鱼腥草种质资源的RAPD分析

目的分析鱼腥草种质资源在分子水平上的遗传多样性。方法应用RAPD技术对92份鱼腥草种质资源进行检测。结果34个随机引物中有32个引物(94.1%)扩增产物具多态性。34个引物共得到200条扩增DNA片段,其中93.5%的片段具多态性。每个多态性引物平均可扩增出5.8个多态性片段。峨眉蕺菜和蕺菜种内平均遗传相似系数(genetic similarity,GS)分别为0.521和0.572,二者种间GS值为0.517。峨眉蕺菜与蕺菜中染色体数目为36的细胞型间相似程度最高,其平均GS值达0.530。栽培蕺菜类群比其野生类群遗传多样性相对较高。聚类分析表明,利用RAPD技术可将全部供试材料区分开,所有材料共划分为14类。其中,绝大多数(62个)聚为一类,且根据RAPD遗传相似系数划分的类群同地理分布有一定关系。结论(1) 鱼腥草种质资源在分子水平上确实存在较大遗传差异。(2) RAPD标记可作为构建鱼腥草DNA指纹图谱的有效工具。(3) 鱼腥草药材道地性与环境因素有关,但更大程度上由其遗传因素所决定。

RAPD ANALYSIS ON THE GERMPLASM RESOURCES OF HERBA HOUTTYNIAE

AIM To discuss the genetic diversity of the germplasm resources of Herba Houttyniae on molecular level. METHODS The genetic diversity of 92 Houttuynia Thunb. accessions were tested by RAPD markers. RESULTS Of 34 10-mer arbitrary primers, 32 (94.1%) were found to amplify polymorphic products. A total of 200 products were amplified of which, 93.5% products were found to be polymorphic. 5.8 polymorphic bands were amplified by each polymorphic primers on the average. The average genetic similarity (GS) within Houttuynia cordata Thunb. and Houttuynia emeiensis Z.Y. Zhu et S.L. Zhang accessions were 0.521 and 0.572, respectively. The GS between them was 0.517. The degree of similarity of Houttuynia emeiensis Z.Y. Zhu et S.L. Zhang accessions and Houttuynia cordata Thunb. cytotype which had the chromosome number of 36 was the highest, with an average of 0.530. The genetic diversity of cultivated groups was higher than that of wild ones. The results of cluster analysis by using UPGMA method showed that all the tested accessions can be differentiated by RAPD markers, and classified as 14 groups. Of which, 62 accessions was classified as one group. The results also showed that the genetic diversity in Herba Houttyniae based on RAPD GS was correlated with geographic distribution. CONCLUSION (1) There actually existed much genetic diversity on molecular level among the germplasm resources of Herba Houttyniae. (2) RAPD markers could be effective tools to construct DNA fingerprintings of Herba Houttyniae. (3) The genuieness of Herba Houttyniae was related with the environments. However, it was affected by genetic facters in more degree.