Construction and Evaluation of Pepper Core Collection Based on Phenotypic Traits and SSR Markers

Abstract 155 pepper germplasm from different region are used to conduct diversity analysis on 24 phenotypic traits, aiming to reduce the resource conservation workload, improve resource utilization and breeding efficiency. The best core collection was selected from three levels: the proportion of samples within the group, the overall sample size, and the gradual clustering of samples within the group. Representative evaluation of the phenotypic trait data of the core collection was conducted using indicators such as mean, variance, range, and coefficient of variation, and the core collection was confirmed by principal component analysis. At the same time, the Shannon Weaver diversity index and phenotype Shannon index were used to evaluate the representativeness of SSR molecular marker data of germplasm. The results showed that the pepper core collection constructed based on phenotype data contained 41 materials, which were found to perfectly preserved the genetic diversity of the original pepper germplasm using basic genetic parameters and principal component analysis. 54 polymorphic loci were obtained from 155 germplasm using SSR molecular markers, and core collection containing 32 materials was screened. Integrate phenotype and molecular core collection, the core collection composed of 57 varieties with the 92.55% phenotype retention ratio and 100% polymorphism site retention ratio were determined, and had the most genetic diversity according to a 90% compression ratio, which can fully represent the genetic diversity of the original germplasm.