Productivity of sunflower is strongly depended on availability of water and greatest yield losses occur when water shortage occurs at flowering stage. In the present study eleven sunflower (Helianthus Annuus) inbred lines were evaluated under stress and non-stress conditions for sensitivity and resistance to drought. The experiment was laid out in a split plot based on a completely randomized design with three replications. Based on grain yield in the stress and non-stress conditions, drought resistance indices including geometric mean productivity (GMP), stress tolerance index (STI), mean productivity (MP), tolerance index (TOL), harmonic mean (HM), stress susceptibility index (SSI), yield stability index (YSI) and yield index (YI) were calculated for each genotype. High grain yield per plant in non-stress and stress environments was exhibited by genotypes B147 (33.72 g) and R46 (14.2 g), respectively. The maximum value of STI (0.61), GMP (21.32) and HM (19.67) was belonging to genotype R46 and highest value of MP (23.19) was observed for genotype B147. Three dimensional and bi-plot graphs indicated that genotypes B147 and R46 have positive characteristics and are suitable for crossing to produce high yielding as well as drought resistant hybrids. STI, GMP, MP and HM indices showed high correlation with grain yield under stress and non-stress conditions and therefore could be used in breeding program for drought tolerance. SSI index due to ability to separate the sensitive genotype from the others is relatively efficient index for genotypic screening.
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