Hu Qun, Zhang Kaiwei, Jiang Weiqin, Qiu Shi, Li Guangyan, Xu Fangfu, Zhu Ying, Liu Guodong, Gao Hui, Zhang Hongcheng, Wei Haiyan
Jiangsu Key Laboratory of Crop Cultivation and Physiology, Research Institute of Rice Industrial Engineering Technology, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
Huaiyin Institute of Agricultural Sciences of Xuhuai Region in Jiangsu, Huai'an 223001, China.
Plants (Basel). 2024 Nov 29;13(23):3351. doi: 10.3390/plants13233351.
The carbon and nitrogen (N) metabolism of rice under different mid-stage N compensation timings is unclear. Two Japonica super rice cultivars were examined under four N compensation timings (N1-N3: N compensation at mid-tillering, panicle initiation, and spikelet differentiation. N0: no N compensation) and CK with no N application. Mid-stage N compensation increased the N concentrations of various tissues, and N2 showed the highest plant N uptake at both the heading stage, maturity, and the grain filling period. Among the treatments, N2 showed the highest N utilization efficiency. With delayed compensation timing, there was a gradual decrease in soluble sugar and starch concentrations in each tissue, accompanied by a decline in the non-structural carbohydrate (NSC) concentration. Specifically, N2 treatment exhibited the highest NSC accumulation and the remobilized NSC reserve, but NSCs per spikelet decreased with delayed compensation timing. The highest yield was also obtained with N2, exhibiting a 4.5% increase compared to the N0 treatment, primarily due to an improvement in spikelets per panicle. Conclusively, N compensation at the panicle initiation stage is a reasonable N management strategy that can coordinate the improvement of carbon and N metabolism, enhance N accumulation with efficient utilization and NSC accumulation, and ultimately increase the yield.
不同中期施氮补偿时期下水稻的碳氮代谢尚不清楚。本研究以两个粳型超级稻品种为材料，设置了四个施氮补偿时期（N1 - N3：分别在分蘖中期、穗分化期和颖花分化期进行施氮补偿。N0：不进行施氮补偿）以及不施氮的对照（CK）。中期施氮补偿提高了各组织的氮浓度，且N2处理在抽穗期、成熟期和灌浆期的植株吸氮量最高。在所有处理中，N2处理的氮利用效率最高。随着补偿时期延迟，各组织中可溶性糖和淀粉浓度逐渐降低，非结构性碳水化合物（NSC）浓度也随之下降。具体而言，N2处理的NSC积累量和再动员的NSC储备量最高，但每个颖花的NSC含量随补偿时期延迟而降低。N2处理的产量最高，与N0处理相比增产4.5%，主要原因是每穗颖花数增加。总之，在穗分化期进行施氮补偿是一种合理的氮肥管理策略，能够协调碳氮代谢的改善，提高氮素积累与高效利用以及NSC积累，最终提高产量。
