Abstract:

Drought occurs frequently in northern and waterlogging is common in southern China during the grain filling period and can sometimes last throughout the entire wheat growing season. Depending on the duration of soil drought or waterlogging, the quality of grain formation in wheat can be significantly affected. Previous studies have focused on effects of either drought or waterlogging on grain quality. Therefore, the present experiment was conducted to investigate the simultaneous effects of both soil drought and waterlogging treatments after anthesis on the quality of grain in two wheat genotypes, ‘Xuzhou 26’ and ‘Yangmai 9’, which differ in grain protein content. Three water treatments were utilized from anthesis to maturity: drought (45% to 50% field capacity), waterlogging and moderate soil water status (70% to 80% field capacity). Compared to controls, both waterlogging and drought treatments reduced grain yields and protein yields. The post-anthesis drought increased the protein content of gliadin, whereas waterlogging reduced the accumulation of protein in the grain. Total starch and amylose content in the grain were the highest under waterlogging treatments while the amylopectin content was the highest with CK. Drought increased the content of wet and dry gluten, SDS-sedimentation volume and falling number, whereas waterlogging reduced processing quality of the wheat grain. Drought and waterlogging had different effects on grain protein content, starch content and composition, and flour quality, and thus had different impacts on the quality of wheat. For the strong-gluten wheat cultivar ‘Xuzhou 26’, moderate soil water deficit improved grain quality, whereas for weak-gluten wheat ‘Yangmai 9’, relatively high soil water content favored the quality of grain produced. These results contribute to our understanding of the mechanisms that control the quality of wheat grain produced under soil water stress (drought and waterlogging) and provide a theoretical basis for the production of high quality and high yield wheat.