Phenotypic diversity indices and multivariate analysis of Peruvian common bean (Phaseolus vulgaris L.) germplasm

Abstract

Background: Phaseolus vulgaris L. is a globally important legume due to its nutritional value and its contribution to food security and agricultural sustainability. Although Peruvian germplasm exhibits high phenotypic variability, information regarding accessions from the INIA Germplasm Bank remains limited. This study characterized the phenotypic diversity of 66 accessions using diversity indices and multivariate analyses under coastal Peruvian conditions. Methods: A total of 35 agro-morphological traits (18 qualitative and 17 quantitative) were evaluated using CIAT descriptors. Diversity was assessed using Shannon and Pielou evenness indices, as well as multivariate analyses including hierarchical clustering based on Gower distance, FAMD, PCA and MCA. Result: High phenotypic variability was observed, resulting in four distinct clusters. FAMD showed that hundred-seed weight, leaf width and length and primary seed color were the main contributors to total variance. PCA revealed a positive correlation between seed weight and leaf traits, whereas the number of pods per plant and seeds per pod showed a negative association with these variables. MCA and diversity indices highlighted seed color, growth habit and standard petal pigmentation as key discriminating traits. Cluster II exhibited the highest dispersion and phenotypic diversity, whereas Cluster IV showed higher yield-related components, demonstrating the potential of these accessions for use in breeding programs and genetic resource conservation.