不同类型专用小麦HMW-GS和GMP含量与面筋含量的关系

高分子质量谷蛋白质亚基(HMW-GS)是决定小麦加工品质的重要因子,以25个小麦品种为材料,采用SDS-PAGE电泳方法研究亚基组成、各位点(Glu-A1、Glu-B1、Glu-D1)亚基积累量、谷蛋白大聚合体(GMP)含量及其与面筋含量的关系.研究结果表明:低蛋白小麦品种HMW-GS组成主要以"N、7+8/7+9、2+12"亚基组合为主,高蛋白小麦品种HMW-GS组成则主要以"1、7+8/7+9、5+10"亚基组合为主,中等蛋白小麦品种兼有以上两种类型亚基组合;亚基组成相同的小麦,籽粒GMP含量和蛋白质含量仍有较大差异.相关分析表明,HMW-GS亚基总积累量与籽粒蛋白质含量和GMP含量呈极显著正相关,与干、湿面筋含量成正相关;GMP含量与干、湿面筋含量、蛋白质含量均呈极显著正相关,说明小麦品质类型虽与HMW-GS组成有关,但亚基积累强度不同可能是导致籽粒品质类型差异的重要因素之一.

Relationship between HMW-GS and GMP Contents with Gluten Content in Wheat for Different End Use

Glutenin macropolyer(GMP)consists of high molecular and low molecular weight glutenin subunits(HMW-GS and LMW-GS).HMW-GS plays an important role in exterminating the gluten quality in common wheat.The aim of this study was to analysis the main HMW-GS components,the accumulation of each subunit at different locus(Glu-A1,Glu-B1 and Glu-D1),and GMP content for 25 wheat varieties by using SDS-PAGE,and to study their relationships with gluten content.Results:the components of HMW-GS in wheat grains with low-protein content are usually N,7+8/7+9,2+12',the frequency of subunit pairs N,7+9,2+12 is high;while those with high protein content are usually 1,7+8/7+9,5+10',the frequency of subunit pairs 1,7+8,5+10 is high;and those with medium protein content has the both types of subunit composition.Different wheat genotypes might haye the same subunit components of HMW-GS,but their subunit accumulations are different.GMP and protein content in grains with the same HMW-GS subunits could still be significantly different.HMW-GS accumulation amount is significantly and positively correlated with grain protein as well as GMP content,and positively correlated with gluten content.GMP content has a very significant positive correlation with gluten and protein contents.In conclusion,even though wheat grain quality for different end use is influenced by HMW-GS composition,HMW-GS accumulation amount might play a key role in affecting wheat grain quality.