Genetic enhancement of onion germplasm through population improvement

Sustainable onion breeding relies on genetic values of the germplasm. Descriptive statistics for the breeding values for economical traits revealed the maximum variability among the 62 onion genotypes studied. The principle components among the genotypes contributed to 75.44% of the variance and their association was differed significantly (α = 0.05). Analysis of genetic diversity among the germplasm population aided for the classification of genotypes and identification of core collections with possible utility for specific breeding strategies. The sixty-two onion genotypes studied were grouped in to five clusters, cluster-I included nine genotypes, cluster-II had thirteen genotypes, cluster-III contained fourteen genotypes, cluster-IV consisted of twelve and cluster-V contained fourteen genotypes. The inter-cluster distance (56.54) was found maximum between cluster-I and -III. The cluster means reveals the cluster-I is the best for bulb weight, equatorial and polar diameter, stem girth and number of leaves, cluster-IV for plant height. The genotypes differed significantly for the bulb yield and their yield attributes. The ample variability and diversity among the genotype population could aid for genetic improvement of qualitative and quantitative traits of onion germplasm.