The Value of Sedimentation Test in the Prediction of Breadmaking Quality of Wheat and Determination of its Variability Through Analysis of Glutenin Subunits by RP-HPLC

In order to evaluate the relationship between SDS-sedimentation value and breadmaking quality of wheat (Triticum aestivum L.), glutenin subunits of different genotypes (foreign and Iranian cultivars) were analyzed by reverse-phase high performance liquid chromatography (RP-HPLC). SDS-sedimentation value was used as an indirect criterion for breadmaking quality. Correlation coefficients revealed a closer relationship between low molecular weight (LMW) glutenin subunits and variation in SDS-sedimentation value. Principal component analysis confirmed the presence of association between some of the glutenin subunits and SDS-sedimentation value. Based on the stepwise regression analysis, two LMW and four high molecular weight (HMW) peaks (subunits) were selected which accounted for 70.2 and 18.7% of variability in SDS sedimentation values, respectively. On the basis of the results of the stepwise regression analysis, a discriminant function was developed. The great efficiency of discriminant function in correct classification of completely different genotypes (Iranian landraces and cultivars) showed that the observed relationship between glutenin subunits and SDS-sedimentation value has a genetic basis and the effects of LMW and HMW glutenin subunits on SDS-sedimentation value are additive. Therefore, it seems that this method based on more protein components (rather than only on HMW glutenin subunits) can be used to predict breadmaking quality of wheat against many genetic backgrounds.