Effects of different fertilization levels on the concentration of high molecular weight glutenin subunits of two spring, hard red bread wheat cultivars

Abstract

Backgrounds and objectives: High molecular weight gluten subunits (HMW-GS) are generally considered to play a key role in gluten formation and structure and are closely related to wheat quality. In this study, two spring wheat cultivars (PAN3497 and SST806) with the same HMW-GS composition (1Ax1, 1Bx7, 1By8, 1Dx2, and 1Dy12) were tested in the greenhouse, over 2 years, in order to determine how different genetic backgrounds, and low-nitrogen and low-phosphorus treatments, influenced the expression and quantity of the HMW-GS, as measured by reverse-phase high-performance liquid chromatography (RP-HPLC). Findings: Cultivar effect was highly significant for all HMW-GS, except for 1By8. A large treatment effect was found on subunits 1Ax1, 1Dy12, and 1By8. Cultivar-by-treatment interaction was highly significant and contributed to variation of subunit 1Dx2. Subunits 1Dy12 and 1By8 were highly influenced by low-N conditions. Ratio of HMW-GS x type/y type was higher for PAN3497 than for SST806. Furthermore, a strong treatment effect was observed for the ratio of x type/y type, which was 45% higher in PAN3497 under optimal and low-N conditions, compared to SST806. Conclusions: This study showed that fertilization level had a considerable effect on HMW-GS composition and on FPC, with low-N conditions having the largest influence, followed by a combination of low N and low P. Significance and novelty: The results highlighted the importance of the y-type subunits in the bread wheat quality breeding programs, especially under low-N and low-P growing conditions.