Optimizing plant spatial competition can change phytohormone content and promote tillering, thereby improving wheat yield

Pan Liu; Baozhong Yin; Xuejing Liu; Limin Gu; Jinkao Guo; Mingming Yang; Wenchao Zhen

doi:10.3389/fpls.2023.1147711

Optimizing plant spatial competition can change phytohormone content and promote tillering, thereby improving wheat yield

Front Plant Sci. 2023 Mar 6:14:1147711. doi: 10.3389/fpls.2023.1147711. eCollection 2023.

Authors

Pan Liu^{1

2

3

4}, Baozhong Yin⁵, Xuejing Liu^{1

2

3

4

6}, Limin Gu^{1

2

3

4}, Jinkao Guo^{1

2

3

4

7}, Mingming Yang⁸, Wenchao Zhen^{1

2

3

4}

Affiliations

¹ College of Agronomy, Hebei Agricultural University, Baoding, China.
² State Key Laboratory of North China Crop Improvement and Regulation, Baoding, China.
³ Key Laboratory of North China Water-saving Agriculture, Ministry of Agriculture and Rural Affairs, Baoding, China.
⁴ Key Laboratory of Crop Growth Regulation of Hebei Province, Baoding, China.
⁵ College of Plant Protection, Hebei Agricultural University, Baoding, China.
⁶ College of Clinical Medicine, North China University of Technology, Tangshan, China.
⁷ Wheat Research Center, Shijiazhuang Academy of Agriculture and Forestry Sciences, Shijiazhuan, China.
⁸ College of Agronomy, Northwest A&F University, Xianyang, China.

Abstract

As an important type of interplant competition, line-spacing shrinkage and row-spacing expansion (LSRE) can increase the number of tillers and improve resource utilization efficiency in wheat. Wheat tillering is closely related to various phytohormones. However, it is unclear whether LSRE regulates phytohormones and their relationship to tillering and wheat yield. This study evaluated tillering characteristics, phytohormone content in tiller nodes at the pre-winter stage, and grain yield factors for the winter wheat variety Malan1. We used a two-factor randomized block trial design with two sowing spacings of 15 cm (15RS, conventional treatment) and 7.5 cm (7.5RS, LSRE treatment) at the same density and three sowing-date groups (SD1, SD2, and SD3). LSRE significantly promoted wheat tillering and biomass at the pre-winter stage (average increases of 14.5% and 20.9% in the three sowing-date groups, respectively) and shortened the accumulated temperature required for a single tiller. Changes in the levels of phytohormones, including decreased gibberellin and indole acetic acid and increased zeatin riboside and strigolactones, were determined by high-performance liquid chromatography and were shown to be responsible for the tillering process under LSRE treatment in winter wheat. LSRE treatment can improve crop yield by increasing the number of spikes per unit area and grain weight. Our results clarified the changes in tillering and phytohormones content of winter wheat under LSRE treatment and their correlation with grain yield. This study also provides insights into the physiological mechanisms of alleviating inter-plant competition to improve crop yield.

Keywords: grain yield; line-spacing shrinkage and row-spacing expansion; phytohormone; tiller; winter wheat.

Grants and funding

This research was funded by the National Key Research and Development Project (Grant No. 2017YFD0300900), the Key R&D projects in Hebei Province (Grant No. 21327001D), and the Modern Agricultural Industrial Technology System in Hebei Province (Grant No. HBCT2018010205).