Determination of genetic diversity in onion (Allium cepa L) by multivariate analysis under long day conditions

Abstract

The present investigation was conducted on thirty eight accessions of onion at the experimental farm of Central Institute of temperate Horticulture to study the variability and their interrelationship and divergence pattern based on quantitative and qualitative traits during 2009 to 2011. Multivariate analysis was used to classify 38 long day onion accessions. All accessions were grouped into six different clusters. The highest inter cluster distance was observed between IV and V and lowest between II and VI. Based on cluster means the important cluster was I for plant height and percent marketable bulbs cluster IV for mean yield, total yield and equatorial diameter and cluster III for the number of leaves, collar thickness and average bulb weight. Accordingly, parents could be selected for hybridization. Principal component analysis, first two principal component accessions accounted for 59.29% of the variance among 38 accessions. The greater part of the variance was accounted for other traits such as plant height, collar thickness, percent marketable bulb yield, polar diameter of the bulb and neck thickness. The high diversity found in the accessions showed its great potential for improving qualitative as well as quantitative traits in long day onion.