Abstract:

Correct identification of high molecular weight glutenin subunits (HMW-GS), and clarify their effects on wheat dough properties are very important in wheat (Triticum aestivum L.) quality study. Sixty-two cultivars or lines were used in present study to identify the composition of HMW-GS by SDS-PAGE and reversed-phase high-performance liquid chromatography (RP-HPLC). The results showed that combination of SDS-PAGE and RP-HPLC can effectively identify the composition of HWM-GS in Glu-B1 loci, especially for Glu-B1(7+8). Thirteen sib lines were used to study the effect of Glu-B1al (7^OE+8*) and protein fractions on wheat quality properties related to dough strength by RP-HPLC and size-exclusion high-performance liquid chromatography (SE-HPLC). The results showed that sib lines with Glu-B1al (7^OE+8*) significantly increased the quantity of HMW-GS, thus significantly improved dough strength, which could be used as high quality subunits in improving wheat gluten strength. Correlation analysis showed that the quantity of total glutenin, HMW-GS, LMW-GS and x-HMW were highly and positively correlated with extensograph maximum resistance (Rmax) with r of 0.76, 0.76, 0.77 and 0.72 (P＜0.01), respectively. The relative content of SDS-unextractable glutenin polymeric protein (UPP percentage) were highly and positively correlated with mixograph development time (MDT), farinograph development time (DT) and stability (ST), and Rmax with r of 0.77 (P＜0.01), 0.90 (P＜0.001), 0.89 (P＜0.001) and 0.87 (P＜0.001) , respectively. The ratio of gliadin to glutenin in quantity was negatively and significantly correlated with MDT, ST and Rmax with r of -0.69 (P＜0.01), -0.58 (P＜0.05) and -0.64 (P＜0.05) , respectively. HPLC is a useful tool for wheat quality breeding.

Key words: Common wheat, Glutenin, Glu-B1 loci, SDS-PAGE, RP-HPLC, SE-HPLC