Analysis of genetic diversity of Centrosema pubescens germplasm based on botanical traits

Centrosema pubescens (family Leguminosae, genus Centrosema) is a perennial herb. This study examined the genetic diversity characteristics of C. pubescens germplasm. Thirty-eight botanical characters were observed in 75 C. pubescens resources. Through the frequency distribution and variability analysis of botanical characters, correlation analysis, and cluster analysis, the genetic diversity characteristics of C. pubescens germplasm were obtained, and high-quality materials were screened. Among the 38 botanical traits, the flag petal color (79.68%), stem hair condition (46.03%), and leaf back hair condition (42.18%) had a large coefficient of variation, indicating that they played a key role in genetic diversity; the analysis of 27 botanical traits of C. pubescens with non-zero standard deviation revealed highly significant correlations (P < 0.01) between the multiple groups of traits. Among these traits, stem hair condition, leaf belly hair condition, and leaf size showed a highly significant relationship with natural height, indicating that natural height was the main factor determining the stem and leaf traits. Seventy-five germplasm resources were divided into 11 categories. The 7th category had larger leaves, less pubescence, and higher natural height, among which Centrosema ‘050319012’, Centrosema ‘CIAT25118’, and Centrosema ‘060301016’ performed best. In this study, the genetic diversity of the germplasm was identified, and the genetic characteristics of C. pubescens were obtained. The findings provided a reference for the evaluation and screening of the nutritional value of C. pubescens germplasm.