SRAP结合SSR标记分析油菜自交系的遗传多样性

Genetic Diversity Analysis of Inbreeding Line Brassica napus by SRAP and SSR Combination

为了掌握陕南地区油菜主要育种材料的遗传多样性,了解其遗传背景,明确各材料间的亲缘关系,为油菜育种提供理论依据。利用34对有多态性的SRAP标记和25对SSR标记,对56份陕南地区油菜自交系材料进行遗传多样性分析。结果表明,SRAP标记共检测到273个等位变异,平均每个标记检测到8个等位基因,每个SRAP位点的遗传多态性信息含量在0.32~0.93,平均值为0.64。供试材料的遗传相似系数集中在0.47~0.93,两两遗传相似系数的平均值为0.69,变幅为0.34~0.93,聚类分析表明。在相似系数0.47处,所有材料被聚为一类。SSR标记共检测到155个等位基因,平均每个标记检测到7个等位基因,每个SSR位点的遗传多态性信息含量在0.03~0.92,平均值为0.54。供试材料的遗传相似系数集中在0.49~0.92之间。两两遗传相似系数的平均值为0.57,变幅为0.30~0.92。在相似系数0.49处,所有材料被聚为一类。因此,SRAP标记的多态性比SSR丰富,56份陕南地区甘蓝型油菜自交系中多数材料亲缘关系较近,在育种中需要创新种质资源。

This study aims to explore the genetic polymorphism of rapedseed materials in southern areas of Shaanxi Province,unreveal the genetic background,identify the relationship among all materials,and provide the theoretical basis for rapedseed breeding. Genetic diversity of56 Brassica napus inbred lines in southern Shaanxi were investigated using variable renaturing temperature-based PCR,in which 34 pairs of SRAP markers and 25 pairs of SSR markers were employed. The results demonstrated that total 273 alleles were verified using SRAP markers,in which 8 alleles were detected by per pair of molecular markers. And genetic polymorphism information content of each SRAP locus was between 0. 32-0. 93,with an average of 0. 64. Meanwhile 168 alleles were found using SSR,and 7 alleles were achieved per pair of SSR markers. Genetic polymorphism information content of each SSR locus was between 0. 03-0. 92,and the average of which was 0. 54.Additionally,the genetic similarity of the 56 varieties ranged from 0. 34 to 0. 93 with an average value of 0. 69 for SRAP and from 0. 30 to 0.92 with an average value of 0. 57 for SSR. Cluster analysis showed that genetic similarity coefficient of 56 different materials were 0. 47-0.93 for SRAP and 0. 49-0. 92 for SSR markers,respectively. UPGMA cluster analysis of genetic similarity showed that all the materials were clustered into one group at the genetic similarity of 0. 47 for SRAP and 0. 49 for SSR. By comparison,SRAP showed higher potential in determining genetic polymorphism than SSR. Very narrow genetic background was observed for the most materials of 56 inbred Brassica napus lines in this study. It is an urgent task for Brassica napus breeders to introduce diversified germplasm resources into Brassica napus breeding program.