Reducing chalkiness and enhancing quality and yield in hybrid indica rice at the middle panicle position through optimal water and nitrogen management

Yuanyuan Sun; Xiaojuan Yuan; Yinghan Luo; Guanzhou Luo; Kun Chen; Ailing Wang; Mingming Hu; Zongkui Chen; Zhiyuan Yang; Jun Ma; Yongjian Sun

doi:10.1016/j.foodchem.2025.145305

Reducing chalkiness and enhancing quality and yield in hybrid indica rice at the middle panicle position through optimal water and nitrogen management

Food Chem. 2025 Jun 24:491:145305. doi: 10.1016/j.foodchem.2025.145305. Online ahead of print.

Authors

Affiliations

¹ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China; Sichuan Climate Center, Sichuan Meteorological Bureau, Chengdu 610072, China.
² Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
³ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China; Rice Research Institute, Sichuan Neijiang Academy of Agricultural Sciences, Neijiang 641099, China.
⁴ State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China; Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China. Electronic address: yongjians1980@163.com.

PMID: 40580598
DOI: 10.1016/j.foodchem.2025.145305

Abstract

Chalkiness considerably impacts rice quality and is influenced by water and fertilizer management. This study investigates the regulatory mechanisms of water and nitrogen management on yield and chalkiness across different panicle positions. Compared to the upper and lower panicle positions, grain yield from the middle panicle position was significantly increased by 8.58-55.63 %, especially significantly increased the starch branching enzyme (SEB), adenosine diphosphate glucose pyrophosphorylase (ADPG), protein content, B₁ chain (DP13-24) and 1045/1022 cm^-1, which were responsible for chalkiness reduction. The water and nitrogen management pattern of implementing straw mulching promoted ADPG and SEB activity 0.12-29.68 %, decreased granule-bound starch synthase activity 2.26-50.49 %, increased small starch granules 2.03-11.81 % and relative crystallinity 1.41-9.69 %, contributed to high yield 9825.91-10,314.64 kg ha^-1 and chalkiness reduction 2.78-14.23 %, and affected to enhance gelatinization enthalpy 8.23-38.88 %. Overall, optimized water and nitrogen management increased grain yield and reduced chalkiness by improving starch synthase activity, protein content and multi-level structures in grains at the middle panicle position.

Keywords: Chalkiness; Grain positions; Indica hybrid rice; Starch structure; Water and nitrogen management pattern.