In Vitro screening of tomato genotypes for drought resistance using polyethylene glycol

Abstract

Drought is a major abiotic factor that limits plant growth and productivity. Tomato is an important vegetable crop and area under production is limited by irrigation water scarcity. Effort was made to screen tomato germplasm under in vitro condition using polyethylene glycol (PEG) at four concentrations (0, 20, 40 and 60 g/l) with two replications in factorial CRD. Important seedling characters like root length and weight; shoot length and weight were recorded. Drought resistant mutant derivatives and hybrid produced using mutant derivative as female parent performed significantly superior for root characters. Decrease in seedling growth was worth notice with increasing concentration of PEG indicating precise nature of the in vitro screening. Mutant hybrid and its derivatives were observed with outstanding ability to continue root growth under in vitro stress conditions indicating there ability to fight with sever water stress situation. These results were further confirmed for early indication traits in raised bed seedlings and fully-grown mature plants under field conditions. At all three experimental conditions, mutant derivatives and hybrids performed better than cultivated genotypes under all levels of water stress. Based on results, Hy-3 and MTG 1-4 were found to be drought resistant due to there remarkable performance at all levels of water stress. This in vitro screening method is potential and cost effective method to screen large set of germplasm within very less time period and accurately.