Genetic Diversity of the Phenotypic Traits Among the Recombinants in Pepper

Genetic diversity analysis can contribute to comparing the relationships between different germplasm resources. Self-recombination is one of the main strategies for the innovation of germplasm resources. In this study, a total of 588 accessions, including two parents and their 586 F2:4 recombinant individuals originated via the single seed descent (SSD) method, were used to explore the genetic diversity of 17 phenotypic traits. The results indicated that most traits of the recombinants represented continuous distribution and transgressive segregation, with their minimum and maximum values exceeding the parental ranges. Correlation analysis shows that 17 phenotypic traits could be roughly divided into three clusters. There was a significant correlation between traits in the same cluster, such as primary stem height, plant height, and plant canopy diameter in Cluster I; transverse diameter of fruit, fruit shape of apex, node pubescence density, and lamina transverse section morphology in Cluster II; and internode anthocyanin pigmentation, immature fruit color, and leaf color in Cluster III, respectively. The 586 recombinant individuals and two parents were generally clustered into three groups, Group I, Group II, and Group III, which contained 320, 226, and 42 recombinants, respectively. In addition, six principal components were extracted from the 17 phenotypic traits, which could explain 62.97% of the cumulative variance contribution. Importantly, ten recombinants with both purple and long fruit were screened as breeding materials. Overall, this study provides useful information and breeding materials for the utilization and innovation of pepper germplasm resources as well as genetic improvement of pepper.