Response of Wheat Genotypes Stressed by High Temperature in Terms of Yield and Protein Composition Across Diverse Environments in Australia

Abstract

Global climate change poses a significant threat to wheat (Triticum aestivum L.) production due to rising temperatures. This study aimed to investigate the impact of high temperatures on wheat yield, thousand kernel weight (TKW), colour, and protein composition to inform breeding strategies for heat tolerance. Two field experiments were conducted: one at three locations in Australia (Horsham, (Vic) Narrabri, (NSW) and Merredin, (W.A.)) in 2019, involving two wheat varieties (Berkut (high-heat-tolerant) and Sokoll (medium-heat-tolerant)) sown at normal (TOS1) and late (TOS2) sowing times; and a second experiment at Narrabri in 2019 and 2020, involving three wheat varieties (Cobra (heat-sensitive), Flanker (high-heat-tolerant) and Suntop (medium-heat-tolerant)) sown at normal (TOS1) and late (TOS2) sowing times. There were reductions in yield and TKW under high temperatures (p < 0.05), particularly in late sowing conditions. The glutenin/gliadin ratio decreased, affecting dough strength and elasticity, especially at Merredin. Heat-tolerant varieties like Flanker and Suntop maintained protein quality, with an increase in the glutenin/gliadin ratio, under high temperature. These findings highlight the necessity for breeding heat-tolerant wheat varieties that can sustain both yield and quality. Future research should focus on genetic traits for heat tolerance, advanced molecular techniques, and interdisciplinary approaches to ensure sustainable wheat production in a changing climate.

Keywords

• heat stress
• yield
• thousand kernel weight
• protein composition
• glutenins/gliadins ratio