Journals
  Publication Years
  Keywords
Search within results Open Search
Please wait a minute...
For Selected: Toggle Thumbnails
Optimization of nitrogen fertilization improves rice quality by affecting the structure and physicochemical properties of starch at high yield levels
ZHOU Tian-yang, LI Zhi-kang, LI En-peng, WANG Wei-lu, YUAN Li-min, ZHANG Hao, LIU Li-jun, WANG Zhi-qin, GU Jun-fei, YANG Jian-chang
2022, 21 (6): 1576-1592.   DOI: 10.1016/S2095-3119(21)63678-X
Abstract268)      PDF in ScienceDirect      
A major challenge in modern rice production is to achieve the dual goals of high yield and good quality with low environmental costs.  This study was designed to determine whether optimized nitrogen (N) fertilization could fulfill these multiple goals.  In two-year experiments, two high yielding ‘super’ rice cultivars were grown with different N fertilization management regimes, including zero N input, local farmers’ practice (LFP) with heavy N inputs, and optimized N fertilization (ONF).  In ONF, by reducing N input, increasing planting density, and optimizing the ratio of urea application at different stages, N use efficiency and the physicochemical and textural properties of milled rice were improved at higher yield levels.  Compared with LFP, yield and partial factor productivity of applied N (PFP) under ONF were increased (on average) by 1.70 and 13.06%, respectively.  ONF increased starch and amylose content, and significantly decreased protein content.  The contents of the short chains of A chain (degree of polymerization (DP) 6–12) and B1 chain (DP 13–25) of amylopectin were significantly increased under ONF, which resulted in a decrease in the stability of rice starch crystals.  ONF increased viscosity values and improved the thermodynamic properties of starch, which resulted in better eating and cooking quality of the rice.  Thus, ONF could substantially compensate the negative effects caused by N fertilizer and achieve the multiple goals of higher grain quality and nitrogen use efficiency (NUE) at high yield levels.  These results will be useful for applications of high quality rice production at high yield levels.
Reference | Related Articles | Metrics
Changes in starch quality of mid-season indica rice varieties in the lower reaches of the Yangtze River in last 80 years
ZHANG Hao, JING Wen-jiang, XU Jing-ju, MA Bing-ju, WANG Wei-lu, ZHANG Wei-yang, GU Jun-fei, LIU Li-jun, WANG Zhi-qin, YANG Jian-chang
2020, 19 (12): 2983-2996.   DOI: 10.1016/S2095-3119(20)63431-1
Abstract119)      PDF in ScienceDirect      
Rice (Oryza sativa L.) quality depends mainly on the characteristics of starch stored in kernels.  Understanding the changes in starch characteristics in kernels during variety improvement would have great significance to improve rice quality.  This study was designed to investigate the starch characteristics in the kernels and associated physiological traits of indica rice varieties in the lower reaches of the Yangtze River in China in last 80 years.  Eight representative mid-season indica rice varieties were grown in the field.  The results showed that the grain yield was significantly increased with the improvement of varieties and such an increase was mainly attributed to the increase in total number of spikelets.  The tall varieties applied in the 1940s–1950s had higher protein content, relative crystallinity and infrared (IR) ratio of 1 045/1 022 cm–1.  The semi-dwarf varieties applied in the 1980s–1990s had higher gel consistency, amylopectin content, IR ratio of 1 022/995 cm–1, and breakdown value.  With the improvement of varieties, the amylose content, large-sized starch granule number and volume distribution, onset and peak of gelatinization temperature, gelatinization and retrogradation enthalpy, setback value, pasting temperature, viscosity of peak, hot and final, and 1-aminocycopropane-1-carboxylic acid (ACC) concentrations in panicles and root bleeding were gradually decreased, whereas the medium-sized starch granule number and volume distribution, activities of key enzymes in grains, and zeatin (Z)+zeatin riboside (ZR) contents in panicles and root bleeding at grain filling stage were gradually increased.  Correlation analysis showed that starch thermodynamic characteristics were closely related to starch structure and components, key enzymes and hormones.  The results suggest that starch quality was enhanced through the optimization of starch components, structure, thermodynamics, and the regulation of key enzymes in grains and hormones in panicles and root bleedings at grain filling stage during the improvement of mid-season indica rice.
Reference | Related Articles | Metrics