分蘖期冷水胁迫下施氮量对寒地粳稻氮代谢和籽粒蛋白质含量的影响

Effects of Nitrogen Fertilizing Levels on Nitrogen Metabolism and Grain Protein Content of Japonica Rice in Cold Region under Cold Water Stress at Tillering Stage

以寒地粳稻东农428、龙稻7和松粳10为试验材料,研究分蘖期冷水胁迫下不同施氮量处理对功能叶片氮代谢关键酶活性、籽粒蛋白质含量以及产量的影响,并探讨功能叶片氮代谢关键酶活性与籽粒蛋白质含量以及产量的关系。研究结果表明,分蘖期冷水胁迫使NR,GS活性及籽粒蛋白质含量升高,GOGAT和GDH活性下降。分蘖期冷水胁迫下,增加施氮量使各品种功能叶酶活性及籽粒蛋白质含量均缓慢升高,其中NR、GS和GOGAT活性在N150处理下最高,GDH活性和籽粒蛋白质含量在N175处理下最高,可知,高施氮量不利于寒地粳稻抗冷。不同品种在冷水胁迫下酶活性表现不一,其中耐冷型品种东农428在各处理下氮代谢关键酶保持较高生理活性,龙稻7次之,松粳10最弱。分蘖期冷水胁迫下,纯氮施用量为100 kg/hm2,其产量表现最佳,3个品种表现一致。

We used japonica rice in cold region Dongnong 428, Longdao 7 and Songjing 10 as experimental materials to analyze the effects of nitrogen fertilizing levels on nitrogen metabolism key enzyme activities in functional leaves, grain protein content and yield under cold water stress at tillering stage, as well as analyzing the relationship between nitrogen metabolism key enzyme activities in functional leaves and grain protein content and yield. The results showed that cold water stress at tillering stage increased NR, GS activities and grain protein content, decreased the activity of GOGAT and GDH. Increasing the amount of nitrogen fertilizer slowly raised the enzyme activities in functional leaves and grain protein content of all varieties under cold water stress at tillering stage. NR, GS and GOGAT activities were the highest in N150 treatment, GDH activity and grain protein content were the highest in N175. Therefore, high level of nitrogen was not conducive to cold resistance of japonica rice in cold region. The enzyme activities in different varieties under cold water stress were different. The nitrogen metabolism key enzymes of cold-resistant variety dongnong 428 maintained high physiological activity in each treatment, Longdao 7 was the second, Songjingl0 was the weakest. The yield was the best under cold water stress at tillering stage when the total amount of nitrogen fertilizer application was 100 kg/hm2; the performance of the three varieties was consistent.