优质粳稻南粳5818氮高效机制初探

Preliminary study on the nitrogen efficiency mechanism of high quality japonica rice Nanjing 5818

探索水稻氮肥吸收利用分子机制对选育氮素高效利用水稻品种有着重要意义。本研究选用优质粳稻品种南粳5718和南粳5818为试验材料,设置低氮处理(150 kg/hm^(2))、中氮处理(300 kg/hm^(2))、高氮处理(450 kg/hm^(2))和不施氮对照,分析两个粳稻品种氮素利用率的差异及其分子机制。结果表明,南粳5818的氮肥农学利用率、氮素回收率和光合氮素利用率均高于南粳5718。随着施氮量的增加,南粳5718和南粳5818的氮肥农学利用率呈下降趋势。南粳5718和南粳5818的氮素利用相关基因OsNRT1.1B、OsNRT2.2、OsNRT2.3a及OsNRT2.4的相对表达量存在显著差异。在南粳5818中OsNRT2.3b相对表达量与OsNRT2.3a相对表达量的比值显著高于南粳5718。本研究利用分子生物学技术探索了水稻氮素利用率的分子机制,为选育氮素高效利用的水稻品种提供了理论依据。

It is important to explore the molecular mechanism of nitrogen absorption and utilization for breeding rice varieties with high nitrogen utilization efficiency.High quality japonica rice varieties Nanjing 5718 and Nanjing 5818 were used as experimental materials in this study.Low nitrogen treatment(150 kg/hm^(2)),medium nitrogen treatment(300 kg/hm^(2)),high nitrogen treatment(450 kg/hm^(2))and no nitrogen control were set up.The difference of nitrogen use efficiency between two japonica rice varieties and the molecular mechanism were analyzed.The results showed that the agronomic nitrogen use efficiency,nitrogen recovery rate and photosynthetic nitrogen use efficiency of Nanjing 5818 were higher than those of Nanjing 5718.With the increase of nitrogen application rate,the agronomic nitrogen use efficiency of Nanjing 5718 and Nanjing 5818 decreased.The relative expression levels of nitrogen use related genes OsNRT1.1B,OsNRT2.2,OsNRT2.3a and OsNRT2.4 were significantly different between Nanjing 5718 and Nanjing 5818.The ratio of the relative expression of OsNRT2.3b to the relative expression of OsNRT2.3a in Nanjing 5818 was significantly higher than that in Nanjing 5718.This study explored the molecular mechanism of nitrogen use efficiency in rice by molecular biological techniques,and the results provided a theoretical basis for breeding rice varieties with high nitrogen utilization efficiency.