通讯机构：
[Min Huang] R;Rice and Product Ecophysiology, Key Laboratory of Ministry of Education for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
通讯机构：
[Min Huang] R;Rice and Product Ecophysiology, Key Laboratory of Ministry of Education for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
关键词：
Grain protein concentration;logistic regression;non-protein accumulation;protein accumulation;rice
摘要：
Protein in rice grains is an important source of nutrition for rice consumers. This study mainly aimed to identify the critical factors that determine grain protein concentration in rice. Accumulation parameters, including mean accumulation rate (R-mean) and active accumulation duration (D-active), for protein and non-protein components and their correlations with protein concentration in rice grains were investigated in field experiments conducted over two years with six rice cultivars. Results showed that grain protein concentration ranged from 9.6% to 11.9% across cultivars and years. Accumulation processes of protein and non-protein components were well fitted by the logistic equation for all six rice cultivars in both years, and the ratio of protein to non-protein for R-mean and D-active ranged from 0.08 to 0.12 and 1.01 to 1.33, respectively. Grain protein concentration was significantly correlated with protein to non-protein ratio for R-mean. This study suggests that grain protein concentration is not solely determined by the accumulation of protein or non-protein component, but by the coordination of protein and non-protein accumulation.
摘要：
Excessive use of inorganic nitrogen (N) fertilizers is the primary anthropogenic cause of low N use efficiency and environmental damage in wetland rice agriculture. However, little is known about the performance of traditional inorganic N sources used in paddy rice production. Biochar (BC) is considered to be a climate change mitigation tool that can enhance N uptake and utilization in N-fertilized crops. To test this hypothesis, we performed a pot experiment to study the fate of 15N-labeled urea, ammonium nitrate, and ammonium sulfate with and without BC at tillering, heading, and maturity stages of rice in the early and late seasons of 2019. Fertilizer N leaching was significantly reduced by 75.69% and 110.32% in BC vs. non-BC treatments across growth stages in the early and late seasons. The rate of leaching was lower for urea than for ammonium nitrate and ammonium sulfate. Furthermore, the addition of BC resulted in 55.58% and 41.33% higher soil 15N concentrations in the early and late season, respectively, indicating that BC increased N adsorption. 15N uptake by roots, stems, leaves, panicles, and grains averaged 52.39%, 37.14%, 40.86%, 36.37%, and 29.94% higher in BC-amended pots than in BC-free pots in both seasons. There were significant differences (p < 0.05) among N sources in terms of fertilizer N loss, residual N, and N uptake, and performance was ranked in the order urea > ammonium sulfate > ammonium nitrate. Overall, our results indicate that urea with BC is a preferable N source for double rice cropping systems compared with ammonium nitrate and ammonium sulfate.
作者机构：
[Liang, Tianfeng] Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China;[Huang, Min; Tao, Zui; Lei, Tao; Cao, Fangbo; Chen, Jiana; Zou, Yingbin] Crop and Environment Research Center, College of Agronomy, Hunan Agricultural University, Changsha 410128, China;[Yin, Xiaohong] Crop and Environment Research Center, College of Agronomy, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China
通讯机构：
[Min Huang] C;[Tianfeng Liang] G;Guangxi Key Laboratory of Rice Genetics and Breeding, Rice Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China<&wdkj&>Crop and Environment Research Center, College of Agronomy, Hunan Agricultural University, Changsha 410128, China
作者机构：
[郭立君; 汤文光; 文丽; 程凯凯; 唐海明; 汪柯; 李超; 肖小平] Hunan Province Soil and Fertilizer Research Institute, Changsha, 410125, China;[黄敏] Crop and Environment Research Center, Hunan Agricultural University, Changsha, 410128, China;[赵杨] Hunan Province Rice Research Institute, Changsha, 410125, China;[崔婷] Nanxian Agricultural Bureau, Nanxian, 413200, China
通讯机构：
[Xiao, X.] H;Hunan Province Soil and Fertilizer Research InstituteChina
通讯机构：
[Huang, Min] H;Hunan Agr Univ, Coll Agron, Crop & Environm Res Ctr, Changsha 410128, Peoples R China.
摘要：
Labor-saving crop establishment methods have rapidly developed for rice (Oryza sativa L.) production in China to address a labor shortage in agricultural production resulting from urban expansion, and many rice farmers who adopt such methods prefer to choose inbred varieties with reduced seed costs. This study aimed to determine which of two labor-saving establishment methods, zero tillage and direct seeding (ZTDS) and rotavator tillage and mechanical transplanting (RTMT), achieves higher grain yield in inbred rice. Field experiments were conducted at two sites across 3 yr to determine grain yield and yield attributes of elite inbred rice cultivar Jinlongsimiao, established under ZTDS and RTMT. Results showed that RTMT produced an 11% higher grain yield than ZTDS. Higher spikelet number per panicle was observed under RTMT compared with ZTDS, but spikelet number per square meter was not necessarily higher because it was compensated for by a reduced panicle number per square meter. The RTMT-established rice conferred higher spikelet filling percentage but lower grain weight than ZTDS-established rice. There was no consistent or significant difference in crop growth rate, total biomass production, or the source/sink ratio between RTMT and ZTDS rice. The RTMT method produced a higher harvest index than ZTDS. These results suggest that RTMT is the favorable method for inbred rice establishment to improve the partitioning of assimilates and, consequently, increase spikelet filling percentage and grain yield compared with ZTDS.
通讯机构：
[Min Huang] C;Crop and Environment Research Center for Human Health, College of Agronomy, Hunan Agricultural University, Changsha, China
关键词：
grain quality;low temperature;rice
摘要：
Late-season rice, a major contributor to the production of high-quality rice in China, often experiences low temperatures during the flowering period. The objective of this study was to determine the effect of low temperature stress on grain quality and to identify related physiological factors in late-season rice. Sink and source characteristics and grain quality traits of two high-quality late-season rice cultivars were compared between a year in which low temperatures occurred during the flowering period (2020) and a normal year (2019) under field conditions. Low temperatures during the flowering period in 2020 resulted in a reduction in spikelet filling and consequent increases in source-sink ratios and grain weight and N content compared to 2019. The head rice rate and protein content of the milled rice were increased in 2020 compared to 2019. Starch gel consistency and peak, trough, breakdown, final, and consistency viscosities were reduced while setback viscosity, paste temperature, and texture properties (hardness, springiness, cohesiveness, resilience, and chewiness) were increased for milled rice (or milled rice flour or cooked milled rice) in 2020 compared to 2019. The glucose production rate and total glucose production from in vitro digestion of cooked milled rice was reduced in 2020 compared to 2019. The results of this study suggest that low temperature stress during the flowering period can improve milling, nutritional, and health qualities but reduce the cooking and eating quality in late-season rice by altering the source-sink relationship.
通讯机构：
[Huang, Min] C;Crop and Environment Research Center for Human Health, Key Laboratory of Ministry of Education for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha, 410128, China.
摘要：
The consumption of good tasting rice, mainly soft-textured white rice with low amylose content, has substantially increased in China as living standards improve. However, this diet change may increase the risk of developing type II diabetes because the soft-textured white rice is generally less resistant to digestion and has a higher glycemic index. In contrast, intake of brown rice is inversely associated with type II diabetes risk. This study was conducted to test the possibility that brown rice processed from soft-textured cultivars has both acceptable texture and improved health benefits. Texture and digestion properties were compared between white and brown rice of five indica cultivars preferred by Chinese consumers. Mean hardness was 33% higher while mean springiness was 5% lower for cooked brown rice than for cooked white rice. As compared to cooked white rice, cooked brown rice had a 41% longer mean active digestion duration but 31% lower mean glucose production rate and 11% lower mean total glucose production from starch digestion. However, the differences in texture and starch digestion properties between cooked brown and white rice were affected by cultivar identity. Brown rice processed from suitable cultivars with both a relatively thinner bran layer and relatively higher grain amylose content met consumer requirements in terms of acceptable texture and improved health benefits.
关键词：
methylcellulose films;starch nanocrystals;molecular weight;degree of substitution;physicochemical properties
摘要：
This research studied the effect of molecular weight (M-w) and degree of substitution (DS) on the microstructure and physicochemical characteristics of methylcellulose (MC) films with or without SNC. The M-w and DS of three types of commercial MC (trade name of M20, A4C, and A4M, respectively) were in the range of 0.826 to 3.404 x 10(5) Da and 1.70 to 1.83, respectively. M-w significantly affected the viscosity of methylcellulose solutions as well as the microstructure and tensile strength of methylcellulose films, while DS had a pronounced effect on their oxygen permeability properties. The incorporation of 15% (w/w) SNC resulted in the efficient improvement of tensile strength, water, and oxygen barrier properties of films, particularly for the A4C nanocomposite films. The results from SEM and FTIR illustrated that relatively homogenous dispersion of SNC was distinguished in A4C-15% (w/w) SNC films. Furthermore, microstructures of MC-SNC nanocomposite films were strongly dependent on both M-w and DS of MC. This work offers a convenient and green method to fabricate MC-based nanocomposite films with desirable mechanical, light, oxygen, and water vapor barrier properties.
通讯机构：
[Huang, Min] C;Crop and Environment Research Center for Human Health, Key Laboratory of Ministry of Education for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha, 410128, China.
摘要：
Producing rice noodles using early-season rice grains is a way to bypass difficulties in marketing early-season rice that does not meet consumer preference for soft-textured rice. In recent years, brown rice foods including noodles have attracted great attention due to their health and nutritional benefits. This study was conducted to evaluate the yield and quality of brown rice noodles processed from two early-season rice cultivars. Results showed that the yield of brown rice noodles was 12-19% higher than that of white rice noodles. Although the cooked break rate and cooking loss rate were 5-10% higher in brown rice noodles compared to white rice noodles, both were within an acceptable range for brown rice noodles. Cooked brown rice noodles had 21-27% lower hardness and chewiness than cooked white rice noodles, though differences in the elasticity parameters springiness, cohesiveness, and resilience were not significant or were inconsistent between cooked brown and white rice noodles. These results suggest that it is feasible to process early-season rice to produce brown rice noodles of desirable yield and quality.
