The effects of nitrogen nutrition and glutenin composition on the gluten quality in wheat genotypes

The effect of nitrogen nutrition treatments on the gluten content and some quality parameters of eight winter wheat cultivars has been studied. Six different nitrogen rates were applied (0, 60, 90, 120, 150 and 180 kg N ha-1) to wheat cultivars chosen according to the structure of their high molecular weight glutenin subunits (HMW-GS) at the Glu-D1 locus. Four genotypes with HMW-GS 2 + 12 and another four with HMW-GS 5 + 10 were used in the study. The analysis of gluten quality involved the wet gluten content and rheological properties determined by the sensory and instrumental methods (“Instron 4301”). It was determined that in all the cultivars the wet gluten content increased significantly (P < 0.05) in parallel with N rate increase. The cultivars reacted differently regarding their wet gluten rheological properties. Libellula, a cultivar with poor bread making quality (HMW-GS 2 + 12), did not react to different N rates. Sremica, a cultivar with excellent bread making quality (HMW-GS 5 + 10), reduced its gluten quality as the N rate increased. The values obtained by the instrumental method “Instron 4301” at 90% wet gluten compression varied widely (from 0.002 to 0.041 kN). The increase of N fertilizer rate was significantly positively correlated (r2 = 0.811) with the wet gluten content and strength in the cultivars with HMW-GS 5+10.