摘要：
Understanding the yield attributes of the popular rice (Oryza sativa L.) hybrids can provide useful information for developing new hybrid rice varieties. Field experiments were conducted at two subtropical sites (Hengyang and Xingyi) in two years (2021 and 2022) to compare grain yield and yield attributes of three currently popular hybrid rice varieties (Jingliangyouhuazhan, Jingliangyou 534, and Longliangyouhuazhan) with three representative super hybrid rice varieties (Y-liangyou 1, Y-liangyou 2, and Y-liangyou 900). No significant differences in grain yield were observed between the group of popular hybrids and the group of super hybrids at Hengyang and Xingyi in 2021 or at Xingyi in 2022, but at Hengyang in 2022, the group of popular hybrids produced a 15% higher grain yield. The grain yield at Hengyang in 2022 was lower than that at Hengyang and Xingyi in 2021 and at Xingyi in 2022. At Hengyang in 2022, the group of popular hybrids had 9-15% higher panicles per m2, spikelet filling percentage, and harvest index but similar spikelets per panicle and total biomass production and 12% lower grain weight compared to the group of super hybrids. Correlation plot analysis showed that grain yield was significantly related to panicles per m2 but not other yield attributes across six varieties at Hengyang in 2022. These results indicated that the currently popular hybrid rice varieties had higher yield performance than the representative super hybrid rice varieties under the condition of relatively lower productivity, and the key factor for this higher yield performance in the popular hybrids was the higher panicles per m2. This finding highlights that more attention should focus on the yield performance under medium- and low-productivity conditions in hybrid rice breeding programs, and an effective breeding strategy is to select the varieties with high panicle numbers.
摘要：
Inspired by the leaf-vein network structure, the pullulan-starch nanoplatelets (SNPs) bioinspired films with enhanced strength and toughness were successfully fabricated through a water evaporation-induced self-assembly technique. SNPs (SNP200 and SNP600) of two sizes were separated by differential centrifugation. Interactions between SNPs and pullulan during drying resulted in the vein-like network structure in both nanocomposite films when the appropriate amounts of SNP200 or SNP600 were added to pullulan, respectively. The TS and toughness values of pullulan with 1% w/w SNP200 films reached up to 51.05MPa and 69.65MJ·m(-3), which were 86% and 223% higher than those of the neat pullulan films, respectively. Moreover, the TS and toughness values of pullulan-SNP200 were significantly higher than those of pullulan-SNP600 films, when SNP content exceeded the 1% w/w level. By applying a graph theory, the network structures were found to correlate with the mechanical properties of the pullulan-SNPs bioinspired films. The new strategy for designing starch nanoplatelets-based edible films that combine mechanical strength and toughness holds promises for the development of novel biobased composite materials for food packaging application.
摘要：
Abstract Background and Objective Texture is critical in determining the eating quality of cooked rice and is dependent on physiochemical properties of rice grains. In this study, relationships between texture properties of cooked rice with grain amylose and protein content were evaluated across 25 high eating quality indica rice varieties. Findings Grain amylose and protein content ranged from 13.2% to 20.0% and from 5.37% to 7.77%, with means of 17.6% and 6.43%, respectively. The ranges of hardness, springiness, cohesiveness, resilience, and chewiness of cooked rice were 425–1074 g, 0.672–0.812, 0.447–0.632, 0.278–0.457, and 130–480 g, with means of 710 g, 0.768, 0.570, 0.394, and 320 g, respectively. Correlation plot analysis and partial correlation analysis showed that all five texture properties of cooked rice were significantly related to grain amylose content, whereas the relationships between each of the five texture properties and grain protein content were not significant or much less significant than the relationships between texture properties and grain amylose content. Conclusions High eating quality indica rice varieties have diverse texture properties when cooked. Selection of texture properties of cooked rice should focus on grain amylose content rather than grain protein content for high eating quality indica rice. Significance and Novelty This study identifies the critical physiochemical property determining cooked rice texture in high eating quality indica rice.
摘要：
Weeds occurred during the fallow season can well perform the function of carbon (C) capture due to receiving little human disturbance. This study aimed to evaluate the C capture potential of fallow weeds in rice (Oryza sativa L.) cropping systems. A six-region, two-year on-farm investigation and a three-year tillage experiment were conducted to estimate C capture in fallow weeds in rice cropping systems. The on-farm investigation showed that the average mean C capture by fallow weeds across six regions and two years reached 112 g m(-2). The tillage experiment indicated that no-tillage practices increased C capture by fallow weeds by 80% on average as compared with conventional tillage. The results of this study not only contribute to an understanding of C capture potential of fallow weeds in rice cropping systems, but also provide a reference for including fallow weeds in the estimation of vegetative C sink.
通讯机构：
[Min Huang] R;Rice and Product Ecophysiology, Key Laboratory of Ministry for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha 410128, China<&wdkj&>Author to whom correspondence should be addressed.
摘要：
Head milled rice is the main form of rice for sale and consumption. However, previous studies on the yield change due to the development of new cultivars in rice generally focus on grain yield but few on head milled rice yield. In this study, field experiments were conducted in two years (2019 and 2020) to compare head milled rice yield and associated traits (grain yield, milled recovery traits, and shape and chalkiness traits of rice grains) between two middle-season hybrid rice cultivars released 18 years apart, i.e., Jingliangyou 1468 (JLY1468), a recently-released cultivar with high eating quality, and Liangyoupeijiu (LYPJ), an old cultivar with high grain yield. JLY1468 had higher head milled rice yield than LYPJ by 30% in 2019 and by 33% in 2020. The higher head milled rice yield in JLY1468 than in LYPJ was attributable to improvements in both grain yield, and head milled rice rate (HMRR). The improvement in HMRR in JLY1468 compared to LYPJ was mainly attributable to a reduction in chalkiness degree, which was associated with a decrease in rice grain size. The results of this study provide evidence for the improvement in head milled rice yield in middle-season hybrid rice with the development of new cultivars in recent years.
摘要：
Rice yield stability is a breeding goal, particularly for short-growth duration rice, but its underlying mechanisms remain unclear. In an attempt to identify the relationship between yield stability and source-sink characteristics in short-growth duration rice, a field experiment was conducted at three sites (Yueyang, Liuyang, and Hengyang) in 2021 and 2022. This study compared yield, yield components, source-sink characteristics, and their stability between two stable-yielding short-growth duration rice cultivars, Zhongzao 39 (Z-39) and Lingliangyou 268 (L-268), and two unstable-yielding short-growth duration rice cultivars, Zhongjiazao 17 (Z-17) and Zhuliangyou 819 (Z-819). The stability of agronomic parameters was represented by the coefficient of variation (CV). The respective CVs of yield in Z-17, Z-819, Z-39, and L268 were 10.2%, 10.1%, 4.5%, and 5.7% in 2021 and 19.7%, 15.0%, 5.4%, and 6.5% in 2022. The respective CVs of grain weight were 6.3%, 5.7%, 3.4%, and 4.5% in Z-17, Z-819, Z-39, and L-268 in 2021, and 8.1%, 6.3%, 1.5%, and 0.8% in 2022. The mean source capacity per spikelet and pre-heading non-structural carbohydrate reserves per spikelet (NSCpre) were 7%-43% and 7%-72% lower in Z-819 and Z-17 than in L-268 and Z-39 in 2021 and 2022. The mean quantum yield of photosystem II photochemistry of leaf, leaf area index, and specific leaf weight of L-268 and Z-39 were higher than those of Z-819 and Z-17 at the heading stage. This study suggests that high NSCpre, caused by great leaf traits before heading, increases source capacity per spikelet and its stability, thereby increasing the stability of grain weight and yield. Increasing NSCpre is critical for achieving grain weight and yield stability in short-growth duration rice.CO 2023 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC
摘要：
Fallow weeds can be abundant in rice paddies without any inputs and provide ecosystem services like those of cover crops, such as reducing nitrogen (N) leaching and capturing carbon. Therefore, allowing fallow weeds to grow is a potential alternative to cover crops in rice cropping systems. To evaluate the feasibility of this strategy, the effect of fallow weeds on grain yield in rice needs to be clarified. In this study, 2-year field experiments were conducted to compare N uptake, biomass production, yield components, and grain yield in rice with and without application of fallow weeds (500 g m-2, sun-dried). Results showed that the application of fallow weeds reduced aboveground N uptake and biomass production by 21-30% during the early growth period (from transplanting to mid-tillering) in rice. However, these reductions did not lead to reduced grain yield because they were compensated for or even exceeded by increased aboveground N uptake and biomass production during the middle and late growth periods (from panicle initiation to maturity). In addition, the application of fallow weeds increased spikelets per panicle in rice by 6-7%. These results provide preliminary evidence that fallow weeds may alter yield formation in rice and highlight the need for further investigations of the ecophysiological mechanism underlying the effect of fallow weeds on N uptake in rice.
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.
摘要：
Inbred rice has been grown more and more widely, while the planting area of hybrid rice has decreased by approximately 25% in China since 1995. This study aimed to assess the changes in grain yield and yield attributes due to cultivar development in indica (Oryza sativa ssp. indica) inbred rice in China. Field experiments were conducted in 2019 and 2020 to determine the performance of grain yield and yield attributes of an indica super inbred rice cultivar Jinnongsimiao (JNSM) released in 2010 by comparing it with an indica high-yielding inbred rice cultivar Guichao 2 (GC2) released in 1978 and an indica super hybrid rice cultivar Y-liangyou 900 (YLY900) released in 2016. Results showed that JNSM produced 18% higher grain yield than GC2 but 6% lower grain yield than YLY900. Compared with GC2, JNSM had higher spikelets per panicle, spikelet-filling percentage, and harvest index by 67%, 4%, and 11%, respectively. Compared with YLY900, JNSM had 14% lower grain weight and 19% lower biomass production during the pre-heading period. The difference in biomass production during the pre-heading period between JNSM and YLY900 was explained more by crop growth rate than growth duration. This study suggests that (1) the recently released indica super inbred rice cultivar JNSM outyields the old indica high-yielding inbred rice cultivar GC2 as a result of increasing panicle size, spikelet-filling percentage, and harvest index, and (2) further improvement in grain yield in indica inbred rice can be achieved by improving biomass production through promoting pre-heading crop growth.
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.
关键词：
cooking properties;grain chemical properties;rice ratooning;rice noodles;texture profiles
摘要：
Rice noodles are usually manufactured using rice grains of the main crop. There is limited information available on rice noodles processed from ratoon rice grains. In this study, two-year field experiments were conducted to compare the cooking and texture properties of noodles and the grain chemical properties of ratoon crops with those of main crops from two rice cultivars (Guichao 2 and Zhenguiai) that are widely used for processing noodles. Results showed that the cooked break rate and the cooking loss rate of rice noodles processed from grains of the ratoon crop were similar to those of the main crop in both cultivars; however, changes in texture of cooked rice noodles processed from grains of the ratoon crop compared with the main crop were cultivar-dependent, being significantly softer in Zhenguiai but not in Guichao 2. Hardness and chewiness of cooked rice noodles were significantly negatively correlated with amylopectin content in milled rice grains in Zhenguiai, indicating that amylopectin content is a key chemical property determining the texture differences between rice noodles processed from grains of ratoon and main crops.
通讯机构：
[Min Huang] A;Rice and Product Ecophysiology, Key Laboratory of Ministry of Education for Crop Physiology and Molecular Biology, Hunan Agricultural University, Changsha, China
关键词：
nitrogen use efficiency;radiation interception;radiation use efficiency;rice
