THE HIGH-MOLECULAR-WEIGHT GLUTENIN SUBUNIT COMPOSITIONS OF CHINESE BREAD WHEAT-VARIETIES AND THEIR RELATIONSHIP WITH BREAD-MAKING QUALITY

The composition of the high-molecular-weight (HMW) subunits of glutenin encoded by Glu-1 in hexaploid wheat (Triticum aestivum L.) was determined for 99 varieties bred in China. Seventy-nine varieties were homogeneous for HMW glutenin subunit composition. The majority of the remainder were heterogeneous at one Glu-1 locus, with two varieties heterogeneous at two loci. One variety carried a pattern of subunits not encountered in previous studies. The majority of varieties, as in previous studies, carried subunits 7 + 8 or 7 + 9 encoded by Glu-B1. In contrast, there was a relatively high occurrence of subunits 2 + 12 at Glu-D1. It was shown that a high proportion, 69%, of the potential variation in bread-making quality, as assessed by SDS-sedimentation volume, was accounted for by variation in the composition of the HMW subunits.