基于SSR标记的76份紫心甘薯品种的遗传多样性分析

为探明中国育成的紫心甘薯品种之间的遗传多样性和遗传差异,本研究利用124对SSR引物对搜集到的76个紫心甘薯品种进行遗传多样性分析。通过6%的聚丙烯酰胺凝胶电泳获得76个品种的PCR扩增条带数据,构建0~1数据矩阵,利用NTSYS 2.10e软件计算Nei’s遗传距离,将遗传距离系数矩阵导入MEGA 7.0.26,进行遗传距离分析和NJ聚类分析;利用Structure 2.3.4软件进行群体结构分析。结果表明:124对引物共扩增出750条条带,其中多态性条带为90.13%,每对引物检测出2~18个等位变异,平均6.05个;76个紫心甘薯品种的遗传距离在0.0442~0.6010之间,平均为0.2921,进一步分析发现,中国各薯区品种间的遗传距离较近,外引品种绫紫与中国各薯区品种间的遗传距离较远,因此可以通过引进国外紫薯品种来扩大中国紫心甘薯的遗传背景;在遗传距离0.2613处可分为3个族群,在0.2253处可分为9个族群,在0.2173处将第Ⅸ族群划分为4个亚群,来源地相近或拥有相同亲本的紫心甘薯材料有聚在一起的趋势;通过对群体结构K值分析,发现76份品种划分为3个稳定的群体,最大Q值分析发现,最大Q值越大群体的遗传背景就越简单,最大Q值<0.6时,品种的遗传成分来源于不同群体,群体间存在明显的基因交流,76个紫心甘薯品种遗传成分有3个变异来源。

Genetic Diversity of 76 Purple Fleshed Sweetpotato Cultivars Revealed by SSR Markers

In order to clarify the genetic relationship and genetic differences between Purple-fleshed Sweetpotato(PFSP)cultivars,124 SSR primer pairs were used to analyze the genetic diversity of the 76 PFSP cultivars.The PCR amplified bands of 76 materials were obtained by 6%polyacrylamide gel electrophoresis,and the 0~1 data matrix was constructed.The Nei’s genetic distance was calculated by NTSYS 2.10 e software,and the genetic distance matrix was imported into MEGA 7.0.26 for genetic distance analysis and NJ(Neighbor-joing tree method)cluster analysis.The software of Structure 2.3.4 were used to analyze population structure.The results showed that a total of 750 bands were amplified by 124 primer pairs,of which the proportion of polymorphic sites was 90.13%,and 2~18 alleles were detected for each pair primers,with an average of 6.05.The genetic distances of the 76 PFSP cultivars ranged from 0.0442 to 0.6010 with an average of 0.2921.Further analysis results revealed that the genetic distances between the introduced cultivar and the domestic cultivars were more far than that of between the cultivars in China.Therefore,the genetic background of domestic PFSP cultivars can be expanded by introducing foreign PFSP cultivars.The 76 cultivars can be divided into 3 groups at a genetic distance of 0.2613 and 9 group at a genetic distance of 0.2253,the IX group is divided into 4 subgroups at a genetic distance of 0.2173,the 76 cultivars with similar sources or the same parent have a tendency to get together.By analyzing the K value of the population structure,it was found that 76 cultivars were divided into 3 stable groups,the maximum Q value analysis found that the larger the maximum Q,the simpler the genetic background of the population,when the maximum Q<0.6,the genetic components of the variety were derived from different groups,and there were obvious genetic exchanges between different groups.There were three sources of variation in the genetic components of the 76 PFSP cultivars.