中国甘薯登记品种SSR标记遗传多样性分析

Genetic Diversity of the Registered Sweetpotato Varieties in China by SSR Markers

该研究基于TP-M13-SSR分子标记荧光毛细管检测技术,以中国已入库登记的99份甘薯品种为材料,利用SSR标记建立登记品种的“01”数据库,导入DPS软件计算不同品种之间的遗传距离,采用MEGA的邻接法进行聚类分析,并利用Structure混合模型对材料进行遗传结构分析,以探讨各品种的遗传构成以及品种间的亲缘关系,揭示中国甘薯登记品种在DNA水平的相似度,为甘薯品种鉴定、亲本选配和品种改良等提供参考。结果显示:(1)28对引物共扩增出162条谱带,多态率为96.30%,每对引物平均获得5.57条多态性谱带。(2)构建了99份甘薯登记品种的遗传进化树,99份品种的遗传距离在0~0.4646之间,平均遗传距离为0.3077;在遗传距离为0.2670处将99份品种分为3个类群,且同一生态薯区的品种或具有同一亲本的品种首先被聚在一起,但不同生态薯区的品种在各类群中相对分散分布。(3)品种间的遗传基础较窄,部分生态薯区的品种相似性较高;群体结构分析将材料分为3个亚群,与聚类分析分群结果基本一致,其中31份材料拥有混合来源,遗传背景较为复杂。

Based on TP-M13-SSR fluorescent capillary detection technology, we analyzed the genetic diversity of 99 registered sweetpotato varieties. The “01” database of the registered varieties was established by SSR markers. The Nei genetic distance among different varieties was calculated using the DPS software. The Neighbor-Joining method in MEGA was used for cluster analysis, and the genetic structure of the accessions was analyzed by the admixture ancestry model in Structure software. The genetic composition of the varieties and the genetic relationship among the varieties were discussed, which revealed the similarity of the sweetpotato varieties at the DNA level and provided references for variety evaluation, excellent parent selection and variety improvement. The results showed that:(1) a total of 162 reproducible bands were amplified from 28 primer pairs with an average of 5.57 bands and polymorphic rate was 96.30%.(2) The dendrogram of 99 registered varieties was constructed. And the genetic distance of 99 varieties ranged from 0 to 0.464 6 with an average of 0.307 7. Cluster analysis at 0.267 0 genetic distance can divide 99 varieties into three groups. Sweetpotato varieties from the same agro-ecological zones or close relationship were clustered in the same groups. The varieties from different agro-ecological zones were relatively scattered in different groups.(3) The genetic background among accessions is relatively narrow. And similarity of some varieties is higher in some certain of the ecological zones. By population structure analysis, the 99 varieties were divided into three subgroups. Clustering results were in coincident with the results of population structure. The 31 accessions have a high degree of mixed ancestry and complex genetic background.