Complementary Effect of High-Molecular-Weight Glutenin Subunits on Bread-Making Quality in Common Wheat

In this study, 10 near isogenic lines (NILs) of wheat (Triticum aestivum L.) cultivar, Yanzhan 1, was developed, which differ from alleles at Glu-A1, Glu-B1, and Glu-D1 loci. The effects of various HMW subunit compositions on bread-making quality (BMQ) were evaluated using these NILs in two-year harvests. Bread-making tests indicated that the expression of 1Ax1 at Glu-A1 locus improved BMQ to most of the lines. The allelic contribution to BMQ at Glu-B1 locus was in the order of 7+8 > 14+15 > 6+8 > 7 when Null was expressed at the Glu-A1 locus and subunits 5′+12 expressed at the Glu-D1 locus. However, the order of allelic contribution was 6+8 > 14+15 > 7 when subunit 1 and subunits 5′+12 were expressed at the Glu-A1 and Glu-D1 loci, respectively. Given the Null at Glu-A1 locus, lines with subunit pairs 14+15 and 5+10 were slightly better than those with subunit pairs 14+15 and 5′+12. Interestingly, the NILs possessing subunit pairs 7+8 and 5′+12 showed much better BMQ than the NILs with subunit pairs 7+8 and 5+10. Compared to the 5+10 lines, silencing of 1Dx5 resulted in significant reduction of BMQ. Therefore, there is a complementary effect between x-type and y-type of HMW-GS on BMQ and the absence of either type will degrade BMQ notably.