Li Qiang, Ren Yun, Fu Hao, Li Zhexin, Kong Fanlei, Yuan Jichao
Chongqing Key Laboratory of Economic Plant Biotechnology, Collaborative Innovation Center of Special Plant Industry in Chongqing, Institute of Special Plants, Chongqing University of Arts and Sciences, Chongqing, China.
Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Ministry of Agriculture, Sichuan Agricultural University, Ya'an, Sichuan, China.
Front Plant Sci. 2022 Sep 9;13:992041. doi: 10.3389/fpls.2022.992041. eCollection 2022.
The balance of carbon (C) and nitrogen (N) metabolism influences plant growth and development as well as yield. A two-year field experiment was conducted in a hilly region in southwest China in 2019-2020 to investigate the correlation between the accumulation and balance of C and N, as well as the grain yield of maize cultivars with contrasting N efficiencies. Using Zhenghong 311 (ZH 311) and Xianyu 508 (XY 508) as research sources, the differences in C and N accumulation and balance in maize cultivars with contrasting N efficiencies were compared to analyze the correlation between the accumulation and balance of C and N with grain yield. According to the results, the ZH 311 cultivar had higher C and N accumulation in each stage and grain yield than the XY 508 cultivar, while the C/N ratio in each stage and organ was significantly lower in ZH 311 than in XY 508, with the greatest difference occurring in the silking stage and leaf, indicating that the N-efficient cultivar ZH 311 had evident advantages in accumulation and balance of C and N and grain yield than the N-inefficient cultivar XY 508. Moreover, the C and N accumulation and grain yield increased significantly with N application, while the C/N ratio in each stage and organ decreased significantly with N application, but the differences between ZH 311 and XY 508 increased first and then decreased with the increase of N level, the optimum N level when obtaining the highest grain yield of ZH 311 (273.21 kg ha) was significantly lower than that of XY 508 (355.88 kg ha). Furthermore, grain yield was positively correlated with C ( = 0.9251) and N ( = 0.9033) accumulation, affected by pre-anthesis N ( = 0.9198) and post-anthesis C ( = 0.8632) accumulation, and negatively correlated with the C/N ratio ( = 0.7664), with the highest correlation between grain yield and the C/N ratio in silking stage ( = 0.7984) and leaf ( = 0.7616). In conclusion, the N-efficient cultivar ZH 311 could better coordinate the C and N balance of the plant, especially the C and N balance in the silking stage and leaf, promote photosynthetic product storage and transport, prolong the leaf function period, and make the pre-anthesis and post-anthesis C and N accumulation of ZH 311 significantly higher than those of XY 508, allowing higher grain yields.
碳（C）和氮（N）代谢的平衡影响着植物的生长发育以及产量。2019年至2020年，在中国西南部的一个丘陵地区进行了为期两年的田间试验，以研究不同氮效率玉米品种碳氮积累与平衡以及籽粒产量之间的相关性。以正红311（ZH 311）和先玉508（XY 508）为研究材料，比较了不同氮效率玉米品种碳氮积累与平衡的差异，分析了碳氮积累与平衡与籽粒产量之间的相关性。结果表明，ZH 311品种在各生育阶段的碳氮积累量和籽粒产量均高于XY 508品种，而ZH 311各生育阶段和器官的C/N比均显著低于XY 508，在吐丝期和叶片中差异最大，表明氮高效品种ZH 311在碳氮积累与平衡及籽粒产量方面比氮低效品种XY 508具有明显优势。此外，施氮显著增加了碳氮积累量和籽粒产量，各生育阶段和器官的C/N比随施氮量显著降低，但ZH 311和XY 508之间的差异随氮水平的增加先增大后减小，ZH 311获得最高籽粒产量时的最佳施氮量（273.21 kg·ha）显著低于XY 508（355.88 kg·ha）。此外，籽粒产量与碳（r = 0.9251）和氮（r = 0.9033）积累呈正相关，受花前氮（r = 0.9198）和花后碳（r = 0.8632）积累的影响，与C/N比呈负相关（r = 0.7664），籽粒产量与吐丝期C/N比（r = 0.7984）和叶片C/N比（r = 0.7616）的相关性最高。综上所述，氮高效品种ZH 311能够更好地协调植株的碳氮平衡，尤其是吐丝期和叶片的碳氮平衡，促进光合产物的储存和运输，延长叶片功能期，使ZH 311花前和花后的碳氮积累量显著高于XY 508，从而获得更高的籽粒产量。
