Rice Yield Losses Research Articles

Surface ozone pollution-driven risks for the yield of major food crops under future climate change scenarios in India.

Surface ozone pollution-driven risks for the yield of major food crops under future climate change scenarios in India.

An annotated near-complete sequence assembly of the Magnaporthe oryzae 70-15 reference genome

Magnaporthe oryzae is a devastating fungal pathogen that causes substantial yield losses in rice and other cereal crops worldwide. A high-quality genome assembly is critical for addressing challenges posed by this pathogen. However, the current widely used MG8 assembly of the M. oryzae strain 70-15 reference genome contains numerous gaps and unresolved repetitive regions. Here, we report a complete 44.82 Mb high-quality nuclear genome and a 35.95 kb circular mitochondrial genome for strain 70-15, generated using deep-coverage PacBio high-fidelity sequencing (HiFi) and high-resolution chromatin conformation capture (Hi-C) data. Notably, we successfully resolved one or both telomere sequences for all seven chromosomes and achieved telomere-to-telomere (T2T) assemblies for chromosomes 2, 3, 4, 6, and 7. Based on this T2T assembly, we predicted 12,100 protein-coding genes and 493 effectors. This high-quality T2T assembly represents a significant advancement in M. oryzae genomics and provides an enhanced reference for studies in genome biology, comparative genomics, and population genetics of this economically important plant pathogen.

Assessment of rice yield losses and nutrition status in response to varied Nilaparvata lugens nymph densities and exposure durations

Assessment of rice yield losses and nutrition status in response to varied Nilaparvata lugens nymph densities and exposure durations

The Trp-574-Leu mutations together with enhanced metabolism contribute to cross-resistance to ALS inhibiting herbicides in Fimbristylis littoralis.

The Trp-574-Leu mutations together with enhanced metabolism contribute to cross-resistance to ALS inhibiting herbicides in Fimbristylis littoralis.

Ponding Water Quality of Rice Paddies Fertilized with Anaerobically Digested Liquid Pig Manure as Affected by Fly Ash and Zeolite

Anaerobically digested liquid pig manure (LPM) is enriched with nutrients and thus can be used as an alternative nutrient source and substitute for chemical fertilizer (CF) in rice (Oryza sativa L.) farming. However, there are concerns regarding the contamination of the surrounding water due to the discharge of ponding water containing dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P) from rice paddies fertilized using LPM. This study investigated the effects of the co-application of fly ash (FA) and zeolite (Z) amendments (FAZ amendments) on the concentration of DOC, N, and P in the ponding water of rice paddies fertilized with LPM at two different rates (standard (LPMS) and double (LPMD) at 11 and 22 g N m−2, respectively). Rice was cultivated using four nutrient treatments, including no input, CF (11 g N m−2), LPMS, and LPMD, with or without FAZ amendments. When FAZ was not amended, LPMS and LPMD application increased the DOC concentration by 32% and 41%, respectively, compared to CF treatments (11 g N m−2), reflecting a high DOC concentration in LPM. The total N and P concentrations in the ponding water were lower in LPMS treatment (by 5 and 8%, respectively) but higher (by 94% and 47%, respectively) in LPMD treatment compared to CF treatments in the absence of FAZ, indicating a high potential for water pollution with a double LPM application rate. With a given nutrient treatment, FAZ amendments decreased DOC by 15–39%, supporting the immobilization of DOC by Z. FAZ consistently decreased the NH4+ concentration by 6–51% across the nutrient treatments, likely via the sorption of NH4+ onto the negatively charged sites of Z, but its effect on total N concentration was not consistent. Unexpectedly, total P concentration increased (by 77–167%) following the FAZ amendment. FAZ amendments tended to increase rice biomass and grain yield for LPM treatments, but these rice growth parameters were poor compared to CF regardless of FAZ amendment. Our results show that the application of LPM as a complete replacement for CF may hamper rice yield while increasing the likelihood of water pollution with DOC and P, although the co-application of FAZ may help to reduce rice yield loss and decrease DOC and NH4+ concentrations.

AMF inoculation reduces yield losses in rice exposed to alternate wetting and drying and low fertilization

Arbuscular mycorrhizal fungi (AMF) enhance the uptake of water and nutrients by host plants. In this study, we examined the response of six rice varieties from two ecotypes (three irrigated and three rainfed upland varieties) to AMF inoculation at five fertilizer levels, under continuous flooding (CF) and alternate wetting and drying (AWD) irrigation over two consecutive years in field conditions. Both irrigated and upland rice varieties experienced significant yield losses with AWD irrigation and reduced NPK fertilizer levels, with irrigated rice being more severely affected. Under AWD irrigation, AMF inoculation mitigated relative yield losses, especially when half of the recommended fertilizer dose was applied. In CF conditions, AMF inoculation often fully compensated for yield losses caused by reduced NPK levels. Furthermore, irrigation regime, fertilizer levels, and ecotype were significant sources of variation in the effects of AMF inoculation on several yield-related traits, such as total biomass, tiller number, panicle number, fertility, and maturity dates. Our findings suggest that AMF inoculation could be integrated with AWD irrigation and/or low NPK inputs to contribute to fertilizer and water savings in both irrigated and upland rice production systems.

Revolutionizing viral resistance strategies in rice: Evolution from RNAi to precision genome editing.

Revolutionizing viral resistance strategies in rice: Evolution from RNAi to precision genome editing.

Molecular characterization of rice blast fungus (Pyricularia oryzae) from West Sumatra and their virulence to several rice cultivars

Global rice production is severely impacted by rice blast disease, which is a devastating condition caused by the fungal pathogen Pyricularia oryzae. Many countries have reported blast diseases associated with rice yield loss. In Indonesia, this disease also destroys rice production in several rice fields in West Java, East Java, Central Java, Sumatra, and Sulawesi. The objectives of this study were to identify rice blast fungal isolates in West Sumatra and assess the resistance level of eight local and modern rice genotypes to this disease. Additionally, the rice genotypes were also evaluated for the presence of Pi genes associated with blast resistance by utilizing 25 simple sequence-repeats (SSR) markers known to be linked to rice blasts. The seedlings of all rice genotypes were exposed to fungal isolates to determine their blast resistance capacity based on leaf morphological traits. Before conducting blast resistance testing, the local isolates of rice blast fungus were molecularly identified by aligning sequences in a pairwise comparison. Based on the identification process, three P. oryzae (MoK19-49, MoK19-45, and MoK19-28) fungal isolates were identified. The confirmed P. oryzae isolate MoK19-28 was then used to assess the blast resistance of the rice genotypes using the SES-blast test. The resistance levels of all genotypes were evaluated by observing the morphology of infected leaves for 24 days. Four genotypes, namely Cantik Manis (CM), Bungo Sungkai (BS), Inpari 48 Blas (IB), and Inpago 9 (Ip9), exhibited resistance to leaf blast caused by P. oryzae isolate MoK19-28. Meanwhile, Pulau Batu (PB), Mundam Putiah (MP), and IR64-Sub1 (IR) displayed intermediate resistance to the disease. In contrast, the blast fungus P. oryzae isolate MoK19-28 severely impacted the Kuriak (K) genotype. The rice variety IB contains several Pi genes, specifically Pi1, Pi9, Pikh, and Pi37, which are associated with enhanced resistance to leaf blast caused by P. oryzae isolate MoK19-28. This genetic characteristic sets it apart from susceptible genotypes. This work has successfully identified multiple blast-resistant rice genotypes that could potentially be used in future rice improvement initiatives.

Fine-tuning gibberellin improves rice alkali-thermal tolerance and yield.

Soil alkalinization and global warming are predicted to pose major challenges to agriculture in the future, as they continue to accelerate, markedly reducing global arable land and crop yields1,2. Therefore, strategies for future agriculture are needed to further improve globally cultivated, relatively high-yielding Green Revolution varieties (GRVs) derived from the SEMIDWARF1 (SD1) gene3,4. Here we propose that precise regulation of the phytohormone gibberellin (GA) to optimal levels is the key to not only confer alkali-thermal tolerance to GRVs, but also to further enhance their yield. Endogenous modulation of ALKALI-THERMAL TOLERANCE 1/2(ATT1/2), quantitative trait loci encoding GA20-oxidases or exogenous application of GA minimized rice yield loss affected by sodic soils. Mechanistically, high GA concentrations induce reactive oxygen species over-accumulation, whereas low GA concentrations repress the expression ofstress-tolerance genes by means of DELLA-NGR5-mediated H3K27me3 methylation. We further showed that ATT1 induces large fluctuations in GA levels, whereas ATT2 is the ideal candidate for fine-tuning GA concentrations to appropriate levels to balance reactive oxygen species and H3K27me3 methylation to improve alkali-thermal tolerance and yield. Thus, ATT2 is expected to be a potential new post-Green Revolution gene that could be harnessed to develop and use marginal lands for sustainable agriculture in the future.

Exploring the potential of amine-functionalized mesoporous silica nanocarrier to conjugate guide RNA for gene delivery

Sugarcane is a key cash crop, with nations such as Brazil, India, and China being the leading producers. The trade of sugar and related products contributes significantly to these economies. Sugarcane is the primary feedstock for producing sugar and ethanol in the sugarcane processing industry, yielding sugarcane bagasse fly ash (SBFA) as a byproduct. This byproduct comes primarily from the combustion of bagasse (the fibrous residue after juice extraction) and contains silica (SiO2), alumina (Al2O3), and other minerals. The use of sugarcane waste materials reduces the need for new raw resources and lowers the environmental impact. Turning waste into valuable nanoparticles also helps manage waste better and reduces the amount that is burnt or dumped in landfills. The fly ash was treated with an alkaline solution (e.g., sodium hydroxide) to extract silica. This process helps dissolve other minerals, leaving a silica-rich residue. After extraction, the silica was purified through acid washing to remove impurities. Mesoporous silica nanoparticles were created using the sol-gel method and 3-aminopropyltriethoxysilane (APTES) was added to them functionally to conjugate sgRNA. The synthesized mesoporous silica nanoparticles were characterized for size and shape, functional groups, and crystallinity using various instruments such as Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Dynamic Light Scattering, Brunauer-Emmett-Teller (BET) Analyzer, and X-Ray Diffractometer (XRD), respectively. Furthermore, synthesized mesoporous silica nanoparticles were bioconjugated with sgRNA of OsEPF1, a gene negative regulation of stomatal development, which in turn, helps reduce yield loss in rice due to drought and heat stress.

Yield Loss Quantification Due to Stalk-Eyed Fly (Diopsidae) Infestations on Rice Crops (Oryza Sativa) in Fogera Plain

Stalk-Eyed Flies (Diopsidae) pose a significant threat to rice crops (Oryza sativa), causing yield loss and affecting crop development. This study aims to quantify yield loss due to Stalk-Eyed Fly infestations and identify susceptible growth stages of rice crops to this insect. Field experiments were conducted to assess the yield loss of rice due to stalk eyed fly at Fogera, in 2021 and 2022. With the treatments Both Thiamethoxam seed treatment and Chlorpyrifos systemic foliar insecticide were applied to combat the infestation, with untreated varieties serving as controls. And the pot experiment was conducted to assess susceptibility of rice growth stage to the stalk eye fly artistically analyses, were employed to evaluate treatment impacts. With the treatments of different crop stages, Seedling Stage, Tillering Stage, Stem Elongation Stage, Panicle Initiation Stage, Booting, Heading, Flowering. The effect of rice growth stage on stalk eyed fly infestation showed that there is statistically significant difference among the different growth stage, tillering stage appears to be the most susceptible to Stalk-Eyed Fly infestations in terms of the impact on tiller growth in rice crops. During this stage, the mean percentage change of tillers is the highest at 59.3%, indicating a substantial impact of infestations on tiller growth. This suggests that rice crops are particularly vulnerable to stalked fly infestations during the tillering stage, highlighting the importance of effective pest management strategies during this critical growth phase to mitigate potential yield losses. In the field experiment, significant variations in yield loss were observed across treatments. The presence of dead hearts, indicative of infestation, varied notably between treated and untreated rice. Rice varieties incorporating pesticide applications demonstrated lower dead heart percentages, suggesting there is rice yield loss if the stalk-eyed fly is not controlled. Notably, treatments influenced grain yield, with insect protection measures resulting in higher yields and lower yield loss compared to controls. In conclusion, stalk-eyed fly infestation impacts rice crop productivity, particularly during vulnerable growth stages. Pesticide applications show promise in reducing infestation severity and mitigating yield loss. We recommend implementing targeted treatment strategies, focusing on susceptible growth stages, to effectively manage infestations and optimize rice crop yields.

An assessment of the relationship between spring frost indicators and global crop yield losses

An assessment of the relationship between spring frost indicators and global crop yield losses

Unveiling the intricacies of the rice-Rhizoctonia pathosystem: a comprehensive review of host-pathogen interactions, molecular mechanisms, and strategies for sustainable management

Sheath blight disease in rice, induced by the necrotrophic basidiomycetes Rhizoctonia solani, has emerged as a significant menace to global rice cultivation, especially with the widespread adoption of high-yielding varieties. The pathogen’s capacity to endure unfavorable conditions and its wide host range contribute to the increased challenge for management. The occurrence of sheath blight in rice is intensified when high-yielding semi-dwarf cultivars are employed, coupled with dense planting and the application of substantial amounts of nitrogenous fertilizers. Managing this pathogen is a formidable challenge due to its broad host range, substantial genetic variability, and the absence of satisfactory levels of natural resistance in the existing rice germplasm. Due to the absence of complete resistance sources, the predominant approach for managing sheath blight has been through chemical control methods. It is imperative to explore solutions to combat this pathogen, in order to reduce rice yield losses and safeguard global food security. Developing genetic resistance provides an alternative to the use of potentially harmful chemical fungicides. This review crucially delivers efforts to enhance the understanding of the host–pathogen relationship, which involves identification of gene loci/markers associated with resistance responses, modification of host genome through transgenic approaches, examining the wide host range, epidemiology and its managemental approaches. Recent advancements and current research on the R. solani–rice pathosystem, along with a gap analysis, are presented.

Game analysis of future rice yield changes in China based on explainable machine-learning and planting date optimization

Game analysis of future rice yield changes in China based on explainable machine-learning and planting date optimization

Expounding the Effect of Harvest Management on Rice (Oryza sativa L.) Yield and Latent Loss Based on the Accurate Measurement of Grain Data

Due to the impact of global environment and climate change, determining how to ensure food production and reduce food loss has become an important research topic for many countries, especially developing countries, and can provide key information for China’s grain harvest management. This article mainly examines the impact of harvesting period on rice yield, the existence of latent losses, and their management value. From 2019 to 2022, our team conducted experiments on the growth curve of rice grains, plants, and populations to investigate the existence of latent losses by establishing the relationship between the standard moisture weight and the days after heading. The results showed that the weight of the rice gradually decreased as the harvest time was delayed, and there were latent losses, of which the dry matter loss was about 3.5%. With the addition of grain shattering loss, the latent loss rate was about 7.0%. In summary, if rice management is strengthened, including harvesting at the optimal time, 4.67% of the loss can be recovered. The timing of the harvest significantly impacts rice yield. Understanding the process and causes of new types of rice losses, increasing the basis for judging the timely harvest period, and providing the best management measures can prevent the post-harvest losses caused by traditional methods and increase the amount of fertile land available.

Assessment of ozone pollution on rice yield reduction and economic losses in Sichuan province during 2015–2020

Assessment of ozone pollution on rice yield reduction and economic losses in Sichuan province during 2015–2020

Modelling rice competition with Leptochloa fusca, Bidens frondosa and Ammannia coccinea in transplanted rice cultivation

AbstractA 2‐year field experiment was conducted in Daejeon, South Korea, to investigate changes in the growth parameters of rice plants during the growth and model the rice yield loss as affected by the competition with Leptochloa fusca, Bidens frondosa and Ammannia coccinea under transplanted rice cultivation. Compared with B. frondosa and A. coccinea, L. fusca significantly reduced the number of tillers at the early growth stage, resulting in more reduction in the number of panicles and other yield components such as the number of spikelets, ripened grain ratio and the ultimate rice yield at the later growth stage. Among the components, the panicle number was the most negatively and positively correlated with weed density and rice yield, respectively. Cousens' rectangular hyperbola model predicted that weed competitiveness value represented by parameter β was 0.0337 and 0.0572 for L. fusca, 0.0124 and 0.0165 for B. frondosa and 0.0059 to 0.0061 for A. coccinea in 20.8 and 15.2 hill m−2 rice densities, respectively, indicating the competition effect of L. fusca on rice yield was greater than that of B. frondosa and A. coccinea. Weed densities corresponding to a 50% reduction in the rice yield were 27 and 18 for L. fusca, 81 and 61 for B. frondosa and 169–164 for A. coccinea in 20.8 and 15.2 hill m−2 rice densities, respectively. Weeds are more competitive in low‐density rice plots, leading to greater yield loss. In addition, the economic thresholds (ET) are positively correlated with rice densities and negatively correlated with weed competitiveness. Although low‐density rice transplanting may offer economic benefits during cultivation, optimal rice density and weed control strategies are important for securing a high yield. Therefore, the model and findings could be applied to decision‐making systems in rice farming where weed interference is present.

The Spread of Southern Rice Black-Streaked Dwarf Virus Was Not Caused by Biological Changes in Vector Sogatella furcifera.

The pandemic of Southern rice black-streaked dwarf virus (SRBSDV) in and after the late 2000s caused serious yield losses in rice in Southeast and East Asia. This virus was first recorded in China in 2001, but its exclusive vector insect, Sogatella furcifera, occurred there before then. To clarify the evolutionary origin of SRBSDV as the first plant virus transmitted by S. furcifera, we tested virus transmission using three chronological strains of S. furcifera, two of which were established before the first report of SRBSDV. When the strains fed on SRBSDV-infected rice plants were transferred to healthy rice plants, those established in 1989 and 1999 transmitted the virus to rice similarly to the strain established in 2010. SRBSDV quantification by RT-qPCR confirmed virus accumulation in the salivary glands of all three strains. Therefore, SRBSDV transmission by S. furcifera was not caused by biological changes in the vector, but probably by the genetic change of the virus from a closely related Fijivirus, Rice black-streaked dwarf virus, as suggested by ecological and molecular biological comparisons between the two viruses. This result will help us to better understand the evolutionary relationship between plant viruses and their vector insects and to better manage viral disease in rice cropping in Asia.

Heat Waves Coupled with Nanoparticles Induce Yield and Nutritional Losses in Rice by Regulating Stomatal Closure.

The frequency, duration, and intensity of heat waves (HWs) within terrestrial ecosystems are increasing, posing potential risks to agricultural production. Cerium dioxide nanoparticles (CeO2 NPs) are garnering increasing attention in the field of agriculture because of their potential to enhance photosynthesis and improve stress tolerance. In the present study, CeO2 NPs decreased the grain yield, grain protein content, and amino acid content by 16.2, 23.9, and 10.4%, respectively, under HW conditions. Individually, neither the CeO2 NPs nor HWs alone negatively affected rice production or triggered stomatal closure. However, under HW conditions, CeO2 NPs decreased the stomatal conductance and net photosynthetic rate by 67.6 and 33.5%, respectively. Moreover, stomatal closure in the presence of HWs and CeO2 NPs triggered reactive oxygen species (ROS) accumulation (increased by 32.3-57.1%), resulting in chloroplast distortion and reduced photosystem II activity (decreased by 9.4-36.4%). Metabolic, transcriptomic, and quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that, under HW conditions, CeO2 NPs activated a stomatal closure pathway mediated by abscisic acid (ABA) and ROS by regulating gene expression (PP2C, NCED4, HPCA1, and RBOHD were upregulated, while CYP707A and ALMT9 were downregulated) and metabolite levels (the content of γ-aminobutyric acid (GABA) increased while that of gallic acid decreased). These findings elucidate the mechanism underlying the yield and nutritional losses induced by stomatal closure in the presence of CeO2 NPs and HWs and thus highlight the potential threat posed by CeO2 NPs to rice production during HWs.

Key Challenges in Plant Pathology in the Next Decade.

Plant diseases significantly impact food security and food safety. It was estimated that food production needs to increase by 50% to feed the projected 9.3 billion people by 2050. Yet, plant pathogens and pests are documented to cause up to 40% yield losses in major crops, including maize, rice, and wheat, resulting in annual worldwide economic losses of approximately US$220 billion. Yield losses due to plant diseases and pests are estimated to be 21.5% (10.1 to 28.1%) in wheat, 30.3% (24.6 to 40.9%) in rice, and 22.6% (19.5 to 41.4%) in maize. In March 2023, The American Phytopathological Society (APS) conducted a survey to identify and rank key challenges in plant pathology in the next decade. Phytopathology subsequently invited papers that address those key challenges in plant pathology, and these were published as a special issue. The key challenges identified include climate change effect on the disease triangle and outbreaks, plant disease resistance mechanisms and its applications, and specific diseases including those caused by Candidatus Liberibacter spp. and Xylella fastidiosa. Additionally, disease detection, natural and man-made disasters, and plant disease control strategies were explored in issue articles. Finally, aspects of open access and how to publish articles to maximize the Findability, Accessibility, Interoperability, and Reuse of digital assets in plant pathology were described. Only by identifying the challenges and tracking progress in developing solutions for them will we be able to resolve the issues in plant pathology and ultimately ensure plant health, food security, and food safety.