Screening of Sunflower Genotypes for Drought Tolerance Based on Certain Morpho-Physiological Parameters

A study was conducted to screen twenty nine sunflower genotypes for tolerance to drought under field conditions based on morpho - physiological characteristics. Moisture stress treatment was imposed at flower bud initiation stage (irrigation withheld for 20 days from 40 DAS to 60 DAS) where as, control plots were irrigated at 10 days intervals throughout the crop growth period. Results revealed that water stress showed repressing effect on plant height, total leaf area, SPAD chlorphyll meter reading, chlorophyll fluorescence (Fv/Fm), total dry matter weight at harvest, capitulum diameter per plant, capitulum weight per plant, seed yield per plant, drought susceptibility index and harvest index. However, genotypic variation was significant for characters studied. Based on drought susceptibility index and various morpho- physiological traits, eight genotypes viz., TSF-103, RSF-107, TSF-106, ASF-104, DSF-104, SH- 491, RSF-106 and DSF-111 were selected as promising lines under water limited situation. These lines may further be used in stress physiology studies and drought resistance breeding.