Morphological variations and relationship among onion germplasm for quantitative and qualitative traits at trans-Himalaya Ladakh, India

Abstract

In the present work, the variability, interrelationship, and divergence pattern of twenty six accessions of onion at high altitude were studied based on quantitative and qualitative traits. Multivariate analysis was used to classify the twenty six onion accessions. Cluster I contained two genotypes, cluster II contained ten genotypes, cluster III contained two and cluster IV contained twelve genotypes. The highest inter-cluster distance was observed between I and IV, and the lowest between I and II. The maximum intra-cluster distance was observed in Cluster II and the minimum in cluster III. The intra-cluster distance in all the four clusters was relatively low, indicating that genotypes within the same cluster were closely related. Based on cluster means, cluster 1 is the best in terms of number of leaves and neck thickness, cluster II best in terms of leaf width, Double/deformed bulb, Polar diameter, equatorial diameter, average bulb weight and bulb yield kg/plot, cluster III is the best in terms of days to maturity, TSS and dry matter content and cluster IV which is best in terms of plant height, leaf length and chlorophyll content. Considering cluster distance and cluster mean, the intra cluster distance revealed that the genotypes from the cluster II and genotypes from the cluster IV may be selected as parents for future breeding program. It was found that, PCA extracted three PCs and contributed 95.61 % of the variation out of which PC1 accounted 77.52 % variability, PC2 for 10.72 % and PC3 7.38 % variability of the variance among 26 accessions. The greater part of the variance was accounted for by other traits such as average bulb weight, bulb yield, leaf length, equatorial diameter and TSS. The high diversity found in the accessions shows great potential for improving qualitative as well as quantitative traits in onion.