基于SSR分子标记的辣椒遗传多样性分析及DNA指纹图谱构建OA

To explore the genetic specificity,diversity,and phylogenetic relationships among different Capsicum annuum varieties and to promote the identification,protection,and innovation of new Capsicum annuum varieties,SSR fluorescent markers combined with capillary electrophoresis detec-tion were used to analyze the genetic diversity of 16 different types of Capsicum annuum varieties and to construct DNA fingerprint profiles.The results showed that six pairs of SSR primers amplified a total of 17 allelic loci,with each primer pair amplifying 2 to 3 alleles and an average of 2.833 alleles per locus.The average effective number of alleles,observed heterozygosity,and expected heterozy-gosity were 2.185,0.510,and 0.504,respectively.Shannon's diversity index ranged from 0.433 to 1.092,with an average of 0.849,and the polymorphism information content ranged from 0.229 to 0.588,with an average of 0.447,indicating that the tested Capsicum annuum varieties possessed rela-tively rich genetic diversity.The genetic similarity coefficients among the tested Capsicum annuum varieties ranged from 0.33 to 1.00,with an average of 0.67,indicating significant differences in their genetic backgrounds.NJ cluster analysis showed that the 16 Capsicum annuum varieties could be di-vided into 3 major groups.The cayenne pepper type and the screw pepper type were clustered into dif-ferent groups,while the cow-horn pepper type was scattered across different groups and could not be effectively distinguished.Based on the 6 pairs of SSR primers,DNA fingerprint profiles and molecular identity cards(QR code profiles)for the 16 Capsicum annuum varieties were successfully construc-ted,providing a scientific basis for the breeding of new Capsicum annuum varieties,variety protec-tion and the identification of variety purity and authenticity.