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应用生态学报 ›› 2022, Vol. 33 ›› Issue (4): 1045-1054.doi: 10.13287/j.1001-9332.202204.034

• 研究论文 • 上一篇    下一篇

低氮诱导玉米幼苗叶片衰老过程中碳氮平衡的动态变化

王宁, 师赵康, 徐世英, 尹凤茹, 王伟杰, 冯万军*   

  1. 山西农业大学农学院, 山西晋中 030801
  • 收稿日期:2021-09-03 接受日期:2022-03-02 出版日期:2022-04-15 发布日期:2022-10-15
  • 通讯作者: * E-mail: fengwj123-123@163.com
  • 作者简介:王 宁, 男, 1997年生, 硕士研究生。主要从事玉米氮素利用机制研究。E-mail: 1546224355@qq.com
  • 基金资助:
    黄土高原特色作物优质高效生产省部共建协同创新中心自主研发项目(SBGJXTZX)、山西省自然科学基金项目(20210302123372)和山西农业大学生物育种工程项目(YZGC090)资助。

Dynamics of carbon and nitrogen balance during leaf senescence of maize seedlings induced by low nitrogen stress

WANG Ning, SHI Zhao-kang, XU Shi-ying, YIN Feng-ru, WANG Wei-jie, FENG Wan-jun*   

  1. College of Agronomy, Shanxi Agricultural University, Jinzhong 030801, Shanxi, China
  • Received:2021-09-03 Accepted:2022-03-02 Online:2022-04-15 Published:2022-10-15

摘要: 叶片适时衰老对保证玉米产量有重要意义。本试验以玉米自交系PH6WC和PH4CV为研究对象,通过水培方法,设置低氮(0.04 mmol·L-1,LN)和正常(4 mmol·L-1,CK)氮素水平两种处理,在培养2、4、6和8 d后,对其幼苗第2和第3叶片表型、光合特性、叶片中氮素和糖分含量及碳氮比进行分析,旨在探究低氮胁迫下玉米幼苗叶片衰老过程中碳氮平衡的动态变化。结果表明: 与CK相比,LN造成两玉米自交系幼苗第2和第3叶片的面积、生物量、相对叶绿素含量、净光合速率、可溶性糖和淀粉含量均下降,而其氮物质生产能力均先后增加,但第2叶片的变化时间均早于第3叶片;在两叶片的各性状上,均为LN下PH6WC的变化幅度大于PH4CV,且仅幼苗叶片中的碳氮比在LN下显著提高;PH6WC的叶片衰老更快,PH4CV有更强的碳氮平衡能力,其叶片衰老相对滞后。综上,低氮会诱导玉米幼苗叶片衰老,高碳氮比具有促进叶片衰老的调控作用,低氮胁迫下幼苗叶片的碳氮平衡能力在两个玉米基因型间存在较大差异。

关键词: 玉米, 叶片衰老, 幼苗, 低氮胁迫, 碳氮比

Abstract: Timing of leaf senescence is important to ensure maize yield. In this study, we investigated the dynamics of carbon and nitrogen balance during leaf senescence in two maize inbred lines PH6WC and PH4CV under normal (4 mmol·L-1, CK) and low nitrogen (0.04 mmol·L-1, LN) treatments. Leaf phenotype, photosynthetic characteristics, nitrogen and sugar contents, and carbon to nitrogen ratio of the second and third leaves were analyzed after 2, 4, 6 and 8 days of cultivation. Results showed that leaf size, biomass, relative chlorophyll content, net photosynthetic rate, soluble sugar content, and starch content of the second and third leaves were decreased, while nitrogen production capacity was increased under low nitrogen treatment compared to the control, with the changes of the second leaf being earlier than that of the third leaf. For all the leaf traits, the variation scales of PH6WC were larger than that of PH4CV under low nitrogen stress, and only the C/N ratio in the seedling leaves was significantly increased. In addition, leaf senescence of PH4CV was slower than PH6WC due to its stronger ability in maintaining carbon and nitrogen balance. In conclusion, low nitrogen could induce leaf senescence of maize seedlings. High C/N ratio could promote leaf senescence. There are significant differences in carbon and nitrogen balance ability of seedling leaves between two maize genotypes under low nitrogen stress.

Key words: maize, leaf senescence, seedling, low nitrogen stress, carbon to nitrogen ratio