Dendrobium loddigesii,YN08 and Dendrobium officinale were located at the same position with nearly identical ITS2 secondary structures.There was no significant difference in structures including Helix and Loop.However,the maximum genetic distance between genus Dendrobium was 0.028,without a very good resolution effect of the phylogenetic tree based on rbcLsequence.The results indicated that ITS2 sequence may be more effective in the identification of different species of Dendrobium with its secondary structure playing a supportive role.