Abstract
Twenty-six onion (Allium cepa L.) germplasm lines were evaluated to obtain information on genetic variability and association of different characters with bulb yield and among themselves at Alemaya Umversity, Ethiopia. Wide range of variability was obtained for the traits studied, viz., plant height, leaves per plant, leaf length, leaf diameter, neck thickness, bulb diameter, bulb yield per plant, bulb dry matter (DM) content, days to maturity, biological yield per plant, and total soluble solids. The estimates of phenotypic coefficient of variation was high compared to genotypic coefficient of variation in majority of the cases, indicating the influence of environment in determining these traits. High values of heritability were observed for most of the characters studied except for bulb diameter. High heritability value coupled with high genetic advance were observed for number of leaves, leaf diameter, bulb DM yield, biological yield per plant, and soluble solids. Correlation and path-coefficient analyses were done to find associations among each of the studied characters and their contribution to bulb yield. Bulb yield showed positive and significant association with plant height, leaf length, leaf diameter, neck thickness, bulb diameter, and biological yield per plant. Path-coefficient analysis revealed that plant height, leaf diameter, neck thickness, and biological yield per plant were the major contributors to bulb yield. These characters should therefore receive priority in developing high-yieldinig onion varieties.
