ABSTRACT

The present investigation on “Genetic variability and diversity studies in white onion (Allium cepa L.) genotypes” was undertaken at Main Agricultural Research Station, UAS, Dharwad during late kharif season of 2023-24. Twenty-six genotypes were evaluated in randomized block design with three replications. Data on growth, yield, quality, storage parameters and pest and disease severity were recorded in white onion genotypes. These data were subjected to analysis for variability, genetic divergence, correlation coefficient and path analysis.
By considering overall mean performances on growth, yield, quality, storage, pest and disease severity, the genotypes like Safed Ghavriyu, Indus WG-5, Bhima Safed and Gadag Local were found promising once. Hence, these genotypes can be utilized for further crop improvement programmes. The analysis of variance revealed significant differences for all the characters indicating existence of ample variability among the genotypes. High heritability estimates coupled with high genetic advance was recorded for marketable yield (t/ha), purple blotch incidence and total yield revealed the presence of additive gene action in expression of these characters.
The D2 analysis revealed that genotypes showed significant diversity and were grouped into six clusters. The highest inter cluster distance exist between cluster II and VI. Genotypes from these clusters can be utilized as parents in breeding programme for obtaining superior recombinants. Character association studies revealed that traits like plant height, number of leaves, leaf length, bulb diameter, fresh weight of plant, average bulb weight, harvest index, neck diameter and dry weight of plant exhibits positive and significant correlations with onion bulb yield. Path coefficient of analysis of plant height, leaf number and bulb diameter had high positive and direct effect on bulb yield ton per hectare.