水稻对硝态氮响应的生理指标筛选

SCREENING OF PHYSIOLOGICAL INDICES FOR RESPONSE OF RICE TO NITRATE

采用温室水培试验方法 ,系统评价了 4 0个遗传特性不同的水稻品种对 3种比例氮营养(NH+ 4 /NO-3 比例分别为 10 0∶0、5 0∶5 0和 0∶10 0 )的反应和对硝态氮响应的生理指标筛选。结果表明 ,4 0个水稻品种 (系 )在NH+ 4 /NO-3 比为 5 0∶5 0的营养液中生长最佳 ,植株总干重最高 ,但各个基因型的表现差异较大。根据水稻在两种比例氮营养液 (10 0∶0和 5 0∶5 0 )中的表现可将水稻分为 3种类型 :硝高度响应型、硝中度响应型、硝不响应型。在混合氮营养液中硝高度响应型水稻地上部干重、根干重、总干重和氮积累量显著比单一铵营养液中的高。在评价不同水稻基因型对硝营养的响应时 。

Rice is one of the main crops in China and needs a lot of nitrogen fertilizer to ensure high yields Thus, nitrogen take up and utilization efficiency by rice is an important issue in agricultural production Due to inhibited nitrificaton in the bulk soil of lowland rice field, researches on nitrogen nutrition of rice mainly focus much more on ammonium (NH + 4) than on nitrate (NO - 3) Much evidence has shown that rice can take up not only NH + 4 N but also NO - 3 N, but is different in capacity which varies with its genotype The responses of rice to different nitrogen forms and their physiological effects are poorly understood Hydroponic culture experiments were carried out to study the response of rice to different nitrogen forms (NH + 4/NO - 3ratios of 100∶0, 50∶50, and 0∶100) Best growth of rice plants of all genotypes tested was found in the mixed solution of NH + 4 and NO - 3 but crops different in genotypes responded differently Based on the rice growth in two nitrogen solutions, i.e., NH + 4/NO - 3ratios of 100∶0 and 50∶50, the 40 varieties of rice tested could be divided into three groups, such as high response to NO - 3, intermediate response to NO - 3 and non response to NO - 3 Rice with high response to NO - 3 had much higher root dry weight and nitrogen accumulation in the mixed solution of ammonium and nitrate than in the single ammonium solution Thus, the root dry weight and nitrogen accumulation could be used as physiological indices for screening rice of genotypes with different responses to nitrate