Vegetos

Abstract

Studies on genetic variability, heritability, and inter-relationships between traits in eighteen diverse onion genotypes were carried out during rabi season for both quantitative and qualitative traits. The estimates of phenotypic coefficient of variation (PCV) were greater than corresponding genotypic coefficient of variation (GCV) for all the traits. The proportion of genetic contribution to the overall phenotypic expression of most of the traits was very high. Heritability coupled with high genetic advance for all the traits except polar diameter of bulb is indicative of additive gene action and selection based on these parameters would be more reliable. The genotypic correlation coefficients were higher than their corresponding phenotypic ones for the most of the characters reflecting predominant role of heritable factors Strong phenotypic relationships were found for plant height (r = 0.949), numbers of leaf per plant (r = 0.914), equatorial diameter of bulb (r = 0.674) and marketable bulb weight (r = 0.704) with marketable bulb yield per plot. The present study revealed that all the quality traits (TSS, vitamin C, phenol and pyruvic acid contents) represent either weak or negative association with bulb yield of onion. Out of eleven yield component traits, plant height (0.533) followed by marketable bulb weight (0.457) exhibited highly positive direct effects on bulb yield per plot suggesting to give emphasis on such traits while imposing selection for amenability in bulb yield of onion. Low residual effect (0.140) suggested inclusion of maximum bulb yield influencing characters of onion in the present analysis.