Rice(Oryza sativa L.)plant protection using dual biological control and plant growth-promoting agents:Current scenarios and future prospects

Various microorganisms live in association with different parts of plants and can be harmful,neutral,or beneficial to plant health.Some microbial inhabitants of plants can control plant diseases by contesting with,predating on,or antagonizing plant pathogens and by inducing systems for plant defense.A range of methods,including plant growth-promoting microorganisms(PGPMs)as biological control agents(BCAs)(BCA-PGPMs)are used for the biological management and control of plant pathogens.Some BCAs interact with plants by inducing resistance or priming plants without direct interaction with the pathogen.Other BCAs operate via nutrient competition or other mechanisms to modulate the growth conditions for the pathogen.Generally,PGPMs can be applied alone or together with other chemicals or carriers to control various crop diseases.This review highlights the effective types of BCA-PGPMs and their applications,roles,carrier based-formulations,and responses to rice(Oryza sativa L.)pathogens.Future plant disease management prospects are promising,and growers’increasing demand for BCA-PGPM products can be exploited as an effective approach to the management of plant diseases,as well as to improve yield,environmental protection,biological resources,and agricultural system sustainability.

Plant growth-promoting properties and anti-fungal activity of endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta in arid lands

Endophytes,as crucial components of plant microbial communities,significantly contribute to enhancing the absorption of nutrients such as nitrogen and phosphorus by their hosts,promote plant growth,and degrade pathogenic fungal mycelia.In this study,an experiment was conducted in August 2022 to explore the growth-promoting potential of endophytic bacterial strains isolated from two medical plant species,Thymus altaicus and Salvia deserta,using a series of screening media.Plant samples of Thymus altaicus and Salvia deserta were collected from Zhaosu County and Habahe County in Xinjiang Uygur Autonomous Region,China,in July 2021.Additionally,the inhibitory effects of endophytic bacterial strains on the four pathogenic fungi(Fusarium oxysporum,Fulvia fulva,Alternaria solani,and Valsa mali)were determined through the plate confrontation method.A total of 80 endophytic bacterial strains were isolated from Thymus altaicus,while a total of 60 endophytic bacterial strains were isolated from Salvia deserta.The endophytic bacterial strains from both Thymus altaicus and Salvia deserta exhibited plant growth-promoting properties.Specifically,the strains of Bacillus sp.TR002,Bacillus sp.TR005,Microbacterium sp.TSB5,and Rhodococcus sp.TR013 demonstrated strong cellulase-producing activity,siderophore-producing activity,phosphate solubilization activity,and nitrogen-fixing activity,respectively.Out of 140 endophytic bacterial strains isolated from Thymus altaicus and Salvia deserta,104 strains displayed anti-fungal activity against Fulvia fulva,Alternaria solani,Fusarium oxysporum,and Valsa mali.Furthermore,the strains of Bacillus sp.TR005,Bacillus sp.TS003,and Bacillus sp.TSB7 exhibited robust inhibition rates against all the four pathogenic fungi.In conclusion,the endophytic bacterial strains from Thymus altaicus and Salvia deserta possess both plant growth-promoting and anti-fungal properties,making them promising candidates for future development as growth-promoting agents and biocontrol tools for plant diseases.

Plant growth-promoting rhizobacteria(PGPR)and its mechanisms against plant diseases for sustainable agriculture and better productivity

Plant growth-promoting rhizobacteria(PGPR)are specialized bacterial communities inhabiting the root rhizosphere and the secretion of root exudates helps to,regulate the microbial dynamics and their interactions with the plants.These bacteria viz.,Agrobacterium,Arthobacter,Azospirillum,Bacillus,Burkholderia,Flavobacterium,Pseudomonas,Rhizobium,etc.,play important role in plant growth promotion.In addition,such symbiotic associations of PGPRs in the rhizospheric region also confer protection against several diseases caused by bacterial,fungal and viral pathogens.The biocontrol mechanism utilized by PGPR includes direct and indirect mechanisms direct PGPR mechanisms include the production of antibiotic,siderophore,and hydrolytic enzymes,competition for space and nutrients,and quorum sensing whereas,indirect mechanisms include rhizomicrobiome regulation via.secretion of root exudates,phytostimulation through the release of phytohormones viz.,auxin,cytokinin,gibberellic acid,1-aminocyclopropane-1-carboxylate and induction of systemic resistance through expression of antioxidant defense enzymes viz.,phenylalanine ammonia lyase(PAL),peroxidase(PO),polyphenyloxidases(PPO),superoxide dismutase(SOD),chitinase andβ-glucanases.For the suppression of plant diseases potent bio inoculants can be developed by modulating the rhizomicrobiome through rhizospheric engineering.In addition,understandings of different strategies to improve PGPR strains,their competence,colonization efficiency,persistence and its future implications should also be taken into consideration.

Synergistic combination of arbuscular mycorrhizal fungi and plant growth-promoting rhizobacteria modulates morpho-physiological characteristics and soil structure in Nitraria tangutorum bobr.Under saline soil conditions

Nitraria tangutorum Bobr.,a typical xero-halophyte,can be used for vegetation restoration and reconstruction in arid and semiarid regions affected by salinity.However,global climate change and unreasonable human activity have exacerbated salinization in arid and semi-arid regions,which in turn has led to the growth inhibition of halophytes,including N.tangutorum.Arbuscular mycorrhizal fungi(AMF)and plant growth-promoting rhizobacteria(PGPR)have the potential to improve the salt tolerance of plants and their adaptation to saline soil environments.In this study,the effects of single and combined inoculations of AMF(Glomus mosseae)and PGPR(Bacillus amyloliquefaciens FZB42)on N.tangutorum were evaluated in severe saline soil conditions.The results indicate that AMF and PGPR alone may not adapt well to the real soil environment,and cannot ensure the effect of either growth promotion or salt-tolerance induction on N.tangutorum seedlings.However,the combination of AMF and PGPR significantly promoted mycorrhizal colonization,increased biomass accumulation,improved morphological development,enhanced photosynthetic performance,stomatal adjustment ability,and the exchange of water and gas.Co-inoculation also significantly counteracted the adverse effect of salinity on the soil structure of N.tangutorum seedlings.It is concluded that the effectiveness of microbial inoculation on the salt tolerance of N.tangutorum seedlings depends on the functional compatibility between plants and microorganisms as well as the specific combinations of AMF and PGPR.

Effect of Plant Growth-Promoting Rhizobacteria at Various Nitrogen Rates on Corn Growth

Plant growth-promoting rhizobacteria (PGPR) colonize plant roots and promote plant growth by producing and secreting various chemical regulators in the rhizosphere. With the recent interest in sustainable agriculture, an increasing number of researchers are investigating ways to improve the efficiency of PGPR use to reduce chemical fertilizer inputs needed for crop production. Accordingly, greenhouse studies were conducted to evaluate the impact of PGPR inoculants on biomass production and nitrogen (N) content of corn (Zea mays L.) under different N levels. Treatments included three PGPR inoculants (two mixtures of PGPR strains and one control without PGPR) and five N application levels (0%, 25%, 50%, 75%, and 100% of the recommended N rate of 135 kg N ha−1). Results showed that inoculation of PGPR significantly increased plant height, stem diameter, leaf area, and root morphology of corn compared to no PGPR application under the same N levels at the V6 growth stage, but few differences were observed at the V4 stage. PGPR with 50% of the full N rate produced corn biomass and N concentrations equivalent to or greater than that of the full N rate without inoculants at the VT stage. In conclusion, mixtures of PGPR can potentially reduce inorganic N fertilization without affecting corn plant growth parameters. Future research is needed under field conditions to determine if these PGPR inoculants can be integrated as a bio-fertilizer in crop production nutrient management strategies.

Assessing the Efficacy of Lemongrass (Cymbopogon citratus) and Sambong (Blumea balsamifera) Extracts in Combating Black Pod Disease: Sustainable Solutions for Controlling Phytophthora megakarya in Cameroon’s Cocoa Plantations

The use of plant extracts as antifungal agents is gaining increasing attention, particularly for the control of black pod disease in cocoa. Despite extensive research, current strategies haven’t been entirely effective. This study evaluated the effectiveness of Cymbopogon citratus and Blumea balsamifora leaf extracts, both individually and in combination, against Phytophthora megakarya. We assessed the efficacy of the most promising combination (75% B. balsamifera, 25% C. citratus) after storage at room temperature for up to 9 days. Agar microdilution and in vivo bioassays were conducted to determine antifungal susceptibility and effectiveness. Blumea extract exhibited the highest overall inhibitory activity, with the lowest minimum inhibitory concentration (117 µl mL−1) while C. citratus had a narrower range of MIC (146 to 233 µl mL−1). The combination of C. citratus and B. balsamifera demonstrated a synergistic effect against P. megakarya, achieving growth inhibition on V8 media (92.72 ± 4.20% to 100%) and on artificially infected detached pod cortex (92.24 ± 4.53% to 98.75 ± 1.25%), which was not significantly different from the positive control (Ridomil). Furthermore, this combination maintained its effectiveness for up to 9 days at room temperature. These findings suggest that combining plant extracts can enhance their antifungal properties.

Potential seed germination-enhancing plant growth-promoting rhizobacteria for restoration of Pinus chiapensis ecosystems

Rhizosphere soil samples of three Pinus chiapensis sites were analyzed for their physicochemical properties,soil bacteria isolated and screened in vitro for growthpromoting abilities.Nine isolates that showed promise were identified to five genera Dyella,Luteimonas,Euterobacter,Paraburkholderia and Bacillus based on the sequences of16 S rRNA gene.All the strains were isolated from nondisturbed stands.These bacteria significantly decreased germination time and increased sprout sizes.Indole acetic acid and gibberellin production and phosphate solubilisation were detected.Results indicate that these biochemicals could be essential for P.chiapensis distribution and suggest the possibility that PGPR inoculation on P.chiapensis seeds prior to planting could improve germination and possibly seedling development.

Application Progress of Plant Growth-promoting Bacteria in Crops

Plant growth-promoting bacteria(PGPBs)can promote plant growth and improve crop yield.They can induce plant systemic resistance to resist biotic and abiotic stresses.In recent years,with the development of green ecological agriculture,new biological fertilizers such as microbial inocula and microbial fertilizers based on PGPBs have been gradually applied in crop planting.Based on plant growth promotion and disease control,the application progress of PGPBs in crops from the aspects of growth promotion mechanism,growth promotion effect,resistance to biological and abiotic stresses were discussed,aiming to provide reference for the relevant research and application of PGPBs in crops.

Decomposition of oil cleaning agents from nuclear power plants by supercritical water oxidation

Oil cleaning agents generated from nuclear power plants(NPPs)are radioactive organic liquid wastes.To date,because there are no satisfactory industrial treatment measures,these wastes can only be stored for a long time.In this work,the optimization for the supercritical water oxidation(SCWO)of the spent organic solvent was investigated.The main process parameters of DURSET(oil cleaning agent)SCWO,such as temperature,reaction time,and excess oxygen coefficient,were optimized using response surface methodology,and a quadratic polynomial model was obtained.The determination coefficient(R^(2))of the model is 0.9812,indicating that the model is reliable.The optimized process conditions were at 515 C,66 s,and an excess oxygen coefficient of 211%.Under these conditions,the chemical oxygen demand removal of organic matter could reach 99.5%.The temperature was found to be the main factor affecting the SCWO process.Ketones and benzene-based compounds may be the main intermediates in DURSET SCWO.This work provides basic data for the industrialization of the degradation of spent organic solvents from NPP using SCWO technology.

Protection and Treatment of Landscape Plant Secondary Disasters (Deicing Agent Damage) Caused by Extreme Weather

Deicing agent is always applied to alleviate urban traffic pressure after snowing in winter,however,such a snow melting agent is extremely harmful for landscape plants.To eliminate or avoid such damages,we have been actively exploring protection and treatment means.By analyzing the protection of landscape plants before using the deicing agent and the treatment after being damaged by the salt,the paper described how landscaping industry of Beijing handled extreme weather and influence of certain urban environment on landscape plants in a high-efficiency and low-cost way,and then figured out the balance point of normal social life and healthy development of ecological environment.

Plant Growth Promoting Rhizobacteria as Biological Control Agent in Rice

The use of agrochemical products to combat diseases in crops has adverse effects on the environment and human health. Plant growth promoting rhizobacterium (PGPR) has been increasingly proposed as an eco-friendly alternative in agriculture. PGPRs have beneficial effects not only in promoting plant growth but also have shown their potential as biological control agent, being able to inhibit plant pathogens. Here, we investigated the use of PGPR Paraburkholderia sp. strain SOS3 to provide disease protection in rice (Oryza sativa L.). The antagonistic activity of SOS3 against five fungal pathogens of rice was assessed by dual culture on plates and on rice seedlings. The results showed that on plate assay, SOS3 inhibits the growth of Curvularia lunata, Rhizoctonia solani, Pyricularia oryzae, Helminthosporium oryzae, and Fusarium moniliforme by 17.2%, 1.1%, 8.3%, 32.5%, and 35.4%, respectively. When inoculated on rice seeds, SOS3 promotes seed germination and significantly reduces disease symptoms in plants infected with R. solani. These results suggest that SOS3 has a great potential to be used in rice agriculture to combat the “Sheath Blight” disease.

A Multi-agent Framework of an Integrated Plant Maintenance System

Based on systematic analysis, an Integrated Plant Maintenance System (IPMS)is proposed in this paper to cope with challenges in plant maintenance. The characteristics of theIPMS are summarized and the necessity of its modeling is set forth. Based on the analysis andcomparison among structured, object-oriented and multi-agent modeling frameworks, a multi-agentmodeling framework is selected in this paper as a theoretical guidance and together with the Troposmethod for modeling, the system model of an integrated plant maintenance system is constructed. Thesystem model developed in this paper provides a guidance template for the Baling company in itsstepwise implementation of the IPMS.

真丝织物的植物染料染色

采用植物红和植物蓝染料对真丝织物进行直接染色,探讨了染液浓度、染色pH、染色温度、染色时间、元明粉用量、固色剂用量对真丝织物染色效果的影响。通过正交试验得到的最佳染色工艺为:植物红染料质量分数1.00%(omf),染液pH为3,染色温度90℃,染色时间40 min,元明粉质量浓度5 g/L,固色剂质量分数1%;植物蓝染料质量分数1.00%(omf),染液pH为7,染色温度90℃,染色时间55 min,元明粉质量浓度5 g/L,固色剂质量分数1%。染色织物具有较好的耐皂洗色牢度、耐摩擦色牢度和耐汗渍色牢度,基本达到3~4级以上。

优化基肥和提苗肥对烤烟生长及品质的影响

【目的】明确基肥中添加微生物菌剂和提苗肥中添加尿素对稻茬烤烟促早生快发的效果。【方法】以云烟87为材料,采用双因素试验,设计基肥施用方法(基肥中未添加微生物菌剂、基肥中添加微生物菌剂),以及提苗肥施用方法(单施烟草专用提苗肥、单施尿素、烟草专用提苗肥和尿素混施),研究了微生物菌剂、优化提苗肥及其互作对烤烟的农艺性状、干物质量、养分积累,以及烟叶的物理性状、化学成分、感官质量和经济性状的影响。【结果】基肥中添加微生物菌剂和烟草专用提苗肥配施尿素可增加最大烟叶面积,提高烤烟干物质量和氮、磷、钾养分积累量,提高烟叶物理性状指数、化学成分可用性指数、感官质量和经济效果指数,增加烟叶产值,但施用尿素作提苗肥可提高叶片厚度、叶面积质量和烟碱含量。优化基肥添加微生物菌剂和提苗肥处理烟叶的物理性状指数、化学成分可用性指数、感官质量和经济效果指数较传统施肥方法分别提高2.85%,18.48%,9.79%和3.76%。【结论】稻茬烤烟穴施基肥中添加微生物菌剂、专用提苗肥中适量配施尿素可以作为促进烤烟早生快发的一项技术措施,但必须控制施氮总量。

10种药剂处理对杨梅凋萎病的防控效果评价

为有效控制杨梅凋萎病发生,减少农残,保证果品安全,在湖南省通道县杨梅基地设置4月25日和5月10日(采果前)喷施0.5%小檗碱水剂500倍液等5种药剂各1次+7月5日(采果后)30%苯甲·咪鲜胺悬浮剂3000倍液等2种药剂1次,共10个药剂组合处理,比较不同药剂处理的病枝减退率、病情指数减退率和相对防效。结果表明,不同药剂处理的杨梅凋萎病的病枝减退率为15.29%~74.07%,相对防效为22.23%~80.00%。其中,杨梅成熟前喷施0.5%小檗碱水剂500倍液2次+采果后喷施30%苯甲·咪鲜胺悬浮剂3000倍液1次处理的防控效果最佳,其病枝减退率达到74.07%,相对防效达到80.00%;杨梅成熟前喷施0.5%小檗碱水剂500倍液2次+采果后喷施40%吡醚·戊唑醇悬浮剂3000倍液,防控效果次之,其病枝减退率为65.35%、相对防效为75.56%;其他处理的相对防效均低于55%。因此,杨梅生产上推荐在杨梅成熟前喷施0.5%小檗碱水剂500倍液,采果后喷施30%苯甲·咪鲜胺3000倍液防控杨梅凋萎病,以避免杨梅果实农残超标且达到较好防控效果。

基于多代理强化学习的多新型市场主体虚拟电厂博弈竞价及效益分配策略

目前新型市场主体规模较小但数量众多,为提高竞争力可以使其组成联盟以多新型市场主体虚拟电厂的形式参与市场博弈,而公平的效益分配方法是维持联盟稳定的基础。为此,该文提出了一种多新型市场主体虚拟电厂博弈竞价及效益分配策略。首先,考虑多新型市场主体虚拟电厂和传统机组均作为价格影响者,构建包含电能量和备用辅助服务的主辅联合市场交易模型,并在不完全信息市场环境下采用多代理强化学习(multi-agentreinforcementlearning,MADDPG)算法求解。其次,采用分布式联盟构造方法得到最优多新型市场主体联盟结构。为解决效益分配方法中的维数灾问题,引入蒙特卡洛近似夏普利值,对虚拟电厂内各新型市场主体的超额收益进行合理分配。最后,算例分析表明所提方法给出了多新型主体虚拟电厂参与主辅联合市场的最优联盟结构和竞价策略,在保证精度的前提下提高了超额收益分配的计算速度,与单独参与市场相比提高了所有新型市场主体的收益。

油凝胶替代脂肪的研究及在植物肉饼中的应用

本研究以菜籽油和椰子油为油相,以单甘酯(monoglyceride,MG)、蜂蜡、米糠蜡、巴西棕榈蜡、小烛树蜡(candelilla wax,CLW)为凝胶剂制备油凝胶,探究不同添加量(5%、10%、15%、20%)凝胶剂对油凝胶持油力、质构特性、流变学性质的影响。结果表明,当凝胶剂添加量为15%及以上时,油凝胶的持油力均达到96%以上;MG的融化特性与牛油最为相似,但单一凝胶剂制备的油凝胶难以模仿牛油的质构性质。因此,本实验固定凝胶剂添加量为15%,选用不同质量比的MG和CLW复配制备油凝胶,并用于制备植物肉饼。结果表明,当MG与CLW复配比为3∶7时,油凝胶的质构性质、流变学性质最接近牛油,植物肉饼的感官品质最佳,显示出较好的脂肪替代潜力。

基于Agent技术虚拟植物模型的研究与探索

该文简述了Agent技术基本原理及应用概况,并从基于Agent技术来解决农业系统问题的角度出发,针对农业系统复杂,系统内的各要素之间存在着很强的交互性和协作性等特点,以及目前虚拟植物模型构建方法可能带来的非结构化问题,提出了利用Agent技术构建虚拟植物模型的观点,给出了Agent植物体的结构模型,阐述了Agent技术在虚拟植物模型构建中的应用方法及技术路线。

基于多Agent的电厂级监控信息系统设计

介绍了电厂级监控信息系统(SIS)的构成和功能以及Agent、多Agent的概念和技术,提出了利用多Agent技术构造SIS的观点,给出了基于多Agent的SIS体系结构的参考模型,并探讨了基于多Agent的SIS的总体开发框架和实现方法。

石榴皮染料在棉织物环保染色中的应用

针对石榴皮色素在棉织物染色中存在的低色牢度、金属媒染剂和化学固色剂导致环境污染以及人体危害等问题,通过优化石榴皮直接染色棉织物的染色工艺,选择3种天然媒染剂和3种金属媒染剂以不同媒染方式染色。利用天然松香固色剂对染色后的棉织物进行固色处理,探讨天然媒染剂提高织物染色性能的可行性,评估松香天然固色剂的固色效果以及不同染色工艺对石榴皮染色棉织物的染色性能的影响。结果表明,石榴皮直接染色棉织物最佳工艺:温度为80℃,染色时间为90min,pH值为7.0;经天然媒染剂媒染(茶卡盐后媒染)的织物可达到最大K/S值(7.64);经固色后染色棉织物的K/S值可提高至10.23,色牢度最高可达4~5级、5级;染色棉织物经过不同的染色工艺,可呈现不同的色相。