154697 - Optimized management practices.pdf (5.47 MB)
Optimized management practices synergistically improved grain yield and nitrogen use efficiency by enhancing post-heading carbon and nitrogen metabolism in super hybrid rice
journal contribution
posted on 2023-05-21, 15:29 authored by Deng, Y, Ye, J, Ke LiuKe Liu, Matthew HarrisonMatthew Harrison, Zhong, X, Wang, C, Tain, X, Huang, L, Zhang, YThe super hybrid rice breeding program in China has raised genetic yield ceilings through mor-phological improvements and inter-subspecific heterosis. Despite this, little information on the physiological basis underlying this yield transformation exists, and less so on the genotype x envi-ronment x management conditions enabling consistent yield gains. Here, we assess grain yield, photosynthetic physiology, and leaf carbon and nitrogen (N) metabolic properties of super rice (Y-liangyou900) under four management practices (i.e., zero-fertilizer control, CK; farmers’ prac-tice, FP; high-yield and high-efficiency management, OPT1; and super-high-yield management, OPT2) using a field experiment conducted over five years. Grain yield and agronomic N use effi-ciency (AEN) of OPT2 were 15% and 10% higher than OPT1, and 30% and 78% higher than FP, respectively. The superior yields of OPT2 were attributed to higher source production capacity, that is, higher leaf photosynthetic rate, carbon metabolic enzyme activity (i.e., AGP and SPS), nitrogen metabolic enzyme activity (i.e., NR, GS, and GOGAT), soluble protein and sugar content, and de-layed leaf senescence (the latter due to elevated activity of protective enzyme systems) during grain filling. The higher AEN of OPT2 was associated with higher activity of leaf carbon metabolic enzyme (i.e., AGP and SPS), nitrogen metabolic enzyme (i.e., NR, GS, GDH, and GOGAT) and protective enzyme (POD) after heading, and lower C/N ratio in grains. We conclude that optimized man-agement (optimized water and fertilizer management with appropriate dense planting) improved grain yield and N use efficiency simultaneously by enhancing post-heading leaf carbon and N metabolism and delayed leaf senescence.
History
Publication title
AgronomyVolume
13Article number
13Number
13Pagination
1-19ISSN
2073-4395Department/School
Tasmanian Institute of Agriculture (TIA)Publisher
MDPI AGPlace of publication
SwitzerlandRights statement
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) license (https://creativecommons.org/licenses/by/4.0/).Repository Status
- Open