Association of high and low molecular weight glutenin subunits with dough strength in durum wheats (Triticum turgidum ssp. turgidum L. conv. durum (Desf.)) in southern Australia

Abstract

A large set of durum wheat lines (79 including 8 advanced Australian breeding lines) randomly collected from 11 countries and 11 bread wheat cultivars were grown in replicated trials at 2 field locations to compare yield and gluten quality. Gluten strength, as measured by the sodium dodecyl sulfate (SDS)-sedimentation (SDSS) test, varied considerably among the durum lines and was associated with the presence of specific glutenins. Unlike some previous reports, the present study showed that durum wheat cultivars having the high molecular weight (HMW) glutenin subunits coded by Glu-B1 genes such as 13 + 16 and 7 + 8 were highly correlated with improved dough strength, which was consistent with the effect of HMW glutenin subunits on dough quality in bread wheat. Cultivars having the low molecular weight (LMW) glutenin allele LMW-2 (or gliadin band r-45) generally gave stronger gluten than lines with allele LMW-1, as reported by earlier workers. The LMW pattern LMW-IIt gave the strongest glutenin. The combined better alleles at Glu-B1 (coded bands 13 + 16, 7 + 8 v. 6 + 8, 20) and Glu-3 (patterns LMW- II, LMW-IIt v. LMW-I) showed linear cumulative effects for dough strength. All the durum lines studied had lower SDSS values than the bread wheat controls (45.8 v. 76.2 mL), though durum wheats tended to possess higher grain protein concentrations (14.0 v. 11.9%) and gave lower grain yield than bread wheat. The Australian advanced lines had higher yield and better dough strength than durums from other countries except those from CIMMYT. The Australian lines also had 1-1.5% higher protein concentration and equal or better grain yield than the bread wheat, suggesting that these lines had potential for commercial use.