灌浆成熟期氮素营养对水稻增产及淀粉品质的影响

选用4个直链淀粉含量差异显著的粳稻品种,研究齐穗期施氮肥对水稻产量性状、籽粒蛋白质含量和淀粉RVA谱特性影响,以及米粉蛋白质水解处理对淀粉RVA谱特性影响。结果表明,齐穗期施氮肥可显著或极显著提高稻谷千粒重、成熟度和结实率及稻米蛋白质含量,降低直链淀粉含量,增减幅度因品种不同而异;齐穗期施氮肥可极显著降低高直链淀粉含量品种最高黏度、最低黏度、最终黏度及下降黏度值,而低直链淀粉含量品种为与之相反极显著增加,黏滞峰消减值既有极显著增加品种,也有极显著降低和无变化品种;蛋白质含量有极显著差异的米粉被碱水处理后蛋白质含量均降低到2.48%~2.64%,施粒肥与否水解处理后供试材料间米粉蛋白质含量均无显著差异;施粒肥与否去除稻米蛋白质可极显著增加米粉最高黏度和下降黏度值,并极显著降低粘滞峰消减值、最低黏度、最终黏度,其中下降黏度值增加幅度和粘滞峰消减值降低幅度较大,且低直链淀粉含量品种变化幅度比高直链淀粉含量品种大。

Effect of grain-filling nitrogen on yield increasing and starch quality in rice

Four japonica varieties with different amylose content were used to investigate the effect of nitrogen nutrition on rice yield and protein content as well as starch RVA properties and the effect of protein hydrolysis on starch RVA properties during grain-filling stage.The results showed that at filling stage,nitrogen application could increase the thousand seeds weight,maturity,setting percentage and protein content to significant or extremely significant level,and also could reduce the amylose content in different varieties;In addition,nitrogen application could decrease the highest viscosity,the lowest viscosity,final viscosity and breakdown value in high amylose content varieties.However,the properties were opposite in low amylose content varieties.Setback viscosity was different in different varieties.The protein content of rice flour with significantly different protein content was reduced to 2.48％-2.64％ after alkaline treatment.Whether grain fertilizer was applied or not,rice protein content were similar in selected materials after alkaline treatment,and degradation of grain protein could significantly increase the highest viscosity and breakdown value,extremely significantly reduced the lowest viscosity,final viscosity and setback value,especially the range of breakdown value and setback value were larger which is more significant in the varieties with low amylose content than that in high amylose content varieties.