小麦Glu-1位点变异和1B/1R易位对谷蛋白亚基表达量和面包加工品质的影响

Effect of Allelic Variation at the Glu-1 Loci and 1B/1R Translocation on the Quantity of Gluten Protein Fractions and Pan Bread Making Quality in Common Wheat

选用北方冬麦区近年来育成的优质强筋品种及山东省主栽品种共42份,采用反相高效液相色谱法(RP-HPLC)和凝胶色谱法(SE-HPLC)对小麦贮藏蛋白组分进行量化,分析了不同高分子量谷蛋白亚基(HMW-GS)组成对其表达量、面团流变学特性和面包加工品质的影响。结果表明,Glu-D1位点对谷蛋白亚基含量和加工品质的加性效应最大,达5%显著水平,贡献率为28.5%～71.3%。在Glu-A1和Glu-D1位点,单个亚基对谷蛋白亚基含量和加工品质的贡献分别为1>2*>N和5+10>2+12>4+12,而在Glu-B1位点,则表现为差异不显著。不同亚基组合的HMW–GS表达量差异达5%显著水平,相同亚基组合的品种间贮藏蛋白组分表达量的变异较大,亚基表达量的差异可能是导致品种间品质差异的重要原因。1B/1R易位显著降低LMW-GS、谷蛋白总量和%UPP,导致加工品质变劣。选择具有优质亚基组合,且谷蛋白亚基表达量高的类型,是有效改良面筋强度,进一步提高优质新品种选育的有效途径。

Composition and quantity of gluten protein fractions play an important role in determining the processing quality in common wheat. Wheat varieties with over-expression of HMW glutenin subunit produced very strong and extensible dough. Thus it is very important to understand the relationship between the quantity of gluten protein fractions and dough properties, and pan bread making quality, In this study, 42 wheat genotypes including newly released high quality cultivars and advanced lines in Northern China Winter Wheat Region and leading cultivars in Shandong province were grown in Jinan in 2005-2006 cropping season. Reversed-phase high-performance liquid chromatography （RP-HPLC） and size-exclusion high-performance liquid chromatography （SE-HPLC） were used to analyze the relationship between the quantity of gluten protein fractions and different storage protein compositions, dough properties, and pan bread making quality. The results showed that Glu-D1 locus had the largest effect on the quantity of gluten protein fractions and pan bread making quality in all loci studied, accounting for 28.5%-71.3% of the variation （P〈0.05）. According to individual glutenin subunit contribution to the expression quantity of gluten protein fractions and pan bread making quality, different glutenin subunit loci could be ranked as： 1〉2^＊〉N at Glu-A1; no significant differences at Glu-B1; and 5＋10〉2＋12〉4＋12 at Glu-D1. Quantity of HMW-GS was significantly different at various loci （P〈0.05）, and expression quantity of gluten protein fractions showed broad variation among genotypes with the same HMW-GS composition. It indicated that the difference of gluten expression quantity could be an important factor resulting in quality difference in wheat cultivars. 1B/1R translocation caused a significant decrease in expression quantity of LMW-GS, gluten content and %UPP, and showed poor pan bread making quality. Both desirable protein composition and high expression quantity are needed to be considered for efficiently improving dough quality.