The association between γ-gliadin 45 and gluten strength in durum wheat varieties: A direct causal effect or the result of genetic linkage?

Abstract

The gliadin proteins of seven durum wheat varieties of diverse origins were analysed by two different two-dimensional electrophoresis techniques. Three of the varieties and biotype A of Duramba, all known to have good pasta cooking qualities, were confirmed to contain a γ-gliadin, usually referred to as band 45, and ω-gliadin band 35. All of these wheats were also shown to contain the same group of low molecular weight (LMW) subunits of glutenin, termed LMW-2. This suggests that genes coding for γ-gliadin 45 and ω-gliadin 35, known to be linked tightly to each other on the short arm of chromosome 1B, are also linked tightly to genes for LMW-2. In similar studies, three other varieties and biotype D of Duramba, all of poor pasta cooking quality, were shown to contain γy-gliadin 42, ω-gliadins 33, 35 and 38 and LMW glutenin subunits, LMW-1. The results are discussed in relation to the identification of those proteins that cause the association between the presence of γ-gliadin 45 and strong gluten in durum wheat varieties.