灌浆期短暂高温下减库对小麦籽粒品质的影响

Effects of Halving Spikelet on the Wheat Grain Quality under Short Period of Heat Shock at the middle Stage of Grain Filling

在大田条件下,以强筋小麦品种济麦20为试验材料,研究了灌浆中期短暂高温胁迫(35～39℃)条件下,减库(开花期去除一半小穗)对强筋小麦籽粒千粒重和品质的影响。试验结果表明,高温胁迫下减库处理导致籽粒千粒重、蛋白质含量、单粒蛋白质积累量、湿面筋含量、面团形成时间和吸水率较正常温度和单纯高温胁迫处理显著提高,公差指数和断裂时间下降。同时减库显著降低了淀粉的总含量和支链淀粉含量,使直链淀粉的含量增加,直/支比值显著变大,面粉的稀懈值和峰值黏度降低。这说明提高源/库比使剩余籽粒的氮素供应状况改善,在面团流变学特性方面表现出对灌浆中期短暂高温较强的适应能力,但使籽粒淀粉质量进一步变差。

Selecting wheat cultivar Jimai20 as experiment material, under short period of heat shock （35- 39℃） at the middle stage of grain filling, the effects of halving spikelet on 1000-grain weight and quality of wheat grain were investigated. The results showed that 1000-grain weight, protein concentration, protein accumulation amount per grain, wet gluten content, flour development time and flour water absorption were improved comparing with the treatments of CK and Heat Shock without halving spikelet. Mixing tolerance index and time to breakdown diminished. Meanwhile, the concentration of starch and amylopectin decreased, amylose content and ratio of amylase to amylopectin increased. The breakdown value and peak viscosity of flour diminished. It was indicated that resulting from improved nitrogen supply to the remained grain by halving spikelet, the rheological properties of dough become more resistant to heat shock but the quality of starch was worsen.