Resistance Monitoring of Field Populations of Panonychus citri to Three Pesticides

[Objectives]The paper was to investigate the development of Panonychus citri resistance to commonly used pesticides in major citrus producing areas in China,and to screen out new green and efficient agents for its control and prevention.[Methods]The resistance changes of field populations of P.citri to abamectin,pyridaben,and bifenazate in 12 locations across five provinces in China were compared using the leaf disc impregnation method.[Results]P.citri in the tested areas exhibited the most severe resistance to abamectin,with approximately 91.7%of the field populations showing high levels of resistance to abamectin(112.1-560.5 times);50%of P.citri populations exhibited high levels of resistance to pyridaben(123.0-202.7 times),while the remaining populations showed intermediate levels of resistance(25.6-80.3 times);except for the Zhejiang Xiangshan 2019 and Jiangxi Yudu 2019 populations,which exhibited a medium level of resistance to bifenazate,the remaining 10 monitored populations demonstrated a high level of resistance to bifenazate(140.4-686.1 times).[Conclusions]It is advisable to discontinue the use of abamectin and bifenazate due to significant resistance observed in populations of P.citri monitored in 12 locations across 5 provinces.It is recommended to reduce the frequency of pyridaben use and alternate with other acaricides that have different mechanisms of action due to the varying degrees of resistance developed.

Overview of Occurrence,Prevention and Control of Panonychus citri in China

In order to further promote the prevention and control research of Panonychus citri and improve its control effect,this paper summarizes the main influencing factors of the outbreak,main control technology and drug resistance of P.citri,and puts forward the research focus and control strategy.

Activation of autophagy by Citri Reticulatae Semen extract ameliorates amyloid-beta-induced cell death and cognition deficits in Alzheimer’s disease

Amyloid-beta-induced neuronal cell death contributes to cognitive decline in Alzheimer’s disease.Citri Reticulatae Semen has diverse beneficial effects on neurodegenerative diseases,including Parkinson’s and Huntington’s diseases,however,the effect of Citri Reticulatae Semen on Alzheimer’s disease remains unelucidated.In the current study,the anti-apoptotic and autophagic roles of Citri Reticulatae Semen extract on amyloid-beta-induced apoptosis in PC12 cells were first investigated.Citri Reticulatae Semen extract protected PC12 cells from amyloid-beta-induced apoptosis by attenuating the Bax/Bcl-2 ratio via activation of autophagy.In addition,Citri Reticulatae Semen extract was confirmed to bind amyloid-beta as revealed by biolayer interferometry in vitro,and suppress amyloid-beta-induced pathology such as paralysis,in a transgenic Caenorhabditis elegans in vivo model.Moreover,genetically defective Caenorhabditis elegans further confirmed that the neuroprotective effect of Citri Reticulatae Semen extract was autophagy-dependent.Most importantly,Citri Reticulatae Semen extract was confirmed to improve cognitive impairment,neuronal injury and amyloid-beta burden in 3×Tg Alzheimer’s disease mice.As revealed by both in vitro and in vivo models,these results suggest that Citri Reticulatae Semen extract is a potential natural therapeutic agent for Alzheimer’s disease via its neuroprotective autophagic effects.

柑桔木虱(Diaphorina citri)抗药性及抗药性机理研究进展

柑桔木虱主要为害柑桔等芸香科植物,是传播柑桔黄龙病的主要自然媒介,严格防治柑桔木虱是当前防控柑桔黄龙病的一项关键性措施。目前防治柑桔木虱最重要的方式是化学防治,而大量化学农药的使用以及使用的不恰当,柑桔木虱对一些杀虫剂产生了不同程度的抗药性。研究柑桔木虱抗药性的发生情况以及抗药性机理对于抗药性治理具有重要意义。为全面了解和总结柑桔木虱抗药性相关认识成果,进而为相关研究的开展及柑桔木虱的科学防治提供参考,综述了近年特别是2018年以来国内外柑桔木虱抗药性测定方法、抗药性现状、交互抗性、抗药性机理以及抗性治理等方面的研究进展。

A Network Pharmacology Study on Active Components and Targets of Citri Reticulatae Pericarpium for Treating Keloids

[Objectives]To investigate the mechanisms and pharmacologic effects of Citri Reticulatae Pericarpium against keloids by network pharmacology systematically.[Methods]TCMSP,Uniprot and BATMAN-TCM databases were used to obtain the active constituents and targets of Citri Reticulatae Pericarpium."Keloid"was used as key word to search for related therapeutic targets from Drug Bank,OMIM,TTD,and GEO databases.The Chinese medicine compound-target network was constructed by Cytoscape software.Besides,gene ontology(GO)and Kyoto Encyclopedia of genes and genome enrichment analysis were also performed.Afterward,Discovery Studio software was used to assess the interaction of key components and genes.[Results]Five active components of Citri Reticulatae Pericarpium,773 compound targets and 676 keloid treatment targets were obtained in the databases.After the intersection,there are 47 targets of Citri Reticulatae Pericarpium for treating keloids.Hub genes were identified such as MMP9,IL6,TNF,TP53,and VEGFA,which were enriched in tumor necrosis factor-α,nuclear factor kappa-B,and other signaling pathways.The molecular docking stimulation confirmed the interaction between the MMP9 and three components of Citri Reticulatae Pericarpium.[Conclusions]Citri Reticulatae Pericarpium may play an important role in treating keloids through modulating genes and signaling pathways.The present study sheds light on the mechanisms of active compounds of Citri Reticulatae Pericarpium for the treatment of keloids.

Acaricidal Activity of Boenninghausenia sessilicarpa Against Panonychus citri

Acaricidal activity of Boenninghausenia sessilicarpa against Panonychus cirri was tested in the laboratory. Four solvents were used to prepare crude extracts, petroleum ether, chloroform, ethyl acetate, and ethanol, among which ethanol was the most effective one. The results suggested that ethanol extracts of B. sessilicarpa had eminent acaricidal and ovicidal activities. Concentrated extracts were prepared using petroleum ether, chloroform, ethyl acetate, or distilled water as solvent. Mite mortality rates in the concentrated extracts by petroleum ether, chloroform, or distilled water were significantly lower than those by ethyl acetate. The LC50 values of eggs and female mites were 0.7639 and 1.1033 mg mL^-1, respectively. After liquid chromatography and thin layer chromatography, the concentrated extracts were separated into 14 groups of fractions and further tests for their acaricidal and ovicidal activities were conducted. Fraction 2 was found to possess higher acaricidal and ovicidal activities. The mortality of eggs and adult mites were 85.83 and 63.07%, respectively. Moreover, fraction 2 showed moderate oviposition inhibition effect （0.8795） against P. citri when the used dose was higher than 2.5 mg mL^-1

Repellent Activity of Extracts of Wild Rice Species against Panonychus citri and Aphis citricola in Associated with Esterase Isoenzyme in Insests

Six species of wild rice with different ecophenotypes including Oryza grandiglumis （E6-1, E6-3 / 6-4）, O. minuta （E13-9, E13-13）, O. officinalis（E15-8, E15-13）, O. punctata （E16-1, E16-3, E16-13）, O. granulata（E7-4）, and O. latifolia（101392, E9-1, E9-10） were extracted with methnol and the repellent activity of the extracts against the two insects Aphis citricola and Panonychus citri were studied. The extracts of O. officinalis E15-8 showed higher repellent rate to the two insects than those of the other species. The repellent rates of the extracts of E15-8 to P. citriand A. citricola were 83.26% and 87.86% at 5×10^4 μg/mL in 24 h and 87.95% and 82.43% in 48 h, respectively. The extracts of O. officinalis E15-8 had the effect of inhibition to the esterase of the two insects.

Analyses of Numerical Responses and Main Life Parameters for Determining the Suppression of Amblyseius cucumeris on Panonychus citri

In this paper, the numeral response and main parameters of experimental population life table were analyzed for determining the suppressing ability of Amblyseius cucumeris on Panonychus citri. The result showed that: (1) Under 21-31°C and 1 - 9 prey densities/leaf fragment condition, the prey consumptions of A. cucumeris increased with the temperature or prey density; (2) In 1:3 predator-prey ratio treatment, the suppression of P. citri (Ro=34.0053; T=19.4369; t=3.8204) was rather weak, it was enhanced as the ratio over 5:30, and the populations of P. citri in these treatments can be fully controlled within 4-5 days; (3) Under 25±1°C, 80-85% RH and 15L: 9D illumination conditions, the net reproductive rate, mean generation duration and the time for population double increase of P. citri (Ro=34.0053; T=19.4369; t=3.8204) were higher than those of A. cucumeris (Ro=21.8750; T=16.8943; t=3.7954). While the intrinsic rate of increase and finite rate of increase of the former (rm=0.1814; λ=1.1989) were lower than those of the latter (rm=0.1826; λ=1.2004). These results indicated that A. cucumeris is a desirable bio-control agent to suppress P. citri at lower population stage in citrus orchard.

Transcriptomic analysis reveals the defense mechanisms of citrus infested with Diaphorina citri

Huanglongbing(HLB) is a devastating disease that has led to an acute crisis for growers of citrus, one of the world's most important fruit crops. The phloem-feeding Asian citrus psyllid(ACP), Diaphorina citri, is the main pest at the new shoot stage and is the only natural vector of HLB pathogenic bacteria. Little is known about how plants perceive and defend themselves from this destructive pest. Here, we characterized changes in the expression of various genes in citrus plants that were continuously infested by D. citri for different durations(12, 24, and 48 h). A total of 5 219 differentially expressed genes(DEGs) and 643 common DEGs were identified across all time points. Several pathways related to defense were activated, such as peroxisome, alpha-linolenic acid metabolism, and phenylpropanoid and terpenoid biosynthesis, and some pathways related to growth and signal transduction were suppressed in response to D. citri infestation. The expression of genes including kinases(CML44, CIPK6, and XTH6), phytohormones(SAMT, LOX6, and NPR3), transcription factors(bHLH162, WRKY70, and WRKY40), and secondary metabolite synthesis-related genes(PAL, 4CL2, UGT74B1 and CYP82G1) was significantly altered in response to D. citri infestation. The findings of this study greatly enhance our understanding of the mechanisms underlying the defense response of citrus plants to D. citri infestation at the molecular level. Functional characterization of the candidate defense-related genes identified in this study will aid the molecular breeding of insect-resistant citrus varieties.

Occurrence of Diaphorina citri in Guangxi and Integrated Control Technique

In order to promote the healthy and sustainable development of citrus industry in Guangxi and reduce the harm of Diaphorina citri and citrus Huanglongbing on citrus industry,the paper summarizes the occurrence of D.citri in Guangxi,and put forward comprehensive control technique,so as to provide the reference for guiding prevention and control of major pests in citrus industry.

金水六君煎物质基准中半夏和陈皮的薄层鉴别研究

目的:建立经典名方金水六君煎物质基准中半夏和陈皮的薄层鉴别方法。方法:以半夏对照药材为对照,对金水六君煎中半夏进行薄层鉴别研究,以橙皮苷和陈皮对照药材为对照,对金水六君煎中陈皮进行薄层鉴别研究,并对其进行方法学验证。结果:建立的薄层色谱法能鉴别出半夏和陈皮,斑点对应较好,阴性无干扰,方法学考察结果显示,方法适应性良好。结论:本法简单可行、结果可靠、重复性好,可作为金水六君煎物质基准的质量控制方法。

基于线粒体基因序列的广西柑橘木虱遗传多样性及种群结构分析

【目的】研究广西柑橘木虱遗传多样性及种群结构,为制定柑橘木虱的防控措施提供理论基础。【方法】通过分析来自我国广东、贵州、云南、海南、广西以及越南太平和柬埔寨暹粒等地区的9个柑橘木虱线粒体基因组序列,确定并设计针对多态性位点的引物。利用获得的引物对采集自广西合浦、环江、富川、西林、永福和右江6个柑橘产区的柑橘木虱线粒体基因序列进行扩增和测序;使用DnaSP 6.12对测序序列进行多态性分析和单倍型多样性分析;采用最大似然法和贝叶斯法构建系统发育进化树;使用PopART绘制单倍型网络图以展示种群进化结构和关系。【结果】对来自我国和越南太平、柬埔寨暹粒的9个柑橘木虱线粒体基因组序列进行比对分析,共获得22个多态性位点,针对多态性位点区域序列设计引物并筛选获得5对有效引物,其中包括8个多态性位点。利用5对引物对采集自广西6个柑橘产区的18个柑橘木虱线粒体基因进行PCR扩增并测序,获得总长度2272 bp的线粒体基因序列,经分析发现广西柑橘木虱共包含6种单倍型,单倍型多样性为0.882、核苷酸多样性为0.00181。最大似然进化树、贝叶斯进化树和单倍型网络分析发现,广西西林柑橘木虱种群与云贵川等我国西南地区高海拔的柑橘木虱种群在遗传距离上较近,其他地区的柑橘木虱种群与我国南方和东南亚的种群更接近。【结论】广西柑橘木虱种群展现较高的单倍型多样性和较低的核苷酸多样性,表现明显的种群结构分化和多样性;广西柑橘木虱种群遗传分化受地理距离影响明显,二者存在相关性。

化橘红成花过程挥发油成分的动态变化及活性分析

本文旨在探索化橘红花挥发油成分的动态变化,为化橘红花的综合利用和其挥发油产品的开发提供理论参考。以现蕾期、花苞期、盛开期和谢花期的化橘红花新鲜样品为材料,水蒸气蒸馏法提取挥发油,采用气质联用法(GC-MS)测定挥发油成分,通过构建“化橘红花-活性成分-靶点”网络图对挥发油活性进行分析。结果表明化橘红花挥发油成分以烯类(56.84%~70.19%)和醇类(21.33%~38.34%)物质为主,包括γ-松油烯、D-柠檬烯、芳樟醇、法尼醇、橙花叔醇和β-蒎烯。烯类物质在成花过程中呈现出逐渐降低的趋势,醇类物质表现出先增多再减少的趋势,盛开期达到峰值。现蕾期、花苞期和盛开期的挥发性物质总量保持在较高水平,谢花期显著降低。法尼醇、芳樟醇、α-水芹烯、橙花叔醇和香茅醇等挥发性成分的抑菌和抗氧化活性较高。各个花期的化橘红花均含有丰富的挥发油,具有开发应用价值。

亚精胺+赤霉素在低温下对化橘红种子萌发及幼苗生理指标的影响

以化橘红种子为材料,在低温下,研究亚精胺(Spd)+赤霉素(GA3)对化橘红种子萌发、幼苗根系的生长、根活力及生理指标的影响,以培育壮苗。设置亚精胺浓度为0(CK)、0.10、0.15、0.20、0.25 mmol/L,分别添加80 mg/L的GA3溶液浸种、培养,测定种子发芽率、发芽势,幼苗根长、苗长、根重、苗重、根长/苗长、根重/苗重、抗氧化酶活性、渗透调节物质及膜质过氧化物含量的变化。结果表明:在低温条件下,亚精胺+赤霉素对化橘红种子的萌发有协同促进作用,发芽率、发芽势和发芽指数明显提高;单一使用赤霉素时,幼苗根的生长受到抑制,添加亚精胺后能明显缓解,缓解程度与Spd的浓度呈正相关。0.20 mmol/L亚精胺+80 mg/L赤霉素处理的根长、根重、根长/苗长、根重/苗重和根活力最高,其幼苗根系的抗氧化酶(SOD、POD、CAT)活性显著增强,渗透调节物质脯氨酸和可溶性蛋白的含量有所提高,丙二醛(MDA)含量降低。亚精胺+赤霉素复配能促进化橘红种子萌发、根系的生长和根活力的提高;能缓解低温对化橘红幼苗根的损害,提高种苗的抗寒性。

柑橘黑点病研究进展

柑橘黑点病是由柑橘间座壳菌(Diaporthe citri)引起的一种重要柑橘病害,在全球柑橘主产区均有发生,主要危害叶片、枝梢和果实,严重影响柑橘的品质和鲜销商品价值。柑橘间座壳菌可以侵染所有当前栽培的柑橘品种,其中以葡萄柚和柠檬最易感病。喷施代森锰锌和铜制剂等杀菌剂是防控柑橘黑点病的重要方法,但柑橘间座壳菌在自然条件下有性生殖频繁,具有丰富的遗传多样性,需加强监测柑橘间座壳菌种群对代森锰锌等药剂的敏感性变化。近年来,关于柑橘间座壳菌的基因组信息、快速检测技术、遗传分化、致病机制以及防治方法等方面的研究取得较为显著的进展。就国内外近年来柑橘黑点病的危害症状与分布、病原种类、遗传多样性、生物学特性、侵染过程、致病机制、发生规律以及防治方法等方面的最新研究进展进行综述,并对柑橘黑点病的未来重点研究方向进行展望,以期为柑橘黑点病的防控策略提供科学依据。

基于中药特色技术传承概述广东芸香科道地药材

基于中药传统特色技术,文章通过现场观摩调研与文献检索,概述在十大广药中占有1/3的芸香科药物的药用历史、产地采收加工、性状鉴别特点。芸香科药物多含挥发油,具有芳香气,大部分具有宽中理气的功效,临床应用广泛。据考证,柚类橘红始自清代,此前使用橘类橘红;广陈皮主产区在新会地区,也称新会陈皮,药用时间至今约有600年;广佛手以肇庆高要地区产量多且质优,“佛手柑”的记载最早见于元朝。化橘红的传统加工方法是将化州柚的外层果皮切成角状,加工成7角的毛橘红药材,称为“毛七爪”;新会陈皮需在新会地区内陈化三年,方可称为“新会陈皮”。化橘红鉴别特点为表面密被柔软毡状细绒毛,有油点,气清香;新会陈皮“鬃眼”明显,对光照视呈半透明状,香气浓郁。广佛手切面的外皮呈黄色,肉呈白色,俗称“金边白肉”。文章基于中药传统理论、技术对广东地区芸香科道地药材进行概述,以期守正创新,使中药的传统特色技术得到传承发展。

基于多智能体模型的柑桔木虱空间扩散研究

柑桔黄龙病是严重危害我国柑桔产业的细菌性病害,柑桔木虱是柑桔黄龙病的唯一自然传播媒介,了解柑桔木虱的发生和空间扩散规律对于有效控制柑桔黄龙病具有重要意义。以广西壮族自治区蒙山县为具体研究区域,借助NetLogo智能体建模平台构建了柑桔木虱空间扩散的模拟模型,模拟并评价了柑桔木虱的空间扩散规律及不同田间管理的效果。模型模拟结果表明,扩散距离以及农药喷施间隔时间均对柑桔木虱扩散速度和空间分布产生明显影响。无田间管理措施时,柑桔木虱扩散风险区总面积占柑桔园面积的比例呈现为持续且快速的上升趋势,长距离扩散(风速≥5 m/s)会导致风险区面积明显增加。当间隔1个月及以内施药(规范田间管理)时,柑桔木虱扩散风险能够得到迅速而有效的控制。验证结果显示,模型的平均TSS值达到0.82,模型仿真灵敏性为85.2%,模型特异性为80.9%,模型仿真结果总体准确率为83.3%,模型能够很好地模拟研究区内柑桔木虱的空间扩散。基于研究结果,建议柑桔种植区合理优化果园空间布局,如采用棋盘式分布,区域间设置防风林或防虫网等进行物理阻隔,田间严格遵循高效农药的使用规定进行柑桔木虱的有效防治,以有效减缓柑桔木虱扩散速度和空间范围,为柑桔黄龙病的区域防控提供有力支持。

连翘与陈皮混合挥发油提取与包合工艺优化

目的优选保和颗粒组方中连翘、陈皮混合挥发油提取工艺及β-环糊精(β-CD)包合工艺。方法以饮片粉碎粒度、提取时间、加水倍数为考察因素,挥发油收率为评价指标,采用L_(9)(3^(4))正交试验法优选。以β-CD与挥发油比例(g∶m L)、包合时间、包合温度为考察因素,挥发油包合率、包合物收率、包合物含油量的综合评分为评价指标,同上法优选包合工艺并验证。结果最佳提取工艺,将饮片粉碎至20目,加10倍水提取3 h。最佳包合工艺,β-CD∶挥发油为7∶1(g∶m L),45℃下包合反应3 h;紫外光谱扫描、X射线衍射、扫描电镜、薄层色谱等结果均证明形成了稳定的包合物。制成的包合物中连翘及陈皮混合挥发油的包合率为95.13%,包合物收率为87.84%,包合物含油量为10.29%,综合评分为76.70分。结论优化后的连翘及陈皮混合挥发油提取、包合工艺稳定可行。

基于近红外光谱技术有监督模式识别的青皮产地溯源分析

利用便携式近红外光谱仪采集不同产地(安徽、广东、四川)青皮外壁和内囊光谱数据,采用单一预处理和组合预处理方法消除光谱中的多种干扰,结合主成分分析(PCA)、簇类独立软模式分类法(SIMCA)及Fisher线性判别分析(FLDA)等模式识别方法建立青皮产地溯源模型。结果表明,光谱预处理可以在一定程度上消除基线漂移、背景噪声和谱峰重叠干扰,但无法实现产地溯源。3种模式识别方法中,PCA无法实现青皮产地溯源;青皮外壁和内囊原始光谱的SIMCA模型获得的青皮产地溯源整体鉴别率分别为99.14%和98.28%;FLDA模型获得的整体鉴别率均为99.57%,优于SIMCA模型;经光谱预处理优化后的SIMCA和FLDA模型对青皮产地溯源的鉴别率均可达100%,即便携式近红外光谱技术结合有监督模式识别方法可实现青皮产地溯源的无损分析,可为食药同源物质产地溯源拓展新途径。

陈皮提取物对APP/PS-1双转基因阿尔茨海默病小鼠学习记忆功能的影响

目的探讨陈皮提取物对APP/PS-1双转基因阿尔茨海默病(AD)小鼠学习记忆功能的影响.方法选用APP/PS-1双转基因AD小鼠16只,随机分为模型对照组和供试品组,8只/组,另取8只C57小鼠为正常对照组,正常对照组和模型对照组分别灌胃等量的生理盐水,供试品组灌胃陈皮提取物的生理盐水溶解液,灌胃体积为10mL/kg,1次/d,连续18d.第11天到第16天,进行Morris水迷宫的定位航行实验及空间探索实验.第17天到第18天,进行5min避暗实验.结果在Morris水迷宫实验中,与正常对照组比较,模型对照组定位航行第2天、第3天、第5天的潜伏期增加(P<0.05);与模型对照组比较,供试品组第5天的潜伏期降低(P<0.05).空间探索阶段,各组的目标象限路程百分比、时间百分比及站台穿越次数差异无统计学意义(P>0.05).在避暗实验中各组的错误潜伏期、错误次数及错误率差异均无统计学意义(P>0.05).结论陈皮提取物对APP/PS-1双转基因AD小鼠的空间学习、记忆能力有一定的改善作用.