The mitogen-activated protein kinase (MAPK) cascade pathway is a highly conserved signal transduction module in eukaryotes, playing a central role in plant growth and development, stress responses, and immune defense. As a globally significant food crop and a model monocot plant, rice directly links yield and quality improvements to food security. Recent studies have extensively revealed that genes of the rice MAPK family play crucial roles in grain shape and grain number formation, anther and embryo development, hormone signaling regulation, disease resistance, and adaptation to abiotic stress. This review systematically summarizes the classification and structural characteristics of the rice MAPK family, outlines recent research advances in its roles during growth and development, hormone signaling transduction, disease immunity, and stress responses, and summarizes the key identified MAPK cascade pathways and their regulatory mechanisms. This work provides a reference for further elucidating the rice MAPK signaling network and lays a theoretical foundation for molecular design breeding to enhance rice yield and stress tolerance.

【Objective】To investigate the function of OsST2, a candidate gene associated with seedling-stage salt tolerance, and to elucidate its molecular mechanism in regulating salt tolerance in rice, an analysis under salt stress conditions was conducted.【Method】The CRISPR-Cas9 gene editing technology was used to generate OsST2 knockout mutants, and the phenotypic and physiological characteristics of these mutants under salt stress were analyzed.【Result】Under salt stress, the OsST2 gene knockout mutants exhibited significant changes in traits such as seedling height, dead leaf rate, root traits, and leaf SPAD value compared to the wild type. Moreover, the OsST2 knockout mutants demonstrated stronger salt tolerance than the wild type. qRT-PCR analysis revealed that the relative expression levels of known genes positively regulating rice salt tolerance, such as SKC1, OsMYB84, OsNAC3, OsMsr9, and ROS-related genes, were significantly higher in the OsST2 knockout mutants compared to the wild type. After salt stress, the levels of malondialdehyde, hydrogen peroxide, and superoxide anion in the OsST2 knockout mutants were significantly lower than those in the wild type. Conversely, the activities of peroxidase and superoxide dismutase, as well as glutathione content, were significantly higher in the mutants compared to the wild type. These findings suggest that the knockout of OsST2 enhances the rice plant’s ability to scavenge reactive oxygen species, thereby improving its salt tolerance. 【Conclusion】OsST2 negatively regulates salt tolerance in rice. Loss of OsST2 function enhanced the scavenging capacity of ROS in rice, thereby improving salt tolerance in rice, confirming that OsST2 plays an important role in the regulation of salt tolerance in rice.

【Objective】 Photosynthesis is a major determinant of dry matter accumulation in rice, with chlorophyll content and vein density being critical for photosynthetic efficiency. Here, a rice gene regulating chlorophyll content and vein density, OsLVD1, was identified and functionally analyzed.【Method】 OsLVD1 was identified based on homology to maize vein development genes, and its protein features, phylogeny, conserved motifs, and subcellular localization were analyzed bioinformatically. An lvd1 mutant was generated using CRISPR/Cas9, with ZH11 as the wild type. Chlorophyll content, vein density, soluble sugar content, and major agronomic traits were examined. The expression of genes related to chlorophyll metabolism and vein development was analyzed by qRT-PCR.【Result】 OsLVD1 encodes a nuclear localized WRKY transcription factor, and the lvd1 mutation caused a frameshift leading to premature termination. Compared with ZH11, the lvd1 mutant showed reductions of 25.90%, 30.75%, and 27.05% in chlorophyll a, chlorophyll b, and total chlorophyll content, respectively, accompanied by increases in minor vein density and bulliform cell number. Plant height was reduced and growth duration was slightly delayed, whereas soluble sugar content, seed setting rate, and thousand grain weight were unaffected. qRT PCR showed that the expression levels of chlorophyll biosynthesis genes OsHEMA1 and OsCHLI were downregulated, while those of the chlorophyll degradation gene OsNYC1 and the vein development gene OsPIN1b were upregulated in the lvd1 mutant. OsLVD1 was predominantly expressed in leaves, with the highest expression at the jointing stage.【Conclusion】 Loss of OsLVD1 resulted in a “low chlorophyll–high vein density” phenotype, which may compensate for reduced photosynthesis by enhancing vein mediated transport and water retention, thereby maintaining yield stability. This study demonstrates a novel role of OsLVD1 in coordinating leaf pigment metabolism and vascular development in rice.

【Objective】The two-line hybrid rice breeding technology relies on thermo-sensitive genic male sterile (TGMS) lines carrying the tms5 locus. This locus originates from a natural mutation and exhibits varying sterility onset temperatures across different genetic backgrounds. Additionally, genetic drift may occur in subsequent generations. Thus, elevated sterility onset temperatures and genetic drift are key bottlenecks restricting the development of two-line hybrid rice technology.【Method】Using the japonica rice variety Zhonghua 11(ZH11) as material, we established a method for creating P/TGMS lines. Rice seeds were treated with ethylmethanesulfonate (EMS), and sterile individuals were screened from the M2 population under high-temperature conditions. After ratooning, these fertility-restored plants were obtained under low-temperature conditions. 【Result】Through years of experimentation, approximately 10% of the sterile plants were able to self-fertilize under low temperatures. Seeds from these fertility-restored lines were collected and further validated for sterility under high temperatures and fertility under low temperatures. These validated P/TGMS lines were subjected to genetic population construction combined with BSA-seq (Bulked Segregant Analysis sequencing) for gene mapping, resulting in the identification of 18 new P/TGMS lines in the ZH11 background. Among these, ostms15, ostms16, ostms18, and ostms19 have been published. Notably, the fertility transition temperature of ostms15 is significantly lower than that of the widely used tms5 locus in the same genetic background. Currently, more than 20 research institutions have utilized this sterile line for hybrid rice breeding. 【Conclusion】The P/TGMS line creation technology proposed in this study can generate a series of novel P/TGMS lines, potentially overcoming the bottleneck of P/TGMS line scarcity in two-line hybrid rice breeding and supporting the sustainable development of hybrid rice breeding.

【Objective】Lodging is a critical constraint on achieving high and stable rice yields, and optimizing fertilization strategies to improve stem strength represents a key approach for reducing lodging risk in rice production. This study aims to elucidate the effects of different fertilizer types on rice yield and lodging-related traits.【Method】We conducted a field experiment including two japonica rice varieties (Huaidao 5 and Nanjing 9108) and two fertilizer types [conventional fertilizer (CF) and controlled-release blended fertilizer (CRBF)] in a rice-wheat rotation system in Jiangsu Province.【Results】Compared to CF, CRBF significantly increased rice yield (+3.7%), with Huaidao 5 and Nanjing 9108 exhibiting yield increases of 3.3% and 4.1%, respectively. The yield improvement was primarily attributed to the increased effective panicles and total spikelets. Regarding lodging traits, CRBF reduced the lodging index (LI) of the first (−5.3%) and second (−4.2%) basal internodes, while its impact on the third internode was not significant. The reduction of LI was attributed to a greater increase in breaking resistance than in bending moment. In addition, CRBF reduced internode length while increasing internode diameter and stem wall thickness at the first and second basal internodes, thereby enhancing stem strength. 【Conclusion】CRBF synergistically improves rice yield and lodging resistance, and provides a scientific basis for high-quality rice production in the rice-wheat rotation system.

【Objective】This study aims to investigate the effects of nano-priming technology on rice seed germination under salt stress, in order to provide technical support for rice cultivation in saline-alkali soils.【Method】The japonica rice variety, Ningjing 47, was used as the experimental material. Salt stress treatments (0 and 150 mmol/L NaCl) were applied, and five concentrations of Fe-Mg nanoparticles (0, 50, 100, 200, and 400 mg/L) were tested under 150 mmol/L NaCl stress. The effects on seed germination, seedling growth, and physiological characteristics were examined.【Result】The results showed that salt stress significantly inhibited rice seed germination and seedling growth. Nano-priming did not significantly affect germination percentage or germination potential but enhanced seedling growth. It increased the activities of superoxide dismutase (by 27.78%–76.39%), peroxidase (by 14.05%–38.71%), and catalase (by 18.67%–120.00%), as well as the content of ascorbic acid (by 4.40%–225.79%), soluble sugars (by 63.08%–145.96%), proline (by 10.33%–16.88%), and chlorophyll (by 45.38%–105.31%). It also reduced malondialdehyde content (by 16.94%–32.41%) and enhanced the selective transport coefficient for K⁺ over Na⁺.【Conclusion】The concentration of 200 mg/L Fe-Mg nanoparticles was identified as optimal for alleviating salt stress and promoting rice germination and seedling growth.

【Objective】 The aim of this study was to clarify the effects of precision drill sowing (PS) on yield of machine-transplanted rice in Guangxi, and to provide technical support for mechanized production and improvement of large-scale yield per unit area of rice in Guangxi Zhuang Autonomous Region. 【Method】The seeds of Changliangyou 8, Changliangyoufuxiangzhan, Huashengyoujingguizhan, Jingmeisixiang, Juxiangsimiao and Guangliangxingui were precisely drill-sown (PS) with the same seed sowing rate used in traditional broadcast sowing (BS) as the control. The seedling quality, mechanical transplanting quality, dry matter production, and yield were investigated. 【Result】1) Compared with BS, PS improved the seedling uniformity and root interlocking force by 5.68%–15.47% and 7.65%–24.21%, respectively. 2) PS significantly reduced the rate of missing hills by 54.72%−76.67%, increased the uniformity of the seedling number per hill, the peak number of seedlings, and the uniformity of the number of productive tillers by 37.91%–104.73%, 16.49%–24.18%, and 6.67%–13.72%, respectively. 3) Compared with BS, PS increased the leaf area index (LAI) and effective LAI during heading stage, photosynthetic potential, and improved the dry matter accumulation from transplanting to jointing and from jointing to heading stages, as well as the dry matter accumulation of population at maturity stage. 4) The significant increase in the number of productive tillers and population spikelets in the PS treatment was one of the important reasons for achieving high grain yield.【Conclusion】Precision drill sowing in mechanical transplanting reduced the rate of missing hills, improved the uniformity of the seedling number under mechanical transplanting, increased the number of productive tillers and its uniformity, LAI, and photosynthetic potential, promoted the accumulation of dry matter, which resulted in an increase in grain yield.

【Objective】This study aims to investigate the effects of key cultivation measures (sowing date, planting density, and nitrogen application rate) on grain yield, rice quality formation, and growth characteristics of the high-quality super rice variety Huazheyou 261. The results are expected to provide a theoretical basis for developing high-yield, high-quality, and high-efficiency cultivation techniques.【Method】A single-factor field experiment was conducted using Huazheyou 261 as the test material. The treatments included four sowing dates (May 15, May 28, June 10, and June 23, denoted as S1, S2, S3, and S4), five transplanting densities (plant spacing of 27.0, 22.5, 19.3, 16.9, and 15.0 cm, denoted as D1 to D5, with a fixed row spacing of 30 cm), and five nitrogen application rates (0, 135, 180, 225, and 270 kg/hm², denoted as N0 to N4). Grain yield, rice quality, and growth characteristics were measured under different treatments. The correlations between yield and dry matter accumulation, as well as temperature and light resources, were analyzed. A comprehensive evaluation of rice quality under each treatment was also performed.【Result】Sowing date, density and nitrogen application rate significantly affected grain yield, rice quality and growth characteristics of rice. Under each cultivation measure, the grain yield and comprehensive evaluation grade of rice quality showed an initial increase followed by a decrease. The grain yield of S3, D3 and N3 treatments was the highest, and the rice quality of S3, D3 and N2 treatments was the best. There was a significant quadratic relationship between grain yield and sowing date, density and nitrogen application rate. The trend of yield components and rice quality indexes varied with different cultivation measures. With the delay of sowing date, the decrease of density and the increase of nitrogen application rate, the growth period was delayed and the whole growth period was prolonged. The number of tillers increased, but the productive tiller percentage (except density treatment) decreased, and the SPAD value of leaves increased. The effective leaf area index, grain-leaf ratio (except under nitrogen treatments), dry matter accumulation from heading to maturity, harvest index, and temperature-light production efficiency all exhibited a trend of initial increase followed by decrease. Statistical analysis indicated that grain yield was significantly positively correlated with total spikelets and dry matter accumulation, with total spikelets contributing the most to grain yield. Principal component analysis identified milled rice rate, head milled rice rate, chalky grain rate, chalkiness, alkali spreading value, and gel consistency as key indicators for evaluating rice quality.【Conclusion】Under the experimental conditions, synergistic optimization of grain yield and rice quality for Huazheyou 261 in southeastern Zhejiang Province was achieved with the following practices: sowing between May 28 and June 15, transplanting at a row spacing of 30 cm and a plant spacing of 19.3−23.3 cm, and applying nitrogen at a rate of 176.6−209.8 kg/hm2.

【Objective】To explore the characteristics of yield formation and root morphology changes of two super japonica rice varieties with excellent eating quality under water-saving irrigation, and lay the foundation for clarifying the characteristics of drought resistance and yield stability of rice varieties and the development of water-saving cultivation techniques.【Method】Using Nanjing 5718 and Nanjing 3908 as materials, three irrigation approaches were adopted in 2023 and 2024: flooding irrigation (W0), mild intermittent irrigation (W1), and moderate intermittent irrigation (W2). The differences in leaf color, tiller number, plant height, dry matter accumulation and transportation, yield and its components, and root morphological and physiological parameters were compared, and the correlations between each trait and yield were analyzed.【Results】Compared with W0, there was no significant change in yield and its components for Nanjing 5718 under W1, while the yield of Nanjing 3908 decreased by 15.3% and 12.5% over two years, respectively. Panicle number and thousand-grain weight were also significantly decreased. Under W2, yield and its components of both varieties significantly decreased, with an average decrease of yield of 9.4% for Nanjing 5718 and 21.3% for Nanjing 3908 in both years. The tiller number, fertile tiller rate, dry matter accumulation, output rate and translocation rate of the stems and leaves of both varieties under W2 were significantly reduced, with the highest output and transport rates in Nanjing 5718 under W1. The leaf SPAD values of both varieties decreased with the increase of water-saving degrees, especially in the late stage of grain filling. Compared with W0, the root morphology parameters of Nanjing 3908 significantly decreased under two water-saving patterns; however, only root tip number, root length, root diameter and root surface area of Nanjing 5718 were significantly decreased under W2. Correlation analysis showed that plant height, leaf color at the late grain-filling stage, root morphological parameters were significantly positively correlated with yield. 【Conclusion】Nanjing 5718 could maintain high yield under water-saving irrigation and exhibited better water-saving effects, while Nanjing 3908 was more sensitive to water-saving irrigation and had a lower yield stability. Appropriate intermittent irrigation effectively maintained the stable yield of Nanjing 5718 by improving key indicators such as plant type, leaf color and root morphology of rice.

【Objective】The effects of different irrigation and straw returning combinations on rice yield and greenhouse gas emissions were studied to provide theoretical basis and practical guidance for rice yield increase and greenhouse gas emission reduction. 【Method】Taking Yongyou 2640 and Nanjing 5718 as the test varieties, two irrigation methods were set up: conventional irrigation (CI), alternate wetting and moderate soil drying irrigation (AWD), and three straw returning methods: no straw returning (S0), straw biochar application(SC), composted straw returning to the field combined with straw biochar(SS). The effects on rice yield, dry matter accumulation, photosynthetic rate, photosynthetic potential, root activity and methane and nitrous oxide emission fluxes during the whole growth period were analyzed. 【Results】1) Compared with CI+S0, the AWD+SC and AWD+SS treatments significantly increased grain yield by 8.30%−13.90% and 18.55%−22.58%, respectively. Compared with S0 treatment, SC and SS significantly increased the effective panicle number and grain number per panicle, and AWD treatment significantly increased the grain number per panicle, seed setting rate and 1000-grain weight. 2) The increase in yield was mainly due to the significant increase of dry matter accumulation in underground and above-ground parts, net photosynthetic rate and photosynthetic potential of leaves, NSC transport in stem sheath and oxidizing power of roots. 3) SC significantly reduced methane and nitrous oxide emissions, while SS increased emissions, but AWD treatment significantly reduced methane emissions, thereby reducing the global warming potential and greenhouse gas emission intensity of rice fields. 【Conclusion】The combination of straw returning technology (AWD+SC/SS) with alternating wet and dry irrigation can significantly improve the accumulation and transport of photosynthetic substances in rice, promote below-ground root growth, and achieve the dual goals of increasing rice yield and reducing greenhouse gas emissions in rice fields.

【Objective】Field operations in rice cultivation, such as dry direct seeding and transplanting, require higher path tracking accuracy of agricultural machinery. To meet the requirements for operational consistency and uniform crop distribution in rice production, we designed an assisted steering control system for wheeled tractors, aiming to assist human operators in achieving precise path tracking during rice field operations. 【Method】First, we constructed a driver steering model using data from driving simulator tests, and combined it with the kinematic model of wheeled tractors to develop an integrated vehicle control model that incorporates the driver-in-the-loop. Then, we used a polytopic linear parameter varying system to describe the uncertainties in the model, including time-varying driver model parameters and vehicle speed. Based on this model, an output feedback robust controller was designed to ensure robust stability of the system under uncertainties described by polyhedral sets. Additionally, a region pole placement method was employed to improve the transient response performance of the system. Finally, driver-in-the-loop tests were conducted to evaluate the performance of the designed controller. 【Result】The results show that this method effectively enhances the path tracking performance of wheeled tractors while alleviating the physical and mental burdens on the operator. In single lane-change maneuvers and complex serpentine driving conditions, the maximum lateral tracking error is reduced by 66.7% and 55.6% compared with that of the PID control algorithm, respectively, while the physical workload of the driver was reduced by 26.86% and 37.6%, and the mental workload was reduced by 4.2% and 31.3%, respectively. 【Conclusion】The proposed control strategy offers a technical foundation for enhancing the operational quality of rice and other crop fieldwork.

【Objective】 To address the problems of high labor intensity and low efficiency in manual measurements of heading date in rice breeding, this study proposes an intelligent prediction method that integrates UAV imagery, the YOLOv10b object detection algorithm, and a random forest regression model to achieve automated and efficient prediction of heading date in rice breeding plots.【Methods】 Using rice breeding plots as the research subject, UAV imagery was acquired at 15 observation time points from booting to maturity. Based on the YOLOv10b algorithm, a rice panicle detection model was trained to recognize and count panicles in plot images. Subsequently, the numbers of panicles at each observation time point were used as input variables, and the number of days from transplanting to heading was used as the prediction variable to construct and compare multiple heading date prediction models. Based on this, feature importance analysis and dimensionality reduction were performed to develop a simplified model.【Results】 Experimental results showed that the YOLOv10b model achieved a precision of 91.7%, a recall of 92.1%, and an F1 score of 0.919 in the panicle detection task. In the heading date prediction task, the random forest model constructed using the sequential features of panicle counts from all 15 observation time points achieved an R² of 0.84, an RMSE of 1.57 days, and an MAE of 1.12 days. Furthermore, after feature dimensionality reduction based on feature importance analysis, a simplified model constructed using 9 observation time points achieved an R² of 0.83, an RMSE of 1.65 days, and an MAE of 1.16 days. This approach effectively reduced feature dimensionality while maintaining prediction accuracy, thereby improving the model's efficiency and practicality.【Conclusion】 The proposed method can effectively reduce the workload of manual measurements, improve the efficiency of heading date monitoring, and realize automated prediction of heading date in breeding plots. It provides a feasible data foundation and technical pathway for intelligent breeding and precision agricultural management.