Studies on Genetic Variability, Heritability and Genetic Advance in Onion (Allium cepa L.) Genotypes

The experimental material for the present investigation was comprised of 38 genotypes of onion. These genotypes were sown in Randomized Complete Block Design with three replications, to estimate the genetic variability, heritability and genetic advance. Observations were recorded on the basis of ten random competitive plants selected from each genotype separately for morphological, yield and quality parameters were evaluated as per standard procedure. Analysis of variance revealed highly significant variance for all the traits depicting greater variability in the existing material. The mean performance of the genotypes revealed a wide range of variability for all the traits. The variation was highest for bulb yield per hectare followed by bulb yield per plant, plant height at 90 DAT, plant height at 60 DAT, plant height at 120 DAT, plant height at 30 DAT, days to maturity and bulb yield per plot. The PCV was higher than the GCV for all the characters. High PCV and GCV was observed for bulb yield per plant, neck thickness and pseudostem diameter,indicating greater diversity for these traits and their further improvement through selection. High heritability supplemented with high genetic advance as percentage of mean was manifested by bulb yield per plant followed by neck thickness, pseudostem diameter, polar diameter of bulb, number of leaves per plant at 120 DAT, pseudestem length, plant height at 120 DAT and equatorial diameter of bulb suggested that they can be improved through direct selection. Considerable variability was observed among the genotypes for foliage colour, foliage cranking, bulb shape and bulb colour. Foliage colour in green onion and shape and colour of onion bulb are most important characteristics to help customers in choosing cultivars on the market.