Drought Tolerance Studies in Rabi Sorghum Sorghum bicolor L Moench Genotypes

Abstract

Sorghum is one of the major staple crops of India and the fifth most important cereal newlinein the world. Drought is a major constraint in sorghum production worldwide and is newlineconsidered as the most important cause of crop growth and yield reduction. Therefore, newlinedevelopment of drought-tolerant genotypes is necessary. This study examined quotDrought newlinetolerance studies in rabi sorghum genotypes.quot The main objective of this study was to newlinedetermine the best drought-tolerant sorghum genotypes. This objective was achieved through newlinesequence of three distinct experiments each conducted independently with sorghum genotypes newlinecollected from AICRP Sorghum, at the College of Agriculture, Dharwad. The initial seed newlinegermination experiment was conducted on sixty sorghum genotypes under poly ethylene newlineglycol (PEG) induced osmotic stress. Increasing PEG levels from 0 to 1% reduced newlinegermination percentage from 77 to 59% due to osmotic stress. SPV-486 showed the highest newlinevigour index II values at 0.5% and 1% PEG (22.44 and 22.17, respectively) and SVD-1358 at newline0% PEG (28.66). Under 1% PEG, genotype M148-138 recorded a lower vigour index II value newline(0.80). Based on their germination and growth performance, twenty sorghum genotypes were newlineselected for subsequent field evaluations. Field experiments were conducted over two rabi newlineseasons (2021-22 and 2022-23) at two moisture regimes (rainfed and irrigated) at the Main newlineAgricultural Research Station (MARS), University of Agricultural Sciences, Dharwad. The newlineperiodic soil moisture content, morpho-physiological, biochemical, and yield observations newlinewere recorded. All parameters, including plant height, leaf area, chlorophyll content, relative newlinewater content, membrane stability index, SPAD value, and yield-related parameters, were newlinenegatively affected by moisture stress. At 60 days after sowing, BJV-44 recorded the highest newlinemean relative water content (84.52%) and M-35-1 recorded the highest mean total chlorophyll newlinecontent (2.962 mg g-1 fresh weight). Among 20 sorghum genotypes, BJV-44 and M-35-1 newlineshowed the least decline