石斛属几种植物遗传关系的SRAP和RAPD比较分析

Comparison of SRAP and RAPD markers for genetic analysis of plants in Dendrobium Sw.

目的利用SRAP和RAPD两种分子标记技术对9份石斛种质进行遗传多样性研究。方法用40对SRAP引物组合和36个RAPD引物分别对供试石斛的基因组DNA进行扩增。结果SRAP引物组合共扩增条带1977条,多态性比率为90.2%,遗传相似系数GS值变化范围为0.3302～0.7892。RAPD引物共扩增出281条带,多态性比率为87.1%,GS值变化范围为0.4942～0.7731。利用两种标记得到的聚类结果存在一定的差异,SRAP聚类结果与传统的基于形态特征建立的分类结果比较一致,较好地体现了供试品种的亲缘关系、地域特性。在9个石斛供试种间,SRAP的标记指数MI值(16.46)是RAPD标记MI值(3.67)的4.5倍,表明SRAP具有更大的标记效率。结论两种标记皆可有效应用于该属植物种质资源的遗传多样性分析。而SRAP标记在石斛的遗传多样性与亲缘关系的研究中,则表现出了极大的优越性。

Objective This study was carried out in order to analyze genetic diversity in plants of Dendrobium Sw. and compare the marker index （MI） between SRAP and RAPD markers. Methods Using 40 SRAP primer combinations and 36 RAPD primers, the genetic diversity of the materials in Dendrobium Sw. was amplified. Results A total of 1 977 loci were generated by 40 SRAP primer combinations, of which 90.2% was polymorphic and the genetic similarity （GS） ranged from 0. 330 2 to 0. 789 2. As for RAPD, 281 bands were obtained, in which 87. 1% was polymorphie, and the GS was from 0. 494 2 to 0. 773 1. There were some differences existing in the two cluster results revealed by SRAP and RAPD markers, they were as follows： compared to that of RAPD, the result of SRAP could more comfortably reflect the kinship and geographical origin, simultaneously conform to the traditional classification. For the experiment materials, SRAP （16.46） got an MI value 4.5 folds higher than that of RAPD （3.67）, which meant SRAP markers were more effective in detecting genomic polymorphisms in the plants of Dendrobium Sw. Conclusion These results show that SRAP and RAPD could be applied to detecting genetic diversity analysis of plants in Dendrobium Sw. SRAP Also shows great superiority and advantage in this study.