披碱草属12个物种遗传多样性的ISSR和SSR比较分析

Comparison of Genetic Diversity of Twelve Elymus Species Using ISSR and SSR Markers

为了比较ISSR和SSR标记在披碱草属(ElymusL.)植物研究中的可应用性,用33个ISSR引物和137对小麦SSR引物对该属12个物种进行了分析。筛选出18个ISSR引物和14对小麦SSR引物可用于遗传多样性分析。12个物种的PCR分析表明,18个ISSR引物和14对SSR引物的多态性位点百分率分别为84%和91%,均表现出较高多态性,基于两种标记的种间聚类状况与物种的倍性水平和形态学相似程度存在较高一致性。在12个种间,ISSR的标记指数MI值(10.2)为SSR(4.3)的2.4倍,表明ISSR具有更大的标记效率;但在亲缘关系较近的肥披碱草、圆柱披碱草、麦宾草和披碱草等4个种间,SSR具有更大的标记效率。Mantel检测显示,在12个种间两种标记的遗传相似性显著相关(r=0.856,t=6.446),但在4个近亲缘关系种间相关不显著(r=0.679,t=1.595)。两种标记的标记效率和相关性在不同亲缘关系水平上的改变,说明不同的标记具有不同的多态性检测范围。

In order to compare the usefulness of ISSRs and SSRs in Elymus species, 33 ISSR primers and 137 wheat SSR primer pairs were employed to detect 12 species of Elymus in this study. The results indicated that 18 ISSR primers and 14 wheat SSR primer pairs were available to analysis genetic diversity of Elymus species. PCR analysis for 12 species showed that both ISSR and SSR markers appear high polymorphism, whose percentage of polymorphic bands were 84% and 91%, respectively. The results of cluster analysis based on ISSR and SSR markers were coincided highly with ploidy level and morphologic taxonomy. For 12 species, ISSRs （10.2） got a MI （marker index） value 1.4 folds higher than that of SSRs （4.3）, whilst SSRs had a higher MI than that of ISSRs for 4 near related species, E. excelsus, E. cylindricus, E. tangutorum and E. dahuricus. Mantel test revealed that the relation of genetic similarity matrix between ISSRs and SSRs was significant （r=0.856, t=6.446） for 12 species, but not significant （r=0.679, t=1.595） for 4 near related species. The variance of maker utility and relateness between the two types of markers at different consanguinity levels showed different effective diversity detection scopes of ISSRs and SSRs.