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Brown spot (BS) is caused by necrotrophs fungi Cochliobolus miyabeanus (C. miyabeanus) which affects rainfed and upland production in rice, resulting in significant losses in yield and grain quality. Here, we explored the meJA treatment that leads to rice resistance to BS. Fibrillins (FBNs) family are constituents of plastoglobules in chloroplast response to biotic and abiotic stress, many research revealed that OsFBN1 and OsFBN5 are not only associated with the rice against disease but also with the JA pathway. The function of FBN6 was only researched in the Arabidopsis. We revealed gene expression levels of OsFBN1, OsFBN5, OsFBN6 and the JA pathway synthesis first specific enzyme OsAOS2 following infection with C. miyabeanus, OsAOS2 gene expression showed great regulation after C. miyabeanus and meJA treatment, indicating JA pathway response to BS resistance in rice. Three FBN gene expressions showed different significantly regulated modes in C. miyabeanus and meJA treatment. The haplotype analysis results showed OsFBN1 and OsFBN5 the diverse Haps significant with BS infection score, and the OsFBN6 showed stronger significance (**** p < 0.0001). Hence, we constructed OsFBN6 overexpression lines, which showed more resistance to BS compared to the wild type, revealing OsFBN6 positively regulated rice resistance to BS. We developed OsFBN6 genetic markers by haplotype analysis from 130 rice varieties according to whole-genome sequencing results, haplotype analysis, and marker development to facilitate the screening of BS-resistant varieties in rice breeding. The Caps marker developed by Chr4_30690229 can be directly applied to the breeding application of screening rice BS-resistant varieties. [ABSTRACT FROM AUTHOR]

Background: Upland rice varieties exhibit significant genetic diversity and broad environmental adaptability, making them ideal candidates for identifying consistently expressed stress-responsive genes. F-box proteins typically function as part of the SKP1-CUL1-F-box protein (SCF) ubiquitin ligase complexes to precisely regulate gene expression and protein level, playing essential roles in the modulation of abiotic stress responses. Therefore, utilizing upland rice varieties for screening stress-responsive F-box genes is a highly advantageous approach. Results: Through mRNA-seq analysis in the Brazilian upland rice (cv. IAPAR9), the research identified 29 drought-responsive F-box genes. Gene distribution and duplication analysis revealed these genes are distributed on 11 of the 12 chromosomes and 10 collinear gene pairs were identified on different chromosomes. 13 cis-elements or binding sites were identified in the promoters of the 29 drought-responsive F-box genes by analysis. Protein domain, stability and subcellular localization analysis results suggest that these F-box proteins possess F-box domain and several other domains, and they are mostly unstable proteins with subcellular localization in cytoplasm, nucleus, chloroplasts, mitochondria and endoplasmic reticulum. Most of drought-responsive F-box genes exhibited expression in various tissues such as root, stem, leaf, leaf sheath and panicle except for OsFBO10 and OsFBX283. These genes exhibited various responses to abiotic stresses such as osmotic, cold, heat, and salt stresses, along with ABA treatment. Importantly, a frame-shift mutation in OsFBX148 was created in the ZH11 variety, leading to altered ABA signal transduction and ROS accumulation. The study further elucidated the interaction of OsFBX148 with SKP1 family proteins OSK4/7/17 to form the SCF complex, dependent on the F-box domain. Conclusions: The research identified and analyzed 29 drought-responsive F-box genes in upland rice and provides valuable insights into the role of OsFBX148 in ABA and ROS responses. It establishes a basis for future exploration of F-box genes in improving resistance to abiotic stresses, especially drought. [ABSTRACT FROM AUTHOR]

Rotational shifting cultivation (RSC) is commonly practiced in northern Thailand for upland rice cultivation, primarily for household consumption. However, the potential health risks from heavy metal contamination in these soils have not been thoroughly explored. This study aimed to evaluate the contamination of six heavy metals (Arsenic (As), Mercury (Hg), Cadmium (Cd), Lead (Pb), Copper (Cu), and Chromium (Cr)) in upland rice across RSC fields with varying fallow periods and assess the associated health risks from rice consumption. Four RSC fields with 5, 6, 10, and 12-year fallow periods were examined. The RSC-6Y and RSC-12Y fields were used for upland rice cultivation in 2022, while the RSC-5Y and RSC-10Y fields were cultivated in 2023. The geo-accumulation index (Igeo) was calculated, and translocation factors (TF) were assessed for the transfer of heavy metals from soil to straw (TFStraw/Soil), straw to grain (TFGrain/Straw), and soil to grain (TFGrain/Soil). The results indicated that after burning vegetation in the RSC fields, the highest concentrations of Pb, Cr, and Hg were found in the ash. In RSC soils, Cu, Cr, As, Pb, and Hg levels were below reference standards, with Cd undetected. In rice grains, the order of concentration was Pb > Cu > Cr > As, with Hg and Cd undetected. Pb levels in rice grains exceeded the safety threshold. Igeo values indicated no contamination to moderate contamination across sites, with negative Igeo values for Cr and Cu, and zero values for Cd. The TF results showed limited transfer of As, Hg, and Cd from soil to rice plants (TFStraw/Soil < 0.1), but notable transfer for Pb, Cr, and Cu. Pb was readily transferred from soil to grain (TFGrain/Soil), posing a potential health risk. The study highlights potential non-carcinogenic and carcinogenic risks from heavy metal exposure, particularly Pb, and underscores the need for further research to determine contamination sources and mitigation strategies. [ABSTRACT FROM AUTHOR]

Lodging is more than just plants falling over; it incurs significant economic losses for farmers leading to a decrease in both yield and quality of the final produce. Human management practices, such as dense sowing, excessive nitrogen fertilizer applications, inappropriate sowing dates, and upland rice cultivation, exacerbate the risk of lodging in rice. While breeders have developed high-yielding rice varieties utilizing the sd1 gene, relying solely on this gene is insufficient to enhance lodging resistance. Identifying the traits that contribute to lodging resistance is crucial. Key factors include biochemical, anatomical, and morphological traits, such as the levels of lignin, cellulose, hemicellulose, silicon, and potassium, along with the number and area of vascular bundles and the thickness, diameter, and length of the culm. Moreover, markers associated with lodging-related genes, like SCM2 , SCM3 , SCM4 , and prl4 , can be utilized effectively in marker-assisted backcrossing to develop rice varieties with desirable culm traits. This literature review aims to aid rice breeders in addressing the issue of lodging by examining traits that influence lodging resistance, developing phenotyping strategies for these traits, identifying suitable instrumentation, exploring methods for screening lodging-resistant plants, understanding the mathematical relationships involved, and considering molecular breeding aspects for pyramiding genes related to lodging. [ABSTRACT FROM AUTHOR]

The recent invasion of the fall armyworm (FAW) into Asia not only has had a major impact on maize yield but is feared to also pose a risk to rice production. We hypothesized that the brown planthopper (BPH) may aggravate this risk based on a recently discovered mutualism between the planthopper and the rice striped stem borer. Here we show that BPH may indeed facilitate a shift of FAW to rice. FAW females were found to strongly prefer to oviposit on BPH‐infested rice plants, which emitted significantly elevated levels of five volatile compounds. A synthetic mixture of these compounds had a potent stimulatory effect on ovipositing females. Although FAW caterpillars exhibited relatively poor growth on both uninfested and BPH‐infested rice, a considerable portion completed their development on young plants. Moreover, FAW were found to readily pupate and survive in exceedingly moist soils typical for rice cultivation, further highlighting FAW's potential to switch to rice. We conclude that BPH, by changing the bouquet of volatiles emitted by rice plants, may greatly facilitate this switch. These findings, together with a current increase of nonflooded upland rice in Asia, warrant careful monitoring and specific control measures against FAW to safeguard Asian rice production. Summary statement: Rice plants infested by the brown planthopper (BPH) were found to be highly attractive to ovipositing fall armyworm (FAW) moths. Moreover, FAW caterpillars readily developed on young rice plants and successfully pupated in exceedingly moist soils, typical for rice cultivation. These findings imply that BPH may help invasive FAW to rapidly adapt to rice, which could then become a major threat to food security in Asia. [ABSTRACT FROM AUTHOR]

Shanlan upland rice is an important landrace resource with high drought stress (DS) tolerance. Despite its importance, genes responsible for yield in Shanlan upland rice have yet to be discovered. Our previous study identified a drought-responsive zinc finger protein, ZOS7, as highly expressed in Shanlandao upland rice. However, the function of this gene in controlling drought tolerance remains largely unexplored. In this study, we found that overexpressing ZOS7, a drought-responsive zinc finger protein, in rice increased biomass and yield under drought stress. Co-overexpressing ZOS7 and MYB60, encoding a protein with which ZOS7 interacted, intensified the yield increase. ZOS7 and MYB60 appear to form a module that confers drought tolerance by regulating stomatal density and wax biosynthesis. The ZOS7-MYB60 module could be used in molecular breeding for drought tolerance in rice. [ABSTRACT FROM AUTHOR]

Background and Aims Root system architecture (RSA) plays a key role in plant adaptation to drought, because deep rooting enables better water uptake than shallow rooting under terminal drought. Understanding RSA during early plant development is essential for improving crop yields, because early drought can affect subsequent shoot growth. Herein, we demonstrate that root distribution in the topsoil significantly impacts shoot growth during the early stages of rice (Oryza sativa) development under drought, as assessed through three-dimensional image analysis. Methods We used 109 F12 recombinant inbred lines obtained from a cross between shallow-rooting lowland rice and deep-rooting upland rice, representing a population with diverse RSA. We applied a moderate drought during the early development of rice grown in a plant pot (25 cm in height) by stopping irrigation 14 days after sowing. Time-series RSA at 14, 21 and 28 days after sowing was visualized by X-ray computed tomography and, subsequently, compared between drought and well-watered conditions. After this analysis, we investigated drought-avoidant RSA further by testing 20 randomly selected recombinant inbred lines in drought conditions. Key Results We inferred the root location that most influences shoot growth using a hierarchical Bayes approach: the root segment depth that impacted shoot growth positively ranged between 1.7 and 3.4 cm in drought conditions and between 0.0 and 1.7 cm in well-watered conditions. Drought-avoidant recombinant inbred lines had a higher root density in the lower layers of the topsoil compared with the others. Conclusions Fine classification of soil layers using three-dimensional image analysis revealed that increasing root density in the lower layers of the topsoil, rather than in the subsoil, is advantageous for drought avoidance during the early growth stage of rice. [ABSTRACT FROM AUTHOR]

Ensuring accurate classification of rice as either cooked or dry is vital for food safety, as improperly stored or cooked rice contain harmful bacteria, emphasizing the importance of maintaining and monitoring food safety standards. In the field of image analysis and food classification, classifying dry and cooked rice samples using photographs is an interesting but difficult task. The main challenge stems from the minute visual variations between cooked and dry rice, which has not always displayed distinct traits that are easily observable by machines. Hence, various machine learning algorithms were implemented to effectively mitigate this issue. However, the existing works have not analysed the physicochemical characteristics due to non-destructive type of experimentation method with image processing. To overcome this issue, this work develops the Classification and Regression Tree (CART) of Decision Tree Learning method for classifying the rice grain samples as dry or cooked based on the physicochemical characteristics such as morphological, texture and color features, which in turn gain an exhaustive facts of rice quality in diverse state. Initially, the images are captured, pre-processed and the features are extracted. From the extracted features, the rice samples are classified as dry and cooked using DT and the results are compared with the existing algorithms like K-Nearest Neighbour (KNN) and Support Vector Machine (SVM). The comparative analysis of these classification algorithms infers the outperformance of the DT learning model under morphological, texture and color features in terms of accuracy, error, precision, recall and F-score. [ABSTRACT FROM AUTHOR]

Background and aims: Interactions between / among nutrients have been widely concerned and studied in recent years. Because of the global industrialization and intensive cultivation of crops in the past few decades, the Cu concentration in soil is gradually increased. Meanwhile, N fertilizers have been widely supplied in arable land to obtain high yield. Therefore, it is necessary and important to investigate the possible interaction between Cu and N in both rice plant and rhizosphere soil, and further to reveal its underlying mechanism. Methods: A short-term pot experiment was conducted during rice vegetative stage. Plants were grown in soils with different combinations of Cu and N, the plant growth, Cu and N status, enzyme activities, and expression levels of genes involved in N and Cu transport in rice plant, as well as the Cu and N transformation, bacteria and fungi communities, enzyme activities, and expression levels of genes involved in N cycling in rhizosphere soil were analyzed. Results: Results showed that HCu significantly decreased the net photosynthetic rate and shoot dry weight of rice, while NN could effectively alleviate this repression. HCu significantly inhibited N uptake, transport, and assimilation by down-regulating OsNRTs expression and reducing NR and GOGAT activities in rice plant, while N supply decreased Cu uptake by down-regulating OsCOPTs in root, but promoted the root-to-shoot translocation and distribution of Cu in leaves by up-regulating OsHMA5 and OsYSL16 in shoot. In rice rhizosphere soil, HCu facilitated N turnover and increased N availability, but decreased soil enzyme activities and the copy numbers of almost all N cycling genes, whereas N supply did not have any impact on Cu turnover. The effect of HCu on bacterial and fungal communities was more pronounced than N treatment. HCu significantly increased the relative abundances of a metal resistant bacteria phyla, Firmicutes, but also increased the relative abundances of two pathogenic fungi, Ascomycota and Zygomycota. Conclusion: Taken together, although HCu facilitated N turnover and increased N availability in rice rhizosphere soil, an antagonistic effect between HCu and N was observed in rice plant that HCu significantly inhibited N uptake, transport, and assimilation. These results are still needed to be verified by field trials in the future. [ABSTRACT FROM AUTHOR]

Background: Rice (Oryza sativa L.) is the major cereal crop grown in India. Rice plays a pivotal role in the socio-cultural life of the people of Assam. The main objective of this study to investigate the influence micro climatic indices in relation to crop growth and yield of upland rice varieties with different dates of sowing in Assam. Methods: A field experiment was carried out at Instructional cum Research Farm, Assam Agricultural University, Jorhat during autumn season of 2017. The experiment consisted of four micro-climatic regimes (M) along with four different rice varieties (V). Result: The results of the experiment revealed that micro climatic indices viz., canopy temperature, growing degree days, soil moisture content, soil temperature, light intensity, depth of ground water table associated with 1st April sown crop recorded positive effect on growth and yield parameters in terms of plant height, leaf area index, number of filled grains per panicle, test weight, harvest index and grain yield (3004 kg/ha), followed by the micro-climate associated with 16th March sown crop. Among the varieties evaluated, CR-Dhan 203 recorded the highest grain yield of 2860 kg/ha and was significantly superior to that of other varieties except Inglongkiri. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) stands as one of the most critical staple crops globally, with its yield and water use efficiency (WUE) being pivotal for food security. This study aimed to evaluate the agronomic and physiological traits and WUE of six rice varieties under two irrigation regimes: alternate wetting and drying (AWD) and conventional irrigation (CI). The results showed the significant improvements in grain yield and WUE with variety improvement under both irrigation treatments. Under AWD, high water use efficiency varieties (HWVs) demonstrated pronounced enhancements, including tillers and spikelet production, filled grain rate, 1000-grain weight, harvest index, leaf area index, non-structural carbohydrate remobilization, photosynthesis and catalase and peroxidase activities of leaf, root and shoot biomass, and root activity. AWD was observed to synchronize and amplify grain yield (2–14%) and WUE, including both leaf-level (13.94–20.72%) and yield-level (23.20–30.87%) water use efficiencies (WUEL and WUEY). The water use potential for HWVs was substantially enhanced under AWD. The integration of variety improvement with AWD irrigation strategies effectively achieves the dual objectives of high yield and WUE, offering a promising approach for sustainable rice production. [ABSTRACT FROM AUTHOR]

Glyphosate IPA 240 g/L herbicide is known as one of the effective chemical solutions in weed control, especially in no-tillage systems. No-tillage systems offer advantages in upland rice cultivation by reducing soil damage and production costs. However, the main challenge in the application of no-tillage systems is the presence of pre-planting weeds that can compete with plants in the absorption of growth factors such as nutrients, light, and water. This experiment aims to test herbicide doses that effectively suppress weed growth and optimize the growth and yield of upland rice with the no-tillage system. The experiment was conducted from December 2023 to April 2024 at Ciparanje Farm, Faculty of Agriculture, Padjadjaran University, Jatinangor District, Sumedang Regency, West Java Province, Indonesia. The experiment used Randomized Block Design (RBD), consisting of 7 treatments, each repeated four times. The treatments consisted of 5 doses of glyphosate IPA 240 g/L herbicide 2.00, 3.00; 4.00, 5.00; 6.00 L/ha with no-tillage system; manual weeding; and control with perfect tillage system. Experimental results showed that glyphosate IPA 240 g/L herbicide at a dose of 3.00 - 6.00 L/ha with the no-tillage system can be used to replace the perfect tillage system because it can suppress the growth of broadleaf weeds, namely Ageratum conyzoides, Cleome rutidosperma, Mollugo pentaphylla and Synedrela nodiflora, and grass Digitaria ciliaris. No phytotoxicity symptoms were found, and had a favorable effect on rice plant growth regarding population size and tillers. The yield of rice plants with the highest milled dry grain yield was 4.45 t/ha. [ABSTRACT FROM AUTHOR]

Variations in the cadmium (Cd) accumulation and root characteristics of different genotypes of rice during three developmental periods of dry cultivation were investigated in pot experiments in which two levels of Cd were added to the soil (0 and 10 mg kg−1). The results show that the Cd concentration in each organ of the different rice genotypes decreased in both the order of roots > shoots > grains and during the three developmental periods in the order of the maturity stage > booting stage > tillering stage. The lowest bioaccumulation factor (BCF) and translocation factor (TF) were found in Yunjing37 (YJ37) under Cd stress. At maturity, Cd stress inhibited the root length of Dianheyou34 (DHY34) the most and that of Dianheyou 918 (DHY918) the least, also affecting the root volume of DHY34 and Dianheyou615 (DHY615) the most and that of YJ37 and Yiyou 673 (YY673) the least; the inhibition rates were 41.80, 5.09, 40.95, and 10.51%, respectively. The exodermis showed the greatest thickening in YY673 and the lowest thickening in DHY615, while the endodermis showed the opposite result. The rates of change were 16.48, 2.45, 5.10, and 8.49%, respectively. The stele diameter of DHY615 decreased the most, and that of YY673 decreased the least, while the secondary xylem area showed the opposite result; the rates of change were −21.50, −14.29, −5.86, and −26.35%, respectively. Under Cd stress treatment at maturity, iron plaque was extracted using the dithionite–citrate–bicarbonate (DCB) method. The concentration of iron (DCB-Fe) was highest in YJ37, and the concentration of cadmium (DCB-Cd) was lowest in DHY34. YJ37 was screened as a low Cd-accumulating variety. The concentration of available Cd in the rhizosphere soil, iron plaque, root morphology, and anatomy affect Cd accumulation in rice with genotypic differences. Our screening of Cd-accumulating rice varieties provides a basis for the dry cultivation of rice in areas with high background values of Cd in order to avoid the health risks of Cd intake. [ABSTRACT FROM AUTHOR]

Gene expression can be highly plastic in response to environmental variation. However, we know little about how expression plasticity is shaped by natural selection and evolves in wild and domesticated species. We used genotypic selection analysis to characterize selection on drought‐induced plasticity of over 7,500 leaf transcripts of 118 rice accessions (genotypes) from different environmental conditions grown in a field experiment. Gene expression plasticity was neutral for most gradually plastic transcripts, but transcripts with discrete patterns of expression showed stronger selection on expression plasticity. Whether plasticity was adaptive and co‐gradient or maladaptive and counter‐gradient varied among varietal groups. No transcripts that experienced selection for plasticity across environments showed selection against plasticity within environments, indicating a lack of evidence for costs of adaptive plasticity that may constrain its evolution. Selection on expression plasticity was influenced by degree of plasticity, transcript length and gene body methylation. We observed positive selection on plasticity of co‐expression modules containing transcripts involved in photosynthesis, translation and responsiveness to abiotic stress. Taken together, these results indicate that patterns of selection on expression plasticity were context‐dependent and likely associated with environmental conditions of varietal groups, but that the evolution of adaptive plasticity would likely not be constrained by opposing patterns of selection on plasticity within compared to across environments. These results offer a genome‐wide view of patterns of selection and ecological constraints on gene expression plasticity and provide insights into the interplay between plastic and evolutionary responses to drought at the molecular level. [ABSTRACT FROM AUTHOR]

Strong early growth vigor is an essential target in both direct seeded rice breeding and high-yielding rice breeding for rice varieties with relatively short growth duration in the double-cropping region. Shoot dry weight (SDW) is one of the important traits associated with early growth vigor, and breeders have been working to improve this trait. Finding stable QTLs or functional genes for SDW is crucial for improving the early growth vigor by implementing molecular breeding in rice. Here, a genome-wide association analysis revealed that the QTL for SDW, qSDW-5, was stably detected in the three cultivation methods commonly used in production practice. Through gene-based haplotype analysis of the annotated genes within the putative region of qSDW-5, and validated by gene expression and knockout transgenic experiments, LOC_Os05g09520, which is identical to the reported GW5/GSE5 controlling grain width (GW) and thousand grain weight (TGW) was identified as the causal gene for qSDW-5. Five main haplotypes of LOC_Os05g09520 were identified in the diverse international rice collection used in this study and their effects on SDW, GW and TGW were analyzed. Phenotypic comparisons of the major haplotypes of LOC_Os05g09520 in the three subpopulations (indica, japonica and aus) revealed the same patterns of wider GW and higher TGW along with higher SDW. Furtherly, the haplotype analysis of 138 rice varieties/lines widely used in southern China showed that 97.8% of the cultivars/lines carry Hap2LOC_Os05g09520. These results not only provide a promising gene source for the molecular breeding of rice varieties with strong early growth vigor, but also elucidate the effect of the LOC_Os05g09520 haplotypes on SDW, GW, and TGW in rice. Importantly, this study provides direct genetic evidence that these three traits are significantly correlated, and suggests a breeding strategy for developing high-yielding and slender grain-shaped indica cultivars with strong early growth vigor. [ABSTRACT FROM AUTHOR]

Background: Improving the efficiency of nitrogen utilization in rice is vital for achieving significant crop yields with minimum harm to the environment. To tackle this challenge, various portable optical sensors and decision-support tools have been emerging in recent times. However, there is currently a lack of comprehensive assessment and comparison of these tools with different levels of fertilizer recommendation with and without additional supplementation of nano urea. Methods: The current study was carried out during the dry season of 2021 and 2022 at the P.G. Experimental Farm of Centurion University of Technology and Management. The investigated treatments encompassed the following: T1: Absolute control, T2: 90-45-45 (N-P2O5-K2O kg/ha), T3: 120-60-60 (RDF), T4: 150-75-75, T5: T2+NU @ 2 ml/L at panicle initiation, T6: T3+NU @ 2 ml/L at panicle initiation, T7: N application at LCC ≤ 3, T8: N application at LCC ≤ 4, T9: N application at SI < 90%, T10: Nutrient Expert (TY: 5.5 t/ha), T11: Rice crop manager (TY: 5.5t/ha) which were allocated in randomized block design with three replications. Result: The findings showed that implementing nitrogen (N) application when the sufficiency index (SI) is below 90% led to a significant 16.85% boost to grain yield of rice compared to the application of 120-60-60 at fixed intervals as per the standard recommendation. In the former approach, 150 kg N/ha was applied in four splits. However, N application at a leaf color chart (LCC) value of 4 or less was considered efficient, with maximum agronomic efficiency (18.22 and 19.22 kg grain/kg N applied) and recovery efficiency (43.27% and 50.25%) observed in 2021 and 2022, respectively since, this approach resulted in a comparable yield increase and nitrogen absorption with a reduced nitrogen input. [ABSTRACT FROM AUTHOR]

Background: Silicon (Si) has been considered a beneficial element for many plants. Si-rich biochar (Sichars) from rice husk or peanut shell have been suggested to be a potential source of bioavailable Si for Si-accumulator plants. Our study aimed to assess the Si-fertilization efficiency from chemical fertilizer and rice husk and peanut shell biochars on rice dry matter and shoot Si uptake. Methods: Pot trials were conducted in two crop seasons in 2023 (from February to April - spring season and from May to Julysummer season) in the close net house. Treatments included 1 treatment with pure soil (control), 4 treatments with Si and N-P-K fertilizers and 6 treatments with biochar amendments and N-P-K fertilizers. These pot experiments were designed in the randomized complete block (RCBD) with 4 replications. Result: Shoot dry matter increased from 35.6 to 66.7% compared with control in different rates of Si fertilizer application and was also found the highest values in RHB and PSB at 15 g/kg soil application. Different Si and biochar application rates had a significant effect (P<0.05) on Si uptake by rice shoot. Therefore, Si-rich biochar considers as potential material for providing available Si to maintain the required level of available Si in soil and plant for healthy and high crop production. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) plant architecture is crucial in rice productivity enhancement, particularly in forecasting agronomic-related traits. The presented research characterized the shoot architecture, photosynthesis, and yield-related traits in the F9 generation of rice recombinant inbred lines (RILs) derived from a cross between cultivar IR64 and local cultivar Hawara Bunar through correlation and path analyses among the various features. Rice RILs and parental cultivars’ sowing transpired in the greenhouse and the field. The greenhouse experiment commenced growing the rice seeds of 90 RILs and their parental lines in PVC tubes (20 cm in diameter and 50 cm in height) with sand soil as a medium. The study employed the upland rice cultivation system for the field experiment to cultivate the rice genotypes. The study used a randomized complete block design (RCBD) with three replications. Shoot plant architecture, physiological, and yield traits observation continued at various stages of plant growth. A significant positive correlation to the seed yield per plant appeared in the maturative stage by the total seed weight, transpiration efficiency, intercellular CO2 concentration, and intercellular CO2 pressure. A substantial positive indirect effect on grain yield also surfaced from the net transpiration rate and its efficiency, intercellular CO2 concentration, and CO2 pressure. Therefore, the shoot architecture significantly affects the photosynthetic rate and grain yield. [ABSTRACT FROM AUTHOR]

Background: As a key agricultural region in China, Heilongjiang Province has experienced significant carbon emissions over the past few decades. To understand the underlying factors and future trends in these emissions, a comprehensive analysis was conducted from 1993 to 2030. Methods: The agricultural carbon emissions from 1993 to 2020 were estimated using the emission factor method. To analyze the influencing factors and future trends of these emissions, the study employed the Logarithmic Mean Divisia Index (LMDI) and integrated it with the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. Results: Results showed that (1) the agricultural carbon emissions in Heilongjiang were primarily driven by rice cultivation, followed by fertilizer production and irrigation electricity. (2) The economic and labor structure effects were the main driving factors of agricultural carbon emissions, while the population, demographic, and intensity effects were the main inhibitors. (3) Agricultural carbon emissions in Heilongjiang Province peaked in 2016 with 69.6 Mt CO2-eq and could subsequently decline by −3.92% to −4.52% between 2020 and 2030 in different scenario simulations. In the future, Heilongjiang Province should prioritize the reduction of agricultural carbon emissions from rice production. Adjusting the planting structure, managing the layout of rice paddies, and promoting the cultivation of dry rice varieties would significantly contribute to mitigating agricultural carbon emissions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rice waterlogging stress test was conducted at the experimental base of the College of Agriculture, Yangtze University, using Yangxian You 418 as the test subject, in order to investigate the impact of waterlogging on rice growth during the period from July to August each year. Six waterlogging stress tests with different waterlogging depth (1/4 plant height (1/4PH), 2/4 PH, and 3/4 PH) and duration (5 d and 7 d) were set up at the jointing–booting stage of rice (T1: 1/4 PH, 7 d; T2: 2/4 PH, 7 d; T3: 3/4 PH, 7 d; T4: 1/4 PH, 5 d; T5: 2/4 PH, 5 d; T6: 3/4 PH, 5 d;) with shallow water irrigation (CK) as control. The plant height, population leaf area, above-ground dry matter, and the yield of rice were measured. The correlation between the waterlogging depth and rice yield reduction was analyzed, and the flood disaster threshold index of rice was established. The results showed that at the end of stress, the plant height of all waterlogged treatments exceeded CK, and the plant height of T3 and T6 treatments significantly increased by 31.90% and 15.93%, respectively. The leaf area of rice treated with T1, T3, T4, and T5 was higher than CK (p < 0.05), and the above-ground dry matter of rice treated with T2, T3, T4, T5, and T6 was higher than CK (p < 0.05). When normal irrigation was restored to the maturity stage, the plant height of all rice treated with waterlogging was still higher than CK (p < 0.05). However, as the degree of waterlogging increased, rice yield decreased significantly, with a notable reduction of 31.68% observed in the T3 treatment compared to CK. Assuming a drainage index based on a 20% decrease in rice yield, it is imperative that the ratio of flooded depth to plant height remains below 37% when waterlogging persists for 7 days in rice cultivation. These research findings offer crucial scientific insights for implementing effective drainage management measures during flood disasters in rice paddies. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Multifunctional microorganisms can play a crucial role in the development of the plant root system, a characteristic that significantly affects agricultural productivity. This study aimed to determine the effect of inoculating isolates of multifunctional rhizobacteria on the in vitro root growth of upland rice seedlings. The experiment had a completely randomized design with four treatments and ten replications. The treatments involved inoculating upland rice with the following rhizobacteria: BRM 32111 (Burkholderia sp.), BRM 63523 (Serratia sp.), BRM 63524 (Bacillus sp.), and the control treatment (without microorganisms). Inoculation with the rhizobacteria BRM 32111 and BRM 63524 had a positive effect on the initial root development of upland rice. Inoculation with isolate BRM 32111 generated significant effects on the length, diameter, total surface area and volume of rice seedling roots. The isolate BRM 63524 had significant effects on the length, diameter and total surface area of the roots. Rice seedlings from the control treatment showed the worst results for the variables analyzed. The use of PGPRs as bioagents is a promising alternative for better root development of rice seedlings. [ABSTRACT FROM AUTHOR]

Intercropping perennial forage grasses into cereal crops is an alternative to recover degraded pastures. However, the intercrop of forage grasses, such as Urochloa ruziziensis (R. Germ. and C. M. Evard) Crins (Congo grass), can lead to losses in cereal yield. Therefore, it is necessary to develop management strategies that allow forage grass establishment without major losses in cereal yield in intercropping. The objective was to study the agronomic and economic impacts of intercropping U. ruziziensis into a Clearfield upland rice (Oryza sativa L.) cultivar in the state of Goiás, Brazil, in two growing seasons. Treatments included forage grass seeds sowing method (broadcast or incorporation to the soil) and sowing times (at rice sowing, 20 days after emergence [DAE], and 45 DAE of rice). Also, imazapyr + imazapic herbicide was applied to restrict the competitive effect on rice yield. Monocropping control plots were also evaluated. Grain yield was measured on rice. Forage grass dry matter yield was measured at 30, 60, and 90 days after harvesting (DAH) of rice. Crude protein content was analyzed at 90 DAH. Profitability was calculated for each cropping system relative to rice monocropping. Intercropping of rice and U. ruziziensis sowed at 45 DAE provided the highest grain yield relative to other assessed intercropping treatments as well as rice monocropping. Concurrent sowing of rice and incorporated U. ruziziensis seeding provided the greatest economic return. This reformed cropping system improved land and pasture output, which can reduce the pressure to convert more land to agricultural use. Core Ideas: The use of herbicide‐resistant rice makes intercropping with forage plants feasible for pasture renewal.Intercropping management with imazapyr + imazapic does not affect rice yield.Intercropping rice with Urochloa ruziziensis increases land use capacity.The intercropping of rice and U. ruziziensis reduces the environmental and social pressure to deforest new areas. [ABSTRACT FROM AUTHOR]

Introduction: Addressing the global demand for rice production necessitates innovative approaches to enhance upland rice yield in rainfed agroecosystems, considering the challenges posed by increasing population, limited land fertility, low productivity, and water availability. Methods: In this study, our study investigated the impact of biochar and organic fertilizer on ten promising rice lines (G1 - G10) and two control (G11 - G12) cultivars under rainfed conditions. The experimental design used a split-plot design with four soil amendments as main plots, namely control, organic fertilizer, biochar, and biochar + organic fertilizer and 12 rice genotypes as subplot. Results: The absolute attainable yield gaps, differentiating organic and control (GAP1), biochar + organic and control (GAP2), and biochar and control (GAP3), ranged from 1.5 to 3.7 or increased of 91-580%, 0.8 to 3.5 (72-560%), and 0.6 to 2.58 tons/ha (58-472%), respectively. Notably, G2+ organic exhibited the highest positive absolute yield gap, ranging from 1.1 to 5.38 tons/ha, based on the yield gap matrix. Furthermore, genotype main effect plus genotype-environment interaction (GGE) biplot analysis identified G2 as the most promising rice line, displaying superior yield performance for cultivation in biochar and organic amended soils. Discussion: These findings provide valuable insights for farmers, governments, and stakeholders, offering a roadmap to optimize rainfed areas for rice production, serving as practical guidance to enhance overall rice productivity in rainfed agroecosystems. [ABSTRACT FROM AUTHOR]

Phosphorus and zinc are important nutrient elements of concern in upland rice production. To determine the suitable combination of phosphorus, nanoparticles (NPs), and bio-fertilizer application as an alternative nutrient management approach in upland rice cultivation, a Polyvinyl Chloride (PVC) column experiment was conducted under controlled conditions in 2015. The treatments consisted of three phosphorus levels, two foliar sprays of NPs (ZnO and TiO2), and PSB seed treatment. The results indicated that the combined application of P (50 kg ha−1), ZnO NPs (500 ppm), and PSB seed treatment (20 g kg−1) improved the root system architecture traits of rice (total root length: 3.73–6.74%, diameter: 8.57–22.22%, and volume: 3.40–3.70%) at depths of 0–30 cm and 30–60 cm, compared to higher P + TiO2 NPs + no PSB. Consequently, this combination led to an enhancement in photosynthetic leaf area (by 3.3%), tiller numbers (by 7%), and dry matter production (by 35.5%). The favorable root growth resulting from the application of higher P and PSB enhanced zinc uptake by rice grains (by 38.44%) and straw (by 26.99%). Furthermore, the supplemental application of PSB improved the activity of soil enzymes such as dehydrogenase and phosphatase. As a result, maximum phosphorus use efficiency (PUE; 31.5%) was achieved through the combined application of P (50 kg ha−1) × ZnO NPs × PSB. In conclusion, this study demonstrated the beneficial effects of an integrated approach involving phosphorus, PSB, and metal oxides (ZnO NPs) as a fertilizer management strategy to enhance the total biomass and PUE of upland rice. [ABSTRACT FROM AUTHOR]

Oryza sativa L. or commonly known as rice belongs to the family of Poaceae. In Malaysia, rice is normally cultivated either as lowland or upland rice. Sarawak is a state with diverse types of rice. All Sarawak rice are landraces. Despite the fact that Sarawak is rich in rice biodiversity, the assessment of the morphological traits which may provide basic information that is useful for the future breeding programs is still unavailable. The nomenclature of the landraces is based on the name given by the farmers. Problems arise when landraces having the same morphological characteristics were given different names and vice versa. In addition, the purity of seeds is unreliable. Common practices by the local farmers such as planting different rice landraces in the same field either in one plot or in different plots but very near to each other has contributed to the impurity of the seeds. The present study was undertaken with the objective to characterise the morphological traits of 22 lowland and 22 upland rice accessions from the North-Western region of Sarawak. The morphological traits observed on the 44 rice accessions viz., blade colour, ligule shape, ligule colour, auricle colour, heading days, flowering days, panicle type, culm length, panicle number, number of filled grain, seed length and grain colour exhibited variations. There are variations which may be considered in future Sarawak rice breeding programs. [ABSTRACT FROM AUTHOR]

Biochar from crop residues plays an important role in reclamation of degraded rice soil due to imbalance fertilizer application and soil carbon sequestration. The objective of this study aimed to evaluate the best type and rate of biochar application for rice dry matter and soil organic carbon improvement. Therefore, pot experiments were carried out in two seasons of spring and summer 2023 at the University of Agriculture and Forestry, Hue University. Twelve treatments including 2 types of biochar (rice husk and peanut shell) and 6 application rates (0, 1, 2, 3, 4, 5%) were used and arranged in a randomized block design with three replications. Research results showed that the shoot dry matter was higher 9.5-27.0% (spring season) and 19.1-26.9% (summer season) at a rate of 5% application in both types of biochar than control. Rice husk biochar application had higher shoot dry matter than peanut shell biochar application in the same application rate from 0.30-0.46 g/plant in both seasons. Similarly, organic carbon was found the highest content (2.15-2.21%) when the application of biochar from crop residues at a rate of 5%. Biochar from crop residues is considered as a good amendment for increasing crop dry matter and soil organic carbon. [ABSTRACT FROM AUTHOR]

One-time application of blended controlled-release nitrogen fertilizer (CRN) has the potential to solve the difficulty of top-dressing fertilizer in the cultivation of rice and reduce the cost of CRN fertilizer application. However, its effects on rice dry matter and nitrogen (N) accumulation and translocation, yield and N-use efficiency (NUE) remain uncertain. Field experiments were carried out at three sites (Mingguang, Chaohu, and Guichi) in the Yangtze River Delta in China to compare the effects of the conventional split applications of urea and the blended CRN and on post-anthesis dry matter and N accumulation and translocation, yield, and NUE in rice at 0, 60, 120, 180, and 240 kg N ha-1. The results showed that at the equal N application rates, compared under the conventional N fertilizer treatment, the blended CRN application significantly increased the rice yield by an average of 0.9-6.9%, mainly due to increase the number of spikelets per panicle. The highest yield achieved with blended CRN treatment occurred at 200 kg N ha-1, with an NUE of 45.9%. Moreover, in comparison to the conventional N fertilizer, the blended CRN treatment increased pre-anthesis N translocation (Pre-NT) by 1.0-19.8%, and the contribution of pre-NT to grain N by 0.2-8.7%, and NUE by 3.2-28.4%. Meanwhile, the blended CRN treatment reduced labor costs by 1800 Yuan ha-1 and enhanced the economic gains by 21.5-68.8%. Therefore, one-time application of blended CRN ≤ 200 kg N ha-1 application rate improved rice yield, NUE, and economic profit compared to equivalent rates of split applied conventional N fertilizers. [ABSTRACT FROM AUTHOR]

As the pre-process of storage and processing, rice drying is a key link to ensuring grain quality. A scientific and reasonable drying process can maintain grain quality and realize grain loss reduction, energy savings, and emission reduction. By establishing the response surface (RSM) regression model, the relationship between various experimental factors and quality indicators was analyzed, and the reasons for the results were explained. The optimized parameter combination was a hot air temperature of 43.14 °C, hot air humidity of 48.00%, initial moisture content of 23.80%, hot air velocity of 0.70 m/s, and hysteresis ratio of 3.55. Under this parameter combination, the drying characteristics (net drying time = 157.61 min, germination rate = 94.15%), processing quality (burst waist increase rate = 3.48%, whole rice rate = 70.458%), and nutritional quality (fatty acid value = 20.93 mg, resistant starch concentration = 195.26 μg/g, protein content change = 8.53 g/100 g, fat content change = 2.37 g/100 g) of rice after drying improved. The relative error between the validation results and the optimized results was 4.68%, indicating that the optimized process parameters can improve the efficiency and quality of rice drying. According to the regression model, the process reference chart with the process retrieval and prediction function was drawn, and the corresponding high-quality control scheme was given, providing a reference for the parameter settings of actual drying operations. The optimized drying process parameter combination effectively reduced the moisture gradient inside rice grains, drying stress, and the occurrence of cracks, thereby improving the appearance, quality and nutritional value of rice after drying. Moreover, the process reference chart can provide a reference for the actual preliminary processing technology of rice after production and a theoretical basis for an in-depth exploration of the mechanism of changes in rice quality. [ABSTRACT FROM AUTHOR]

Improper drying of rice can cause significant kernel defects. A rice material state diagram consisting of glass transition temperature (Tg) at various moisture content (MC) levels is a tool that helps predict the appropriate drying temperatures to employ. The present diagrams were however developed for old rice cultivars which may be inadequate for predicting the drying behavior of contemporary cultivars. The objective of this study was therefore to develop material state diagrams along with updated Tg prediction models tailored to accommodate the contemporary rice cultivars presently grown. In the study, 23 rice cultivars were analyzed and revealed average Tg values of approximately 39, 41, 43, 45, and 47 °C at MC levels of 20%, 18%, 16%, 14%, and 12%, respectively. The updated material state diagrams developed from the results incorporated a Tg prediction model, indicating elevated Tg values and an improved R2 value of 0.72, when compared to prior research findings. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate fluid flow and coupled heat-moisture transfer in the hot-air drying of grain piles, this study integrated the discrete-element method with computational fluid dynamics. A model for a thin-layer grain pile, consisting of nonspherical rice particles represented by 13 spheres, was developed. Using a heat-moisture transfer model based on fluid–solid coupling, the drying process with hot air was simulated and validated against experimental data. Finally, by controlling the drying temperature and the initial moisture content of rice, the variations in temperature and moisture content during the hot-air drying process were explored. The numerical results indicated that the nonuniform pore structure within the grain pile, gaps on the surface of nonspherical rice, and the wall effect led to complex airflow patterns, resulting in the formation of dead zones within the grain pile. The oscillation frequency and amplitude of radial porosity near the wall were relatively large, and the minimum porosity occurred at a radial distance of 1/2dg. Heat and moisture transfer rates between the rice and drying air were influenced by the temperature and moisture concentration differences. During the drying process, variations in temperature and moisture content were observed among rice particles. Limited by the moisture diffusion coefficient, there existed a notable disparity in moisture content between the interior and surface of the rice. The results also showed that the curvature of the drying curve in the grain pile varied and was influenced by the drying conditions, especially under the high-temperature drying condition of 60°C. Practical Applications In this study, a grain pile model for nonspherical rice particles composed of 13 spheres was developed based on the discrete-element method and computational fluid dynamics. Furthermore, in accordance with the heat and mass transfer mechanism of fluid–solid coupling, a heat-moisture transfer model for the hot-air drying of the grain pile was constructed. This was done to deeply explore the internal fluid dynamic characteristics and the heat-moisture transfer within the grain pile during the drying process. The newly established model can be widely applied to numerical simulation studies of drying and also has reference value for the design of drying systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Sciences, Belgrade is the property of University of Belgrade, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Dry cultivation of rice is a water‐saving, emission reduction and labor‐saving rice farming method. However, the development of rice under dry cultivation is hampered by the limitations of dry cultivation on rice yield and rice quality. We hypothesized that additional silicon (Si) would be a measure to address these limitations or challenges. RESULTS: In the present study, we set up field trials with three treatments: flooded cultivation (W), dry cultivation (D) and dry cultivation plus Si. Yield and quality were reduced under D treatment compared to W treatment. The addition of Si promoted root development, increased plant height and leaf area, increased photosynthetic enzyme activity, net photosynthetic rate and SPAD values, and increased biomass under dry crop conditions. Under the drought conditions, silica up‐regulated the expression of AGPSI, SBEI, SBEIIb, SSI and SSII‐1 genes and the activities of ADP‐glucose pyrophosphorylase (AGPase), soluble starch synthetase (SSS) and starch branching enzyme (SBE) enzymes, which reduced protein, amylose, chalkiness percentage and chalkiness degree, increased brown rice rate, milled rice rate and head milled rice rate, and also improved rice quality. In addition, the increase of AGPase, SSS and SBE enzyme activities promoted the filling rate and the number of spikes was guaranteed, whereas the yield was improved by promoting the seed setting rate and 1000‐grain weight. CONCLUSION: The results of the present study indicate that adding appropriate amounts of Si fertilizer can improve the yield and quality of rice under dry cultivation by regulating source supply capacity and grain starch synthesis. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The Shanlan landrace rice in Hainan Province, China, is a unique upland rice germplasm that holds significant value as a genetic resource for rice breeding. However, its genetic diversity and its usefulness in rice breeding have not been fully explored. In this study, a total of eighty-four Shanlan rice, three typical japonica rice cultivars, and three typical indica rice cultivars were subjected to resequencing of their genomes. As a result, 11.2 million high-quality single nucleotide polymorphisms (SNPs) and 1.6 million insertion/deletions (InDels) were detected. Population structure analysis showed all the rice accessions could be divided into three main groups, i.e., Geng/japonica 1 (GJ1), GJ2, and Xian/indica (XI). However, the GJ1 group only had seven accessions including three typical japonica cultivars, indicating that most Shanlan landrace rice are different from the modern japonica rice. Principal component analysis (PCA) showed that the first three principal components explained 60.7% of the genetic variation. Wide genetic diversity in starch physicochemical parameters, such as apparent amylose content (AAC), pasting viscosity, texture properties, thermal properties, and retrogradation representing the cooking and eating quality was also revealed among all accessions. The genome-wide association study (GWAS) for these traits was conducted and identified 32 marker trait associations in the entire population. Notably, the well-known gene Waxy (Wx) was identified for AAC, breakdown viscosity, and gumminess of the gel texture, and SSIIa was identified for percentage of retrogradation and peak gelatinization temperature. Upon further analysis of nucleotide diversity in Wx, six different alleles, wx, Wxa, Wxb, Wxin, Wxla/mw, and Wxlv in Shanlan landrace rice were identified, indicating rich gene resources in Shanlan rice for quality rice breeding. These findings are expected to contribute to the development of new rice with premium quality. [ABSTRACT FROM AUTHOR]

Summary: Upland rice is a distinctive drought‐aerobic ecotype of cultivated rice highly resistant to drought stress. However, the genetic and genomic basis for the drought‐aerobic adaptation of upland rice remains largely unclear due to the lack of genomic resources. In this study, we identified 25 typical upland rice accessions and assembled a high‐quality genome of one of the typical upland rice varieties, IRAT109, comprising 384 Mb with a contig N50 of 19.6 Mb. Phylogenetic analysis revealed upland and lowland rice have distinct ecotype differentiation within the japonica subgroup. Comparative genomic analyses revealed that adaptive differentiation of lowland and upland rice is likely attributable to the natural variation of many genes in promoter regions, formation of specific genes in upland rice, and expansion of gene families. We revealed differentiated gene expression patterns in the leaves and roots of the two ecotypes and found that lignin synthesis mediated by the phenylpropane pathway plays an important role in the adaptive differentiation of upland and lowland rice. We identified 28 selective sweeps that occurred during domestication and validated that the qRT9 gene in selective regions can positively regulate drought resistance in rice. Eighty key genes closely associated with drought resistance were appraised for their appreciable potential in drought resistance breeding. Our study enhances the understanding of the adaptation of upland rice and provides a genome navigation map of drought resistance breeding, which will facilitate the breeding of drought‐resistant rice and the "blue revolution" in agriculture. [ABSTRACT FROM AUTHOR]

Rice provides ~20% of human dietary energy and, for many people, a similar share of their protein. Rice cultivation, however, produces significant greenhouse gas (GHG) emissions, comparable to those from the aviation sector. The main GHG from rice production is methane, mostly a result of conventional rice cultivation (CRC) keeping rice fields continuously flooded during the crop cycle. There is extensive evidence that alternate wetting and drying (AWD) of rice fields substantially reduces methane emissions. AWD is one component of the System of Rice Intensification (SRI), an agroecological approach to the management of plants, water, soil, and nutrients. This article reviews field studies measuring GHG emissions associated with the adoption of AWD and SRI. The review confirms that both AWD and SRI offer substantial reductions in methane emissions per hectare compared with CRC. These benefits are, however, partly offset by increases in emissions of nitrous oxide and carbon dioxide. The studies also show that SRI (but not AWD) improves yield and therefore further reduces GHG emissions per kg of rice. The review concludes that while both AWD and SRI substantially reduce emissions per hectare and per kilogram of rice, SRI can simultaneously contribute to food security while addressing the drivers of climate change. Further investigation of carbon emissions and sequestration under different rice cultivation methods is needed to strengthen the evidence base. [ABSTRACT FROM AUTHOR]

Rice, a crucial staple in China, is cultivated through various techniques, including seedling transplanting, dry direct seeding, and film mulching. Despite its significance, rice production is a considerable environmental burden. Using a life cycle assessment (LCA) methodology, this study aimed to evaluate the environmental impacts of four rice cultivation methods (transplanting rice, dry direct-seeding rice, dry direct-seeding rice with polyethylene film (PE), and dry direct-seeding rice with biodegradable film) in Northeast China. The results indicate that the magnitude of environmental impacts among treatments was consistent across years. The potential values of all environmental impacts of the four different cultivation methods of rice in the 2021 field trial were smaller than the results of the same cultivation method of rice system in the 2022 field trial. Among the four rice cultivation methods, the consumption of energy showed inconsistency over the two years, with the highest energy consumption in the first year being for dry seeding with PE film and in the second year for dry seeding without film. Additionally, transplanting exhibited the highest impact on water resource consumption and climate change. Dry direct-seeding rice displayed the highest eutrophication and ecotoxicity. Dry direct-seeding rice with a biodegradable film had the least impact in terms of acidification. Moreover, dry direct-seeding rice with a biodegradable film minimized water consumption and greenhouse gas emissions without compromising yield. [ABSTRACT FROM AUTHOR]

Root‐knot nematodes, Meloidogyne spp., are considered one of the major biotic constraints for global rice production. Although the role of Meloidogyne graminicola in root‐knot disease progression is well investigated, negligible research has been performed to understand the damaging potential of M. incognita in rice. In this study, the comparative infection biology of M. incognita and M. graminicola was investigated in the basmati rice cultivar PB1121 growing in Pluronic gel medium and soil. Intriguingly, M. incognita laid eggs outside the galled root, whereas M. graminicola egg masses were deposited inside the galled root. This differential egg‐laying pattern can be correlated with their specific adaptations in irrigated and upland rice production systems. Although M. incognita induced a greater number of galls than M. graminicola, M. graminicola gall sizes were comparatively larger than those of M. incognita. The greater reproductive success of M. graminicola than M. incognita did not cause any difference in their yield reduction potential in PB1121. PB1121 was equally vulnerable to M. incognita and M. graminicola in terms of reduction in plant height, tiller numbers per plant and grain yield per plant. Our research suggests that M. incognita also causes economic damage to rice, and nematode management tactics must consider the damaging potential of both nematode species. [ABSTRACT FROM AUTHOR]

Background: Rice is the major crop in India in terms of area, production and consumption. Rice occupies about 23% of the gross cropped area and 35% of the total area under food grains in the country. Rice is of one key importance to the economy as well as a staple food for Telangana people, requiring about 50 lakh tons annually to feed the state population. In recent times the area under rice cultivation has been increased and is expected to hit the one crore acre mark by rabi season 2022. In any type of crop production system an accountability of inputs, energy spent, yield and costs must be monitored, by that one can modify it or substitute it for obtaining the better results. Methods: Due to decline in the share of agriculture workers in the country, there is a need to adopt new technologies in rice cultivation. Dry direct seeding of rice refers to direct sowing of rice seeds in the dry field rather than by transplanting seedlings from the nursery. A study was conducted to compute the inputs and energy consumptions in manual transplanted rice production (MTR) and dry direct seeding rice production (DDSR) methods of paddy cultivation in the combined Nalgonda district of Telangana State, during 2020-21. Firstly, the different operations performed in these two methods were listed out, then by using suitable energy equivalents total energy consumed in two methods of operations were calculated. Result: The human energy spent in the manual transplanted rice production and dry direct seeded rice productions were 506 and 92.84 MJ/ha respectively. Specific energy noted for dry direct seeded rice production and manual transplanted rice productions were 2.10 and 2.28 MJ/kg respectively. A total saving of Rs. 16,000/-ha-1 was recorded by practicing the dry direct seeded rice production method over the manual transplanted rice production method. On comparing both the methods for overall energy consumption, manual energy consumption and cost of cultivation DDSR method was found to be more efficient than MTR method in the district. [ABSTRACT FROM AUTHOR]

The southeast coast of China is a crucial area for the spread of agriculture from mainland Asia to Taiwan and the islands of Southeast Asia. However, whether prehistoric rice cultivation in this region was lowland or upland remains unclear. This study used a detailed phytolith analysis to evaluate temporal changes in structure at three coastal sites of varying altitudes in the Fujian Province of China, Longgang, Zhengjiashan, and Gehongshan. Samples were collected from two cultural phases, the Neolithic Huangguashan and Bronze Age Huangtulun cultures. Additionally, a new physical index, the sensitive-to-fixed phytolith ratio, was used to identify the environmental conditions in which crops were cultivated. Using this method, the number of sensitive types can be less or greater than that of fixed types, corresponding to drought or paddy field rice cultivation systems, respectively. The results showed an interplay of rice and millet farming at these sites. The crop phytolith ratio revealed that rice was dominant in the crop structure. However, notable differences existed in the proportion of different crops and phytolith assemblages across the various sites. The sensitive-to-fixed phytolith ratios, indicative of wet-dry environmental changes, were 1.56 and 1.07 at the low-altitude Longgang and water-rich Zhengjiashan sites, respectively, suggesting lowland rice cultivation. In contrast, the sensitive-to-fixed ratio at the high-altitude Gehongshan site was only 0.8, implying upland rice cultivation. The phytolith assemblage variation among the different sites also revealed an increase in dryland crops from low to high altitudes, indicating that the inhabitants of the southeastern coastal mountainous area modified their crop structure and rice cultivation methods during the Neolithic–Bronze Age transition to overcome environmental limitations. In summary, this study presents phytolith evidence for prehistoric upland rice cultivation on the southeast coast of China, offering valuable insights into the development of the prehistoric subsistence economy in the region. [ABSTRACT FROM AUTHOR]

The complex behavior of arsenic (As) in soil in conjunction to crop mediated transfer through the food chain necessitates a thorough evaluation of its phyto-availability. In this pretext, the present experiment has been conducted to determine the best chemical extractant for plant available As under the As-prone, rice-dominant agro-ecosystems of Gangetic West Bengal, India. Based on the tube-well arsenic data (JPOA, UNICEF), surface soil samples from high, medium, low and uncontaminated As sites have been collected. A pot study with rice cv. IR-36, exposed to varying levels of As (0, 0.1, 0.2, 0.3 and 0.4 mg L−1) was conducted. Ten chemical extractants were used in this study. The As extraction pattern followed the pattern of (HCl+H2SO4)>; (NH4-oxalate+Ascorbic acid)>; (Malic+Citric)> NaOH> KH2PO4> NaHCO3>; (H2O2+HNO3)> NH4F> NH4Cl> NH4OAc. On the 85th day after sowing, the rice plants were harvested keeping in mind that the maximum uptakes of heavy metals like As occurs during the peak vegetative growth (panicle initiation) stage. The soil As correlated with rice dry matter As accumulation as: NH4-oxalate+ascorbic acid (r = 0.729**)> NH4Cl (r = 0.698**)> H2O2+HNO3 (r = 0.697**)> NH4F (r = 0.693**)>Malic+Citric (r = 0.666**)> KH2PO4 (r = 0.615**)> HCl+H2SO4 (r = 0.608**)> NaOH (r = 0.589**)> NaHCO3 (r = 0.571**)> NH4OAc (r = 0.533*). Statistical analyses through correlation sum and stepwise multiple regression modeling revealed that NH4-oxalate+ascorbic acid had the best relationship with all other extractants, As fractions and soil physicochemical characters and therefore emerged as the best suited extractant of As for the wide-scale experimental locations under rice cultivation system. [ABSTRACT FROM AUTHOR]

Hanyou 3015 is a new Indica hybrid of water-saving and droughtresistance rice (WDR), combining rapid maturation and high yield potential. Whole genome sequencing results show that Hanyou 3015 carries many superior alleles that could explain its drought tolerance, high water use efficiency, rapid maturation, and wide adaptability. [ABSTRACT FROM AUTHOR]

Improving seed germination under drought stress has the potential to increase crop yield in dry direct‐seeded rice. In this study, a genome‐wide association study (GWAS) was conducted to determine the genetic basis of seed germination under drought stress in a panel of 165 rice accessions using a multi‐locus compressed variance‐component mixed model, 3VmrMLM. A total of 33 quantitative trait nucleotides (QTNs) were identified in association with drought tolerance during seed germination. Around these QTNs, eight were found to be co‐localized with known drought‐related genes. Furthermore, a causal candidate gene, OsGA2ox5, which encodes a gibberellin (GA) 2‐oxidase, was identified for QTN‐Chr07_242906 by integrating linkage disequilibrium (LD) analysis and gene expression analysis. Knockout mutation of OsGA2ox5 resulted in delayed seed germination and retarded seedling growth under drought stress. RNA‐seq analysis revealed that OsGA2ox5 regulates drought tolerance during seed germination mainly by modulating carbohydrate metabolism. Additionally, a non‐synonymous coding variant in OsGA2ox5, SNP‐Chr07_218893, was found to be strongly associated with drought tolerance level during seed germination. These findings provide valuable information for further exploration of novel drought‐related genes and genetic improvement of rice drought tolerance in the future. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have been increasingly employed for fungicide applications in plant disease control. However, due to weight limitations, the fungicides sprayed through UAVs must be in low volumes with high concentrations in many instances, which may result in potential phytotoxicity. Here we evaluate the safety of low-volume spray of chemicals on rice plants. The plants were sprayed with propiconazole emulsifiable concentrate (EC) at 250 g/L mixed with various adjuvants and applied at a low volume, which contained the fungicide at concentrations equivalent to or higher than that used in UAV application. The spray adjuvants included YS-20, Biaopu adjuvant, TriTek, Yipinsongzhi, AgriSolv-C100, and Hongyuyan. Potential phytotoxicity on rice plants was examined based on surface tension and crop growth. Additives suitable for a low-volume spray of propiconazole were also assessed on three rice varieties for phytotoxicity. The results showed that after 72 h of fungicide application at 2, 4, and 8 times the recommended dose of 7500 μg/mL for UAV spray, rice leaves exhibited abnormal growth, and the dry weight of rice significantly decreased 21 days after application. Phytotoxicity was evaluated on three rice varieties 5 days after spraying propiconazole EC at 2 × recommended dose with one of the spray adjuvants. The addition of 1% YS-20, Biaopu adjuvant, TriTek, and Yipinsongzhi significantly augmented the phytotoxicity. However, both AgriSolv-C100 and Hongyuyan significantly reduced the comprehensive index of phytotoxicity and, therefore, could be used for UAV applications. [ABSTRACT FROM AUTHOR]

The frequent occurrence of drought–flood abrupt alternation (DFAA) seriously affects crop yield. It is particularly important to explore the dynamics of material accumulation and distribution under DFAA stress to analyze the mechanism of yield formation. In this study, a bucket experiment with DFAA stress groups, drought control (DC) groups, flood control (FC) groups, and normal irrigation (CK) groups was set up from the jointing to the heading stage of rice to analyze the interaction effects of DFAA stress on rice yield and dry matter partitioning. The results showed that compared with the CK group, the average yield reduction rate of rice in the DFAA groups was 23.03%, and the number of grains per panicle, total grain number, thousand-seed mass, and seed setting rate decreased. Compared with the DC groups, the DFAA groups had a significant reduction in yield and its components during the flooding period. Compared with the FC groups, the DFAA groups showed a compensation phenomenon in the yield and its components during the drought period. From the end of DFAA stress to the harvest period, the root partitioning index (PI) of the DFAA groups decreased, the stem PI increased first and then decreased, the leaf PI decreased, and the panicle PI increased. The results showed that the rice leaves increased and thickened, and the stems thickened under DFAA conditions to enhance the ability to resist drought and flooding stress, but the panicle rate was reduced, the growth period of rice was delayed, and the redundant growth of stems and leaves was increased. It is suggested that the depth and duration of stagnant water storage during the flood period of DFAA should be controlled, and the transfer and supply of photosynthetic products to grains should be increased to avoid serious yield reductions. The research results provide a theoretical basis for the rational development of farmland DFAA mitigation measures. [ABSTRACT FROM AUTHOR]