野生花生种质的SSR遗传多样性

Genetic Diversity Analysis of Arachis Gerplasm by SSR

以花生属(Arachis)6个区组24种(包括栽培种)84份种质为材料,用SSR技术对其亲缘关系和遗传多样性进行了分析。从206对SSR引物中筛选到59对能扩增出稳定的多态性条带的引物,这些引物能在花生属基因组DNA中扩增出1～6个DNA片段。结果表明,84份种质的遗传距离为0.04～0.93,平均为0.64,其中匍匐区组的A.appressipila的2份种质(G4与G5)的遗传距离最小(0.04),匍匐区组的A.rigonii(G14)与根茎区组的A.glabrata(G28)的遗传距离最大(0.93)。聚类分析结果与花生属的区组分类基本一致,栽培种花生被聚在花生区组中,而且7份栽培种被聚在同一亚亚组中,相同植物学类型(相当于变种)的材料均被分别聚在一起。异形花区组与直立区组的亲缘关系最近,与花生区组的亲缘关系较近的是匍匐区组。花生区组的二倍体野生种A.villosa、A.duranensis和A.benensis与栽培种花生关系较近,可以作为桥梁物种来转移其他野生花生的优良基因。

The relationship and genetic diversity among 84 Arachis gerplasm of 24 species belonging to 6 sections were systematically investigated based on SSR markers. 59 SSR primer pairs with polymorphic bands ranging from 1 to 6 were selected through 206 primer pairs screening. The genetic distance varied from 0.04 to 0.93 with average of 0.64 among Arachis species. Two accessions （G4 and G5） of A. appressipila belonging to section Procumbentes showed the least distance （0.04）, while the largest genetic distances was detected between GI4 （A. rigonii） belonging to section Procumbentes and G28 （A. glabrata） belonging to section Rhizomatosae. This clustering result was almost consistent with the taxonomic of Section in Arachis by Krapovickas and Gregory in 1994. The 7 genotypes of cultivated peanut were grouped into one cluster in section Arachis, and different botanical types were grouped into different sub-clusters. Section Procumbentes had the closest relationship with Section Arachis, while the relationship between sections Heteranthae and Erectoides were very closer. Some diploid species including A. villosa, A. duranensis and A. benensis had closer relationship with cultivated peanut based on the dendrogram, and they could be used as bridge genotypes to transfer elite genes from wild species to cultivated peanut.