Extreme temperature events associated with climate change have led to significant declines in rice production, particularly when they occur during reproductive growth stages. However, existing models lack the ability to capture the distinct effects of sustained versus episodic low-temperature stress. In this study, a two-year temperature-controlled experiment was conducted with two temperature levels to compare the impacts of individual and combined low-temperature stress at booting (BS), flowering (FS), and combined (BS + FS) stages on rice yield and its components. Low-temperature stress occurring at booting and combined stages significantly reduced spikelet fertility in the upper spike and grain number in the lower spike, whereas it showed a stronger effect on the spikelet fertility in the lower spike at flowering stage. Under the same cooling degree-days (CDD), continuous low temperature at 12 degrees C for 8 days at booting caused the largest yield loss (55.3 %), compared with 15.5 % at flowering and 39.3 % under the combined treatment, suggesting that low-temperature stress exerts different cumulative effects across booting and flowering stages. We refined the ORYZA yield formation algorithms using these experimental insights, enabling the model to account for both intermittent low-temperature events and combined stress across booting and flowering stages, thereby better reflecting the conditions observed in rice production. The improved model substantially enhanced simulation accuracy (RMSE reduced from 7.18 to 2.05 g plant-1; D index increased from 0.72 to 0.93), and was further validated against historical low-temperature events at multiple sites in Northeast China. This improvement enhances the reliability of rice yield predictions under field low-temperature scenarios, thereby supporting climate risk assessment and cold-tolerance breeding.

ABSTRACT Under increasing climate variability and the expansion of rice cultivation into marginal cold‐prone environments, low temperature has become a major constraint on yield stability and sustainable rice production. Rice is particularly vulnerable to transient cold stress during reproductive development, and cold injury at the booting stage often causes severe and irreversible yield losses. Improving booting‐stage cold tolerance through genetic approaches is therefore essential for safeguarding food security in high‐latitude rice‐growing regions. In this study, we developed a recombinant inbred line (RIL) population of 144 lines derived from a cross between the highly cold‐tolerant landrace Lijiangxintuanheigu (LTH) and the northern elite japonica cultivar Shennong 265 (SN265) to dissect the genetic basis of booting‐stage cold tolerance. Using spikelet sterility as the primary indicator, we conducted quantitative trait locus (QTL) mapping under controlled cold‐stress conditions across two consecutive years. In total, nine QTLs associated with spikelet sterility were identified on chromosomes 2, 3, 4, 6, 7, and 11, each explaining 10.56%–32.49% of the phenotypic variance. Among these loci, a major‐effect QTL on chromosome 2, designated qCTB2, was consistently detected across years and mapping methods and was subsequently validated using near‐isogenic lines derived from a residual heterozygous line. Interaction‐effect analysis revealed strong additive and complementary effects between qCTB2 and other favorable loci, highlighting its central role in pyramiding‐based breeding strategies. Comparative mapping and sequence comparison indicated that qCTB2 is unlikely to be allelic to the known cold‐tolerance‐related gene LGS1, suggesting that qCTB2 likely represents an independent locus contributing to booting‐stage cold tolerance. Overall, this study identifies a robust major‐effect locus, qCTB2, and demonstrates its additive and complementary interactions with other loci, providing a practical genetic framework for pyramiding‐based improvement of booting‐stage cold tolerance and yield stability in high‐latitude rice production systems under increasing climate variability.

The increasing frequency and intensity of low-temperature events in temperate and cold rice production regions threatens rice yields under climate change. While process-based crop models can project climate impacts on rice yield, their accuracy under low-temperature conditions has not been well evaluated. Our 6 year chamber experiments revealed that low temperatures reduce spikelet fertility from panicle initiation to flowering, grain number per spike during panicle development, and grain weight during grain filling. We examined the algorithms of spikelet fertility response to temperature used in crop models. The results showed that simulation performance is poor for crop yields if the same function was used at different growth stages outside the booting stage. Indeed, we replaced the algorithm for the spikelet fertility parameter of the ORYZA model and developed the function of estimated grain number per spike and grain weight. After that, the algorithm with improved equations was applied to 10 rice growth models. New functions considered the harmful effects of low temperatures on rice yield at different stages. In addition, the threshold temperatures of cold tolerance were set for different rice varieties. The improved algorithm enhances the ability of the models to simulate rice yields under climate change, providing a more reliable tool for adapting rice production to future climatic challenges.

Rice yield and quality decline due to excessive fertiliser use is problematic in China. To increase rice grain filling and improve rice yield and quality, a nitrogen reduction and density increase study in 2023 and 2024 was imposed on a long-term experimental field. The four treatments adopted for the study were normal nitrogen and normal density (CK), normal nitrogen and increased density (NN+ID), reduced nitrogen in panicle fertiliser and increased density (RPN+ID), and reduced nitrogen in basal fertiliser and increased density (RBN+ID). RPN+ID and RBN+ID, respectively, produced a 3.0% and 5.1% higher yield than CK in both years. The mean grain filling rate (Va) of superior grains in RBN+ID increased by 12.5%, while the mean grain filling rate (Va) of inferior grains in the RPN+ID treatment increased by 4.2% with respect to CK. RPN+ID caused 0.4%, 9.6%, and 13.3% decline in the brown rice rate, chalkiness degree, and chalkiness rate, respectively, while RBN+ID triggered 0.4%, 7.2%, and 11.0% decline in the brown rice rate, chalkiness degree, and chalkiness rate, respectively. RPN+ID stimulated 4.2% and 3.1% increases in flavour and straight-chain amylose values, respectively. Whereas a 20% reduction in basal nitrogen fertiliser and a 32% increase in density improved the yield and appearance quality of rice, a 20% reduction in nitrogen fertiliser at the panicle stage and a 32% increase in density promoted a higher steaming flavour quality. Therefore, an appropriate reduction in nitrogen fertiliser while simultaneously increasing rice density has a significant impact on rice quality, fertiliser pollution reduction, and is a theoretical basis for rice yield and quality improvement in Northeast China.

Epigenetic pathways could provide a mechanistic explanation for the inheritance of acquired characteristics, as proposed by Lamarck in 1802, but epigenetic alterations that endow adaptive hereditary traits have rarely been observed. Here, in cultivated Asian rice (Oryzasativa L.), we identified an epiallele conferring acquired and heritable cold tolerance, an adaptive trait enabling northward spread from its tropical origins. We subjected cold-sensitive rice to multigenerational cold stress and identified a line with acquired stable inheritance of cold tolerance. DNA-hypomethylation variation in the acquiredcoldtolerance 1 (ACT1) promoter region rendered its expression insensitive to cold. This change is, in large part, responsible for the acquired cold tolerance, as confirmed by DNA-methylation editing. Natural variation in ACT1 DNA hypomethylation is associated with cold tolerance and rice geographic distribution. Hypomethylation at ACT1 triggers adaptive cold tolerance, presenting a route to epigenetic-variation-driven inheritance of acquired characteristics.

Crop production is heavily dependent on fertilizers that negatively impact the environment; therefore, research on biochar to improve the soil’s properties and reduce greenhouse gas emissions has intensified over the years. To elucidate rice yield and greenhouse gas emission (GHG) arising from the application of biochar and N fertilizer on paddy soil in Northeast China, a 3-year (2015–2017) field experiment was established. Adopting a split-plot design with three replicates, two nitrogen (N) fertilizer levels in the main plots were designated as follows: 120 kg N ha−1 (N1, 2/3 of N application rate for optimal local rice yield); 180 kg N ha−1 (N2, full N application rate for optimal local rice yield); and four biochar application rates of no biochar (C0, control); 1.0 t ha−1 biochar (C1); 1.5 t ha−1 biochar (C2); and 2.0 t ha−1 biochar (C3) were designated as sub-treatments. The results showed that in 2015, biochar amendment increased GHG emissions while between 2016 and 2017, biochar amendment of 1.5 t ha−1 decreased CH4 emissions, global warming potential (GWP), and greenhouse gasses intensity (GHGI) by 11.3%, 10.9%, and 17.0%, respectively. On average, for the years 2016 and 2017, the N2O fluxes were 17.0% lower in the N2 plots compared to the N1 plots. Biochar amendment of 1.5 t ha−1 recorded an 8.6% increase in rice yield compared to the control. The soil properties of the study site showed that biochar amendment of 1, 1.5, and 2 t ha−1 augmented soil organic matter by 3.3%, 5.3%, and 5.2%, respectively, and soil phosphorus availability by 6.4%, 11.2%, and 22.6%, respectively. The co-application of biochar at 1.5 t ha−1 and 180 kg N ha−1 effectively regulated GHG emissions while maintaining crop yield. Appropriate co-application of biochar with N fertilizer can be adopted for emission reduction and rice yield maintenance while maintaining soil fertility in Northeast China.

Climate warming has caused increased air temperature as well as increased subsurface temperature. Many previous studies on subsurface warming simplified heat advection by neglecting the horizontal component of regional groundwater flow or even neglected heat advection accompanying groundwater flow. In this study, the simultaneous control of heat advection and conduction on subsurface warming is numerically investigated in a 2D hypothetical basin cross section. By calculating the increment of subsurface temperature, we find that heat advection could accelerate subsurface warming. In a given basin, subsurface warming in the recharge area with downward groundwater flow is more significant than that in the discharge area with upward groundwater flow. By using a 1D model with vertical groundwater flow only for comparison, we find that in any part of a basin, even if the horizontal flux is very small compared with the vertical flux, neglecting the horizontal flux would underestimate the propagation depth of climate warming. This implies that when the propagation depth of climate warming is a priori known variable, existing 1D models would overestimate downward groundwater flux or underestimate upward groundwater flux. Moreover, we find pumping would cause deeper propagation depths of climate warming by accelerating groundwater circulation, whereas basin-scale heterogeneity and anisotropy of hydraulic conductivity would cause shallower propagation depths of climate warming because of the relative dominance of horizontal flow. By demonstrating the importance of 2D groundwater flow on subsurface warming, the results provide new insight into understanding the regulation of temperature among the atmosphere, the hydrosphere and the lithosphere.

Tillage practices are of critical importance in maintaining soil quality on cropland and for food production, with rice cultivation representing a significant portion of the world’s food production and greenhouse gas (GHG) emissions. While numerous studies have examined the effects of reduced and no-tillage on soil GHG emissions and rice yields, the impact of adopting a rotational approach to tillage practices on the rice cultivation cycle remains uncertain. In this study, we conducted a four-year (2017–2020) field experiment in a single rice-growing area in Northeast China with the aim of investigating the effects of different tillage practices on GHG emissions from paddy fields and rice yields under full straw return conditions. We set up three experimental treatments: rotary tillage, plowing, and rotational tillage (i.e., a combination of one year of plowing and one year of rotary tillage). The results showed that averaged across all treatments, average methane (CH4, 302.6 ± 51.1 kg ha−1) and nitrous oxide (N2O, 0.86 ± 0.361 kg ha−1) emissions and rice yield (9.0 ± 0.9 t ha−1) did not exhibit significant inter-annual variability during the entire experimental period and were comparable to the average for the region. The ranking of GHG emissions during the rice-growing season was as follows: rotary tillage > plowing > rotational tillage. Across the experimental period, CH4 and N2O emissions were 9.1% and 8.5% lower in the plowing treatment and 21.2% and 13.1% lower in the rotational tillage treatment compared to the rotary tillage treatment. During the experimental period, there was no significant effect of tillage treatments on rice yield. This reduction in emissions may be attributed to changes in soil penetration resistance. In the rotational and plowing treatments, soil penetration resistance was in a range more adapted to rice growth and GHG emissions reduction compared to the rotary tillage treatment. The yield-scale GHG emission intensity was reduced by 12.7% and 26.1% in the plowing and rotational tillage treatments, respectively, in comparison to the rotary tillage treatment. This suggests that rotational tillage is a management practice that can achieve greenhouse gas emission reductions in paddy fields and stabilize or possibly increase rice yields. Consequently, the results demonstrated that a rotational alternation of multiple tillage practices is a synergistic strategy for achieving low carbon and high yield in rice in the cold rice-growing region of Northeast China.

Globally, acquiring information on region- and crop-specific nitrous oxide (N2O) emissions is vital for establishing effective N2O mitigation strategies. Soil cultivated with cotton (Gossypium hirsutum L.) is an important source of N2O in agricultural production. However, little is known about the magnitudes and main drivers of soil N2O emissions from cotton fields worldwide. In this meta-analysis, we were the first to synthesize 34 peer-reviewed papers (298 observational datasets) to quantify the magnitudes and controlling factors of area-scaled N2O emissions (N2Oarea), direct N2O emission factors (EFd), and yield-scaled N2O emissions (N2Oyield) from the soils of cotton fields and to explore associated potential mitigation strategies. On average, the N2Oarea from global cotton-planted soils was 2.10 kg N ha(-1), with a mean EFd of 0.92 %, which is comparable to those reported for cereal crops (e.g., maize, 1.02 %) and the Intergovernmental Panel on Climate Change default value of 1 % for global croplands. The global mean N2Oyield estimated here was 622 g N Mg-1. At the global scale, the variations in all N2O-related indices in the soils of cotton fields were demonstrated to be primarily controlled by climatic conditions (e.g. climate type) and soil properties (e.g., bulk density, pH, C/N or soil texture) rather than by well-recognized management practices (e.g., N fertilization rate). Furthermore, our analysis showed that the application of urease and/or nitrification inhibitors significantly reduced soil N2O emissions while maintaining seed cotton yields. These findings emphasize that cotton production has an obvious climate footprint and provide potential N2O mitigation options for the sustainable intensification of cotton production.

Early-matured aromatic japonica rice from the Northeast is the most popular rice commodity in the Chinese market. The Qigeng10 (QG10) was one of the varieties with the largest planting area in this region in recent years. It was an early-matured japonica rice variety with a lot of superior traits such as semi-dwarf, lodging resistance, long grain, aromatic and good quality. Therefore, a high-quality assembly of Qigeng10 genome is critical and useful for japonica research and breeding. In this study, we produced a high-precision QG10 chromosome-level genome by using a combination of Nanopore and Hi-C platforms. Finally, we assembled the QG10 genome into 77 contigs with an N50 length of 11.80 Mb in 27 scaffolds with an N50 length of 30.55 Mb. The assembled genome size was 378.31Mb with 65 contigs and constituted approximately 99.59% of the 12 chromosomes. We identified a total of 1,080,819 SNPs and 682,392 InDels between QG10 and Nipponbare. We also annotated 57,599 genes by the Ab initio method, homology-based technique, and RNA-seq. Based on the assembled genome sequence, we detected the sequence variation in a total of 63 cloned genes involved in grain yield, grain size, disease tolerance, lodging resistance, fragrance, and many other important traits. Finally, we identified five elite alleles (qTGW2Nipponbare, qTGW3Nanyangzhan, GW5IR24, GW6Suyunuo, and qGW8Basmati385) controlling long grain size, four elite alleles (COLD1Nipponbare, bZIP73Nipponbare, CTB4aKunmingxiaobaigu, and CTB2Kunmingxiaobaigu) controlling cold tolerance, three non-functional alleles (DTH7Kitaake, Ghd7Hejiang19, and Hd1Longgeng31) for early heading, two resistant alleles (PiaAkihikari and Pid4Digu) for rice blast, a resistant allele STV11Kasalath for rice stripe virus, an NRT1.1BIR24 allele for higher nitrate absorption activity, an elite allele SCM3Chugoku117 for stronger culms, and the typical aromatic gene badh2-E2 for fragrance in QG10. These results not only help us to better elucidate the genetic mechanisms underlying excellent agronomic traits in QG10 but also have wide-ranging implications for genomics-assisted breeding in early-matured fragrant japonica rice.

在黑龙江稻区采集病样、分离病原菌的基础上,获得形态差异明显的20株水稻叶褐条斑病菌,利用ITS序列鉴定其均为Nigrospo?ra oryzae,由此推断Nigrospora oryzae为当地主要的水稻黑孢菌种群.此外,依据水稻叶褐条斑病的生物学特征,摸索了人工接种鉴定技术.该研究结果为抗水稻叶褐条斑病的遗传育种研究奠定基础.

为促进盐碱地快速改良和高效利用,以不施肥(T0)、常规施肥(T1)、化肥配施(T2)处理为对照,研究化肥配施有机物料[化肥配施生物炭有机肥(T3)、化肥配施秸秆有机肥(T4)、化肥配施秸秆有机肥和生物菌肥(T 5)]对水稻产量和品质的影响.结果表明,化肥配施有机物料能降低土壤p H和电导率,有利于盐碱地土壤改良,与未施有机物料处理相比,化肥配施有机物料对水稻增产效果明显,化肥配施秸秆有机肥和生物菌肥(T 5)产量最高;龙稻21增产范围为12.76％ ～189.87％,海稻2号的增产范围为88.46％ ～151.40％;施用有机物料使穗长变长,穗粒数增多,株高、实粒重、结实率、千粒重均高于未施有机物料处理,穗数、穗粒数、结实率和和千粒重4个产量构成因子与产量呈极显著正相关,相关系数大小依次为穗粒数>结实率>穗数>千粒重;在保证产量的前提下,化肥配施不同有机物料能提高稻米的加工品质和食味值,降低蛋白质含量,化肥配施生物炭有机肥(T 3)处理稻米的整体品质最佳.

以变电站一次设备作为研究对象,具体分析在安装测试过程中可能出现的故障问题,并给出相应解决方案,确保变电站一次设备能够顺利完成安装,保证质量达到预期目标,为电力系统运行奠定坚实基础.

Increasing simulation bias with climate warming is a common problem for current rice phenology models. This study integrated data from three rice cultivars via chamber experiments and long-term observation datasets to evaluate three temperature response functions, i.e., bilinear, beta and logistic/exponential saturation functions. The chamber experiments showed that maturity simulation was biased by a 3.8-14.05 day/degrees C change in temperature using the same parameters for the entire rice growth cycle. Such simulation bias trends were reduced to 0.07-1.88 day/degrees C by the separate parameterization of the pre- and post-flowering phases, reflecting substantial diversity in the functions between the two phases. This conclusion was confirmed using other cultivars from long-term observation dataset. Comparably, the beta function can efficiently minimize the maturity simulation bias from 1.54 to 13.25 day/degrees C to 0.94-1.33 day/degrees C. Therefore, we recommend the separate parameterization of the beta function for the pre- and post-flowering phases to estimate the phenological response of rice to climate warming.

盆栽条件下,以耐冷性不同的2个水稻(Oryza sativa L.)品种龙稻5(耐冷型)和龙粳11(冷敏型)为材料,于开花期在人工气候室进行低温(15℃,分别持续1,2,3,4,5 d)处理,研究开花期低温对不同耐冷性水稻结实率及叶鞘膜透性、抗氧化酶等生理指标的影响.结果表明:低温处理2 d时,龙稻5和龙粳11的花粉活力分别下降了8.21％和16.10％,差异达极显著水平;低温处理3 d后,龙稻5的结实率下降到99.90％,与CK相比差异达到显著水平;低温处理1 d后,龙粳11的结实率下降到60.04％,与对照相比差异达到极显著水平.低温处理提高了水稻叶鞘相对电导率和脯氨酸、可溶性蛋白含量,处理5 d时各指标达最大值,与CK相比,龙稻15和龙粳11分别提高了38.01％和20.77％、25.06％和84.85％、25.82％和23.63％.同时低温处理也提高了叶鞘超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,处理3 d时酶活性达最大值,龙稻15和龙粳11分别较CK提高了10.57％和14.90％、86.26％和68.71％、17.73％和28.25％.综上所述,开花期低温引起水稻叶鞘膜脂过氧化程度升高,但也诱导水稻叶鞘抗氧化系统开启、保护酶活性上升以抵御低温伤害;开花期低温导致水稻花粉活力降低并引起结实率降低,耐冷品种较冷敏品种抵御能力强.

植物生长调节剂能够调控马铃薯的多项生育过程,包括代谢生理、产量形成、品质改善等.笔者综合了国内外研究成果,概述了植物生长调节剂对马铃薯的影响,详细介绍了植物生长调节剂对马铃薯产量和营养品质的调控效应.基于植物生长调节剂在马铃薯上的应用,展望了中国在该领域未来的研究方向与发展趋势,为以后的研究提供相应理论依据.

Northeast China (NEC) is one of the most important rice production areas in China, accounting for approximately 15% of its total national rice production, and is one of the regions most vulnerable to global climate change. Knowing crops' potential yields is crucial to understanding comparisons of different cultivars, crops and environments as well as plausible future increases and limits to crop yields. To mitigate the impacts of climate change and enhance food security, investigating yield potential (YP), attainable yield (YPA), nitrogen-limited potential yield (YPN), and actual farmers' yield (Y-a) as well as rice yield gaps and their causes in NEC under the climate change background is necessary. In this study, the ORYZA (v3) crop model was calibrated and validated for rice phenology and yields. The validated model was then used to determine YP, YPA and YPN values as well as yield gaps caused by nitrogen management factors (YG(AN)) and other agronomic and socioeconomic factors (YG(Na)) for five agroclimatic zones in NEC from 1981 to 2010. The regional area-weighted mean YP levels estimated by the model were 12.9 t ha(-1) for YP and 11.6 t ha(-1) for YPA with decreasing trends and 8.7 t ha(-1) for YPN with an increasing tendency. The Ya was 6.8 t ha(-1), with a significant increase of 1.1 t ha(-1) per decade (p < 0.01), and farmers achieved 58.6% of the YP. The YPA accounted for 80.9-94.8% of the YP in NEC. The regional exploitable yield gap (YG(E)) was 4.8 t ha(-1). The regional yield gaps were shrinking at 0.47 and 0.88 t ha(-1) per decade for YG(AN) and YG(Na) respectively. In conclusion, because of the persistently large yield gap between farmers and YPN, YPA provides the government and farmers an opportunity to significantly increase rice production by controlling socioeconomic factors and adopting high-yield agronomic management practices based on site-specific conditions, including optimized irrigation and fertilization practices and "super" rice cultivars.

Cereals have a pivotal position in future sustainable development of agriculture in China.This study reviewed the research achievements on cereals in Heilongjiang in recent years based on the status of cereals in agriculture,and summarized the cultivation characteristics of coarse cereals,expounded the cereals processing status quo and introduced the cereal import and export trade.At last,we discussed the research direction,development trend and corresponding countermeasures of cereals industry,and provided rationalization suggestions for the future development of the industry.

文章探讨叶菜用甘薯茎尖产量与种植密度的关系,并对不同品种及不同采收时期茎尖食用品质进行评价,为叶菜型甘薯品种在重庆地区的推广种植提供参考

红小豆是重要的豆类作物,在中国种植范围较广.笔者综合了国内大量研究成果,概述了红小豆栽培技术研究现状,详细介绍了红小豆生理水平的研究进展.基于红小豆生产过程中存在的问题,提出了对应的解决策略,展望了红小豆未来的研究方向与发展趋势,为以后的研究提供相应理论依据.