Phenotypic Assessment of Genetic Diversity among Twenty Groundnut Genotypes under Well-watered and Water-stressed Conditions Using Multivariate Analysis

摘要

Background and Objective: Assessment of the genetic diversity in the available germplasm has high importance for its effective utilization in breeding programs. The aims of the present investigation were to determine the extent of genetic diversity in 20 groundnut genotypes, under well-watered and water-stressed conditions and assess interrelationships between pod yield and yield-related traits under both environments. Materials and Methods: Two experiments were conducted in two seasons; the first under well-watered and the 2nd under water-stressed conditions. A randomized complete block design with three replications was used. Principle Component Analysis (PCA) and GT-Biplot technique were used. Results: Groundnut genotypes recorded significant differences (p 0.01) for all studied characteristics under each environment. The promising genotype(s) for each trait were identified. Results of GT biplot indicated that the traits, pods/plant, pod yield/plant seeds/plant and seed yield /plant were strongly correlated with pod yield/ha, had high estimates of heritability and genetic advance from selection and thus could be considered as secondary traits for high pod yield either under well-watered or water-stressed conditions. The clustering analysis assigned the 20 groundnut genotypes into four groups. The highest genetic dissimilarity Euclidean coefficients were recorded between IL34 and each of G13, IL8, IL41 and IL13; they are the most unrelated genotypes, but the lowest dissimilarity was between IL 18 and IL 35, they are the most related genotypes. Conclusion: The identified promising genotypes and secondary traits could be offered to groundnut breeders for use in future breeding programs to improve drought tolerance.