LAUSR

Abstract Drought and heat stress during the grain-filling period has been found to significantly alter gluten protein composition in wheat. Reversed phase-high performance liquid chromatography was used to assess the effect of environmental stress conditions (moderate and severe drought and heat stress) on variation of gluten proteins in six durum wheat cultivars with the same high molecular weight (HMW) and low molecular weight (LMW) - glutenin subunit composition. The gliadin fractions were highly affected by genotype, and the LMW glutenins not at all. The LMW glutenins and γ-gliadin were significantly reduced by all stress treatments. The γ-gliadins were highly significantly correlated with dough strength and other alveograph characteristics, and mixograph development time under all growing conditions. All stress treatments caused an increase in α-gliadins. HMW glutenins were significantly and negatively correlated with dough strength under all treatments except severe heat stress conditions. The γ-gliadins showed positive significant correlations with dough strength, alveograph tenacity and mixograph peak time for most treatments. The ω- and α-gliadins had a negative influence on alveograph characteristics, irrespective of the conditions the wheat was grown under.