Abstract An experiment was conducted to evaluate 75 diverge genotypes of onion during rabi season for genetic variability, heritability and genetic advance. Analysis of variance revealed that mean squares due to genotypes were significant for all the 12 characters. The values of phenotypic coefficients of variation (PCV) were slightly higher than that of genotypic coefficients of variation GCV) for most of the traits studied indicating less effect of environment on the expression of characters studied. GCV and PCV for bolting and double onion bulb were high. This indicated the presence of wide genetic variation for these characters. High heritability (broad sense) estimates were found for bolting, double onion bulb per plot, neck thickness of bulb, pseudo stem length and TSS of bulb. Genetic advance expressed as per cent of mean was high for bolting and double onion bulb, whereas the values with moderate magnitudes were observed for number of leaves per plant, bulb weight, neck thickness of bulb, pseudo stem length, bulb equatorial diameter and bulb yield per plot.
Keywords Genetic variability, heritability, GCV, PCV, genetic advance, onion.