Influence of genetic and environmental factors on incidence of bolting in short day onions

Abstract

Bolting is the premature flowering malady in bulb crop of onion cultivation. It has detrimental effects on bulb quality and market value. This research aimed to investigate the relationship between genetic predisposition and environmental conditions in relation to bolting in different onion genotypes and hybrids. Findings revealed that, the divergent patterns between the regions of Bengaluru and Bagalkot indicate that weather differences in geographical locations play a significant role in influencing the bolting tendencies of onions. The rabi season exhibited the highest bolting rate (15.09%), surpassing the kharif (0.21%) and summer (1.53%) seasons, emphasizing the role of seasonality in triggering bolting. Interestingly, even under identical environmental conditions, yellow onions demonstrated higher bolting percentage compared to red and white onions, suggesting the presence of genetic variation. This variation could be attributed to disparities in the presence and expression levels of the bolting genes. Collectively, these results highlight the combined influence of genetic and environmental factors, as well as their interactions on onion bolting tendencies.