Genotypic variability in physiological response to deficit water condition in bell pepper (Capsicum annuum L.)

Abstract

Deficit or excess water conditions are the most important factors constraining vegetable crop production all over the world under the scenario of climate change. The present study was conducted to evaluate the physiological response of bell pepper (Capsicum annuum L.) genotypes i.e. Arka Mohini, Arka Gaurav, PBC-848, CHT 3-1 and CHT 3-2 to deficit water stress. Genotypic variability was observed for gas exchange characteristics, chlorophyll (Chl) a fluorescence, water use efficiency and plant water relation (relative water content (RWC), leaf water potential and osmotic potential. Genotypes, Arka Mohini and Arka Gaurav showed higher photosynthetic rate and better plant water relations during stress as compared to other genotypes. A positive relationship between Chl a fluorescence and RWC indicated the involvement of non-stomatal factors towards reduction in PN during deficit water stress. The genotypic differences were observed in pollen germination and root characteristics (root length, root volume and root fresh and dry weights) during stress. The genotypes, Arka Mohini and Arka Gaurav showed better root growth under stress conditions. Deficit water stress resulted in reduction of IAA, DHZR and ZR coupled with ABA accumulation. High levels of auxins and cytokinin- zeatinriboside were recorded in stressed plants of Arka Gaurav, Arka Mohini and CHT 3-2 implying better tolerance to water deficit stress by maintaining higher photosynthesis rate and root development through modulations in phytohormones.