944 resultados para Citrus leprosis mite


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This is the eleventh Annual report of the Cumberland River Board on information of its activities and responsibilities on river management in its area between the beginning of April 1961, to the end of March 1962. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes information on the building of gauging stations, abstraction of water, and rainfall and river flow. The section on land drainage looks at work on improvement schemes and information on maintenance work carried out on rivers including Wampool, Waver, Wiza, Ellen, Cocker, Irt, Mite, Keekle, Eden, Esk, Caldew and Petteril. The fisheries section covers 5 districts of the River Eden, Esk, Derwent, Ellen and South West Cumberland. It includes angling information and a general report for salmon and sea trout, Brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as Byelaws and fisheries protection. The fourth section on pollution deals with water quality and information on sewage and trade effluents. The River Boards preceded the Environment Agency which came into existence in 1996.

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This is the twelfth Annual report of the Cumberland River Board on information of its activities and responsibilities on river management in its area between the beginning of April 1962, to the end of March 1963. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes information on the completion of gauging stations, abstraction of water and rainfall. The section on land drainage looks at work on improvement schemes, floods and information on maintenance work carried out on rivers including Wampool, Waver, Wiza, Ellen, Cocker, Greta, Marron, Ehen, Keekle, Esk, Bleng, Mite, Annas, Eden, Caldew and Petteril. The fisheries section covers 5 districts of the River Eden, Esk, Derwent, Ellen and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as Byelaws and fisheries protection. The fourth section on pollution covers water quality and information on sewage and trade effluents. The River Boards preceded the Environment Agency which came into existence in 1996.

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This is the thirteenth Annual report of the Cumberland River Board on information of its activities and responsibilities on river management in its area between the beginning of April 1963, to the end of March 1964. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes information on the completion of gauging stations, abstraction of water and rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods and information on maintenance work carried out on rivers including Wampool, Waver, Wiza, Derwent, Cocker, Keekle, Marron, Ehen, Irt, Esk, Mite, Lowther, Eden, Caldew and Petteril. The fisheries section covers 5 districts of the River Eden, Esk, Derwent, Ellen and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as Byelaws and fisheries protection. The fourth section on pollution deals with water quality and information on sewage and trade effluents. The River Boards preceded the Environment Agency which came into existence in 1996.

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This is the fourteenth Annual report of the Cumberland River Board on information of its activities and responsibilities on river management in its area between the beginning of April 1964, to the end of March 1965. The report contains 5 main sections on water resources, land drainage, fisheries, pollution, and finally the expenditure and income for the 12 month period. The first area that the report deals with is water resources, which includes information on the completion of gauging stations, abstraction of water and rainfall and river flow. The section on land drainage looks at work on improvement schemes, floods and information on maintenance work carried out on rivers including Wampool, Waver, Wiza, Ellen, Cocker, Keekle, Marron, Ehen, Bleng, Esk, Mite, Caldew and Petteril. The fisheries section covers 5 districts of the River Eden, Esk, Derwent, Ellen and South West Cumberland. It includes angling information and a general report for salmon and sea trout, brown trout and freshwater fish. Fish disease and fish hatchery are also covered as well as Byelaws and fisheries protection. The fourth section on pollution deals with water quality and information on sewage and trade effluents. The River Boards preceded the Environment Agency which came into existence in 1996.

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A asma é um distúrbio crônico pulmonar caracterizado por inflamação, obstrução e remodelamento brônquico, levando a sintomas como sibilo, tosse e falta de ar. A terapia antiasmática consiste em corticosteroides inalados e agonistas β2 de curta ou longa duração. O tratamento é limitado por efeitos colaterais e refratariedade de alguns pacientes, justificando a necessidade de novas terapias. Estudos demonstram que a 15-deoxy-delta- 12,14-prostaglandina J2 (15d-PGJ2), um ligante endógeno de receptores ativados por proliferadores de peroxissomos do tipo gama (PPAR-γ), é capaz de reduzir a expressão de citocinas pró-inflamatórias, o que pode resultar em benefícios no tratamento de doenças com esse perfil. O objetivo deste estudo foi avaliar o potencial anti-inflamatório e antiasmático da 15d-PGJ2 em modelos experimentais de asma. Camundongos A/J machos foram sensibilizados nos dias 0 e 7 através de injeção subcutânea (s.c.), contendo ovoalbumina (OVA) e Al(OH)3, e desafiados com 4 instilações intranasais (i.n.) de OVA em intervalos semanais. O tratamento com 15d-PGJ2 (30 e 100 g/Kg, s.c.) foi realizado 30 min antes dos desafios a partir da terceira provocação antigênica. Em outro modelo, camundongos A/J foram desafiados intranasalmente com extrato de ácaro 3 vezes por semana durante 3 semanas. As administrações de 15d-PGJ2 (30, 70 e 100 g/Kg, s.c. e 0,65; 1,5 e 2,3 g/animal, i.n.) foram realizadas a partir da 3 semana, 30 min antes dos desafios. As análises ocorreram 24 h após o último desafio. Nossos resultados mostraram que, em camundongos previamente sensibilizados e desafiados com OVA, a administração de 15d-PGJ2 limitou significativamente o influxo peribrônquico de eosinófilos e neutrófilos, bem como a produção de muco por células caliciformes e fibrose sub-epitelial, além da hiperreatividade das vias aéreas e produção de IL-5. A redução do epitélio brônquico e das citocinas IL-13 e TNF-α foram observadas somente na maior dose administrada. No modelo HDM a inflamação e o remodelamento foram atenuados em todas as doses administradas do composto, enquanto que a hiperresponssividade brônquica foi inibida apenas nas doses de 70 e 100 μg/Kg (via sistêmica) e na dose intermediária dada topicamente (1,5 μg/animal, i.n.). Os níveis de citocinas foram atenuados pelo tratamento subcutâneo, porém somente os níveis de IL-17, eotaxina-1 e TNF-α foram inibidos com a dose intranasal de 0,65 g/animal. O aumento da expressão de NF-κB, induzido por provocação com HDM também foi reduzido significativamente pela administração de 15d-PGJ2. Em conjunto, nossos dados indicam que o tratamento com 15d-PGJ2 inibe alterações cruciais associadas à patogênese da asma, em modelos experimentais distintos da doença, demonstrando possuir grande potencial para controlar e reverter inflamação, hiperreatividade e remodelamento pulmonar desencadeados por provocação alérgica.

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系统获得性抗性(Systematic acquired resistance, SAR)是植物抵御病原菌侵染的最有效手段,利用基因工程技术导入SAR信号发生过程中的关键基因后,植物的SAR基因表达量提高并且对病原菌侵染的反应速度加快,因此植物的抗病性得以增强,与传统的抗病基因工程技术相比它对病原菌没有专一性,许多学者称之为广谱抗病基因工程,该领域已成为目前抗病基因工程研究的热点和前沿。 NDR1和NPR1基因在植物的SAR发生中起着重要的作用,前者功能定位在ROS(reactive oxygen species)的激活和随后的水杨酸(SA)诱导合成之间,突变株病原菌诱导后SA合成能力降低,SAR发生减弱,目前还没有对该基因进行过量表达分析的报道;后者功能定位在SAR信号转导级联反应之中的SA积累和随后的SAR基因表达之间。该突变株在病原菌侵染时不产生病程相关蛋白(PRs),表现为感病,而对照抗病;过量表达该基因的转基因拟南芥对多种病原菌的侵染产生抗性,PR1等PRs蛋白的表达量也提高,异源表达该基因的水稻对白叶枯病的抗性也提高。本研究利用RT-PCR方法从拟南芥中克隆了这两种基因,序列分析表明拟南芥Wassilewskija生态型的NDR1基因与Columbia生态型相比,共有7处碱基不同,引起编码氨基酸变化4处,而NPR1基因与报道的Wassilewskija生态型来源的NPR1基因完全相同。 我们构建了35S启动子驱动的NDR1和NPR1基因的植物组成型高效表达载体,利用农杆菌介导法转化烟草,PCR和Southern鉴定外源基因已经整合到植物基因组中。抗病性分析显示过量表达NDR1和NPR1基因的烟草对晚疫病和赤星病的抗性都有明显提高,说明这两个基因的在其它植物中异源表达后,都能提高植物对多种病原菌的抗性。 本论文提出了利用这两个基因来培育抗黄萎病棉花的设想,一方面为解决这个“世纪性”难题积累新的资料,另一方面也为其它作物的抗病基因工程提供新的经验。利用35S启动子驱动的NDR1和NPR1基因的植物组成型表达载体分别对陆地棉品种石远321进行花粉管通道法转化。同时,还探讨了这两个基因在棉花中的共转化实验,希望它们的“协同增效”能进一步提高棉花的抗病性。对其中2001年夏天在南京注射所获得的5,000粒种子在三亚进行100 g/ml卡那霉素筛选,初步鉴定分别获得转NDR1和NPR1基因株系26和24棵,PCR进一步鉴定其中分别有12和7棵为转基因阳性,转基因频率分别为0.50%和0.27%,目前利用营养钵蘸根法对其二代进行抗枯、黄萎病鉴定,结果显示有转基因植株对枯、黄萎病的抗性都明显增强,进一步的鉴定正在进行中。2002年初海南注射分别获得转NDR1和NPR1基因以及共转化种子22,000、10,500和12,500粒种子,2002年夏在中国农科院植保所黄萎菌病圃筛选抗黄萎病单株,并利用100 g/ml卡那霉素初步筛选出了一批抗性植株,每种转基因株系随机挑选5株进行PCR鉴定,结果显示为阳性。进一步的抗黄萎病鉴定和筛选以及分子分析正在进行中。 同时,本文还探讨了病原菌诱导型启动子在广谱抗病基因工程应用的可能性。根据烟草的Pr1-a启动子已知序列设计引物,PCR扩增启动子序列后,构建病原菌诱导型NPR1基因植物表达载体,并对棉花进行转化,获得种子11,500粒,利用同上的筛选方法,获得了一致的结果,目前抗黄萎病鉴定、分子检测以及生物学分析正在进行中。 最后,鉴于抗生素标记在转基因植物的应用引起了许多“安全性”争论的事实,还构建了无筛选标记的表达载体对抗虫棉进行转化,这样在生产上可以直接获得抗虫棉抗黄萎病棉花新材料,也为其它作物抗病基因工程积累经验。 本研究还提出了一种较为有效的提取高质量棉花总RNA的方法,与原来一些棉花RNA纯化方法相比,该方法所用都为常规试剂,易于重复,质量高。并且利用获得的总RNA构建了黄萎菌激发子诱导的cDNA文库,滴度测定为1╳107pfμ/μg,插入片段大小在5 00~2 000 bp范围内。 鉴于NPR1基因研究的重要性,本研究还利用简并引物PCR技术从海岛棉和陆地棉的基因组中都分离到了NPR1基因的同源片段,大小都为208 bp,与拟南芥NPR1基因的相应部分的同源性分别为66%和65%,它们之间的同源性为87%,目前该基因的全长正在分离鉴定中。 多聚半乳糖醛酸酶抑制蛋白(PGIPs)在植物的防御反应中起着重要的作用,通过分析已知20余种pgip基因序列的保守区,设计简并引物,PCR扩增海岛棉(Gossypium barbadense)7124 cDNA文库,得到一条长561 bp的片段,序列测定后分析确认为pgip基因的一部分。根据此序列和棉花病原菌诱导的cDNA文库载体中已知部分设计RACE引物,扩增后,5’和3’RACE分别得到666bp和906 bp的片段。序列分析表明它具有完整的编码框,产物为330 aa的蛋白质。序列分析该蛋白具有10个串联的LRR(leucine-rich repeat)区,与柑桔(Citrus)和枳(Poncirus)的pgip基因的同源性分别为69.2%和68.7%。进一步PCR扩增得到该基因的全长阅读框,并且获得了相应的基因组片段,序列分析发现该基因没有内含子。这是从棉属植物中克隆的第一个pgip基因。

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捷安肽素是一种由枯草芽孢杆菌(Bacillus subtilis)ZK 产生的抗真菌多肽。本文以柑桔青霉菌(Penicillium italicum)和绿霉菌(Penicillium digitaum)为供试真菌,研究了捷安肽素的抑菌性能及作用机理,为捷安肽素开发为有效的生物杀菌剂提供理论依据。全文共分两部分:第一部分:捷安肽素对柑桔青霉菌和绿霉菌抑制效果研究。采用琼脂扩散法测定捷安肽素对柑桔青霉菌和绿霉菌的抑菌活性。53.9 µg/mL 捷安肽素对绿霉菌和青霉菌的抑菌圈直径分别为26.7mm 和24.1mm。结果表明捷安肽素能够抑制柑桔青绿霉菌的生长,柑桔绿霉菌比青霉菌对捷安肽素敏感。在柑桔果实上,研究了不同浓度、不同接入时间的捷安肽素对柑桔青霉病和绿霉病的防治效果,并与常用化学杀菌剂抑霉唑、咪鲜胺、甲基硫菌灵和多菌灵作比较。53.9 µg/mL捷安肽素处理柑桔果实,柑桔青霉病和绿霉病发病率分别为5.0 %和5.3 %,比对照低95.0 %和94.7 %;柑桔青霉病和绿霉病的病情指数分别为1.87 和2.18,比对照低73.73 和97.82。结果表明,捷安肽素能够有效地防治柑桔青绿霉病。与对照相比,捷安肽素先于或后于柑桔青绿霉菌接入时,对柑桔青绿霉菌均有抑制作用,但抑制效果随接入间隔时间的增长而降低。第二部分:捷安肽素对绿霉菌作用机理研究。首先在光学显微镜和透射电镜下观察捷安肽素处理后绿霉菌菌丝表面形态结构与菌丝体内超微结构的变化。形态观察发现,捷安肽素处理24h以内,绿霉菌菌丝结构无变化。捷安肽素作用36h后,绿霉菌菌丝不规则缢缩和膨大。48h后,在绿霉菌菌丝顶端、中部、末端的多处细胞均可发生畸形的球状结构,这种畸变结构随处理的延长而增加,致使细胞成为捻珠状。处理72 h后,畸变球形细胞开始断裂离解。处理96h后,镜下几乎无完整菌丝,成单个的球状细胞,部分细胞出现破裂。而对照菌丝表面光滑,结构完整。通过透射电镜观察发现,与对照相比,捷安肽素处理后,绿霉菌细胞壁、细胞膜轮廓模糊不清,细胞质外泄。推测捷安肽素能够使绿霉菌细胞膜通透性发生改变。进一步实验利用紫外-可见分光光度计检测捷安肽素作用后绿霉菌胞外液紫外吸光度的变化,表明捷安肽素作用于绿霉菌菌丝后,细胞内蛋白质、核酸缓慢泄漏。通过Atomscan Advantage单道扫描等离子体发射光谱仪(ICP)测定捷安肽素作用后菌丝体内K+浓度的改变,结果表明捷安肽素作用于柑桔绿霉菌1h内,菌丝体内K+含量迅速下降,为对照绿霉菌K+含量的37.53 %,1 h后菌丝体内K+含量变化趋于平缓。K+的迅速泄漏,以及蛋白质、核酸的泄漏表明捷安肽素通过迅速改变绿霉菌细胞膜通透性,使绿霉菌菌丝生长受到抑制。Jiean-peptide produced by Bacillus subtilis ZK has broad-spectrumresistance to plant pathogens. In this study, we investigated the antifungal propertyand the possible antifungal mechanism of jiean-peptide against two commonphytopathogenic fungi of citrus fruits: blue molds (P. italicum) and green molds (P.digitatum).The paper involved two parts:Part 1 is the study of the antifungal property of jiean-peptide against blue moldsand green molds of citrus fruits. The in vitro inhibition effect of jiean-peptide againstblue molds and green molds was detected by agar diffusion method. The diameters ofinhibition zones of green molds and blue molds are 26.7mm and 24.1mm respectivelyby treating with 53.9 µg/mL jiean-peptide. It shows that jiean-peptide effectivelyinhibits the both phytopathogenic fungi, and it is more effective for inhibiting greenmolds than blue molds. The effectiveness of jiean-peptde to inhibit green molds andblue molds in vivo was investigated compared with four conventional fungicides thatare imazalil, prochloraz, carbendazin and methylthiophanate. The result is that the incidences of the blue mold disease and green mold disease are 5.0 % and 5.3 %, thedisease severities are 1.87 and 2.18 respectively when citrus are inoculated with 53.9µg/ml jiean-peptide. The decay incidences and disease severities were significantlyreduced by treating with jiean-peptide compared with the control. The results indicateJiean-peptide is effective for controlling blue molds and green molds on citrus. Theoptimized inoculation time was also investigated. When inoculated with jiean-peptideat 0 h, 6 h, 12 h, 24 h and 48 h before or after pathogens’ inoculation, Jiean-peptidecan suppress the occurrence of blue molds and green molds compared with the control, but the effect of later inoculation decreases compared with the inoculation at the sametime.In Part 2, we investigated the possible antifungal mechanism against greenmolds of citrus. At first, we observed the exterior morphological changes andultrastructural changes of blue molds under light microscopy (LM) and transmissionelectron microscopy (TEM). Compared with untreated control cells which aregenerally uniform in shape, the appearances of treated hyphae change obviously. Itshows that some cells of hyphae irregularly shrink or enlarge when cultured for 36h.When the treating time of jiean-peptide increases, the aberrance of the hyphaebecomes more obvious, and hyphae exhibit the moniliform appearances. Finally, thereis no intact hypha leaved except only single cells, and some of which appear fractured.By transmission electron microscopy (TEM) observation, we find that the outline ofthe cell wall and the cell membrane of hyphae are blurry, and the cytoplasma oozesout. The observation result under LM and TEM suggests that jiean-peptide mightchange the permeability of the cell membrane. So we conducted further experiment todetect the change of permeability when the cells of blue molds were treated withjiean-peptide. And the effect of jiean-peptide on non-growing cells of blue molds wastested. By the spectrophotometer measurement, we found that compounds with lightabsorption at 260 nm and 280 nm were released and amounts increased within 12 hcompared with the control. Moreover, by the ICP measurement, the leakage of K+occurred immediately in the presence of jiean-peptide within 1 h, but with nearly nofurther change after 1 h. All these results indicate that jiean-peptide could change themembrane permeability of blue molds immediately and result in leaking nucleotides,proteins and K+ from cells.

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以广西西北部喀斯特地区的开垦草地生态系为对象,研究了草地开垦变为不同农田后对土壤有机碳库的效应。结果表明,草地开垦为农田后,土壤可溶性有机碳、微生物生物量碳及总有机碳的含量显著下降。自然草地开垦后,柑桔地土壤有机碳含量高于农作用地土壤。玉米与甘蔗轮作土壤有机碳含量高于甘蔗连作。13C示踪结果表明,柑桔地土壤有机碳中来源于草地的含量高于农田土壤;农田土壤有机碳中来源于草地的随种植年限的增加而降低。在玉米与甘蔗轮作的农田中,土壤有机碳中来源于玉米的高于甘蔗连作土壤有机碳中来源于甘蔗的。

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Gold nanoparticles were used to enhance the immobilization amount and retain the immunoactivity of recombinant dust mite allergen Der f2 immobilized on a glassy carbon electrode (GCE). The interaction between allergen and antibody was studied by electrochemical impedance spectroscopy (EIS). Self-assembled Au colloid layer (Phi = 16 nm) deposited on (3-mercaptopropyl)trimethoxysilane (MPTS)-modified GCE offered a basis to control the immobilization of allergen Der f2. The impedance measurements were based on the charge transfer kinetics of the [Fe(CN)(6)](3-/4-) redox pair, compared with bare GCE, the immobilization of allergen Der f2 and the allergen-antibody interaction that occurred on the electrode surface altered the interfacial electron transfer resistance and thereby slowed down the charge transfer kinetics by reducing the active area of the electrode or by preventing the redox species in electrolyte solution from approaching the electrode. The interactions of allergen with various concentrations of monoclonal antibody were also monitored through the change of impedance response. The results showed that the electron transfer resistance increased with increasing concentrations of monoclonal antibody.

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Os citros podem ser infectados por várias espécies de viróides, dentre elas destaca-se o Citrus exocotis viróide, CEVd como o agente causal da exocorte dos citros. Esta doença está presente em praticamente todos as regiões citrícolas do mundo, associada aos sintomas de descamação em porta-enxertos como o limão ´Cravo' (Citrus limonia Osbeck) e o Poncirus trifoliata e ao nanismo de plantas neles estabelecidas. Na América Latina a lima ácida ´Tahiti' (C. latifolia Tan) é também descrita como suscetível à exocorte.

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A citricultura é uma das principais atividades do agronegócio brasileiro, estando presente em todas as regiões do país em diferentes ambientes de produção. A presença da doença huanglongbing (HLB), constatada no Brasil em 2004, vem provocando perdas expressivas em importantes regiões produtoras e colocando em cheque a sustentabilidade da cadeia citrícola. Estratégias de controle atual se baseiam no uso de mudas sadias, inspeção e erradicação sistemática de plantas sintomáticas e controle químico do inseto vetor. Pesquisas vêm sendo conduzidas pela Embrapa e outras instituições brasileiras com o objetivo de alcançar a resistência ao HLB por melhoramento genético via biotecnologia. Contudo, as limitações inerentes a essas ações determinam que proposições adicionais e não-excludentes sejam consideradas para a mitigação de efeitos do HLB. Práticas horticulturais com possibilidade de emprego imediato na citricultura são apresentadas de forma a contribuir com o enfrentamento a essa doença. As proposições a seguir são discutidas: seleção de materiais tolerantes de ocorrência natural, mudança geográfica da produção, conceitos não usuais de mudas protegidas, plantas repelentes e atrativas, sistemas de produção de baixo ingresso, uso de elicitores de resistência, cultivo protegido, consorciação e ultra-adensamento.

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Descricao sobre a leprose dos citros e medidas de controle para o estado do Amazonas.

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Medidas de controle para lagarta Sibine nesea, ocorrendo em citros em Manaus,AM.

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Identificacao e combate a podridao floral dos citros no estado do Amazonas.

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Informacoes sobre as principais doencas que atacam os citros no Amazonas, com descricoes dos sintomas e controle.