Genetic Analysis and Character Association in Different Genotypes of Onion (Allium Cepa L.)

Analysis of variance revealed highly significant difference among the genotypes for all the characters studied which was highest for total bulb yield among all traits under study. High PCV and GCV higher were observed for B grade bulbs, unmarketable bulb yield (q ha⁻¹), marketable bulb yield (q ha⁻¹), total bulb yield and bulb yield plant⁻¹. High heritability supplemented with high genetic advance as a percentage of the mean was manifested by bulb yield plant⁻¹ and total yield (q ha⁻¹). The association study resulted that the advantages of upgrading onion genotypes through simultaneous selection for equatorial diameter, followed by polar diameter, the number of leaves plant⁻¹ at90 DAT, neck thickness, plant height at 90 DAT and TSS. Path coefficient analysis revealed that polar diameter had highest positive direct effect followed by plant height at 60 DAT, TSS, plant height at 90 DAT, the number of leaves plant⁻¹ at 90 DAT and polar: equatorial diameter were the most important traits contributing towards bulb yield plant⁻¹. Direct selection of equatorial diameter, neck thickness, days to maturity, the number of leaves plant⁻¹ at 30 and 60 DAT and plant height at 30 DAT should be avoided instead of indirect selection. The highest production observed in genotype OSR-1344 and Agrifound Light Red. Low incidence percentage of stemphyliumblight was found in genotype ON14–06 incidence percentage of thrips was found in genotype ON14–15. Considerable variability was observed among the genotypes for foliage character, bulb shape, bulb colour and bolting tendency. Foliage color in green onion and shape and colour of onion bulb are most important characteristics to help customers in choosing cultivars in the market.

31 diverse genotypes of onion were selected for the study of genetic variability, correlation and path analysis.

Highest PCV and GCV was observed for B grade bulbs, unmarketable bulb yield (q ha⁻¹), marketable bulb yield (q ha⁻¹), total bulb yield and bulb yield plant⁻¹.

The association estimated higher for equatorial diameter, and polar diameter had the highest positive direct effect.

The highest production observed in OSR-1344 and Agrifound Light Red. Low incidence % of stemphylium blight was found in ON14–06 incidence %of thrips was in ON14–15.