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.