Determination of drought tolerance related traits in , , and their hybrids.

Drought is a major constraint for sunflower () production worldwide. Drought tolerance traits have been identified in the related wild species . This study was initiated to develop sunflower drought-tolerant genotypes by crossing cultivated sunflower with this species and analyze drought tolerance traits in the and populations, intraspecific hybrids, and × interspecific hybrids along with the commercial hybrid Hysun-33 under three stress regimes: exogenous application of ABA, both by foliar spray and irrigation, and 5% PEG-induced osmotic stress. populations had a significantly lower leaf area and higher water-use efficiency and leaf cuticular wax content under all treatments, and maintained a higher net photosynthetic rate and stomatal conductance under osmotic stress. Small leaf area and high cuticular waxes content of the wild species were, however, not inherited in interspecific hybrids which suggested for selection in F for these traits. Therefore, transgressive plants were selected in the F population to establish F plant progenies with silver-leafed canopy of which showed higher achene yield under stress condition. These results are discussed with a view to using to improve drought tolerance in cultivated sunflower.