Abstract:

High molecular weight glutenin subunits (HMW-GS) play the major role in determining bread-making quality (BMQ). In this paper, effect of different HMW subunit compositions on bread making quality (BMQ) was evaluated using 10 near isogenic lines and Yanzhan 1 as recurrent parent. The results of correlation analysis showed that the composition of HMW-GS had great impact on bread score, and the variation coefficient between near isogenic lines with different HMW-GS compositions was 21.5%. Bread volume was significantly correlated positively with dough formation time (r = 0.90, P < 0.01), Zeleny sedimentation (r = 0.89, P < 0.01), dough stability time (r = 0.67, P < 0.05) and flour protein content (r = 0.52, P < 0.05). Therefore, bread score was significantly correlated positively with bread volume (r = 0.98, P < 0.01), Zeleny sedimentation (r = 0.93, P < 0.01), and dough formation time (r = 0.89, P < 0.01). The results of BMQ tests indicated that the expression of 1Ax1 at Glu-A1 locus could improve BMQ in most lines. Contribution of alleles at Glu-B1 to BMQ was 7+8>14+15>6+8>7 in lines with Null at Glu-A1and 5’+12 at Glu-D1. However, it was 6+8>14+15> 7 in the lines with 1 at Glu-A1 and 5’+12 at Glu-D1. When Null was at Glu-A1, lines with 14+15 and 5+10 subunits were slightly better than those with 14+15 and 5’+12. In addition, lines with 7+8 and 5’+12 were much better than those with 7+8 and 5+10. Compared to the 5+10 lines, silence of 1Dx5 caused significant BMQ decline. Therefore, it seems that there is complementary effect between X-type and Y-type of HMW-GS on BMQ, either absence will cause decline of BMQ.

Key words: Wheat, HMW-GS, Near isogenic lines, Bread making quality, Complementary effect