Changes of Glutenin Subunits due to Water–Nitrogen Interaction Influence Size and Distribution of Glutenin Macropolymer Particles and Flour Quality

Abstract

ABSTRACTThe composition of high‐molecular‐weight glutenin subunit (HMW‐GS) and low‐molecular‐weight glutenin subunit (LMW‐GS) in wheat (Triticum aestivum L.) kernel affects the size of glutenin macropolymer (GMP), which is considered the important flour quality traits in wheat. Three wheat cultivars with different end‐use quality were used to study the effects of water–nitrogen (W × N) management on relative HMW‐GS and GMP contents. Under irrigation, increased N levels promoted the accumulation of HMW‐ and LMW‐GS, GMP content, and the proportion of the larger particle of GMP, with higher yield and better end‐use quality. Under rainfed conditions, increased N fertilizer also increased protein content in the three cultivars. As opposed to ‘Gaocheng8901’, ‘Shannong1391’ and ‘Taishan23’ got higher HMW‐ and LMW‐GS contents and larger GMP particles, but reduced yields of both. Irrigation increased the yield markedly, the N application significantly affected the glutenin, but the W × N interaction was not significant. On one hand, increased N levels improved the dough development time by increasing the numbers of larger GMP particles and enhancing volume and surface area percentages on the other. It was suggested that the interaction was a complicated network and some individual effect might be important. When managing for wheat yield and quality, growers should first consider the water factor, then the N fertilizer factor to improve the end‐use quality of wheat.