Exploring the phenotypic diversity of clove bean (Ipomoea muricata (L.) Jacq.) landraces for DUS-based morphological traits through multivariate analysis
Clove bean (Ipomoea muricata (L.) Jacq.) is an underutilised vegetable crop with significant potential for strengthening sustainable agriculture and global nutritional security. The conservation and utilisation of clove bean landraces are essential for breeding advancement and global nutritional security, owing to the limited availability and characterisation of germplasm resources. The present study evaluated fifteen clove bean landraces using 26 morpho-physiological, inflorescence, pod and seed descriptors to assess the extent of genetic diversity. Significant variability was observed across all studied traits, indicating the presence of substantial morphological divergence among the landraces. Correlation analysis revealed strong positive associations among plant type, canopy cover, vine internode length, mature leaf size and pigmentation traits, suggesting coordinated genetic control and the possibility of simultaneous improvement through selection. Floral characteristics, including flower length, flower width, sepal shape and sepal apex, exhibited highly significant positive correlations. Cluster analysis grouped the landraces into four distinct clusters, reflecting varying levels of divergence and identifying unique landraces such as Im-1 and Im-11. Principal component analysis indicated that the first six principal components had eigenvalues greater than one and together explained 88.95 % of the total variation, with PC1 contributing 39.86 %. Floral dimensional traits and vegetative vigour were the primary contributors to divergence. The identified landraces provide valuable genetic resources for future breeding, conservation and crop improvement programmes in clove bean.