1. Nitrogen rate effects reproductive development and grain set of summer maize by influencing fatty acid metabolism.
- Author
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Yu, Ningning, Ren, Baizhao, Zhao, Bin, Liu, Peng, and Zhang, Jiwang
- Subjects
FATTY acids ,METABOLISM ,LIPID metabolism ,NITROGEN ,FIELD research - Abstract
Purpose: The developmental status of the male and female spike determines grain number (GN) per ear and yield. A better understanding of the effect of N on male and female spike differentiation and GN formation could help to gain insight into the mechanism of N regulation on yield. Methods: A field experiment was conducted with four nitrogen rates: 0 (N0), 129 (N1), 185 (N2), and 300 kg N ha
−1 (N3) with a single summer maize hybrid to determine tassel and ear development and the resulting GN. Results: The expression of key proteins and genes related to fatty acid metabolism of N0 were down-regulated and the tapetum was abnormally degraded. This inhibited the synthesis of long-chain fatty acids (LCFAs) in the tassel and ear. Both pollen and silk development at the mononucleate stage were abnormal and presented as misshapen pollen, uneven silk tube, reduced silk, and poor pollination. Finally, anthesis-silking interval (ASI) was increased and the length of male and female spikes, fertilized florets, floret fertility percentage, and grain set rate were reduced in N0 treatment resulting in reduced GN. N application promoted fatty acid metabolism but N application greater than 185 kg N ha−1 did not increase LCFA of either male or female spike traits. Conclusions: A nitrogen rate of 185 kg N ha−1 was sufficient to promote lipid metabolism, and increase the content of LCFAs. This resulted in normal pollen and silk development, shortened ASI and led to an increase in the number of fertile florets, fertilization percentage, and GN. [ABSTRACT FROM AUTHOR]- Published
- 2023
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