Morphological, physiological and yield responses of durum wheat to pre-anthesis water-deficit stress are genotype-dependent

Abstract

Durum wheat production in southern Australia is limited when water deficit occurs immediately before and during anthesis. This study was conducted to determine the effect of genotypic variation on various yield, morphological and physiological responses to pre-anthesis water-deficit stress by evaluating 20 durum wheat (Triticum turgidum L. ssp. durum) genotypes over 2 years of glasshouse experiments. Grain number was the major yield component that affected yield under pre-anthesis water-deficit stress. Genotypes with less yield reduction also had less reduction in chlorophyll content, relative water content and leaf water potential, suggesting that durum genotypes tolerant of water-deficit stress maintain a higher photosynthetic rate and leaf water status. Weak to moderate positive correlations of morphological traits, including plant height and fertile tiller number, with grain number and biomass make the evaluation of high-yielding genotypes in rainfed conditions possible. Morphological traits (such as plant height and tiller number) and physiological traits (such as chlorophyll content, relative water content and leaf water potential) could therefore be considered potential indicators for indirect selection of durum wheat with water-deficit stress tolerance under Mediterranean conditions.