EFFECTS OF GROWING LOCATION ON RESPONSE OF PROTEIN POLYMERIZATION TO INCREASED NITROGEN-FERTILIZATION FOR THE COMMON WHEAT CULTIVAR SOISSONS - RELATIONSHIP WITH SOME ASPECTS OF THE BREADMAKING QUALITY

A French soft wheat cultivar, Soissons, was grown in 20 locations and treated by the application or various nitrogen fertilizations at diffe rent stages. Phosphate sodium dodecyl sulfate (SDS) extraction and siz e-exclusion high-performance liquid chromatography (SE-HPLC) combined with nitrogen determination were used to quantify different protein po ols according to SDS solubility and apparent molecular site: F-i, F-1, F-2, F-3, and F-4 (glutenin macropolymers, large SDS-soluble polymers [MW > 500 kDa], small SDS-soluble polymers [MW 100-500 kDa], gliadins , and albumins-globulins, respectively). The yields, the quality prope rties, and the amounts of all the protein fractions were affected more strongly by the nitrogen treatment than by the environmental factor, whereas the kernel weight, the protein proportion of three glutenin po lymer fractions (F-i%, F-1%, and F-2%) and (F-1 + F-2)/F-i ratio appea red to be influenced only by the environmental factor. The differences in the distribution between SDS-soluble (F-1 + F-2) and SDS-insoluble glutenin polymers (F-i) resulted in a different contribution to the p otential breadmaking quality properties. These results suggest that th e baking strength of wheat flour is not only determined by the quantit y of total glutenin polymers or macro-polymers, but also by the polyme rization mode and the distribution of polymers between the SDS-extract able polymers and SDS-unextractable polymers. Environmental factors ap pear to be the main origin of the differences in the polymerization mo des and in the polymer distribution.