Unveiling the Genetic Diversity of Winged Bean (Psophocarpus tetragonolobus (L.) DC.) Genotypes: A Phenotypic and Genotypic Assessment for Crop Improvement

Abstract The winged bean (Psophocarpus tetragonolobus), a highly nutritious yet underutilized legume, exhibits significant genetic diversity across different agro-climatic regions. However, more attention is needed to fully exploit its potential due to lack of adequate knowledge of the existing genetic diversity in the available winged bean germplasm. To bridge this gap, the study evaluates 28-winged bean genotypes collected from various districts of Kerala, Tamil Nadu, Manipur, India and NBPGR. The research aimed to assess the phenotypic variability of these genotypes to support future breeding programs. A randomized block design (RBD) was used for the experiment, with observations recorded for 12 quantitative traits, including vine length, pod yield, seed characteristics, and germination parameters. The results revealed significant variability among genotypes in traits such as pod length (14.31 cm to 46.18 cm), pod width (2.14 cm to 3.63 cm), and number of seeds per pod (5.34 to 22.68). Genetic component analysis indicated high heritability for most traits, particularly the number of seeds per pod (98.98%) and pod length (96.84%), suggesting their strong genetic influence. Principal component analysis (PCA) demonstrated that four principal components accounted for 74.67% of the total variance, with pod- and seed-related traits contributing the most to diversity. Cluster analysis grouped the genotypes into three clusters based on yield and growth characteristics, with Cluster I genotypes exhibiting the highest pod yield per plant (742.15 g). The findings highlight the potential of selected genotypes for genetic improvement, emphasizing the need for further hybridization programs to enhance productivity and adaptability.