Bao Shuqin, Chai Xingying, Liao Linzheng, Li Xiaoying, Shi Lin, Dong Xixi, Long Sida, Li Huifu, Wang Hanyu, Li Zhenghong, Wang Mengting, Ren Yun, Li Qiang
Chongqing Key Laboratory for Germplasm Innovation for Special Aromatic Spice Plants, Institute of Special Plants, College of Landscape Architecture and Life Science, Chongqing University of Arts and Sciences, Chongqing, China.
College of Biology and Food Engineering, Chongqing Three Gorges University, Chongging, China.
Front Plant Sci. 2025 Jun 18;16:1577962. doi: 10.3389/fpls.2025.1577962. eCollection 2025.
This study aimed to establish and verify a critical nitrogen dilution model for different organs of maize varieties with different nitrogen efficiencies and clarify differences in nitrogen nutritional characteristics.
Two maize varieties (nitrogen-efficient variety ZH 311 and nitrogen-inefficient variety XY 508) were grown under four nitrogen levels to evaluate N dynamics and dry matter accumulation.
The results showed that the critical nitrogen concentration dilution curves based on root dry matter, stem-sheath dry matter, leaf dry matter, and plant dry matter, with coefficient of determination (R²>0.90), all reached significant levels and could be used for nitrogen nutrition diagnosis of maize. However, a and b values of the critical nitrogen concentration models for different organs differed significantly; e.g., the root model had the lowest a value and the leaf model had the lowest b value. ZH 311 exhibited higher a values and lower b values (except in roots) than XY 508. The model established on ZH 311 based on stem-sheath had the highest stability, and the model established on XY 508 based on leaf had the highest stability. Relative yield (RY), nitrogen nutrition index (NNI), and cumulative nitrogen deficit (AND) were significantly correlated at different growth stages of different organs (R²>0.80) using each critical nitrogen concentration dilution curve to predict yield.
In the high-nitrogen efficiency variety ZH 311, roots, stem-sheath, leaves, and plants showed weaker responses to AND than those of the low nitrogen-efficiency variety ZH 311 with at all growth stages. ZH 311 roots exhibited stronger responses to NNI at the early growth stage, and stem-sheath, leaves, and plants had stronger responses to NNI at the later growth stage, indicating that the high nitrogen-efficiency variety ZH 311 was not sensitive to nitrogen deficiency and was more efficient for nitrogen nutrition.
本研究旨在建立并验证不同氮效率玉米品种不同器官的临界氮稀释模型，并阐明氮营养特性的差异。
两个玉米品种（氮高效品种ZH 311和氮低效品种XY 508）在四个氮水平下种植，以评估氮动态和干物质积累。
结果表明，基于根干物质、茎鞘干物质、叶干物质和植株干物质的临界氮浓度稀释曲线，决定系数（R²>0.90）均达到显著水平，可用于玉米的氮营养诊断。然而，不同器官临界氮浓度模型的a和b值差异显著；例如，根模型的a值最低，叶模型的b值最低。ZH 311的a值高于XY 508（根除外），b值低于XY 508。基于ZH 311茎鞘建立的模型稳定性最高，基于XY 508叶建立的模型稳定性最高。利用各临界氮浓度稀释曲线预测产量，不同器官不同生长阶段的相对产量（RY）、氮营养指数（NNI）和累积氮亏缺（AND）显著相关（R²>0.80）。
在高氮效率品种ZH 311中，根、茎鞘、叶和植株在所有生长阶段对AND的响应均比低氮效率品种XY 508弱。ZH 311根在生长前期对NNI的响应较强，茎鞘、叶和植株在生长后期对NNI的响应较强，表明高氮效率品种ZH 311对缺氮不敏感，氮营养效率更高。
