应用RAPD分子标记探讨拟鹅观草属的种间关系

Relationships among Pseudoroegneria species based on random amplified polymorphic DNA (RAPD)

采用随机扩增多态性DNA(RAPD)技术,分析了拟鹅观草属(Pseudoroegneria)8种1亚种和鹅观草属(Roeg neria)7种植物。35个引物产生的344条DNA扩增片段中,328条(95.35%)具有多态性,利用344个RAPD标记,在NTSYS软件中,计算Jaccard遗传相似系数,建立UPGMA聚类图。结果表明:1)物种间遗传差异明显,具有丰富的遗传多样性;2)R.elytrigioides、R.alashanica和R.magnicaespes与拟鹅观草属的物种聚类在一起,表明它们与拟鹅观草属的亲缘关系较近,而与鹅观草属的亲缘关系较远;3)RAPD分子标记可以将拟鹅观草属的物种分开,而且形态相似,地理分布相同或相近的物种聚类在一起;4)RAPD结果与形态学和细胞学的分析结果一致,表明RAPD技术能为拟鹅观草属植物的系统学研究提供DNA水平上丰富的资料。

Eight species and one subspecies of Pseudoroegneria and seven species of Roegneria were analyzed using random amplified polymorphic DNA (RAPD) markers. A total of 344 products were amplified by 35 10-mer arbitrary primers, among which 328 (95.35%) products were found to be polymorphic. The data of 344 RAPD bands were used to generate Jaccard's similarity coefficients and to construct a dendrogram by means of UPGMA in the NTSYS-pc program. It is concluded as follows: 1) Distinct genetic differences and extensive genetic diversity were present among the species; 2) The 3 species in Roegneria, i. e. R. elytrigioides, R. alashanica and R. magnicaespes, and 9 accessions in Pseudoroegneria were grouped together, indicating that these three Roegneria species were closer to the species of Pseudoroegneria than to the other four species of Roegneria analysed in this study; 3) Pseudoroegneria species were separated clearly from each other based on RAPD markers. The species from the same areas or neighboring geographical regions were clustered together; 4) RAPD results were basically consistant with those obtained from studies on morphology and cytology. It is concluded that RAPD is a useful method for assessing the genetic relationships among Pseudoroegneria species.