Biochemical and yield evaluation of onion (Allium cepa L.) genotypes under waterlogging condition

Abstract

The present investigation entitled “Biochemical and yield evaluation of onion (Allium cepa L.) genotypes under waterlogging condition” was carried out at ICAR-Directorate of Onion and Garlic Research, Rajgurunagar, Pune (Maharashtra). Onion crop is extremely sensitive to waterlogging or soil flooding stress due to its shallow root growth habit. The climate change and rainfall distribution pattern most of the onion growing belt might be subjected to heavy rainfall leading to soil flooding condition and cope up with such situation need to identify the improved onion genotypes with better adaptive traits and tolerance for waterlogging condition Therefore, the main objective of the present study was screening of elite genotypes for water logging tolerance under pot condition. The experiment was laid out in factorial CRD for pot condition during kharif, 2018. The pot experiment was conducted in rainout shelter using plastic pot and plants were treated with creating artificial waterlogging condition with the help of tank pit and another set were kept outside in rainout shelter as control. The experimental materials comprises of 17 onion entries including red and white onion entries. The seedlings of each entry were raised from seeds in nursery for 45 days with recommended cultural practices and transplanted in pot. The biochemical traits leaf antioxidant, leaf flavonoids and phenol content exhibited maximum in genotype RGP 5 under waterlogging condition. The waterlogging condition was increased quality traits which producing more secondary metabolites for defense strategy of the plant. Further, the yield attribute like bulb yield percent was minimum decreased in genotype RGP 5 with the percent reduction of 18.59% and the genotype W 344 recorded maximum percent reduction with decline by 83.49% under water logging treatment. It may due the water logging condition inhibits the translocation of assimilates from source organs to sink organ. Therefore, on the basis of overall yield reduction percentage and other important traits, genotype RGP 5 can be categorized as water logging tolerant genotypes, whereas genotype W 344 and W 448 recognized as water logging sensitive genotypes among all the tested onion genotypes.