Effect of multiple substitution of glutenin and gliadin proteins on flour quality of Canada Prairie Spring wheat

The effect of genetic substitution of two to four glutenin and gliadin subu nits from a Canada Prairie Spring (CPS) cv. Biggar BSR into Alpha 16, anoth er CPS wheat line, was studied for rheological and baking quality. Results from double substitution showed that the presence of a gliadin component fr om Biggar BSR (BGGL) and low molecular weight glutenin subunit 45 (LMW 45) contributed to improved dough strength characteristics. Presence of BGGL in combination with high molecular weight glutenin subunit I (HMW 1) or 17+18 (HMW 17+18) also showed improved dough strength over control Alpha lines. When three or four protein subunits were substituted, even though improved quality performance was observed, it was associated with the negative effec t of lowered flour water absorptions in spite of similar protein contents. The study confirms that LMW glutenins, as well as gliadins, play an importa nt role along with HMW glutenins in wheat flour quality. CPS wheat lines wi th improved dough strength properties can be selected from the double subst itution lines with the combination of BGGL/LMW 45 and BGGL/HMW 1.