Skip to main content

ORIGINAL RESEARCH article

Front. Plant Sci.
Sec. Plant Nutrition
Volume 15 - 2024 | doi: 10.3389/fpls.2024.1469264

Evaluating rice lipid content, yield, and quality in response to nitrogen application rate and planting density

Provisionally accepted
Guangyi Chen Guangyi Chen 1Congmei Li Congmei Li 2*Mingming Hu Mingming Hu 1Xingmei He Xingmei He 1*Hong Yang Hong Yang 1Qiuqiu Zhang Qiuqiu Zhang 1*Chaoyue Wu Chaoyue Wu 1*Qiang Duan Qiang Duan 1*Ligong Peng Ligong Peng 1*Yao Zhang Yao Zhang 1*Ziyu Li Ziyu Li 1*Yuyuan Ouyang Yuyuan Ouyang 2*Yan Lan Yan Lan 3*Tian Li Tian Li 1*
  • 1 College of Agronomy, Sichuan Agricultural University, Chengdu, China
  • 2 Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China
  • 3 School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China

The final, formatted version of the article will be published soon.

    To investigate the effects of nitrogen (N) application rate and planting density (D) on the contents of lipid and free fatty acid, fatty acid composition, yield and quality of rice grain, a field experiment was conducted using Koshihikari (japonica) as experimental material from 2021 to 2022 with three N levels (90, 150 and 210 kg ha-1, denoted as N1, N2 and N3, respectively) and three transplanting densities (19.0 × 104, 26.7 × 104 and 40.0 × 104 plants ha-1, denoted as D1, D2 and D3, respectively). The results showed that N application rate and planting density had highly significant impacts only on the contents of free fatty acid and saturated fatty acid, respectively. Increased N and planting density enhanced the contents of lipid (29.41 mg g-1) and free fatty acid (21.47%). The highest values were obtained under N3D3 increasing by 7.02% and 3.23 percentage points, respectively, compared to other treatments. No significant differences in lipid content were found among treatments, whereas free fatty acid exhibited significant differences. The unsaturated fatty acid content increased with increasing N but first decreased and then increased with increasing planting density, while saturated fatty acid content showed the opposite trend. Appropriate N level and planting density improved the relative chlorophyll content and net photosynthetic rate of rice flag leaves, as well as increased grain yield, effective panicle number and spikelete number per panicle, but decreased the seed setting rate. Under N2D2, the relative chlorophyll content and net photosynthetic rate remained relatively high throughout the grain filling stage, resulting in the highest grain yield, with increases of 43.87-47.03% compared to other treatments. A moderate N level improved the milling quality of rice, while increased planting density reduced it. However, both increased N and planting density reduced the appearance quality and cooking and eating quality of rice. Overall, the effects of increasing N application rate and planting density on enhancing rice lipid and free fatty acid contents were limited. A combination of 150 kg ha-1 N application rate and 26.7 × 104 plants ha-1 was recommended for achieving relatively higher yield, lipid content and better grain quality.

    Keywords: rice, lipid content, Nitrogen application rate, planting density, yield, quality

    Received: 23 Jul 2024; Accepted: 30 Oct 2024.

    Copyright: © 2024 Chen, Li, Hu, He, Yang, Zhang, Wu, Duan, Peng, Zhang, Li, Ouyang, Lan and Li. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence:
    Congmei Li, Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China
    Xingmei He, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Qiuqiu Zhang, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Chaoyue Wu, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Qiang Duan, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Ligong Peng, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Yao Zhang, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Ziyu Li, College of Agronomy, Sichuan Agricultural University, Chengdu, China
    Yuyuan Ouyang, Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, China
    Yan Lan, School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, China
    Tian Li, College of Agronomy, Sichuan Agricultural University, Chengdu, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.