Relationship between Composition of High molecular weight Glutenin Subunits and Breadmaking Quality

Composition of high molecular weight glutenin subunits (HMW GS) and their content, sedimentation value and flour glutenin macropolymer (GMP) content of 163 Chinese wheat cultivars from nine major wheat growing provinces and 11 cultivars introduced from abroad were determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). Different HMW GS as well as their composition had different effects on wheat quality significantly. Some HMW GS affected the quality of Chinese wheat cultivars quite differently from that of foreign cultivars, for instance the effect of subunits 4+12 was greater and 7+8 smaller, but both individual subunit quality score and cultivar Glu 1 quality score were correlated to all quality parameters significantly. Therefore, the quality scoring system of Payne et al . can be used in breeding programme. However, it might be more effective if the system was adjusted according to Chinese cultivars. Although more and more cultivars possessed desirable HMW GS, Chinese cultivars still possessed relative poorer quality and lower Glu 1 quality scores as a whole. Therefore, increasing frequencies of desirable subunits such as 5+10, 13+16 and 17+18, may be one of the most effective measures to improve breadmaking quality of Chinese wheat.