不同施氮量对饲料稻糙米蛋白质含量的影响及其机理

Effects and mechanisms of different nitrogen fertilization rate on the protein concentrations of forage rice grains

采用田间小区试验探讨了"氮中量施肥法"(N,P2O5,K2O施用量为190,90,100kg·hm-2)、"氮高量施肥法"(N,P2O5,K2O施用量为210,90,100kg·hm-2)、"氮低量施肥法"(N,P2O5,K2O施用量为170,90,100kg·hm-2)对饲料稻威优198糙米蛋白质质量分数的影响及其机理。结果表明,与氮高量施肥法和氮低量施肥法相比,氮中量施肥法能明显促进孕穗期、乳熟期水稻旗叶中硝酸还原酶,乳熟期旗叶中蛋白水解酶活性,齐穗期旗叶谷氨酰胺合成酶以及齐穗期和乳熟期籽粒中谷氨酰胺合成酶活性,明显促进水稻对氮素营养的吸收与转运,显著提高糙米中蛋白质质量分数和蛋白质质量分数。氮中量施肥法处理糙米蛋白质质量分数分别比氮高量施肥法处理和氮低量施肥法处理提高了1.39%和17.93%,籽粒产量分别提高了12.02%和8.47%,糙米蛋白质产量分别提高了12.54%和18.32%。研究表明,氮中量施肥法能满足饲料稻高蛋白高产栽培的需要。

Plot trials were carried out to study the effects and mechanisms of three nitrogen fertilization rate on the protein concentrations of forage rice （Weiyou 198） grains in 2003. The three N treatments were HN, MN, and LN with the N application rate being 210, 190, and 170 kg·hm^2, respectively; and additional 90 kg·hm^-2 P2O5 and 100 kg·hm^2 K2O were applied in every treatment. Results showed that the activities of nitrate reductase in flag leaves at the booting and milk stage, protease in flag leaves at the milk stage, glutamine synthase in flag leaves at the full heading stage, and glutamine synthase in grains at the full heading and milk stage were significantly higher to improve the absorption and transportation of nitrogen under MN treatment than those under HN or LN treatment. Protein concentrations of forage rice grains, grains yield, protein yield of brown rice in MN treatment was increased by 1.39, 12.02, 12.54%, and 17.93, 8.47, 18.32% compared with that in HN or LN treatment, respectively. So MN treatment was more suitable for high protein forage rice cultivation.