Genetic Divergence and Associations Studies among Forage and Quality Characters in Guar (Cyamopsis tetragonoloba L.) Germplasm

Abstract

The objective of the current study was to assess the extent of genetic variation among guar genotypes using morpho-agronomic data based on Principal Component Analysis (PCA) and to measure the genetic distance among these genotypes using hierarchical cluster analysis. The study consisted of 32 guar accessions collected from different regions of India. These 32 guar genotypes were grown in a randomized complete block design with three replications for two years. Analysis of variance revealed the significant differences present for the genotypes under investigation. Higher PCV and GCV values were recorded for leaf-stem ratio (L: S) followed by the number of branches per plant (B/P), stem girth (SG), dry matter yield (DMY) and green fodder yield (GFY). High heritability (>95%) was present for the characters such as plant height (PH), number of leaves (NOL/P), number of branches (B/P) and leaf-stem ratio (L:S). Heritability for quality traits was also high, i.e., 92.83% for neutral detergent fiber (NDF) and 89.16% for in vitro dry matter digestibility. The highest genetic advance was observed for leaf stem ratio (46.98%) whereas moderate genetic advance was recorded for the number of branches (B/P), stem girth (SG), green fodder yield (GFY), number of leaves (NOL/P) and plant height (PH). The PCA reveals five principal components that contribute to the maximum variations and traits related to these components. Further, the cluster analysis based on centroid distance diversified the genotypes into five groups. Cluster-I includes nine genotypes with higher GFY followed by Cluster-III includes 10 genotypes with average GFY. The genotypes lying under Cluster-I and Cluster-III showing better plant height, stem girth, and number of branches per plant with higher crude protein, acid detergent fiber, neutral detergent fiber, in vitro dry matter digestibility content can be utilized in further breeding programs.