The high-molecular-weight glutenin subunit compositions of Chinese bread wheat varieties and their relationship with bread-making quality

Abstract

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-I 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-BI . In contrast, there was a relatively high occurrence of subunits 2 + 12 at Glu-Dl. It was shown that a high proportion, 69%, of the potential variation in bread-making quality, as assessed by SDSsedimentation volume, was accounted for by variation in the composition of the HMW subunits .

The Chinese bread wheat cultivar Xiaoyanmai 7 harbours genes encoding a pair of novel high-molecular-weight glutenin subunits inherited from cereal rye

“…The origin of the unusual HMW-GS in the Xiaoyanmai 7 endosperm was not resolved in an earlier study (Wang et al 1993), but the present experiments have shown unequivocally that they could not have been inherited from A. elongatum, a species that is represented in the pedigree of this cultivar. Instead, the evidence, based on a variety of assays, strongly implicated cereal rye as the progenitor.…”

“…A major survey of the HMW-GS composition in Chinese bread wheat germplasm has identified an unusual profile in the cultivar Xiaoyanmai 7 (Wang et al 1993). A suggestion, based on pedigree information, was that the origin of the genes encoding these unusual HMW-GS was the wheat close relative Agropyron elongatum.…”

Effect of High‐Molecular‐Weight Glutenin Subunit Allelic Composition on Wheat Flour Tortilla Quality

“…In fact, Lukow et al (1989) reported that almost all wheat lines encoding 2 + 12 at Glu-D1 had poor breadmaking quality and that subunit 5 + 10 was needed at this locus to provide adequate gluten strength for bread. Wang et al (1993) observed that within Glu-1, composition at subunits A1 and D1 accounted for the majority (≈86%) of variations in gluten strength as measured by a microsedimentation test. In our study, it was clear that the Glu-D1 allele encoding subunits 2 + 12 was a major contributor to desirable tortilla quality.…”

“…Thus, all wheat groups encoding for 2 + 12 at Glu-D1 produced good quality tortillas. Presence of 2 + 12 at Glu-D1 has been reported to weaken dough strength relative to 5 + 10 at the same domain (Lukow et al 1989;Wang et al 1993). In fact, Lukow et al (1989) reported that almost all wheat lines encoding 2 + 12 at Glu-D1 had poor breadmaking quality and that subunit 5 + 10 was needed at this locus to provide adequate gluten strength for bread.…”

“…Thus, it seems that wheat lines expressing 2 + 12 alleles at the Glu-D1 locus provide a more likely viable target for tortilla production than the lines encoding for 5 + 10 at Glu-D1, which are more suitable for bread. With the relatively high frequency of occurrence of the 2 + 12 subunits at Glu-D1 reported in the world wheat collection (Lukow et al 1989;Morgunov et al 1990;Kolster et al 1991;Wang et al 1993), it is likely that development of specialty wheat lines targeting tortillas (and possibly other flatbreads) adaptable to various regions is possible. However, in this study we did not identify a definitive wheat protein compositional attribute that was a good predictor of tortilla quality.…”