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Parasitism of Rhizoctonia solani by strains of Trichoderma spp. Parasitismo de Rhizoctonia solani por linhagens de Trichoderma spp.  

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Full Text Available Rhizoctonia solani causes serious diseases in a wide range of plant species. The fungus Trichoderma has been shown to be particularly effective in the control of the pathogen. Thus, this research was carried out to screen fourteen Trichoderma strains against R. solani in vitro. All strains tested inhibited the growth of R. solani. Three T. koningii strains produced toxic metabolites with strong activity against R. solani, inhibiting the mycelial growth by 79%. T. harzianum, Th-9 reduced the viability of sclerotia of R. solani by 81.8% and T. koningii, TK-5 reduced by 53%. Electron microscopic observations revealed that all T. harzianum strains interacted with R. solani. Th-9 grew toward and coiled around the host cells, penetrating and destroying the hyphae. Penetration of host cells was apparently accomplished by mechanical activity.Rhizoctonia solani é um dos mais destrutivos patógenos de plantas cultivadas. Métodos alternativos de controle têm sido empregados com sucesso, particularmente, utilizando-se o fungo Trichoderma. Este trabalho visou, portanto, selecionar linhagens efetivas desse micoparasita contra o patógeno. Onze linhagens de T. harzianum e três de T. koningii foram testadas in vitro com relação ao parasitismo de hifas e de escleródios e produção de metabólitos tóxicos. Todas as linhagens de Trichoderma spp. inibiram o crescimento miceliano de R. solani e as três linhagens de T. koningii produziram potentes antibióticos, que inibiram mais de 79% o crescimento do patógeno. Uma linhagem de T. harzianum, Th-9, reduziu a viabilidade dos escleródios em 81,8% e uma de T. koningii em 53%. Microscopia eletrônica de varredura revelou que todas as linhagens de T. harzianum parasitaram R. solani enquanto nenhuma linhagem de T. koningii interagiu com R. solani, possivelmente, devido à forte inibição causada pelos metabólitos que impediu o contato entre os dois fungos. T. harzianum, Th-9, cresceu ao redor, penetrou e destruiu as hifas de R. solani. A penetração das células hospedeiras parece ser acompanhada por atividade mecânica.

Itamar Soares de Melo

2000-03-01

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Patogenicidade de Rhizoctonia solani em morangueiro Pathogenicity of Rhizoctonia solani to strawberry  

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Full Text Available O fungo Rhizoctonia solani Kuhen tem sido isolado com maior freqüência de mudas e plantas adultas de morangueiro com sintomas de subdesenvolvimento, declínio progressivo, avermelhamento ou arroxeamento dos folíolos, pecíolos e estolhos, além do apodrecimento do ápice da coroa, estipulas e base dos pecíolos. As plantas doentes apresentavam, com freqüência, raízes escuras ou com áreas necrosadas. Fusarium spp. e Pythium spp. também estavam, reiteradamente, associados às plantas doentes. Para determinar a causa dos sintomas descritos e verificar, isoladamente ou em mistura, possível interação entre os patógenos R. solani, Fusarium sp. e Pythium sp., testaram-nos quanto à patogenicidade, em mudas de morangueiro, em casa de vegetação. Observou-se que somente quando R. solani estava presente havia reprodução dos sintomas, de modo semelhante ao observado no campo, comprovando sua patogenicidade. Fusarium e Pythium, no entanto, foram reisolados de lesões radiculares, o que indica seu possível envolvimento no complexo da doença, aumentando os sintomas de declínio em condições de campo.Rhizoctonia solani was consistently associated with strawberry plants in nurseries or in fruit production fields, with symptoms of progressive decline, stunt, reddening of leaflets, petioles and runners, besides dry rots of the crown apex, estipules and base of the petioles. These plants showed frequently roots with necrotic lesions. Fusarium spp. and Pythium spp. also were isolated from the diseased plants. This study was conducted to determine the role of each referred fungus on the disease and to investigate a possible interaction between them. For this purpose, R. solani, Pythium sp. and Fusarium sp., alone or combined one with other, were inoculated in strawberry plants, in the greenhouse. The results showed that only when R. solani was present, there was an identical reproduction of the symptoms observed in the field. Fusarium and Pythium, nevertheless, were reisolated from root lesions, indicating the possibility of its involvement with the disease, increasing the symptoms of decline under field conditions.

Maria Aparecida de Souza Tanaka

1995-01-01

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Resistência de cultivares de arroz a Rhizoctonia solani e Rhizoctonia oryzae Resistance of rice cultivars to Rhizoctonia solani and Rhizoctonia oryzae  

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Full Text Available Isolados de Rhizoctonia solani e Rhizoctonia oryzae, agentes causais da queima-da-bainha e mancha-da-bainha, respectivamente, foram coletados em lavouras de arroz irrigado no Estado do Tocantins. O objetivo deste trabalho foi avaliar a resistência de 12 cultivares de arroz a essas doenças, sob condições artificiais de inoculação, em casa de vegetação. Não houve correlação entre resistência das cultivares a R. oryzae e R. solani quanto ao comprimento da lesão na bainha infectada pelo método de palito de dentes. A relação entre tamanho da lesão na bainha e folha foi linear e significativamente negativa (r = -0,66, PIsolates of Rhizoctonia solani and Rhizoctonia oryzae, the causal agents of sheath blight and sheath rot diseases, respectively, were collected from irrigated rice fields in the State of Tocantins, Brazil. The main objective of the investigation was to assess the resistance of 12 genotypes to these diseases, under artificial inoculation tests in greenhouse condition. There was no correlation between the resistance of cultivars to R. oryzae and R. solani for lesion extension on sheath infection obtained by the toothpick method. The relationship between lesion size on sheath and leaf was linear and significantly negative (r = -0.66, P<=0.05, thereby indicating that there is no relationship between resistance of sheath and leaf to infection by R. solani in rice cultivars. Among the early maturing genotypes Labelle was highly susceptible in all methods of inoculation. The area under disease progress curve based on lesion height on the culm and the inoculation method with rice husk and grain were found more adequate for determining the differences in the degree of resistance among cultivars. Leaves exhibited resistance to infection by R. oryzae in inoculation tests with mycelial discs.

Anne Sitarama Prabhu

2002-05-01

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The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields  

Science.gov (United States)

Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) ...

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A quitosana como fungistático no crescimento micelial de Rhizoctonia solani Kuhn / Chitosan as fungistatic mycelial growth of Rhizoctonia solani Kuhn  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Rhizoctonia solani é um fungo causador de tombamento de plântulas em várias espécies vegetais. A quitosana é um polímero derivado do processo de desacetilação da quitina, a qual é encontrada em grande quantidade na carapaça de crustáceos, insetos e parede celular de fungos. A quitosana tem sido test [...] ada para diversos usos, inclusive no controle de fitopatógenos em agricultura, já que apresenta atividade antimicrobiana, para controle de patógenos. O presente trabalho teve como objetivo avaliar o efeito fungistático de diferentes concentrações de quitosana (0; 0,25; 0,5; 1 e 2%) no crescimento micelial do fungo R. solani in vitro. Os resultados obtidos demonstraram efeito significativo de quitosana nas diferentes concentrações utilizadas, na redução do crescimento micelial de R. solani. Observou-se também aumento do efeito fungistático da quitosana conforme o aumento da dose. Abstract in english Rhizoctonia solani is a fungus that causes damping-off of seedlings in various plant species. Chitosan is a polymer derived from the process of desacetylation of chitin, which is found in large quantities in the exoskeleton of crustaceans, insects and fungal cell wall. Chitosan has been tested for v [...] arious uses, including the control of plant pathogens in agriculture, since it presents antimicrobial activity to control pathogens. This study aimed to evaluate the fungistatic effect of different chitosan concentrations (0; 0.25; 0.5; 1 and 2%) in mycelial growth in vitro of the fungus R. solani. The results showed a significant effect of different concentrations of chitosan, in reduccing the mycelial growth of R. solani. It was also observed increased fungistatic effect with increasing of the concentration.

Álvaro Rodrigo, Freddo; Sérgio Miguel, Mazaro; Eleandro José, Brun; Américo, Wagner Júnior.

2014-01-01

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Pea seed treatment for Rhizoctonia solani control / Desempenho de sementes de ervilhas em função do controle químico de Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Durante o estabelecimento das lavouras de ervilha, a ocorrência de Rhizoctonia solani causando tombamento de plântulas tem sido observada. O presente trabalho teve como objetivo verificar a eficiência do uso de fungicidas no tratamento de sementes de ervilha cultivar Mikado, visando o controle de Rh [...] izoctonia solani e seus efeitos na qualidade fisiológica dessas sementes. Sementes foram tratadas com os seguintes fungicidas: Carbendazim, Carbendazim + Thiram, Captan, Iprodione, Iprodione + Thiram, Metalaxil-M + Fludioxonil, Pencicurom, Procimidone e Tolifluanida. Como testemunha, foi utilizada sementes tratadas com água destilada. A avaliação da qualidade fisiológica das sementes após o tratamento foi realizada pelos seguintes testes: germinação, primeira contagem, envelhecimento acelerado, condutividade elétrica e emergência de plântulas. As sementes tratadas foram semeadas em solo não inoculado e inoculado com R. solani. A emergência de plântulas foi reduzida em solo inoculado, sendo que os tratamentos que apresentaram melhores resultados foram Carbendazim, Pencicurom, Iprodione e Carbendazim + Thiram. O fungicida Captan prejudicou a qualidade fisiológica das sementes tanto em laboratório como no campo. Com relação à germinação, os tratamentos que apresentaram melhores resultados foram Carbendazim, Pencicurom, Iprodione e Carbendazim + Thiram. Abstract in english The objectives of this study were to evaluate the efficiency of fungicides for pea seed treatment against damping-off caused by Rhizoctonia solani and to verify their effects on physiological seed quality. 'Mikado' pea seeds were treated with the following fungicides: Carbendazim, Carbendazim + Thir [...] am, Captan, Iprodione, Iprodione + Thiram, Metalaxyl-M + Fludioxonil, Pencycuron, Procymidone and Tolyfluanid. Control seeds were treated with deionized water. Physiological seed quality was evaluated with the following tests: germination, first count, accelerated aging and electrical conductivity. Seeds were sown in soil inoculated and no inoculated with R. solani. The experimental design was completely random with four replications. Seedling emergence was reduced in inoculated soil and the best treatments for R. solani control were Carbendazim, Pencycuron, Iprodione and Carbendazim + Thiram. Captan reduced seed physiological quality in both the laboratory and field.

Patrícia Pereira da, Silva; Raquel Alves de, Freitas; Warley Marcos, Nascimento.

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Some Properties of Inulinase from Rhizoctonia solani  

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Full Text Available The preparation and some biochemical properties of inulinase from R. solani which isolated from soil in Tekirdag - Turkey, was carried out by dialysis and concentrated with silica gel-60 then, further proceeded with Sephadex G-150 and DEAE-Cellulose chromatographies. The specific activity of the enzyme was enhanced from 0.256-5.43 U mg -1. The enzyme showed maximum activity at 35?C and pH 5.0, it was stable in the pH range of 5.0-6.5 and up to 40?C. The activity of enzyme was inhibited strongly by Hg2+ and Ag2+ and KCN and DTNB. The action mode of enzyme for inulin was determined as endohydrolitic-action by TLC.

Figen Ertan

2005-01-01

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Rhizoctonia root rot (Rhizoctoni solani K ü h n) of sugar beet in province Vojvodina  

OpenAIRE

Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopa...

Stojšin Vera B.; Bagi Ferenc F.; Jasni? Stevan M.; Balaž Ferenc F.; Budakov Dragana B.

2006-01-01

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REAÇÃO DE CULTIVARES DO FEIJOEIRO COMUM ÀS PODRIDÕES RADICULARES CAUSADAS POR Rhizoctonia solani E Fusarium solani f. sp. phaseoli  

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Full Text Available REACTION OF COMMON BEAN CULTIVARS TOROOT ROT CAUSED BY Rhizoctonia solaniAND Fusarium solani f. sp. phaseoliRhizoctonia solani Kuhn is a necrotrophic fungus andsoil inhabitant that attacks great number of vegetable species. Inbean plants, R. solani can induce different symptoms includingtoppling, root and colon plant rottenness. Fusarium solani (MartSacc. f. sp. phaseoli (Burcholder occurs in practically all beanproducing areas in Brazil and can cause root rots and death tobean plants. This study evaluated the reaction of commercialcommon bean cultivars growing in R. solani or F. solani f. sp.phaseoli infested soil, under green house conditions. Theexperimental design was entirely randomized, with 24 treatmentsand four replications. A Oxisol was infested with trituratedsorghum grains that were previously colonized by R. solani (1.0g/1.4 L of soil or F. solani f. sp phaseoli (8.0 g/1.4 L of soil. Thedisease evaluations were accomplished 21 days after planting.All plants were carefully removed, their root systems werewashed in running water and the disease severity was evaluatedaccording to Abawi & Pastor-Corrales (1990 scale for diseaseseverity. The cultivar behavior ranged according to the inoculatedpathogen, all cultivars were susceptible with different degrees ofsusceptibility. Among evaluated common bean cultivars Pérolawas less susceptible to R. solani, and Radiante was lesssusceptible to F. solani f. sp. phaseoli.

Braycia Afonso de Miranda

2007-12-01

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SCREENING AND CHARACTERIZATION OF STREPTOMYCES ISOLATES FOR BIOCONTROL OF RHIZOCTONIA SOLANI AND OTHER PLANT PATHOGENS  

Science.gov (United States)

Rhizoctonia solani, a ubiquitous soilborne fungal plant pathogen, is responsible for economic losses of agricultural, forestry, horticultural and ornamental crops worldwide. Soil actinomycetes are known to enhance fertility and possess antimicrobial properties against various plant pathogens. One hu...

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Transgenic expression of Lactoferrin imparts resistance to a soilborne fungal pathogen Rhizoctonia solani  

Science.gov (United States)

Transgenic tobacco (Nicotiana tabacum var Xanthi) and Arabidopsis (A. thaliana) plants expressing an antimicrobial bovine lactoferrin (BLF) gene were developed and evaluated for resistance against an economically important fungal pathogen Rhizoctonia solani, the causal agent of damping off diseases....

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Caracterização morfológica de fontes de resistência de meloeiro a Rhizoctonia solani / Reaction of melon accessions to Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available A rizoctoniose, ocasionada pelo fungo Rhizoctonia solani, é uma doença frequente em áreas cultivadas, intensivamente com melão (Cucumis melo) no nordeste brasileiro. O objetivo do presente trabalho foi identificar e caracterizar morfologicamente fontes de resistência de meloeiro a R. solani. No prim [...] eiro ensaio foi avaliado o nível de resistência de 22 acessos de meloeiro coletados no nordeste brasileiro, frente ao isolado RS-21. Os acessos resistentes do primeiro experimento juntamente com 13 linhagens do cruzamento ACP x AF-646 foram avaliados para reação aos isolados RS-22 e RS-23 em um segundo ensaio. Utilizou-se o delineamento inteiramente casualizado com cinco repetições. Foram identificados como fontes de resistência os acessos T-A-08, T-A-09, T-A-19 e a linhagem ACP-AF-06. Nos dois ensaios de inoculação, as sementes foram plantadas em solo infestado com o patógeno pela incorporação de 50 mg de substrato (grãos de arroz) colonizado/kg de solo. A avaliação dos acessos foi realizada após 45 dias, com o auxílio de escala de notas de 0 a 4, para agrupamento de cada genótipo em cinco classes. As fontes de resistência foram caracterizadas morfologicamente em um ensaio em blocos casualizados com três repetições. A caracterização identificou os acessos T-A-08 e T-A-19 como sendo pertencentes à variedade botânica momordica e o acesso T-A-09 e a linhagem ACP-AF-06, pertencentes às variedades acidulus e inodorus, respectivamente. As fontes de resistência poderão ser utilizadas em futuros programas de melhoramento genético visando obter genótipos (linhagens e híbridos simples) resistentes a R. solani. Abstract in english ABSTRACT Rhizoctonia root rot, caused by Rhizoctonia solani, is a common disease in areas intensively cultivated with melon (Cucumis melo) in the Northeastern Brazil. The objective of this study was to identify and characterize morphologically resistance sources of melon to R. solani. In the first [...] trial, twenty-two melon accessions collected in the Northeastern Brazil were evaluated for their reaction to the isolate RS-21, in an experiment with the completely randomized design and five replications. The resistant accessions of the first experiment and 13 inbred lines of the ACP x AF -646 cross were evaluated for their reaction to the RS-22 and RS-23 isolates on a second trial carried out in a randomized design with five replications. The accessions T-A-08, T-A-09, T-A-19 and the line ACP-AF-06 were identified as sources of resistance. In both inoculation trials, seeds were planted in infested soil (50 mg of colonized rice grains/1.0 kg of soil). The evaluation of accessions was performed after 45 days, with a score scale from 0.0 to 4.0 to cluster genotypes in five classes. Resistance sources were characterized morphologically in an essay carried out in randomized block design with three replications. The characterization identified the T-A-08 and T-A-19 accessions as belonging to the botanical variety momordica and the T-A-09 accession and the ACP-AF-06 inbred line as belonging to the varieties acidulus and inodorus, respectively. Resistance sources may be used in future breeding programs aiming to obtain genotypes (inbred lines and hybrids) resistant to R. solani.

Rui, Sales Júnior; Glauber HS, Nunes; Katchen JP, Silva; Gabriel G, Costa; Izabel M, Guimarães; Sami J, Michereff.

2015-06-01

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Identifikasi dan Kuantifikasi Metabolit Bakteri Pelarut Fosfat dan Pengaruhnya terhadap Aktivitas Rhizoctonia solani pada Tanaman Kedelai  

OpenAIRE

Phosphate solubilizing bacteria (PSB) metabolites are organic acids, phosphomonoesterase enzyme (alkaline phosphatase) and antibiotic, which is able to dissolve insoluble phosphate. Phosphate solubilizing bacteria used in this study was expected to suppress Rhizoctonia solani attacks. This experiment was aimed at (1) identifiying and quantifying PSB metabolites, and (2) examining their capability as biocontrol agent for Rhizoctonia solani in vitro and hydroponics soybean. This study was con...

Tri Candra Setiawati; Paniman Asna Mihardja

2008-01-01

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Metodologias de inoculação de Rhizoctonia solani na cultura da cenoura / Inoculation methodology of Rhizoctonia solani in carrot  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Rhizoctonia solani pode causar diferentes tipos de doenças em cenoura (Daucus carota L.). Para a avaliação de métodos de controle geralmente se utiliza inoculação artificial. Objetivou-se neste trabalho, ajustar uma concentração de inóculo de R. solani (AG-4) no cultivo de cenoura. Utilizou-se delin [...] eamento experimental em blocos ao acaso, com 5 repetições sendo a unidade experimental um vaso de 3L com 40 sementes. Como substrato, utilizou-se solo/areia (3:1). Os tratamentos em esquema fatorial 4 x 3 sendo, 4 densidades de inóculo (9; 18; 36; 72; mg de inóculo·kg-1 de solo) e 3 métodos de infestação artificial (incorporados a todo o solo; incorporados na superfície; contato direto com as sementes) e uma testemunha adicional. O experimento foi conduzido em câmara de crescimento a 20(0)C, com fotoperíodo de 12 h. As avaliações foram realizadas diariamente do 8º ao 30º dia após a semeadura, registrando-se o estande e o número de plântulas com tombamento. Analisou-se o índice de velocidade de emergência, porcentagem média de tombamento pré e pós emergência. A densidade de 72 mg de inóculo·kg-1 de solo incorporado na superfície foi o método mais eficiente. Abstract in english Rhizoctonia solani may cause different diseases in carrot (Daucus carota L.). To test control methods, artificial inoculation is generally employed. This work aimed to adjust a methodology to inoculate R. solani (AG-4) in carrot. A randomized block outline with five replicates was used, with an expe [...] rimental unit of a 3L-pot with 40 seeds and a substact composed by a mixture of soil/sand (3:1 v/v). Treatments were those in a factorial experiment 4 x 3, with 4 inoculum densities (9; 18; 36; 72 mg of inoculum.kg-1 of soil) and three forms of artificial infestation (incorporated to the substract as a whole; incorporated on the surface; with direct contact with seeds) and an additional control. The experiment was carried out in a growth chamber at 20(0)C and a 12h photoperiod. The evaluations were daily performed from the 8th to the 30th day after sowing, recording plant stand and number of seedlings with damping-off. The emergence index, averge percentage of pre and post emergence. Were analyzed the density of 72 mg of inoculum·kg-1 of soil, incorporated on the surface of the susbtract was the most efficient inoculation method.

Amanda Cabral Corrêa de, Oliveira; Paulo Estevão de, Souza; Edson Ampélio, Pozza; Felipe de Carvalho, Manerba; Maurício Ferreira, Lopes.

2008-06-01

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Influence of Rhizoctonia solani on Egg Hatching and Infectivity of Rotylenchulus reniformis  

OpenAIRE

The effects of culture filtrates of Rhizoctonia solani and root exudates of R. solani-infected cotton (Gossypium hirsutum) seedlings on hatching of eggs and infectivity of females of Rotylenchulus reniformis were evaluated in an attempt to account for the enhanced nematode reproduction observed in the presence of this fungus. Crude filtrates of R. solani cultures growing over sterile, deionized distilled water did not affect egg hatching. Exudates from roots of cotton seedlings increased hatc...

Sankaralingam, A.; Mcgawley, E. C.

1994-01-01

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Real-time pcr (qpcr) assay for rhizoctonia solani anastomoses group ag2-2 iiib  

International Nuclear Information System (INIS)

Rhizoctonia solani anastomosis group AG2-2 IIIB is a severe sugar beet and maize pathogen. It causes crown and root rot disease which leads to yield losses world-wide. The soil-borne pathogen is difficult to detect and quantify by conventional methods. We developed a real-time PCR (qPCR) assay for the quantification of genomic DNA of Rhizoctonia solani AG2-2 IIIB based on the ITS region of rDNA genes. The limit of quantification of the assay is 1.8 pg genomic DNA. The amplification efficiency was 96.4. The assay will be helpful in the diagnoses of Rhizoctonia solani infection of sugar beet and maize roots and in the quantification of R. solani AG2-2 IIIB inoculum in plant debris and soil. (author)

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Susceptibility of leguminous green manure species to Rhizoctonia solani and Sclerotium rolfsii / Suscetibilidade de espécies de leguminosas usadas como adubo verde a Rhizoctonia solani e Sclerotium rolfsii  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Estudou-se a suscetibilidade de leguminosas utilizadas como adubos verdes em campos cultivados com feijão à podridão-radicular (Rhizoctonia solani) e à podridão-do-colo (Sclerotium rolfsii). Crotalaria breviflora, Canavalia ensiformis, Cajanus cajan, Dolichos lablab, Stizolobium cinereum, S. aterrim [...] um, e as cultivares de feijão Pérola, Valente e Carnaval foram semeadas em solo infestado por R. solani AG-4 ou S. rolfsii em casa de vegetação. A emergência de D. lablab em solo infestado por R. solani foi reduzida a 62%. C. breviflora, C. ensiformis e Valente apresentaram a menor severidade de podridão-radicular. O fungo S. rolfsii reduziu drasticamente a emergência de todas as espécies; nenhuma plântula de C. cajan e S. cinereum emergiu. Todas as espécies apresentaram alta severidade de podridão-do-colo. As espécies de leguminosas testadas não são apropriadas para serem utilizadas como adubo verde em áreas de cultivo de feijão com alta população de R. solani e S. rolfsii. Abstract in english We studied the susceptibility of species used as green manure in common bean fields to root rot (Rhizoctonia solani) and southern blight (Sclerotium rolfsii). Seeds of Crotalaria breviflora, Canavalia ensiformis, Cajanus cajan, Dolichos lablab, Stizolobium cinereum, S. aterrimum, and the bean cvs. " [...] Pérola", "Valente" and "Carnaval" were sown in soil infested by either R. solani AG-4 or S. rolfsii in greenhouse. The emergence of D. lablab seedlings in soil infested by R. solani dropped to 62%. C. breviflora, C. ensiformis and cv. "Valente" presented the lowest root rot severity. The pathogen S. rolfsii drastically reduced seedling emergence in all species; no C. cajan and S. cinereum seedling emerged. All plant species presented high southern blight severity. We conclude that leguminous crops are not suitable as green manure for areas of bean cultivation with high R. solani and S. rolfsii populations.

Trazilbo José de, Paula Júnior; Hudson, Teixeira; Rogério Faria, Vieira; Miller da Silva, Lehner; Renan Cardoso de, Lima; Telma Fallieri Nascimento, Queiroz.

2011-12-01

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Effects of Meloidogyne spp. and Rhizoctonia solani on the Growth of Grapevine Rootings  

OpenAIRE

A disease complex involving Meloidogyne incognita and Rhizoctonia solani was associated with stunting of grapevines in a field nursery. Nematode reproduction was occurring on both susceptible and resistant cultivars, and pot experiments were conducted to determine the virulence of this M. incognita population, and of M. javanica and M. hapla populations, to V. vinifera cv. Colombard (susceptible) and to V. champinii cv. Ramsey (regarded locally as highly resistant). The virulence of R. solani...

Walker, G. E.

1997-01-01

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A greenhouse test for screening sugar beet (Beta vulgaris) for resistance to Rhizoctonia solani  

OpenAIRE

Rhizoctonia solani Kühn is a serious plant pathogenic fungus, causing various types of damage to sugar beet (Beta vulgaris L.). In Europe, the disease is spreading and becoming a threat for the growing of this crop. Plant resistance seems to be the most practical and economical way to control the disease. Experiments were carried out to optimise a greenhouse procedure to screen plants of sugar beet for resistance to R. solani. In the first experiment, two susceptible accessions were evaluate...

Scholten, O. E.; Panella, L.; Bock, T. S. M.; Lange, W.

2001-01-01

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REAÇÃO DE CULTIVARES DO FEIJOEIRO COMUM ÀS PODRIDÕES RADICULARES CAUSADAS POR Rhizoctonia solani E Fusarium solani f. sp. phaseoli REACTION OF COMMON BEAN CULTIVARS TO ROOT ROT CAUSED BY Rhizoctonia solani AND Fusarium solani f. sp. phaseoli  

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Rhizoctonia solani Kuhn é um fungo necrotrófico, habitante do solo, que ataca grande número de espécies vegetais. Em feijoeiro, R. solani pode induzir sintomas como tombamento, podridões de raízes e de colo da planta. Fusarium solani (Mart Sacc. f. sp. phaseoli (Burcholder ocorre em praticamente todas as regiões produtoras de feijão no Brasil e pode causar podridão radicular e morte das plantas. Neste trabalho, avaliou-se a reação de cultivares de feijoeiro comum às podridões radiculares causadas por R. solani e F. solani f. sp. phaseoli, em solo artificialmente infestado, em condições de casa de vegetação. O delineamento experimental foi inteiramente casualizado, com 24 tratamentos e quatro repetições. Utilizou-se solo Latassolo vermelho-escuro, infestado com 1,0 g de grãos de sorgo triturado e previamente infestado com R. solani para cada 1,4 kg de solo e para F. solani f. sp. phaseoli utilizaram-se oito gramas para cada 1,4 kg de solo. A avaliação da doença foi realizada 21 dias após o plantio, em plantas cujo sistema radicular foi cuidadosamente retirado e lavado em água corrente. A severidade da doença foi avaliada de acordo com escala de notas proposta por Abawi & Pastor-Corrales (1990. O comportamento das cultivares variou de acordo com o patógeno utilizado, ou seja, os genótipos reagiram diferentemente aos dois patógenos, sendo todas suscetíveis, mas com diferentes níveis de suscetibilidade. Entre as cultivares avaliadas, a cultivar Pérola mostrou ser a menos suscetível a R. solani, e Radiante, a menos suscetível a F. solani f. sp. phaseoli.

PALAVRAS-CHAVE: Phaseolus vulgaris; patógenos de raiz.

Rhizoctonia solani Kuhn is a necrotrophic fungus and soil inhabitant that attacks great number of vegetable species. In bean plants, R. solani can induce different symptoms including toppling, root and colon plant rottenness. Fusarium solani (Mart Sacc. f. sp. phaseoli (Burcholder occurs in practically all bean producing areas in Brazil and can cause root rots and death to bean plants. This study evaluated the reaction of commercial common bean cultivars growing in R. solani or F. solani f. sp. phaseoli infested soil, under green house conditions. The experimental design was entirely randomized, with 24 treatments and four replications. A Oxisol was infested with triturated sorghum grains that were previously colonized by R. solani (1.0 g/1.4 L of soil or F. solani f. sp phaseoli (8.0 g/1.4 L of soil. The disease evaluations were accomplished 21 days after planting. All plants were carefully removed, their root systems were washed in running water and the disease severity was evaluated according to Abawi & Pastor-Corrales (1990 scale for disease severity. The cultivar behavior ranged according to the inoculated pathogen, all cultivars were susceptible with different degrees of susceptibility. Among evaluated common bean cultivars Pérola was less susceptible to R. solani, and Radiante was less susceptible to F. solani f. sp. phaseoli.

KEY-WORDS: Phaseolus vulgaris; resistance, soil pathogen.

Murillo Lobo Júnior

2007-12-01

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Ultrastructural analysis of anastomosis group 9 of Rhizoctonia solani  

International Nuclear Information System (INIS)

The ultrastructure of R. solani AG-9 (S-21, ATCC 62804) was investigated with transmission electron microscopy (TEM). The most important characteristics were those related with cell wall thickness, cytoplasmic matrix composition, number of nuclei and nucleoli and secretory material production. The majority of examined hyphae showed lateral cell walls thinner than those recorded before. The cytoplasmic matrix consistently appeared differentiated into two classes, one formed by a highly electron dense granular fine material and the other one showing a coloidal substance of very low density which give these cells a 'tiger-like' aspect. The granular dense matrix always had abundant free ribosomes and usually surrounded the cytoplasmic organelles and the septal pore apparatus. The somatic cells showed up to 5 nuclei, some of which with three nucleoli. Masses of secretory material surrounded by membrane were regularly seen in the cytoplasm, with sizes similar to those of nuclei

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Development of an Agrobacterium-based transformation system for Rhizoctonia solani  

Science.gov (United States)

A 8.7 kb binary vector containing the 1.9 kb hygromycin B phosphortransferase (hyg) gene was constructed with promoter and terminator regions from the glyceraldehyde-3-phosphate- dehydrogenase (gpd) gene of Rhizoctonia solani anastomosis group 3 (AG-3) at the 5'- and 3'- gene termini of hyg. Promot...

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Reação de resistência de genótipos de tomateiro (Lycopersicum spp. à infecção por Rhizoctonia solani Kuhn Resistance reaction of tomato genotypes (Lycopersicum spp. to Rhizoctonia solani Kuhn  

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Full Text Available Dada a importância da tomaticultura no Brasil e das enfermidades que atacam esta cultura, da mesma forma que visando futuros estados em programas de melhoramento vegetal para resistência à patógenos, este trabalho teve por objetivos: avaliar o grau de patogenicidade de quatro isolados de Rhizoctonia solani obtidos de plantas doentes de tomateiro (RT, berinjelas (RB1 e RB2 e pimentão (RP, em viveiros, frente a 9 genótipos de tomateiros e avaliar a reação de resistência de 73 genótipos de tomateiros ao R. solani. Nos experimentos utilizou-se solo esterilizado, em condições de casa de vegetação. Para o experimento I, os isolados de R. solani, oriundos das plantas de tomateiro (RT e berinjela (RB, foram igualmente mais patogênicos que os isolados de berinjela (RB, e pimentão (RP, com relação aos 9 genótipos de tomateiro testados. Pode-se dizer que os isolados variaram em graus de agressividade. Quanto às reações de resistência a R. solani, observou-se que os diferentes genótipos não diferiram estatisticamente entre si. Com relação ao experimento II, entre os 73 genótipos de tomateiro (incluindo espécies selvagens, variedades nacionais e introduções, pode-se observar que houve grande variabilidade quanto a reação de resistência a R. solani (isolado do tomateiro - RT, com percentuais de sobrevivência de plantas variando de 91%, para a cultivar Quinck Pick, até 0% de sobrevivência para o genótipo LA-462. Não foi verificada imunidade em nenhum material avaliado e sim níveis de resistência, onde esta, expressa em percentagem de sobrevivência, ocorreu de uma maneira contínua, desde uma reação de suscetibilidade até altos níveis de resistência.The present study was undertaken with the following objectives: 1 to evaluate the level of pathogenicity of four Rhizoctonia solani isolates obtained from diseased tomato plants (RT, from eggplant (RB1 and RB2, and pepper (RP and tested on 9 tomato genotypes grown in experimental plots; and 2 evaluate the resistance reaction of 73 tomato genotypes to the pathogen. Experiments were performed in greenhouse using sterilized soil. In experiment I, R. solani isolates from RT and RB2 plants were identically more pathogenic RB1 and RP. In experiment II, wide variability in the resistance reaction to R. solani (isolated from a tomato plant - RT was observed among the 73 tomato genotypes (which included wild species, Brazilian varieties and introduced material, with percentage of plant survival ranging from 91% for the cultivar Quick Pick to 0% for the genotype LA-462. None of the materials tested showed immunity, but different levels of resistance were observed, ranging from susceptibility to high resistance, as expressed by the survival percentages.

A.M. Rodrigues Cassiolato

1994-12-01

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Stem Rot on Adzuki Bean (Vigna angularis) Caused by Rhizoctonia solani AG 4 HGI in China  

Science.gov (United States)

During late August and early September 2011, stem rot symptoms were observed on adzuki bean plants (Vigna angularis) growing in fields located in Beijing and Hebei Province, China, respectively. In this study, four isolates were obtained from infected stems of adzuki bean plants. Based on their morphology, and sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the ribosomal DNA internal transcribed spacers (rDNA-ITS) region, the four isolates were identified as Rhizoctonia solani in anastomosis group (AG) 4 HGI. Pathogenicity tests showed that all isolates were strongly pathogenic to adzuki bean and resulted in serious wilt symptoms which was similar to observations in the fields. Additionally, the isolates infected several other crops and induced related rot on the roots and basal stems. To our knowledge, this is the first report of Rhizoctonia solani AG 4 HGI causing stem rot on adzuki bean.

Sun, Suli; Xia, Changjian; Zhang, Jiqing; Duan, Canxing; Wang, Xiaoming; Wu, Xiaofei; Lee, Suk-Ha; Zhu, Zhendong

2015-01-01

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Stem Rot on Adzuki Bean (Vigna angularis) Caused by Rhizoctonia solani AG 4 HGI in China.  

Science.gov (United States)

During late August and early September 2011, stem rot symptoms were observed on adzuki bean plants (Vigna angularis) growing in fields located in Beijing and Hebei Province, China, respectively. In this study, four isolates were obtained from infected stems of adzuki bean plants. Based on their morphology, and sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the ribosomal DNA internal transcribed spacers (rDNA-ITS) region, the four isolates were identified as Rhizoctonia solani in anastomosis group (AG) 4 HGI. Pathogenicity tests showed that all isolates were strongly pathogenic to adzuki bean and resulted in serious wilt symptoms which was similar to observations in the fields. Additionally, the isolates infected several other crops and induced related rot on the roots and basal stems. To our knowledge, this is the first report of Rhizoctonia solani AG 4 HGI causing stem rot on adzuki bean. PMID:25774112

Sun, Suli; Xia, Changjian; Zhang, Jiqing; Duan, Canxing; Wang, Xiaoming; Wu, Xiaofei; Lee, Suk-Ha; Zhu, Zhendong

2015-03-01

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INDUCE SYSTEMIC RESISTANCE AGAINST BLACK SCARF DISEASE CAUSED BY Rhizoctonia solani IN POTATO (Solanum tuberosum)  

OpenAIRE

In present study influence of ?-aminobutyric acid, salicylic acid and hydrogenperoxide were tested to induced systemic resistance against black scarf disease caused by Rhizoctonia solani in potato. Results of the present study revealed that both salicylic acid and hydrogen peroxide treatments effectively reduced percentage severity of black scarf on potato tubers. This reduction was recorded 10.00 and 23.34% for salicylic acid at150 and 250 mg/L respectively, while these redu...

Matny, Oadi N.; Al-jarrh, Nerain S.

2014-01-01

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SUPRESSIVIDADE NATURAL DE SOLOS DA REGIÃO CENTRO-OESTE A Rhizoctonia solani KÜHN NATURAL SUPPRESSIVENESS OF SOILS FROM WEST CENTRAL BRAZIL TO Rhizoctonia solani Kühn  

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Rhizoctonia solani é um fungo cosmopolita que habita o solo, com vasto número de hospedeiros, e causa importantes doenças na maioria das plantas cultivadas em todo o mundo. É uma espécie complexa, com muitos biotipos que diferem quanto à patogenicidade, aos hospedeiros, à distribuição na natureza e à aparência em meio de cultura. O feijoeiro comum é suscetível a este patógeno e a sua suscetibilidade é inversamente proporcional ao desenvolvimento da planta. A atividade microbiana de alguns solos pode prevenir o estabelecimento de fungos fitopatogênicos. Solos com esta propriedade são denominados antagônicos, de longa vida, resistentes ou supressivos. O objetivo deste trabalho foi avaliar os níveis de supressividade natural a R. solani de alguns solos classificados como latossolo roxo, latossolo vermelho-escuro, areia quartzoza e latossolo roxo, respectivamente, coletados nos municípios de Itumbiara, Silvânia, Jussara e Santa Helena de Goiás, no Estado de Goiás, em três áreas contíguas com os seguintes históricos de uso: a solo cultivado com feijão irrigado via pivô central por mais de quatro anos consecutivos; b solo sob vegetação nativa; e c solo sob pastagem de Brachiaria decubens. Os solos foram coletados na camada de 0-20 cm e armazenados em casa de vegetação. Para a inoculação dos solos foram utilizados grãos de sorgo, inoculados com Rhizoctonia solani, em seis densidades – 0, 100, 500, 1.000, 5.000 e 10.000 propágulos/g de solo – e triturados. O experimento foi conduzido sob condições de casa de vegetação, em um delineamento de blocos completos casualizados e esquema fatorial 6 x 4 x 3. A unidade experimental foi constituída de bandejas plásticas com 4 kg de solo e 40 plantas. Quinze dias após a emergência, as plantas foram arrancadas e avaliadas. Posteriormente, foi calculado o índice de McKinney. A análise de variância apresentou interação tripla significativa, e os graus de liberdade foram desdobrados em análises de regressão entre as doses de inóculo e o índice de doença em porcentagem, numa equação exponencial do tipo: ID = A x e (-B/dose do inóculo + 1. Nas regiões de Itumbiara e Silvânia, o índice de doença progrediu como aumento do número de propágulos por grama de solo, atingindo valores superiores a 70%. Porém, para ambas as regiões, não houve diferenças significativas entre os solos de mata, pastagem e feijão com relação ao índice de doença. Por outro lado, nos solos de Jussara e Santa Helena, foi observado um incremento do índice da doença com o aumento da dose de inóculo para todos os históricos, e os solos de mata e de pastagem apresentaram índice de doença semelhante em todas as doses de inóculo utilizadas. Em solos provenientes de área de feijão irrigado, da região de Santa Helena, os incrementos no índice de doença foram menores, não ultrapassando a 60%.

PALAVRAS-CHAVE: Podridão radicular de Rhizoctonia; controle biológico; população microbiana do solo.

Rhizoctonia solani is a highly destructive world wide soil fungus, with a large host-range, that causes important diseases in a great number of the crops. It is a complex specie whichpossesses many biotypes, differing in their pathogenicity, hosts,distribution in the nature and cultural appearance in solid media.Dry beans are susceptible to this pathogen and the susceptibility is inversely proportional to the host development. The microbial activity of some soils can prevent the establishment of phytopathogenic fungi. Soils with this property are named antagonistic, long life, resistant or supressive. The objective of this work was to evalu

Sheila Andrade Botelho

2007-09-01

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Rhizoctonia root rot (Rhizoctoni solani K ü h n of sugar beet in province Vojvodina  

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Full Text Available Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Ba?ka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die.

Stojšin Vera B.

2006-01-01

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Production of Chitinases and ?-1,3-Glucanases by Stachybotrys elegans, a Mycoparasite of Rhizoctonia solani  

OpenAIRE

The in vitro production of chitinases and ?-1,3-glucanases by Stachybotrys elegans, a mycoparasite of Rhizoctonia solani, was examined under various culture conditions, such as carbon and nitrogen sources, pH, and incubation period. Production of both enzymes was influenced by the carbon source incorporated into the medium and was stimulated by acidic pH and NaNO3. The activity of both enzymes was very low in culture filtrates from cells grown on glucose and sucrose compared with that detect...

Tweddell, Russell J.; Jabaji-hare, Suha H.; Charest, Pierre M.

1994-01-01

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Activity of alkanediol alkanoates against pathogenic plant fungi Rhizoctonia solani and Sclerotium rolfsii.  

Science.gov (United States)

Thirty known dialkanoates of ethylene, propylene and diethylene glycols were synthesized by reacting the glycols with acyl chlorides and their structures confirmed by IR, NMR and mass spectral analyses. They exhibited significant antifungal activity against two phytopathogenic fungi Rhizoctonia solani Kuehn and Sclerotium rolfsii Sacc in a dose dependent manner. Propylene glycol dipentanoate was the most active against R. solani. followed by diethylene glycol dibutanoate and ethylene glycol dibutanoate. Against S. rolfsii ethylene glycol diheptanoate was found to be most active followed by diethylene glycol diisobutanoate As compared to the standard reference benomyl (EC50 5.16 microg/mL), the potential alkanediol dialkanoates showed EC50 in the range of 33 - 60 microg/mL. PMID:23074913

Shukla, Paraj; Walia, Suresh; Ahluwalia, Vivek; Parmar, Balraj S; Nair, Muraleedharan G

2012-09-01

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RL-SAGE and microarray analysis of the rice transcriptome after Rhizoctonia solani infection.  

Science.gov (United States)

Sheath blight caused by the fungal pathogen Rhizoctonia solani is an emerging problem in rice production worldwide. To elucidate the molecular basis of rice defense to the pathogen, RNA isolated from R. solani-infected leaves of Jasmine 85 was used for both RL-SAGE library construction and microarray hybridization. RL-SAGE sequence analysis identified 20,233 and 24,049 distinct tags from the control and inoculated libraries, respectively. Nearly half of the significant tags (> or =2 copies) from both libraries matched TIGR annotated genes and KOME full-length cDNAs. Among them, 42% represented sense and 7% antisense transcripts, respectively. Interestingly, 60% of the library-specific (> or =10 copies) and differentially expressed (>4.0-fold change) tags were novel transcripts matching genomic sequence but not annotated genes. About 70% of the genes identified in the SAGE libraries showed similar expression patterns (up or down-regulated) in the microarray data obtained from three biological replications. Some candidate RL-SAGE tags and microarray genes were located in known sheath blight QTL regions. The expression of ten differentially expressed RL-SAGE tags was confirmed with RT-PCR. The defense genes associated with resistance to R. solani identified in this study are useful genomic materials for further elucidation of the molecular basis of the defense response to R. solani and fine mapping of target sheath blight QTLs. PMID:17579886

Venu, R C; Jia, Yulin; Gowda, Malali; Jia, Melissa H; Jantasuriyarat, Chatchawan; Stahlberg, Eric; Li, Huameng; Rhineheart, Andrew; Boddhireddy, Prashanth; Singh, Pratibha; Rutger, Neil; Kudrna, David; Wing, Rod; Nelson, James C; Wang, Guo-Liang

2007-10-01

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The supernatant of Bacillus pumilus SQR-N43 has antifungal activity towards Rhizoctonia solani.  

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For clarification of the antagonistic mechanism of Bacillus pumilus SQR-N43 (N43) against Rhizoctonia solani Q1, production of antibiotics by N43 was determined, and the effect of the antibiotics on the pathogen mycelium was microscopically observed. Further more, the control efficiencies of the antifungal compounds on damping-off disease were investigated. The results obtained are listed as follows: N43 produced antibiotic substances towards R. solani Q1 at logarithmic growth phase. The antibiotics caused hyphal deformation and enlargement of cytoplasmic vacuoles in R. solani Q1 mycelia. 70% saturation of ammonium sulfate made a complete precipitation of the antibiotics in culture broth. When treated with protease K and trypsase, the activities of antibiotics were decreased by 79% and 53%, respectively, compared with control. The antibiotics were sensitive to high temperature and were alkaline stable. The molecular weights of the substances were about 500-1000 Da. The bio-control efficiencies of the antibiotics had no significant difference with that of N43 cell suspension. It is a first report that B. pumilus strain produced oligopeptides which had inhibitory effect on R. solani Q1 at logarithmic growth phase. PMID:23417338

Huang, Xinqi; Yong, Xiaoyu; Zhang, Ruifu; Shen, Qirong; Yang, Xingming

2013-08-01

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Induction of Laccase Activity in Rhizoctonia solani by Antagonistic Pseudomonas fluorescens Strains and a Range of Chemical Treatments  

OpenAIRE

Fungi often produce the phenoloxidase enzyme laccase during interactions with other organisms, an observation relevant to the development of biocontrols. By incorporating the laccase substrate 2,2?-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) into agar, we analyzed laccase induction in the plant-pathogenic fungus Rhizoctonia solani when paired against isolates of the soil bacterium Pseudomonas fluorescens. Substantial induction of R. solani laccase was seen only in pairings with ...

Crowe, Jonathan D.; Olsson, Stefan

2001-01-01

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Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn.  

Science.gov (United States)

An investigation was made to manage strawberry black root rot caused by Rhizoctonia solani (R. solani) through the integration of Trichoderma harzianum (T. harzianum) isolate STA7, mustard oil cake and Provax 200. A series of preliminary experiments were conducted to select a virulent isolate of R. solani, an effective isolate of T. harzianum, a suitable organic amendment, and a suitable fungicide before setting the experiment for integration. The pathogenicity of the selected four isolates of R. solani was evaluated against strawberry and isolate SR1 was selected as the test pathogen due to its highest virulent (95.47% mortality) characteristics. Among the 20 isolates of T. harzianum, isolate STA7 showed maximum inhibition (71.97%) against the test pathogen (R. solani). Among the fungicides, Provax-200 was found to be more effective at lowest concentration (100 ppm) and highly compatible with Trichoderma isolates STA7. In the case of organic amendments, maximum inhibition (59.66%) of R. solani was obtained through mustard oil cake at the highest concentration (3%), which was significantly superior to other amendments. Minimum percentages of diseased roots were obtained with pathogen (R. solani)+Trichoderma+mustard oil cake+Provax-200 treatment, while the highest was observed with healthy seedlings with a pathogen-inoculated soil. In the case of leaf and fruit rot diseases, significantly lowest infected leaves as well as fruit rot were observed with a pathogen+Trichoderma+mustard oil cake+Provax-200 treatment in comparison with the control. A similar trend of high effectiveness was observed by the integration of Trichoderma, fungicide and organic amendments in controlling root rot and fruit diseases of strawberry. Single application of Trichoderma isolate STA7, Provax 200 or mustard oil cake did not show satisfactory performance in terms of disease-free plants, but when they were applied in combination, the number of healthy plants increased significantly. The result of the current study suggests the superiority of our integrated approach to control the sclerotia forming pathogen R. solani compared to the individual treatment either by an antagonist or by a fungicide or by mustard oil cake. PMID:25595298

Asad-Uz-Zaman, Md; Bhuiyan, Mohammad Rejwan; Khan, Mohammad Ashik Iqbal; Alam Bhuiyan, Md Khurshed; Latif, Mohammad Abdul

2015-02-01

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Diversity of Rhizoctonia solani associated with pulse crops in different agro-ecological regions of India.  

Science.gov (United States)

Four hundred seventy Rhizoctonia solani isolates from different leguminous hosts originating from 16 agro-ecological regions of India covering 21 states and 72 districts were collected. The disease incidence caused by R. solani varied from 6.8 to 22.2 % in the areas surveyed. Deccan plateau and central highlands, hot sub-humid ecoregion followed by northern plain and central highlands and hot semi-arid ecoregion showed the highest disease incidence. R. solani isolates were highly variable in growth diameter, number, size and pattern of sclerotia formation as well as hyphal width. The isolates obtained from aerial part of the infected plants showing web blight symptoms produced sclerotia of 1-2 mm in size whereas, the isolates obtained from infected root of the plants showing wet root rot symptoms produced microsclerotia (<1 mm). Majority of R. solani isolates showed <8 ?m hyphal diameter. Based on morphological characters the isolates were categorized into 49 groups. Seven anastomosis groups (AGs) were identified among the populations of R. solani associated with the pulse crops. The frequency (25.6 %) of AG3 was the highest followed by AG2-3 (20.9 %) and AG5 (17.4 %). The cropping sequence of rice/sorghum/wheat-chickpea/mungbean/urdbean/cowpea/ricebean influenced the dominance of AG1 (16.3 %). Phylogenetic analysis utilizing ITS-5.8S rDNA gene sequences indicated high level of genetic similarity among isolates representing different AGs, crops and regions. ITS groups did not correspond to the morphological characters. The sequence data from this article has been deposited with NCBI data libraries with JF701707 to JF701795 accession numbers. PMID:24399024

Dubey, Sunil C; Tripathi, Aradhika; Upadhyay, Balendu K; Deka, Utpal K

2014-06-01

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DNA Microsatellite Analysis of Kenyan Isolates of Rhizoctonia solani from Common Bean (Phaseolus vulgaris L.  

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Full Text Available Seven hundred and fifty bean plant samples with root rot symptoms were collected from farmers' fields during two surreys carried out in Embu district, Kenya. Various fungal pathogens were isolated in the laboratory from these samples; among them were 50 isolates of Rhizoctonia solani, which were subjected to pathogenicity tests in a glasshouse. Thirty-six isolates of R. solani obtained from beans with root rots were subjected to DNA microsatellite analysis. Five isolates of R. solani that cause black scarf of potatoes (Solanum tuberosum L. were also analysed alongside those from the beans. A total of 50 alleles were detected when six microsatellite loci were typed in the 41 samples, with the mean of 8.33 and a range of 3 at locus RB23 to 19 at locus AF513014. The smallest allele size was 129 basepair at locus RE102 and the largest was 297 basepair at locus AY212027. Microsatellite analysis showed a moderate variation among the isolates from different agro-ecological zones and administrative boundaries (divisions. Phylogenetic analysis revealed 3 major clusters within the population of 41 isolates of R. solani from Kenya. Clusters 1, 2 and 3 had 15, 10 and 75% isolates, respectively. However, cluster 3 had 4 sub-clusters and cluster 1 had 2 sub-clusters, while cluster 2 did not have a sub-cluster. There was no relationship between microsatellites and geographical origin of the isolates. This is the first study on the genetic diversity of R. solani using DNA microsatellite analysis in Kenya.

A.W. Mwang`Ombe

2007-01-01

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Diversidad genética de aislados de Rhizoctonia solani (Kuhn) de chile en México / Genetic diversity of Rhizoctonia solani isolates (Kuhn) from pepper in Mexico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Una de las principales limitantes para la producción de chile son los hongos patógenos causantes de la enfermedad conocida como "marchitez del chile" o "secadera". Esta enfermedad puede ser devastadora cuando las condiciones climáticas son favorables para el patógeno. A pesar de que se han intentado [...] diferentes medios de control (químicos y culturales) ninguno ha tenido éxito. Una alternativa para su control es producir germoplasma resistente, sin embargo para poder establecer un programa de mejoramiento efectivo es necesario conocer la distribución y diversidad genética de los patógenos involucrados, particularmente de Rhizoctonia solani, que por su ubicuidad representa un peligro potencial en todas las zonas productoras. Por ello el objetivo fue caracterizar a R. solani en las zona Centro Norte de México y determinar su diversidad genética. Para cumplir con este objetivo se consideraron los estados de Chihuahua, Durango, Zacatecas, San Luis Potosí, Colima, Querétaro y Guanajuato donde en 2009 se colectaron plantas adultas de Chile con síntomas de marchitez, se aisló al hongo y se encontró una incidencia del 33%, encontrándose tanto en tallo como en raíz. Las células miceliales fueron multinucleadas, características de las cepas patogénicas. Las pruebas de anastomosis demostaron la presencia en México de los grupos GA4, GA-2.1, GA-IIB, GA-2IV, GA7, GA11, GA12 y GA13. La diversidad genética de este hongo fue muy alta, de tal manera que las relaciones demostradas por la construcción de dendrogramas no muestran tendencias homogéneas pues los principales grupos formados contienen elementos de todos los estados. Abstract in english One of the major constraints for the production of pepper are pathogenic fungi causing diseases known as "pepper blight" or "damping off". This disease can be devastating when weather conditions are favorable for the pathogen. Although different means of control (chemical and cultural) have benn use [...] d but none has been successful. An alternative to control is to produce resistant germplasm, however in order to establish an effective breeding program is necessary to know the distribution and genetic diversity of the pathogens involved, particularly Rhizoctonia solani, which by its ubiquity represents a potential danger in all producing areas. Thus, the objective was to characterize R. solani in North Central area from Mexico and determine its genetic diversity. To achieve with this goal are considered the states of Chihuahua, Durango, Zacatecas, San Luis Potosi, Colima, Queretaro and Guanajuato where in 2009 were collected adult plants of pepper with pepper blight symptoms, the fungus was isolated and found an incidence of 33%, finding it in both stem and root. Mycelial cells were multinucleated, a characteristic from pathogenic strains. The anastomosis testing showed that in Mexico are present the groups GA4, GA-2. 1, GA-IIB, GA-2IV, GA7, GA11, GA12 and GA13. The genetic diversity of this fungus was very high, so that the relationships demonstrated by the construction of dendrogram show no homogeneous trends so as the main groups formed contain elements of all states.

Víctor, Montero-Tavera; Brenda Zulema, Guerrero-Aguilar; José Luis, Anaya-López; Talina Olivia, Martínez-Martínez; Lorenzo, Guevara-Olvera; Mario Martín, González-Chavira.

1043-10-01

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Promotion of growth and control of damping-off (Rhizoctonia solani) of greenhouse tomatoes amended with vermicompost  

Scientific Electronic Library Online (English)

Full Text Available The pathogen Rhizoctonia solani (teleomorph Tanatephorus cucumeris) can affect tomatoes germination and emergence and cause basal rot of seedlings. It is generally accepted that composts suppress plant diseases, improve soil nutrient availability and stimulate plant growth. However, no reports have [...] been found on the simultaneous evaluation of vermicompost as plant growth promoter and suppressive to damping-off caused by R. solani on tomatoes. This research evaluated the suppressive effects of different concentrations of vermicompost against R. solani and the ability of vermicompost to promote tomato seedlings growth. The microbial composition of the substratum was explored. Thirty six microorganisms were isolated, 13 of which were antagonic to R.solani in vitro. The addition of 25 to 100% of vermicompost promoted seedlings growth and prevented damping-off caused by R. solani.

MC, Rivera; ER, Wright; MV, López; D, Garda; MY, Barragué.

2004-12-01

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Chitosan-cinnamon beads enhance suppressive activity against Rhizoctonia solani and Meloidogyne incognita in vitro.  

Science.gov (United States)

A novel chitosan-cinnamon bead carrier was prepared in this study. Chitosan was mixed with cinnamon powder (CP) and cinnamon extract (CE) to obtain chitosan-cinnamon powder (CCP) beads and chitosan-cinnamon extracted (CCE) beads, respectively. The potential antifungal and nematicidal activities of CCP and CCE were investigated against Rhizoctonia solani and Meloidogyne incognita in vitro. Relative antifungal activity of the CCP (5% CP) bead-treated R. solani was 30.9 and 23.9% after 1 and 2 day incubations, respectively. Relative antifungal activity of the CCE (0.5% CE) bead-treated R. solani was 4.3, 3.0 and 4.2% after 1, 2 and 3 days of incubation. Inhibition of hatch by CCP beads with CP of 5% was 78.8%. Inhibition of hatch by CCE beads with CE of 0.5% was 82.0%. J2 mortality following the CCP (5% CP) and CCE (0.5% CE) bead treatments was 85.0 and 95.8%, respectively against M. incognita after 48 h incubations. PMID:24417978

Seo, Dong-Jun; Nguyen, Dang-Minh-Chanh; Park, Ro-Dong; Jung, Woo-Jin

2014-01-01

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Investigating the roles of MicroRNAs in biotic stress response induced by Rhizoctonia solani in rice  

Science.gov (United States)

Sheath blight disease, caused by Rhizoctonia solani 1802/KB was screened on two rice varieties, Oryza sativaindica cultivar MR219 and Oryza sativa indica cultivar UKMRC9. The disease symptom was severe in MR219 compared to UKMRC9. Total RNA from R. solani 1802/KB, infected rice leaves of MR219 and infected rice leaves of UKMRC9 were extracted using TRIzol reagent, purified and sent for small RNA sequencing. Three miRNA libraries were generated and analyzed. The libraries generated 65 805, 78 512 and 81 325 known miRNAs respectively. The structure of miRNA of these samples was predicted. The up-regulated and down-regulated of miRNAs target gene prediction and its target functions were discovered and were mainly related to the growth and development of metabolism, protein transport, transcriptional regulation, stress response, and hormone signaling and electron transfer. Sheath blight-induced differential expression of known miRNAs tends to targetMYB transcription factor, F-box proteins, NBS-LRR, leucine-rich repeat receptor protein kinases and zinc finger proteins. Detecting new miRNAs and measuring the expression profiles of known miRNAs is an important tasks required for a better understanding of various biological conditions. Therefore, further analysis using Gene Ontology Slim will be conducted to deduce some biological information from the datasets obtained.

Syuhada, O. Nurfarahana; Kalaivani, N.

2014-09-01

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Investigating the roles of MicroRNAs in biotic stress response induced by Rhizoctonia solani in rice  

International Nuclear Information System (INIS)

Sheath blight disease, caused by Rhizoctonia solani 1802/KB was screened on two rice varieties, Oryza sativaindica cultivar MR219 and Oryza sativa indica cultivar UKMRC9. The disease symptom was severe in MR219 compared to UKMRC9. Total RNA from R. solani 1802/KB, infected rice leaves of MR219 and infected rice leaves of UKMRC9 were extracted using TRIzol reagent, purified and sent for small RNA sequencing. Three miRNA libraries were generated and analyzed. The libraries generated 65 805, 78 512 and 81 325 known miRNAs respectively. The structure of miRNA of these samples was predicted. The up-regulated and down-regulated of miRNAs target gene prediction and its target functions were discovered and were mainly related to the growth and development of metabolism, protein transport, transcriptional regulation, stress response, and hormone signaling and electron transfer. Sheath blight-induced differential expression of known miRNAs tends to targetMYB transcription factor, F-box proteins, NBS-LRR, leucine-rich repeat receptor protein kinases and zinc finger proteins. Detecting new miRNAs and measuring the expression profiles of known miRNAs is an important tasks required for a better understanding of various biological conditions. Therefore, further analysis using Gene Ontology Slim will be conducted to deduce some biological information from the datasets obtained

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Allelopathic Effect of Some Cruciferous Seeds on Rhizoctonia solani kuhn and Gossypium barbadense L.  

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Full Text Available Phenolic substances, lipoidal matters and fatty acid contents of some cruciferous powdered seeds, Raphanus sativus L., Brassica oleracea L. var capitata, Sinapis alba L., Brassica nigra Koch, Eruca sativa Mill, Brassica napus L. and Lipidium sativum L., were determined. The results indicated that R. sativus L., B. napus L. and B. oleracea L. var capitata contained higher percentage of phenolic compounds, lipoidal matters and unsaturated fatty acids, respectively, compared to other tested plants. The aqueous and ethanolic extracts of the above seeds were prepared. The alcoholic extract was fractionated with petroleum ether 60-80oC, chloroform and ethyl acetate, respectively. The prepared extracts and fractions were subjected to phytochemical screening and the results indicated the presence of various active constituents. Their allelopathic effect on Rhizoctonia solani Kuhn was tested in vitro. The tested extracts have variable inhibitory effect on R. solani Kuhn. The effect depends on the concentration of the extracts, plant species and the active constituents. Rhizoctania solani infested and non-infested soil sowed with cotton (Gossypium barbadense L seeds were treated with the above powdered seeds. All treatments reduced cotton seed germination, decreased significantly root length but increased seedling shoot height. The results indicated that application of powdered seeds of R. sativus L., E. sativa MILL and S. alba L., to the soil infested with R. solani Kuhn, enhanced the germination percentage of cotton, reduced damping off precentage and improved the growth criteria of the cotton seedlings. Fatty acids composition and mineral contents of the untreated cotton and infested cotton seedlings treated with seed powders were also investigated

I.M.El-Refai

2004-01-01

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Identifikasi dan Kuantifikasi Metabolit Bakteri Pelarut Fosfat dan Pengaruhnya terhadap Aktivitas Rhizoctonia solani pada Tanaman Kedelai  

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Full Text Available Phosphate solubilizing bacteria (PSB metabolites are organic acids, phosphomonoesterase enzyme (alkaline phosphatase and antibiotic, which is able to dissolve insoluble phosphate. Phosphate solubilizing bacteria used in this study was expected to suppress Rhizoctonia solani attacks. This experiment was aimed at (1 identifiying and quantifying PSB metabolites, and (2 examining their capability as biocontrol agent for Rhizoctonia solani in vitro and hydroponics soybean. This study was conducted in three stages. The first stage of this study was culturing two PSB isolates (Pseudomonas putida 27.4B and Pseudomonas diminuta in the Pikovskaya medium to analyze their metabolites. The second and third stage of this study was testing the antagonist of two bacteria to suppressed R. solani activity, which was conducted in vitro, and in hydroponics medium soybean as indicator plant. The results showed that P. putida 27.4B and P. diminuta produced organic acids i.e.: citrate, formic, succinic, acetic, propionate, butyrate, and oxalate. The totals of organic acids from each bacterium were 70,3 mg.kg-1 and 61,9 mg.kg-1. Production of alkaline phosphatase enzyme in Pikovskaya medium of P. Putida 27.4B was 11,71 ìg pNP .mL-1.h-1 and P. diminuta was 24,04 ìg pNP.mL-1.h-1. Concentration of this enzyme in soil medium was higher than that in Pikovskaya medium with 26,27 ìg pNP.g-1.h-1 and 39,03 ìg pNP.g-1.h-1 respectively. This study also showed that total concentration of antibiotics (tetracycline, oxitetracycline and penicillin produced by the PSB, were 3,2 ìg.mL-1 (P. putida 27.4B and 10,96 ìg.m1-1 (P. diminuta, respectively. The results from second stage of this study showed that by using in vitro, the reduced growth of R. solani was observed 58,35% with P. putida 27.4B and 41,96% with P. diminuta. In addition, inoculations of PSB in hydroponics medium reduced the fungal pathogenesis from 10,71% to 21,42% of pre and post emergence damping-off. Visually, the symptom of pathogen attack appeared within the period of 2 untill 14 days after infection.

Tri Candra Setiawati

2008-09-01

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High protection of protein kinase NtPK against the phytopatogenic fungus Rhizoctonia solani / La proteína quinasa NtPK confiere alto nivel de protección contra el hongo fitopatógeno Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available Con el objetivo de identificar los genes involucrados en la resistencia y susceptibilidad de la Nicotiana tabacum al hongo fitopatógeno Rhizoctonia solani, se generaron (a través de librerías substractivas) transcriptos que se expresan diferentemente en cada interacción. Ello permitió el aislamiento [...] de un gen que codifica para una proteína quinasa que se silencia durante la interacción de susceptibilidad y se activa durante la resistencia. La expresión de este gen en plantas de tabaco incrementó significativamente su resistencia frente a un aislado agresivo de R. solani. Sin embargo, el silenciamiento del gen redujo drásticamente la resistencia a una cepa no agresiva de R. solani. Además se evaluaron genes como superóxido dismutasa, hsr203j, quitinasas y fenilalanina amonio-liasa relacionados con la resistencia a enfermedades en plantas de tabaco en las que se sobrexpresa o silencia el gen que codifica para la proteína quinasa. Este gen se puede utilizar para el diseño de una estrategia de resistencia a R. solani en cultivos de tabaco u otras plantas de la familia Solanácea, susceptibles a este fitopatógeno. Abstract in english To identify Nicotiana tabacum genes involved in resistance and susceptibility to the phytopathogenic fungus Rhizoctonia solani, transcripts were generated (by subtractive libraries), which were differentially expressed in each interaction. This enabled isolation of a gene coding for a protein kinase [...] that becomes silent during the susceptibility interaction and is activated during resistance. The expression of this gene in tobacco plants significantly increased resistance against an aggressive isolate of R. solani. However, silencing the gene drastically reduced resistance to a non-aggressive isolate of R. solani. Besides, genes such as: superoxide dismutase, hsr203j, chitinases and phenylalanine ammonia lyase, related with resistance to tobacco plant diseases, in which the gene coding for the protein kinase is overexpressed or silenced, were evaluated. This gene can be used to design a strategy of resistance to R. solani in tobacco cultures or other plants of the Solanaceae family, susceptible to this phytopathogen.

Orlando, Borrás; Osmani, Chacón; Marleny, González; Roxana, Portieles; Ernesto, González; Merardo, Pujol.

2012-12-01

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Antifungal activity of volatile compounds-producing Pseudomonas P2 strain against Rhizoctonia solani.  

Science.gov (United States)

Several volatile organic compounds (VOCs) producing endophyte bacteria were isolated from the leaves of olive trees and tested for their antifungal activity against several pathogenic fungi. An antagonistic strain called P2 showed 97 % of homology with Pseudomonas sp. strains on the basis of its 16S rDNA sequence and biochemical properties. P2 strain drastically inhibited the growth of Rhizoctonia solani mycelia (86 %) at 5 day-post-confrontation (dpc) and strongly reduced fungi infection on potato slices at 10(7) bacteria ml(-1) for 3 and 7 dpc. P2 strain was also positive for protease activity as well as siderophore production. Light microscopy analysis showed that treatment of R. solani mycelia with P2 strain induced thickening of the cell-wall, vesiculation of protoplasm and blockage of fungal hyphae branching. VOCs analysis using GC-MS allowed the detection of two major products with m/z of 93.9910 and 125.9630 corresponding to dimethyl disulfide and dimethyl trisulfide respectively. VOCs-producing P2 strain could be a promising agent in the protection of tuber crops against fungal diseases. PMID:25384611

Elkahoui, Salem; Djébali, Naceur; Yaich, Najeh; Azaiez, Sana; Hammami, Majdi; Essid, Rym; Limam, Ferid

2015-01-01

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Virulence and molecular characterization of Costa Rican isolates of Rhizoctonia solani from common bean  

Scientific Electronic Library Online (English)

Full Text Available Web blight is one of the main diseases that affects bean (Phaseolus vulgaris) cultivation. It infects diverse organs at any growth stage of the plant and can be present at different altitudes in a humid tropical climate. The causal agent of this disease is Thanatephorus cucumeris in its sexual stage [...] and Rhizoctonia solani in the anamorph. The objective of this investigation was to characterize molecular isolates of R. solani obtained from bean plants from diverse production regions in Costa Rica and determine their virulence. Fifty-one samples of symptomatic bean plants were collected using a global positioning system. Virulence was evaluated using the detached leaf technique. Isolates were identified using AG 1-IA, AG 1-IB, AG 1-IC, AG 1-ID, AG 2-2, AG 2-2IIIB, AG 2-2IV and AG 4 molecular markers. ITS sequences were obtained and analyzed with BLAST, aligned, and a phylogenetic tree was constructed. A high degree of virulence and genetic variability between isolates was identified and the anastomosis subgroups of isolates were independent of their geographical origin.

Floribeth, Mora-Umaña; Natalia, Barboza; Ricardo, Alvarado; Marcela, Vásquez; Graciela, Godoy-Lutz; James R., Steadman; Pilar, Ramírez.

2013-12-01

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Isolation and characterization of siderophore producing antagonistic rhizobacteria against Rhizoctonia solani.  

Science.gov (United States)

Plant protection through siderophore producing rhizobacteria (SPR) has emerged as a sustainable approach for crop health management. In present study, 220 bacteria isolated from tomato rhizosphere were screened for in vitro antagonistic activity against Rhizoctonia solani AG-4. Nine potent antagonistic strains viz., Alcaligenes sp. (MUN1, MB21, and MPF37), Enterobacter sp. (MPM1), Pseudomonas sp. (M10A and MB65), P. aeruginosa (MPF14 and MB123) and P. fluorescens (MPF47) were identified on the basis of physiological characters and 16S rDNA sequencing. These strains were able to produce hydrolytic enzymes, hydrogen cyanide, indole acetic acid, although, only few strains were able to solubilize phosphate. Two strains (MB123 and MPF47) showed significant disease reduction in glasshouse conditions were further evaluated under field conditions using three different application methods. Application of P. fluorescens (MPF47) in nursery as soil mix?+?seedling root treatments prior to transplantation resulted in significant disease reduction compared to control. Total chlorophyll and available iron were significantly higher in the MPF47 treated plants in contrast to infected control. In conclusion, siderophore producing bacteria MPF47 have strong biocontrol abilities and its application as soil mix?+?seedling root treatments provided strong shield to plant roots against R. solani and could be used for effective bio-management of pathogen. PMID:23686438

Solanki, Manoj Kumar; Singh, Rajesh Kumar; Srivastava, Supriya; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok K; Arora, Dilip K

2014-06-01

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INDUCE SYSTEMIC RESISTANCE AGAINST BLACK SCARF DISEASE CAUSED BY Rhizoctonia solani IN POTATO (Solanum tuberosum  

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Full Text Available In present study influence of ?-aminobutyric acid, salicylic acid and hydrogenperoxide were tested to induced systemic resistance against black scarf disease caused by Rhizoctonia solani in potato. Results of the present study revealed that both salicylic acid and hydrogen peroxide treatments effectively reduced percentage severity of black scarf on potato tubers. This reduction was recorded 10.00 and 23.34% for salicylic acid at150 and 250 mg/L respectively, while these reduction were 6.67 and 3.37% respectively at both the concentration (150 and 250 mg/L of hydrogen peroxide. All the treated plants with BABA, salicylic acid and hydrogen peroxide were showed a significant increase in potato tuber yield as compared with check (R. solani only at150 and 250 mg/l, it was82.50, 137.5, 128.5, 128.7, 149.0 and 414.2 g for pathogen treatment. Treatment containing spraying of 250 mg/l Hydrogen peroxide showed the maximum improvement in fresh and dry weight, and potato tubers yield as compared with all treatments. Furthermore, plant characters results showed that treatment containing 150 mg/l BABA and H2O2 was significantly increase the content of chlorophyll type A and B as compared with check (R. solani only at (0.74, 1.07 and (0.71, 1.06 and (0.69, 1.00 µg/ml respectively, as well as total chlorophyll was significantly increased to same treatments at 1.82, 1.75 and 1.69 µg/ml respectively. Hydrogen peroxide 150 mg/L showed significantly increased peroxidase activity after 48 h from spray compared with pathogen treatment (R. solani only at 5.71 and 4.68 change the absorption respectively, While after 30 day of spray with chemicals inducer all treatments showed a significantly increased with peroxidaes activity compared with pathogen treatment (R. solani only and this improvement was 7.21, 5.91, 7.55, 6.37, 7.78, 8.19 and 5.18 respectively.

Oadi N Matny

2014-07-01

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INTERACTIONS BETWEEN Fusarium solani f. sp. phaseoli AND Rhizoctonia solani ON THE SEVERITY OF DRY BEAN ROOT ROT INTERAÇÕES ENTRE Fusarium solani f. sp. phaseoli E Rhizoctonia solani NA SEVERIDADE DA PODRIDÃO RADICULAR DO FEIJOEIRO  

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Full Text Available

The present work aimed to evaluate the effect of inoculum densities of Fusarium solani f. sp. phaseoli (Fsp and Rhizoctonia solani (Rs and their interactions on the severity of root rot and on the dry mass of bean plants. Soil was infested by the addition of Rs or Fsp-colonized sorghum seeds, in the amounts of 0.00 g; 0.06 g; 0.12 g; 0.25 g; 0.50 g; and 1.00 g for Rs, and 0 g; 1g; 2 g; 4 g; 8 g; and 16 g for Fsp per pot (1.4 kg of soil. The densities used for the joint soil infestations with both pathogens were the same used in the separate pathogen infestations. A progressive rise in the severity of root rots was observed with the increase of inoculum density for both pathogens. Maximum disease severities for Rs were 67% and 22%, in separate or combined infections with Fsp, respectively. Maximum disease severities with Fusarium were 14% and 38%, in separate or combined infections with Rs, respectively. The results suggest that Rhizoctonia solani stimulated the expression of symptoms of Fusarium solani f. sp. phaseoli, while Fsp inhibited the expression of symptoms caused by Rs. Negative correlations between the inoculum density and bean dry weight were generally observed, except for the single infestation with Fsp.


KEY-WORDS: Soilborne fungus; bean diseases; soil infestation.

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Queima foliar e tombamento de mudas em plantas medicinais causadas por Rhizoctonia solani AG1 - 1B / Leaf blight and seedling damping-off of medicinal plants caused by Rhizoctonia solani AG1 - 1B  

Scientific Electronic Library Online (English)

Full Text Available Recentemente, em plantas medicinais da família Labiatae (Rosmarinus officinalis, Lavandula sp., Salvia officinalis e Thymus vulgaris), constatou-se tombamento de mudas em pós-emergência e queima foliar ascendente. Em isolamentos efetuados a partir de tecidos doentes, observou-se o desenvolvimento de [...] um fungo com hifas ramificadas em ângulo de aproximadamente 90º, constrição na base da ramificação, septo próximo à inserção da hifa lateral e outras características típicas do gênero Rhizoctonia. Inoculou-se o fungo em plantas sadias cultivadas em vasos plásticos. Naquelas inoculadas por pincelamento de inóculo, ocorreu queima foliar de forma generalizada aos quatro dias da inoculação, enquanto nas inoculadas pela deposição de inóculo na superfície dos vasos, houve queima foliar ascendente, como observado em condições naturais, aos dez dias da inoculação. Com base na morfologia da colônia, crescimento micelial, número de núcleos, identificação do grupo e subgrupo de anastomose e da fase teleomórfica, o patógeno foi caracterizado como Rhizoctonia solani (fase anamórfica de Thanatephorus cucumeris). Com a reprodução dos sintomas da doença por inoculação artificial nas mudas e o reisolamento, em meio de batata dextrose ágar (BDA), do mesmo fungo a partir de tecidos doentes confirmou-se R. solani como o agente etiológico da doença. Abstract in english Recently, seedling damping off and blight progressing from old to young leaves were found on medicinal plants of the family Labiatae (Rosmarinus officinalis, Lavandula sp., Salvia officinalis and Thymus vulgaris). A fungus was isolated from diseased tissues, in which the hyphae had diameter, ramific [...] ation angle of about 90º, basal constriction, a septum next to the lateral hyphae, and other typical characteristics of the genus Rhizoctonia. The fungus was inoculated on healthy plants cultivated in plastic pots by brushing inoculum suspension on leaves (brushing) or by pouring the inoculum suspension on the surface of pots (soil infestation). On plants inoculated by brushing, disease symptoms occurred on all leaves four days after inoculation. On plants inoculated by soil infestation, leaf blight continued to ascent for ten days after inoculation under natural conditions. Based on colony morphology, mycelial growth, number of nuclei, identification of anastomosys group and subgroup, and on the teleomorph, the pathogen was considered to be Rhizoctonia solani (anamorph of Thanatephorus cucumeris). As disease symptoms were reproduced by artificial inoculation on plants and the fungus was reisolated on potato dextrose agar (PDA) from diseased tissues, R. solani was confirmed to be the causal agent of the disease.

Reginaldo G., Mafia; Acelino C., Alfenas; Luiz A., Maffia; Gizella M., Ventura; Eraclides M., Ferreira; Irislei F., Neves; Cláudia A., Vanetti; Clarice, Silva.

2005-06-01

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Genetic analyses of Rhizoctonia solani isolates from Phaseolus vulgaris grown in the Atlantic Rainforest Region of São Paulo, Brazil / Análise genética de isolados de Rhizoctonia solani de Phaseolus vulgaris da região da Mata Atlântica de São Paulo, Brasil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A diversidade genética de 18 isolados de Rhizoctonia solani de feijoeiro (Phaseolus vulgaris) cultivado na Mata Atlântica de São Paulo, Brasil foi avaliada através da análise do espaçadores transcritos internos (ITS), microssatélites e iniciadores ("primers") específicos para sequências teloméricas. [...] A análise de restrição da região ribossomal ITS1/5,8S/ITS2 produziu um padrão de bandas específico para o grupo de anastomose 4 (GA 4) e seus subgrupos. O padrão obtido com ITS/RFLP, microsatélites e os iniciadores teloméricos permitiram identificar cinco a 11 genótipos entre os isolados de R. solani. Enquanto todos os isolados foram patogênicos em feijoeiro, não houve correlação entre patogenicidade e diferenças genotípicas. Os diferentes iniciadores para PCR revelaram que muitos isolados são geneticamente similares, análise esta que pode ser confirmada por mais de um conjunto de iniciadores, fortalecendo a relação deste agrupamento. Abstract in english Rhizoctonia solani isolates obtained from common beans (Phaseolus vulgaris) grown in the mountainous Atlantic Rainforest (Mata Atlântica) region of São Paulo, Brazil, were analyzed to determine their genetic diversity using internal transcribed spacer (ITS), microsatellite and telomere sequence-base [...] d PCR primers. Restriction digestion of the ITS1/5.8S/ITS2 ribosomal regions yielded unique banding patterns specific for AG4 and its subgroups. The ITS restriction digestion (ITS/RFLP), telomere and microsatellite primers identified five to 11 genotypes within the isolates of R. solani. While all isolates were pathogenic on beans, there was no correlation found between genotypic differences and pathogenicity. The different PCR primers revealed a number of isolates that were genetically similar. Some of these genetic groups were supported by more than one of the primers utilized in this study, thus confirming their relationship.

LYNDEL W., MEINHARDT; NELSON A., WULFF; CLÁUDIA M., BELLATO; SIU M., TSAI.

2002-06-01

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Genetic analyses of Rhizoctonia solani isolates from Phaseolus vulgaris grown in the Atlantic Rainforest Region of São Paulo, Brazil Análise genética de isolados de Rhizoctonia solani de Phaseolus vulgaris da região da Mata Atlântica de São Paulo, Brasil  

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Full Text Available Rhizoctonia solani isolates obtained from common beans (Phaseolus vulgaris grown in the mountainous Atlantic Rainforest (Mata Atlântica region of São Paulo, Brazil, were analyzed to determine their genetic diversity using internal transcribed spacer (ITS, microsatellite and telomere sequence-based PCR primers. Restriction digestion of the ITS1/5.8S/ITS2 ribosomal regions yielded unique banding patterns specific for AG4 and its subgroups. The ITS restriction digestion (ITS/RFLP, telomere and microsatellite primers identified five to 11 genotypes within the isolates of R. solani. While all isolates were pathogenic on beans, there was no correlation found between genotypic differences and pathogenicity. The different PCR primers revealed a number of isolates that were genetically similar. Some of these genetic groups were supported by more than one of the primers utilized in this study, thus confirming their relationship.A diversidade genética de 18 isolados de Rhizoctonia solani de feijoeiro (Phaseolus vulgaris cultivado na Mata Atlântica de São Paulo, Brasil foi avaliada através da análise do espaçadores transcritos internos (ITS, microssatélites e iniciadores ("primers" específicos para sequências teloméricas. A análise de restrição da região ribossomal ITS1/5,8S/ITS2 produziu um padrão de bandas específico para o grupo de anastomose 4 (GA 4 e seus subgrupos. O padrão obtido com ITS/RFLP, microsatélites e os iniciadores teloméricos permitiram identificar cinco a 11 genótipos entre os isolados de R. solani. Enquanto todos os isolados foram patogênicos em feijoeiro, não houve correlação entre patogenicidade e diferenças genotípicas. Os diferentes iniciadores para PCR revelaram que muitos isolados são geneticamente similares, análise esta que pode ser confirmada por mais de um conjunto de iniciadores, fortalecendo a relação deste agrupamento.

LYNDEL W. MEINHARDT

2002-06-01

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Silicon potentiates the activities of defense enzymes in the leaf sheaths of rice plants infected by Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available This study aimed to assess the ability of silicon (Si) to potentiate defense enzyme activities in rice leaf sheaths and thus reduce sheath blight, caused by Rhizoctonia solani, development. Rice plants of BR-Irga 409 and Labelle cultivars were grown in a hydroponic solution containing 0 (-Si) or 2 m [...] M (+Si) Si and inoculated with R. solani. Silicon concentration in the leaf sheaths was significantly higher in the +Si plants than the -Si plants by 727% for BR-Irga 409 and 714% for Labelle. The area under relative lesion expansion progress curve was significantly lower for +Si plants than -Si plants, by 34.2% for BR-Irga 409 and 30.59% for Labelle. Increases in the activities of phenylalanine ammonia-lyases, peroxidases, polyphenoloxidases and chitinases in the leaf sheaths of plants supplied with Si, especially of those from BR-Irga 409, led to reduced progress of sheath blight lesions.

Daniel A., Schurt; Maria F. A., Cruz; Kelly J. T., Nascimento; Marta C. C., Filippi; Fabrício A., Rodrigues.

2014-12-01

65

Dried powders of velvetbean and pine bark added to soil reduce Rhizoctonia solani-induced disease on soybean Pós secos de mucuna e casca de pinus adicionados ao solo reduzem a doença causada por Rhizoctonia solani em soja  

Directory of Open Access Journals (Sweden)

Full Text Available Diseases induced by Rhizoctonia solani, like damping-off and root and stem rot on soybean (Glycine max, are a serious problem around the world. The addition of some organic material to soil is an alternative control for these diseases. In this study, benzaldehyde and dried powders of kudzu (Pueraria lobata, velvetbean or mucuna (Mucuna deeringiana, and pine bark (Pinus spp. were used in an attempt to improve soybean plant growth and to reduce the disease R. solani (AG-4 causes on soybean. Benzaldehyde (0.1-0.4 mL/kg of soil and velvetbean (25-100 g/kg significantly (P As doenças em soja (Glycine max causadas por Rhizoctonia solani são um sério problema ao redor do mundo. A incorporação ao solo de resíduos orgânicos é uma alternativa para o controle destas doenças. Neste estudo, benzaldeido e pós-secos de kudzu (Pueraria lobata, mucuna (Mucuna deeringiana e casca de pinus (Pinus spp. foram usados com o objetivo de melhorar o crescimento de plantas de soja e de diminuir a doença causada por R. solani (AG-4. Benzaldehyde (0,1-0,4 mL/kg de solo e mucuna (25-100 g/kg reduziram significativamente (P < 0.05 o crescimento micelial de R. solani em experimentos de laboratório. Em experimentos conduzidos em casa de vegetação a porcentagem de plantas sobreviventes foi maior em solo com casca de pinus e mucuna (50-100 g/kg. Em solo tratado com kudzu (r²=0,91 ou mucuna (r²=0,94, houve tendência significativa em aumentar a massa fresca das plantas de soja. Em microparcelas de campo solos com mucuna (r²=0,85 ou com casca de pinus (r²=0,61 reduziram significativamente a quantidade de doença. A quantidade de Bacillus megaterium (r²=0,87 e Trichoderma hamatum (r²=0,92 e a hidrólise de diacetato fluoresceina (r²=0,91 foram maiores em solo com doses crescentes de mucuna, indicando uma maior atividade microbiana. Neste estudo conclui-se que pós-secos de mucuna e casca de pinus, incorporados ao solo, podem reduzir a doença causada por R. solani em soja.

Luiz E. B. Blum

2006-06-01

66

Genetic Variability in Rhizoctonia solani Isolated from Vitis vinifera Based on Amplified Fragment Length Polymorphism  

OpenAIRE

Problem statement: Rhizoctonia solani is a potential grapevine pathogen. In order to develop effective methods of control, it is necessary to document its genetic diversity. Approach: The objective of this study was to analyze the genetic variability of R. solani isolated from the rhizosphere of ungrafted V. vinifera var. perlette seedless planted in Sonora, Mexico using Amplified Fragment Length Polymorphism (AFLP). Results: In the selective amplification using eight primer combinations we o...

Amparo Meza-Moller; Martin Esqueda; Felipe Sanchez-Teyer; Georgina Vargas-Rosales; Gardea, Alfonso A.; Martin Tiznado-Hernandez

2011-01-01

67

A gene for plant protection: expression of a bean polygalacturonase inhibitor in tobacco confers a strong resistance against Rhizoctonia solani and two oomycetes  

OpenAIRE

We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance.

Borras-hidalgo, Orlando; Caprari, Claudio; Hernandez-estevez, Ingrid; Lorenzo, Giulia; Cervone, Felice

2012-01-01

68

A gene for plant protection: expression of a bean polygalacturonase inhibitor in tobacco confers a strong resistance against Rhizoctonia solani and two oomycetes.  

Science.gov (United States)

We have tested whether a gene encoding a polygalacturonase-inhibiting protein (PGIP) protects tobacco against a fungal pathogen (Rhizoctonia solani) and two oomycetes (Phytophthora parasitica var. nicotianae and Peronospora hyoscyami f. sp. tabacina). The trials were performed in greenhouse conditions for R. solani and P. parasitica and in the field for P. hyoscyami. Our results show that expression of PGIP is a powerful way of engineering a broad-spectrum disease resistance. PMID:23264779

Borras-Hidalgo, Orlando; Caprari, Claudio; Hernandez-Estevez, Ingrid; Lorenzo, Giulia De; Cervone, Felice

2012-01-01

69

Rhizoctonia solani Kühn aislado de papa (Solanum tuberosum L.): En los estados Táchira, Mérida, Trujillo y Lara. I. Caracterización cultural / Rhizoctonia solani Kühn isolated from potato (Solanum tuberosum L.): in Táchira, Mérida, Trujillo and Lara States, Venezuela. I. Cultural characterization  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish La papa es uno de los rubros más importantes en la economía de Venezuela. Este cultivo se ve afectado por diferentes patógenos, uno de ellos es el hongo Rhizoctonia solani, que ocasiona la rizoctoniosis, enfermedad que está ampliamente distribuida en el país y es la causa de pérdidas económicas cons [...] iderables. Con la finalidad de comparar las poblaciones del hongo en Venezuela, se llevó a cabo el trabajo; para ello se colectaron muestras en diferentes zonas productoras de papa de los estados Táchira, Mérida, Trujillo, y Lara. El patógeno fue caracterizado culturalmente mediante el estudio de su condición nuclear y determinación del grupo de anastomosis (AG), así como la evaluación del desarrollo micelial, número y diámetro de esclerocios, a 10, 20 y 30 °C. Se encontraron diferencias significativas (P?0,01) en cuanto a las características culturales de las cepas evaluadas, las cuales mostraron mejor comportamiento en su desarrollo a 20 °C; se determinó que 97,5 % de las cepas fueron AG-3 y 2,5 % AG-2.1. Los resultados indicaron diferencias culturales entre las poblaciones de R. solani analizadas lo que puede estar asociado con el comportamiento de la enfermedad en las diferentes localidades. Abstract in english Potato is one of the most important crops in Venezuelan economy. This crop is affected by different pathogens, one of which is the fungus Rhizoctonia solani, the inducer of rhizoctonia disease; which is widely distributed and is the cause of considerable economic losses. In order to know phenotypic [...] variation among fungus populations, this research was carried out with samples collected at different potato producing areas of Táchira, Merida, Trujillo, and Lara States. The pathogen was culturally characterized by the study and determination of its nuclear condition, anastomosis group (AG), as well as colony growth, and number and diameter of sclerotia at 10, 20 and 30 °C. Significant differences (P?0.01) were found among strains with regard to the cultural characteristics; in general, strains showed better behavior of their development at 20 °C; 97.5 % of the strains were found to be AG-3 and the other 2.5 %, AG-2.1. Results indicated differences in cultural characteristics among the R. solani populations, which may be associated with disease behavior at the different localities.

Yoleidy, Escalona; Dorian, Rodríguez; Alexander, Hernández.

2011-12-01

70

Trichoderma harzianum strain SQR-T37 and its bio-organic fertilizer could control Rhizoctonia solani damping-off disease in cucumber seedlings mainly by the mycoparasitism.  

Science.gov (United States)

Damping-off disease is caused by Rhizoctonia solani and leads to serious loss in many crops. Biological control is an efficient and environmentally friendly way to prevent damping-off disease. Optical micrographs, scanning electron micrographs, and the determination of hydrolytic enzymes were used to investigate the antagonism of Trichoderma harzianum SQR-T37 (SQR-T37) against R. solani. Experiments were performed in pots to assess the in vivo disease-control efficiency of SQR-T37 and bio-organic fertilizer. The results indicate that the mycoparasitism was the main mechanism accounting for the antagonistic activity of SQR-T37. In one experiment, the population of R. solani was decreased from 10(6) internal transcribed spacer (ITS) copies per gram soil to 10(4) ITS copies per gram soil by the presence of the antagonist. In this experiment, 45% of the control efficiency was obtained when 8 g of SQR-T37 hyphae per gram soil was applied. In a second experiment, as much as 81.82% of the control efficiency was obtained when bio-organic fertilizer (SQR-T37 fermented organic fertilizer, BIO) was applied compared to only 27.27% of the control efficiency when only 4 g of SQR-T37 hyphae per gram soil was applied. Twenty days after incubation, the population of T. harzianum was 4.12 × 10(7) ITS copies per gram soil in the BIO treatment, which was much higher than that in the previous treatment (8.77 × 10(5) ITS copies per gram soil), where only SQR-T37 was applied. The results indicated that SQR-T37 was a potent antagonist against R. solani in a mycoparasitic way that decreased the population of the pathogen. Applying BIO was more efficient than SQR-T37 application alone because it stabilized the population of the antagonist. PMID:21484203

Huang, Xinqi; Chen, Lihua; Ran, Wei; Shen, Qirong; Yang, Xingming

2011-08-01

71

Estudio de Rhizoctonia solani Kühn aislado de papa (Solanum tuberosum L.) en los estados Táchira, Mérida, Trujillo y Lara: II. virulencia y caracterización molecular / Rhizoctonia solani Kühn isolated from potato in various Venezuelan states: II. Virulence and molecular characterization  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish Rhizoctonia solani ocasiona la enfermedad conocida como rizoctoniosis en el cultivo de la papa y constituye un serio problema en Venezuela. En el país se han identificado los grupos anastomósicos presentes y se ha realizado la caracterización cultural del hongo pero no la molecular ni la de virulenc [...] ia, por lo que estos objetivos fueron planteados en el presente trabajo. Se utilizaron cuarenta aislamientos obtenidos de los estados Táchira, Mérida, Trujillo y Lara. Se utilizaron las técnicas de RAPD, UPR e ITS para la caracterización molecular, y pruebas de patogenicidad en papa ‘Kennebec’ para determinar la virulencia. Con las tres técnicas moleculares se observaron variaciones genéticas entre las cepas del hongo y se confirmó la presencia de AG-3 y AG-2.1 de R. solani. Las cepas mostraron diferencias significativas en la virulencia, la cual estuvo influenciada por la temperatura. Abstract in english Rhizoctonia solani causes the disease known as rizoctoniosis in potato and it is a serious problem in Venezuela. Anastomosis groups and cultural characterization have been determined in the country, but neither molecular nor virulence characterization. Therefore, the research focused on those two ob [...] jectives. Forty isolates from Táchira, Merida, Trujillo and Lara States were used on which RAPD, UPR and ITS techniques were performed; also, pathogenicity tests were run on ‘Kennebec’ potato plants. Genetic variability among isolates was observed with all three molecular techniques and presence of AG-3 and AG-2.1 was confirmed. Isolates showed significant difference with regard to virulence, which was influenced by temperature.

Yoleidy, Escalona; Dorian, Rodríguez; Alexander, Hernández.

2012-04-01

72

Efeito do silicato de cálcio e da autoclavagem na supressividade e na conducividade de dois solos à Rhizoctonia solani / Influence of calcium silicate and sterilization on the natural suppressiveness and on the conduciveness of two soils to Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Objetivou-se verificar o efeito da aplicação de silicato de cálcio e da esterilização na supressividade natural de um Latossolo Vermelho-Escuro (LEa) álico textura muito argilosa e na conducividade natural de uma Terra Roxa Estruturada eutrófica (TRe) ao fungo Rhizoctonia solani, em condições de cas [...] a de vegetação. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 2 x 3 x 2. Os fatores foram: duas classes de solo (LEa e TRe - 0-20 cm); três tratamentos (esterilização ou não por autoclavagem, aplicação de silicato e testemunha) e infestação ou não com R. solani, com três repetições e 16 plântulas de feijoeiro por parcela. A aplicação de silicato foi feita incorporando 0,63 g do produto em 1 kg de cada material de solo, seguido de incubação por 30 dias. Para promover a infestação artificial, foram colocados 800 mg de inóculo em 1 kg de cada material de solo. O silicato de cálcio aumentou os teores de Ca trocável e a soma de bases nos dois solos. Um decréscimo na saturação por Al de 70 para 19% e um aumento na saturação por bases de 9 para 21% alteraram significativamente a supressividade natural do LEa à R. solani. Com relação à TRe, a aplicação de silicato não teve nenhum efeito na sua conducividade, dado ao seu natural caráter eutrófico, o qual já é favorável ao desenvolvimento deste fungo. A esterilização não influiu no desenvolvimento de R. solani, o que sugere que os fatores abióticos foram os responsáveis pela supressividade ou conducividade desses solos. Abstract in english The effect of calcium silicate slag and soil sterilization on the natural suppressiveness of a Typic Acrustox (clay Dark Red Latosol -- LEa) and the natural conduciveness of an Oxic Haplustoll (TRe) to Rhizoctonia solani were studied under greenhouse conditions. The experimental design was a three-r [...] eplicate completely randomized one, with 2 x 3 x 2 factorial combination of the following treatments: two soil kinds (LEa and TRe, collected at 0-20 cm layer); three treatments with and without soil sterilization, calcium silicate slag and nontreated control; and uninfested and infested with R. solani. Each soil material was infested previously with 800 mg of the inoculum per kg soil. Application of silicate was done mixing 0,63 g of this product with 1 kg each soil material and incubated for 30 days. The application ofsilicate increased the exchangeable Ca2+ and bases amount in both soils. The decrease in the aluminum saturation level from 70 to 19% and the increase in base saturation from 9 to 21% altered significantly the natural suppressiveness of LEa to R. solani. Application of silicate to the TRe had no effect on its conduciveness, for its natural eutrophic character, which is benefic to R. solani development. Sterilization by autoclavation did not influence disease development on bean by R. solani. This suggests that possibly other abiotic factors were responsible for either suppressiveness or conduciveness of these soils.

Fabrício de Ávila, Rodrigues; Gilberto Fernandes, Corrêa; Gaspar Henrique, Korndörfer; Maria Amelia dos, Santos; Lawrence Elliot, Datnoff.

1367-13-01

73

Solarização do solo em casa-de-vegetação e campo para o controle de Rhizoctonia solani AG-4 / Soil solarization under greenhouse and field conditions to the control of Rhizoctonia solani AG-4  

Scientific Electronic Library Online (English)

Full Text Available Os cultivos em ambientes protegidos apresentaram uma grande expansão na década de 1990 no Brasil. O solo desses locais pode, por ser intensa e sucessivamente cultivado, se tornar infestado por patógenos como Rhizoctonia solani, responsável por tombamento e podridão de raízes em muitas espécies de pl [...] antas. O presente trabalho avaliou o emprego da solarização, dentro e fora de uma casa-de-vegetação vedada com plástico transparente, para o controle de R. solani. Quatro experimentos foram realizados, dois no verão de 1997/1998 e outros dois no verão seguinte, 1998/1999, em Piracicaba, SP (latitude 22º 42' e longitude 47º 38'). Bolsas de náilon contendo solo autoclavado misturado a grãos de trigo colonizados com R. solani AG-4 foram enterradas a 10 e a 20 cm de profundidade em parcelas solarizadas e não solarizadas, dentro e fora da casa-de-vegetação, sendo coletadas após 20, 30 e 40 dias para os dois primeiros experimentos e 15, 30 e 45 dias para o terceiro e quarto. Avaliou-se a viabilidade do patógeno após a recuperação dos grãos dos solos, por meio do plaqueamento destes em ágar-água, contando-se, dois dias depois, sob microscópio estereoscópio, os que apresentaram crescimento micelial característico de R. solani. Foi obtida a erradicação do patógeno após 20 e 30 dias de solarização na casa de vegetação e após 30 a 45 dias no campo, provavelmente porque houve menor perda de calor durante a noite no ambiente protegido, pois as temperaturas médias (40 a 45 º C, dependendo do experimento) e máxima (49º C) dos solos solarizados às 15:00 horas, a 10 cm de profundidade, foram semelhantes nos dois ambientes. Nas parcelas não solarizadas da casa-de-vegetação o patógeno também perdeu a viabilidade, porém mais lentamente (40 dias de tratamento para sua erradicação) que nas parcelas solarizadas. Abstract in english Crops grown under protected environment have had a great expansion in Brazil in the decade of 1990. In such environments soil is intensively and successively used and it may become infested with soilborne plant pathogens, such as Rhizoctonia solani, responsible for seedling damping-off and root rots [...] of several plant species. In the present work soil solarization was used to the control of R. solani under greenhouse and field conditions. Four experiments were carried out, two in the summer of 1997/1998 and the other two in 1998/1999 in Piracicaba city, São Paulo state, Brazil (latitude 22º 42' and longitude 47º 38'). Nylon bags containing disinfested soil with propagules of R. solani AG4 (wheat grains previously colonized with the pathogen) were buried at 10 and 20 cm soil depth in solarized and non-solarized plots. After 20, 30, and 40 days in the two first experiments and 15, 30, and 45 days in the third and fourth experiments, the bags were removed from the soil. The grains were collected from the soil of each bag and placed in water-agar Petri dishes. After two days of incubation, grains showing typical growth of R. solani mycelium were assessed. Eradication of R. solani was accomplished after 20 to 30 days of soil solarization inside the greenhouse and after 30 to 45 days in the field, probably because in the protected environment the heat loss was smaller at night, since at 15:00 h the soil temperatures were similar in the solarized soils of both environments; with maximum of 49º C and medium temperatures between 40 and 45 º C, at 10 cm soil depth. In the non-solarized soil of the greenhouse the pathogen also lost its viability, although more slowly (40 days of treatment) than in the solarized plots.

Flávia Rodrigues Alves, Patrício; Hiroshi, Kimati; João, Tessarioli Neto; Ademir, Petenatti; Benedito Camargo, Barros.

2007-09-01

74

Efeito do silicato de cálcio e da autoclavagem na supressividade e na conducividade de dois solos à Rhizoctonia solani Influence of calcium silicate and sterilization on the natural suppressiveness and on the conduciveness of two soils to Rhizoctonia solani  

Directory of Open Access Journals (Sweden)

Full Text Available Objetivou-se verificar o efeito da aplicação de silicato de cálcio e da esterilização na supressividade natural de um Latossolo Vermelho-Escuro (LEa álico textura muito argilosa e na conducividade natural de uma Terra Roxa Estruturada eutrófica (TRe ao fungo Rhizoctonia solani, em condições de casa de vegetação. Utilizou-se o delineamento inteiramente casualizado em esquema fatorial 2 x 3 x 2. Os fatores foram: duas classes de solo (LEa e TRe - 0-20 cm; três tratamentos (esterilização ou não por autoclavagem, aplicação de silicato e testemunha e infestação ou não com R. solani, com três repetições e 16 plântulas de feijoeiro por parcela. A aplicação de silicato foi feita incorporando 0,63 g do produto em 1 kg de cada material de solo, seguido de incubação por 30 dias. Para promover a infestação artificial, foram colocados 800 mg de inóculo em 1 kg de cada material de solo. O silicato de cálcio aumentou os teores de Ca trocável e a soma de bases nos dois solos. Um decréscimo na saturação por Al de 70 para 19% e um aumento na saturação por bases de 9 para 21% alteraram significativamente a supressividade natural do LEa à R. solani. Com relação à TRe, a aplicação de silicato não teve nenhum efeito na sua conducividade, dado ao seu natural caráter eutrófico, o qual já é favorável ao desenvolvimento deste fungo. A esterilização não influiu no desenvolvimento de R. solani, o que sugere que os fatores abióticos foram os responsáveis pela supressividade ou conducividade desses solos.The effect of calcium silicate slag and soil sterilization on the natural suppressiveness of a Typic Acrustox (clay Dark Red Latosol -- LEa and the natural conduciveness of an Oxic Haplustoll (TRe to Rhizoctonia solani were studied under greenhouse conditions. The experimental design was a three-replicate completely randomized one, with 2 x 3 x 2 factorial combination of the following treatments: two soil kinds (LEa and TRe, collected at 0-20 cm layer; three treatments with and without soil sterilization, calcium silicate slag and nontreated control; and uninfested and infested with R. solani. Each soil material was infested previously with 800 mg of the inoculum per kg soil. Application of silicate was done mixing 0,63 g of this product with 1 kg each soil material and incubated for 30 days. The application ofsilicate increased the exchangeable Ca2+ and bases amount in both soils. The decrease in the aluminum saturation level from 70 to 19% and the increase in base saturation from 9 to 21% altered significantly the natural suppressiveness of LEa to R. solani. Application of silicate to the TRe had no effect on its conduciveness, for its natural eutrophic character, which is benefic to R. solani development. Sterilization by autoclavation did not influence disease development on bean by R. solani. This suggests that possibly other abiotic factors were responsible for either suppressiveness or conduciveness of these soils.

Fabrício de Ávila Rodrigues

1999-08-01

75

Micoflora asociada a dos sustratos orgánicos y su efecto en el control de Rhizoctonia solani Kühn / Mycoflora of two organic substrates and its effect on the control of Rhizoctonia solani Kühn  

Scientific Electronic Library Online (English)

Full Text Available Los abonos orgánicos se vienen utilizando como ente supresor de enfermedades de la raíz de la planta, debido a la gran cantidad de microorganismos que interactúan en ellos, lo que ha llevado a considerarlos como parte de las estrategias de control biológico. En este contexto, se evaluó la diversidad [...] de la micoflora de dos sustratos orgánicos (suelo orgánico y lombricompuesto) y su efecto sobre el control del hongo Rhizoctonia solani. La diversidad de la micoflora de los sustratos se determinó a través del método de dilución de placas de Warcup, que permitió contar el número de colonias e identificar los hongos. Los aislamientos más abundantes de cada sustrato fueron seleccionados para realizar cultivos duales con Rhizoctonia solani. Se encontraron 16 aislamientos de hongos pertenecientes a tres ordenes y ocho géneros, incluyendo (Penicillium sp., Aspergillus sp., Fusarium sp. y Trichoderma harzianum Rifai). En el lombricompuesto se encontró una micoflora significativamente más abundante (P?0,05) que en el suelo orgánico. En los cultivos duales, T. harzianum presentó un porcentaje de inhibición de R. solani significativamente superior (P?0,05) al del resto de los hongos. Con la incorporación del lombricompuesto no se introdujeron nuevos hongos, pero sí se incrementaron las poblaciones existentes en la micoflora nativa. T. harzianum resultó ser el hongo de mayor crecimiento y mayor porcentaje de inhibición, lo que sugiere que es un controlador biológico de R. solani, y que es factible incorporarlo al suelo durante la preparación del mismo. Abstract in english The use of organic manures for root disease control, which results from the remarkable diversity of microorganisms that interact there, has led to consider them as part of biological control strategies. In this context, we evaluated the mycological diversity of two organic substrates, (organic soil [...] and vermicompost) and their effect on the control of the fungus Rhizoctonia solani. The mycoflora of the two organic substrates was assessed through Warcup's soil plate method, which allowed identifying the fungi and counting the number of colonies. The most abundant isolates were grown against R. solani in dual cultures. The results allowed identifying 16 isolates belonging to three orders and eight genera of fungi, including Penicillium sp., Aspergillus sp., Fusarium sp. and Trichoderma harzianum Rifai. A significantly more abundant mycoflora (P?0.05) was found in the vermicompost substrate. In the dual cultures, T. harzianum attained a higher pathogen inhibition percentage (P?0.05) than the other fungi. The vermicompost substrate did not determine the growth of new fungi, but enhanced the development of the pre-existing native ones. Not only having shown the best results in controlling R. solani, but also the most vigorous growth among the identified fungi, T. harzianum comes up as a promissory biological controller of the pathogen, that can be incorporated to the soil during its preparation.

Clemencia, Guédez; Luis Miguel, Cañizalez; Carmen, Castillo; Rafael, Olivar.

2009-12-01

76

Essential oil of mustard to control Rhizoctonia solani causing seedling damping off and seedling blight in nursery Utilização de óleo essencial de mostarda no controle de tombamento e requeima causadas por Rhizoctonia solani em viveiro  

Directory of Open Access Journals (Sweden)

Full Text Available The essential oil extracted from mustard (Brassica rapa seeds was evaluated for its effect on suppression of Rhizoctonia solani growth in vitro, and in field soils, for reducing saprophytic substrate colonization and seedling damping off and blight using snap beans as indicator plant, the in vitro growth was completely inhibited at a concentration of 50 mul/l. The saprophytic substrate colonization in soils 24 h after treatment was drastically reduced to 45% at 150 mul/kg soil concentration, in contrast to 100% colonization at concentrations of 0, 50, or 75 mul/kg. This recovery rate gradually declined to 6% and 60%, respectively, in nine days. A control of pre and post-emergence seedling damping off and blight in common beans (Phaseolus vulgaris, without any apparent phytotoxic effect was achieved by irrigating R. solani infested soils with water containing the emulsified essential oil to provide 150 mul/l soil volume ten days prior to planting, gave over 95%. The effect of the mustard essential oil was not influenced by the physical soil texture, and it appears to be a good substitute for methyl bromide fumigation in nurseries for seedling production.Foi avaliado o efeito do óleo essencial extraído de sementes de mostarda (Brassica rapa na supressão do crescimento in vitro de Rhizoctonia solani, na redução da colonização saprofítica no solo, e no tombamento e requeima de plântulas, utilizando feijão-vagem (Phaseolus vulgaris como planta indicadora. O crescimento in vitro de R. solani foi completamente inibido na concentração de 50 mil/l. A colonização saprofítica do substrato foi drasticamente reduzida para 45% na concentração de 150 mil/kg, 24 h após o tratamento. Nas concentrações de 0, 50 e 75 mil/kg de solo houve 100% de colonização do substrato. Esta taxa de recuperação diminuiu gradualmente para 6% e 60%, respectivamente, em nove dias. A irrigação de solos infestados por R. solani com água contendo o óleo essencial emulsificado para fornecer 150 mil/l de solo, dez dias antes do plantio, resultou em 95% de controle do tombamento e requeima em mudas de feijão-vagem, sem qualquer efeito aparente de fitotoxidez. O efeito do óleo essencial não foi influenciado pela textura do solo e parece ser um bom substituto para o fumigante brometo de metila em viveiros.

Onkar D. Dhingra

2004-12-01

77

Essential oil of mustard to control Rhizoctonia solani causing seedling damping off and seedling blight in nursery / Utilização de óleo essencial de mostarda no controle de tombamento e requeima causadas por Rhizoctonia solani em viveiro  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foi avaliado o efeito do óleo essencial extraído de sementes de mostarda (Brassica rapa) na supressão do crescimento in vitro de Rhizoctonia solani, na redução da colonização saprofítica no solo, e no tombamento e requeima de plântulas, utilizando feijão-vagem (Phaseolus vulgaris) como planta indica [...] dora. O crescimento in vitro de R. solani foi completamente inibido na concentração de 50 mil/l. A colonização saprofítica do substrato foi drasticamente reduzida para 45% na concentração de 150 mil/kg, 24 h após o tratamento. Nas concentrações de 0, 50 e 75 mil/kg de solo houve 100% de colonização do substrato. Esta taxa de recuperação diminuiu gradualmente para 6% e 60%, respectivamente, em nove dias. A irrigação de solos infestados por R. solani com água contendo o óleo essencial emulsificado para fornecer 150 mil/l de solo, dez dias antes do plantio, resultou em 95% de controle do tombamento e requeima em mudas de feijão-vagem, sem qualquer efeito aparente de fitotoxidez. O efeito do óleo essencial não foi influenciado pela textura do solo e parece ser um bom substituto para o fumigante brometo de metila em viveiros. Abstract in english The essential oil extracted from mustard (Brassica rapa) seeds was evaluated for its effect on suppression of Rhizoctonia solani growth in vitro, and in field soils, for reducing saprophytic substrate colonization and seedling damping off and blight using snap beans as indicator plant, the in vitro [...] growth was completely inhibited at a concentration of 50 mul/l. The saprophytic substrate colonization in soils 24 h after treatment was drastically reduced to 45% at 150 mul/kg soil concentration, in contrast to 100% colonization at concentrations of 0, 50, or 75 mul/kg. This recovery rate gradually declined to 6% and 60%, respectively, in nine days. A control of pre and post-emergence seedling damping off and blight in common beans (Phaseolus vulgaris), without any apparent phytotoxic effect was achieved by irrigating R. solani infested soils with water containing the emulsified essential oil to provide 150 mul/l soil volume ten days prior to planting, gave over 95%. The effect of the mustard essential oil was not influenced by the physical soil texture, and it appears to be a good substitute for methyl bromide fumigation in nurseries for seedling production.

Onkar D., Dhingra; Maria L. N., Costa; Geraldo J., Silva, Jr.; Eduardo S. G., Mizubuti.

2004-12-01

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Biocontrol of Rhizoctonia solani damping-off disease in cucumber with Bacillus pumilus SQR-N43.  

Science.gov (United States)

Biological control is an efficient and environmentally friendly way to prevent damping-off disease. Micrographs were used to investigate the ability of Bacillus pumilus (B. pumilus) SQR-N43 to control Rhizoctonia solani (R. solani) Q1 in cucumbers. The root colonization ability of B. pumilus SQR-N43 was analyzed in vivo with a green fluorescent protein (GFP) tag. A pot experiment was performed to assess the in vivo disease-control efficiency of B. pumilus SQR-N43 and its bio-organic fertilizer. Results indicate that B. pumilus SQR-N43 induced hyphal deformation, enlargement of cytoplasmic vacuoles and cytoplasmic leakage in R. solani Q1 mycelia. A biofilm on the root surface was formed when the roots were inoculated with 10(7)-10(8)cells g(-1) of soil of GFP-tagged B. pumilus SQR-N43. In the pot experiment, the biocontrol reduced the concentration of R. solani. In contrast to applications of only B. pumilus SQR-N43 (N treatment), which produced control efficiencies of 23%, control efficiencies of 68% were obtained with applications of a fermented organic fertilizer inoculated with B. pumilus SQR-N43 (BIO treatment). After twenty days of incubation, significant differences in the number of CFUs and the percentage of spores of B. pumilus SQR-N43 were recorded between the N treatment (2.20×10(7)CFU g(-1) of soil and 79%, respectively) and the BIO treatment (1.67×10(8)CFU g(-1) of soil and 52%, respectively). The results indicate that B. pumilus SQR-N43 is a potent antagonist against R. solani Q1. The BIO treatment was more effective than the N treatment because it stabilized the population and increased the active form of the antagonist. PMID:21775112

Huang, Xinqi; Zhang, Nan; Yong, Xiaoyu; Yang, Xingming; Shen, Qirong

2012-03-20

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Interaction of Rhizoctonia solani and Rhizopus stolonifer Causing Root Rot of Sugar Beet  

Science.gov (United States)

In recent years, growers in Michigan and other sugar beet production areas of the United States have reported increasing incidence of root rot with little or no crown or foliar symptoms in sugar beet with Rhizoctonia crown and root rot. In addition, Rhizoctonia-resistant beets have been reported wit...

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INDUCED SUPPRESSIVENESS TO Rhizoctonia solani KÜHN BY THE ADDITION OF DIFFERENT VEGETABLE AMENDMENTS TO THE SOIL SUPRESSIVIDADE INDUZIDA A Rhizoctonia solani Kühn PELA ADIÇÃO DE DIFERENTES RESÍDUOS VEGETAIS AO SOLO  

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Organic matter of several origins is used in the agriculture to stimulate microbial activity and to limit the activity of plant pathogens. Its decomposition induces the activity of some microorganisms that are useful to other species establishing synergistic and antagonistic relationships that maintain the biological balance. The present work aimed to evaluate the effect of different vegetable amendments incorporated in the soil on the incidence of root-rot, caused by Rhizoctonia solani. In greenhouse, plastic trays containing 4 kg of cultivated soil were inoculated with 104 propagules of Rhizoctonia solani g-1 of soil and in each tray it was incorporated the equivalent of 10 t/ha plant of debris mater of the following species: Panicum miliaceum, Sorghum maximum, Dolichos lab-lab, Canavaria ensiformis, Braquiaria brizanta, Panicum maximum and Crotalaria juncea. The incorporation of the vegetable amendments were realized simultaneous by and the soil was maintained near field capacity for 60, 30 and 0 days, before the bean cultivar Pérola was sown. Symptom intensity was evaluated 15 days after the emergence, using a descriptive scale, varying from 0 to 8. After the completion of the experimental microbial population was estimated in the soil samples collected
from each plastic tray serial dilution test using selective culture media. Bacteria and fungi colonies were counted after a seven days incubation period and those of actinomycetes after ten days. Results showed that only vegetable materials incubated for 60 days were able to reduce disease index. No significant differences were observed among the studied plant species. The relationship among number of propagules of fungi, actinomycetes, and bacteria with the disease index revealed that the amendments with a larger induced microbial population in the soil were those that presented smaller disease index.

KEY-WORDS: Rhizoctonia root rot; biological control; soil microbial population.

A matéria orgânica de diversas origens é utilizada na agricultura visando, entre outras finalidades, a estimular a atividade microbiana para limitar a atividade dos patógenos do solo. Sua decomposição induz a atividade de alguns organismos, que se tornam úteis a outros tipos de vida, e estabelece relações sintróficas e antagônicas que mantêm o equilíbrio da comunidade biológica como um todo. O presente trabalho teve como objetivo avaliar o efeito da incorporação de diferentes restos vegetais na incidência de podridão radicular do feijoeiro, cujo agente causal é o fungo Rhizoctonia solani. Em casa-de-vegetação, foram utilizadas bandejas plásticas contendo 4 kg de solo cultivado, inoculado com 104 propágulos de Rhizoctonia solani g-1, ao qual foi incorporado o equivalente a 10 t/ha de matéria seca das seguintes origens: Panicum miliaceum, Sorghum maximum, Dolichos lab-lab, Canavaria ensiformis, Braquiaria brizanta, Panicum maximum e Crotalaria juncea. A incorporação do inóculo e dos resíduos vegetais no solo foi realizada simultaneamente. O solo, nas bandejas, foi mantido próximo da capacidade de campo por 60, 30 e 0 dias, antes de ser realizada a semeadura da cu

Wilson Mozena Leandro

2007-09-01

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Caracterización y evaluacion de virulencia en aislamientos de rhizoctonia solani kühn, causante de la mancha bandeada en maíz / Characterization and evaluation of virulence in rhizoctonia solani kühn isolates, causal agent of leaf banded spot on maize / Caracterização e avaliação de virulência em isolamentos de rhizoctonia solani kühn, causante da mancha bandeada no milho  

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Full Text Available SciELO Venezuela | Language: Spanish Abstract in portuguese Na Venezuela a mancha bandeada do milho, causada por Rhizoctonia solani Kühn, tem uma alta incidência e distribuição nas principais áreas de plantio de milho, causando diminuição do rendimento. Em 2004 foram conduzidos ensaios com o objetivo de caracterizar e avaliar a virulência de 25 isolamentos d [...] e R. solani. Para a caracterização se realizaram avaliações culturais, microscópicas e moleculares, estas últimas utilizando uma seqüência de amplificação específica da região espaçadora transcrita interna do DNA ribossomal (rDNA-ITS). Para a avaliação da virulência se realizaram provas de inoculação nas línhas de milho CML-254 e L-82201-22-1-1, tanto em laboratório, usando uma solução de cinetina (6- furfuril-amino-purina), como em estufa, inoculando plântulas. As provas de caracterização demonstraram que os isolamentos efetivamente correspondiam a R. solani, ainda quando houve diferenças na cor das colônias, crescimento micelial e tamanho de esclerócios, entre outras. A análise molecular demonstrou que os isolamentos pertencem ao grupo de anastomosis AG1-IA. Na prova de inoculação em laboratório os isolamentos G1SOM1 e P2TUR3 tiveram maior índice de virulência. Em estufa, os isolamentos mais virulentos foram B1TOR1, P2TUR6 e B2SAB1. A linha CML-254 mostrou o maior nível de resistência à enfermidade em ambas provas de virulência. Os resultados permitiram identificar e caracterizar isolamentos que podem ser utilizados em programas de melhoramento genético para a identificação de possíveis fontes de resistência e na avaliação do germoplasma melhorado. Abstract in spanish En Venezuela la mancha bandeada del maíz, causada por Rhizoctonia solani Kühn, tiene una alta incidencia y distribución en las principales zonas maiceras, causando disminución de los rendimientos. En 2004 se condujeron ensayos con el objetivo de caracterizar y evaluar la virulencia de 25 aislamiento [...] s de R. solani. Para la caracterización se realizaron evaluaciones culturales, microscópicas y moleculares, estas últimas utilizando una secuencia de amplificación específica de la transcrita región espaciadora interna del ADN ribosomal (rADN-ITS). Para la evaluación de la virulencia se realizaron pruebas de inoculación en las líneas de maíz CML-254 y L-82201-22-1-1, tanto en laboratorio, usando una solución de cinetina (6- furfuril-amino-purina), como en invernadero, inoculando plántulas. Las pruebas de caracterización demostraron que los aislamientos efectivamente correspondían a R. solani, aun cuando hubo diferencias en el color de las colonias, crecimiento micelial y tamaño de esclerocios, entre otras. El análisis molecular demostró que los aislamientos pertenecen al grupo de anastomosis AG1-IA. En la prueba de inoculación en laboratorio los aislamientos G1SOM1 y P2TUR3 tuvieron mayor índice de virulencia. En invernadero los aislamientos más virulentos fueron B1TOR1, P2TUR6 y B2SAB1. La línea CML-254 mostró el mayor nivel de resistencia a la enfermedad en ambas pruebas de virulencia. Los resultados permitieron identificar y caracterizar aislamientos que pueden ser utilizados en programas de mejoramiento genético para la identificación de posibles fuentes de resistencia y en la evaluación del germoplasma mejorado. Abstract in english In Venezuela, banded leaf spot caused by Rhizoctonia solani Kühn is a widely distributed disease in the most important maize growing areas, causing important yield losses. In 2004, experiments were conducted with the purpose of characterizing and evaluating the virulence of 25 isolates of R. solani. [...] Characterization tests were performed throughout cultural, microscopic, and molecular evaluations, the latter using a specific ribosomal internal transcribed spacer region (rADN-ITS). Virulence tests were performed on the maize inbred lines CML-254 y L-82201-22-1-1, both in the laboratory using KIN solution (6-furfurilaminopurine), and in a greenhouse inoculat

Rosaura, Perdomo; Alexander, Hernández; Alex, González; Juan, Pineda; Jesús, Alezones.

2007-01-01

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Efeito do silício nas concentrações de lignina e de açúcares em bainhas de folhas de arroz infectadas por Rhizoctonia solani / Effect of silicon on lignin and sugar concentrations of leaf sheaths in rice plants infected by Rhizoctonia solani  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A queima das bainhas, causada pelo fungo Rhizoctonia solani Kühn, é uma das mais importantes doenças que afetam a produção de arroz no mundo. Este trabalho teve como objetivo verificar o efeito do silício (Si) nas concentrações de lignina solúvel e insolúvel e de açúcares totais em bainhas de folhas [...] de arroz infectadas por R. solani. Plantas de arroz dos cultivares BR-Irga-409 e Labelle foram cultivadas em solução nutritiva sem (0 mM) ou com (2 mM) Si. A concentração de Si nas bainhas das folhas das plantas dos cultivares BR-Irga-409 e Labelle supridas com Si aumentou em 77% e 84%, respectivamente, em relação às plantas não supridas com Si. O comprimento relativo da lesão de queima das bainhas foi significativamente menor nas bainhas das plantas supridas com Si em relação às bainhas das plantas não supridas com esse elemento. Não houve efeito do Si e nem da inoculação com R. solani nas concentrações de mananas, galactanas, arabinanas, xilanas, glucanas e de açúcares totais nas bainhas das plantas dos dois cultivares. Para as plantas dos dois cultivares supridas com Si, a concentração de açúcares totais foi menor quando comparada com a dos dois cultivares na ausência de Si. Não houve variação na concentração de lignina insolúvel, solúvel e total entre os cultivares. As concentrações de lignina insolúvel e total foram maiores nas plantas supridas com Si, independentemente da inoculação com R. solani. Em conclusão, plantas de arroz supridas com Si foram mais resistentes à queima das bainhas devido a uma maior lignificação dos tecidos das bainhas e menor concentração de açúcares totais. Abstract in english Sheath blight, caused by the fungus Rhizoctonia solani Kühn, is the major disease affecting rice production worldwide. This study aimed to verify the effect of silicon (Si) on the concentrations of soluble and insoluble lignin and sugars in the leaf sheaths of rice plants infected by R. solani. Rice [...] plants from cultivars BR-Irga-409 and Labelle were grown in nutrient solution without or with Si (2 mM). As compared to plants non-supplied with Si, the Si concentration in leaf sheaths in cultivars BR-Irga-409 and Labelle supplied with Si increased by 77% and 84%, respectively. The relative lesion length of sheath blight was significantly lower in plants supplied with Si compared to non-supplied plants. There was no effect of Si or inoculation with R. solani on the concentrations of mannans, galactans, arabinans, xylans, glucans and sugars in the sheaths of plants from both cultivars. There was no variation in the concentrations of insoluble, soluble and total lignin between the cultivars. The concentrations of total and insoluble lignin were higher on plants supplied with Si regardless of inoculation with R. solani. In conclusion, the rice plants supplied with Si were more resistant to sheath blight due to an increase in the lignifications of the leaf sheath tissues and the lower concentration of total sugars.

Daniel Augusto, Schurt; Fabrício Ávila, Rodrigues; Jorge Luiz, Colodette; Vivian, Carré-Missio.

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Evaluación de aislamientos de Trichoderma spp. contra Rhizoctonia solani y Sclerotium rolfsii bajo condiciones in vitro y de invernadero / Evaluation of Trichoderma spp. isolates against Rhizoctonia solani and Sclerotium rolfsii under in vitro and greenhouse conditions  

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Full Text Available Se evaluó la eficacia biológica de ocho aislamientos de Trichoderma spp. provenientes de suelos de Colombia para el control de los agentes causales de volcamiento, Sclerotium rolfsii y Rhizoctonia solani, bajo condiciones in vitro y de invernadero. Los análisis in vitro mostraron la capacidad antagó [...] nica de todos los aislamientos evaluados. En condiciones de invernadero, cuatro aislamientos fueron altamente eficaces contra S. rolfsii en plantas de fríjol en semillero (>90% de reducción de la enfermedad) y dos aislamientos fueron eficaces contra R. solani en plantas de algodón en semillero (58 y 61% de reducción de la enfermedad). El análisis UP-PCR y DS-PCR permitió determinar tres grupos de aislamientos; dentro de estas asociaciones formadas no se encontró ninguna relación evidente entre la posición en el dendrograma y la actividad antagónica, pero sí permitió separar las especies de Trichoderma por grupos, e incluso encontrar diferencias dentro de aislamientos de una misma especie. Los resultados muestran que el comportamiento micoparasítico de los aislamientos de Trichoderma spp. varía según el hongo fitopatógeno, evidenciando una amplia especificidad del antagonista por su sustrato, es decir por el hongo atacado; por lo tanto es necesario realizar cuidadosas selecciones del aislamiento de Trichoderma que se utilice en programas de control de fitopatógenos. Abstract in english The biological effectiveness of eight isolates of Trichoderma spp. coming from Colombian soils was evaluated under in vitro and greenhouse conditions for the controlled causal agents of damping-off, Sclerotium rolfsii and Rhizoctonia solani. In vitro analysis showed the antagonistic capacity of all [...] evaluated isolates. Under greenhouse conditions, four isolates were highly effective against S. rolfsii in bean nursery plants (>90% of disease reduction) and two isolates were effective against R. solani in cotton nursery plants (58 and 61% of disease reduction). The analysis UP-PCR and DS-PCR permitted the determination of three groups of isolates. Within these associations no clear link between the position in the dendrogram and antagonistic activity was found, but it allowed separation of species of Trichoderma by groups and even within isolates of the same species. The results indicate that the mycoparasitic capacity of Trichoderma spp. varies according to the phytopathogen fungi, showing a broad specificity of the antagonist for its substrate that is attacked by the fungus. Therefore it is necessary to make careful selections of the isolates of Trichoderma to be used in pathogens control programs.

Liliana, Hoyos-Carvajal; Paola, Chaparro; Miriam, Abramsky; Ilan, Chet; Sergio, Orduz.

2008-12-01

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Encapsulamento de Trichoderma inhamatum para o controle biológico de Rhizoctonia solani na propagaç??o clonal de Eucalyptus  

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Full Text Available Testou-se um novo sistema para o encapsulamento de Trichoderma inhamatum em grânulos de alginato de sódio, visando o controle biológico de Rhizoctonia solani, agente etiológico da mela de estacas/miniestacas de Eucalyptus spp. para enraizamento. No novo sistema idealizado, foi utilizado um aparato simples capaz de substituir eficientemente o equipamento (Bomba Peristáltica anteriormente utilizado, sendo possível aumentar a produção de 594 grânulos/min para aproximadamente 6.734 grânulos/min. Com este novo sistema, um isolado de T. inhamatum (UFV - 03 foi encapsulado em grânulos contendo as fontes alimentares: farelo de trigo, palha de arroz, farelo de aveia, folhas de eucalipto ou farelo de milho na concentração de 50 g/l. Na segunda etapa, a melhor fonte alimentar foi testada nas concentrações de 0 a 60 g/l. Os grânulos foram veiculados em substrato de enraizamento de eucalipto na concentração de 2% (p/p inoculado com micélio triturado de R. solani (2 mg/g de substrato e a atividade saprofítica do patógeno foi quantificada por meio do método de iscas. Posteriormente, os grânulos produzidos com a fonte alimentar e concentração que promoveram maior inibição do desenvolvimento de R. solani foram utilizados para determinar o tempo mínimo de pré-incubação e competição para supressão do patógeno, com a mesma metodologia. Observou-se aumento da supressão da atividade saprofítica de R. solani ao acréscimo de uma fonte alimentar. Daquelas testadas, farelo de trigo foi a melhor. Além disso, houve interação significativa e positiva ao aumento de sua concentração na formulação.

Mafia Reginaldo G.

2003-01-01

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Expression of genes of Rhizoctonia solani and the biocontrol Stachybotrys elegans during mycoparasitism of hyphae and sclerotia.  

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Knowledge of mycoparasitism has been focused on how antagonists affect pathogens in relation to mechanisms, metabolites and gene expression. Just as microbial antagonists use a diverse arsenal of mechanisms to dominate interactions with hosts, hosts also have diverse responses to counteract antagonism. In this study differential gene expression of eight mycoparasitism-induced genes and eight host-response genes was monitored during in vivo interactions between the mycoparasite Stachybotrys elegans and hyphae and sclerotia of the host, Rhizoctonia solani over 5 d of interaction. Using real time reverse transcription polymerase chain reaction, comparative analyses demonstrated that hyphal and sclerotial structures triggered different expression patterns. These results indicated that multiple regulatory mechanisms might be involved. The high elevated expression of some genes belonging to the mycoparasite and the host suggest that these genes play an important role during the mycoparasitic process and host defense respectively. PMID:21193602

Chamoun, Rony; Jabaji, Suha

2011-01-01

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Controle de Rhizoctonia solani e Fusarium oxysporum f.sp. phaseoli por biopreparados de isolados de Trichoderma spp. / Rhizoctonia solani and Fusarium oxysporum f.sp. phaseoli control by biopreparation with Trichoderma spp. isolates  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os experimentos objetivaram avaliar em condições de casa de vegetação o biocontrole dos fitopatógenos Rhizoctonia solani (RS) e Fusarium oxysporum f.sp. phaseoli (FOP) em alface (Lactuca sativa L.) cultivar Regina, e feijão-vagem (Phaseolus vulgaris L.) cultivar Alessa, respectivamente, utilizando c [...] omo agentes antagonistas, 10 isolados de Trichoderma spp. selecionados em testes in vitro. Foram feitos biopreparados à base de arroz previamente colonizado por isolados de Trichoderma spp. e posteriormente triturados. Para a realização dos testes, os biopreparados foram inoculados previamente na proporção de 10(9) conídios.mL-1, em substrato comercial para produção de mudas. Após sete dias, os patógenos foram introduzidos separadamente em duas concentrações distintas: R. solani na proporção de 144 mg de meio de arroz por kg de substrato e F. oxysporum f.sp. phaseoli inoculado na forma de suspensão contendo 4,75 x 10(6) conídios.mL-1. Avaliou-se a influência dos biopreparados na % de damping-off de pós-emergência em plantas de alface e a severidade de murcha em plantas de feijão-vagem. O biopreparado referente ao isolado T-03 foi o mais eficiente no controle de R. solani em plantas de alface cultivar Regina, por ter reduzido a incidência de damping-off de pós-emergência nessa cultura. Por outro lado, nenhum dos biopreparados apresentou efeito antagonista satisfatório à F. oxysporum f.sp. phaseoli em plantas de feijão-vagem. Abstract in english The experiments aimed to evaluate under greenhouse conditions the biocontrol of plant pathogens Rhizoctonia solani (RS) and Fusarium oxysporum f.sp. phaseoli (FOP) in lettuce (Lactuca sativa L.) cultivar Regina and in common bean (Phaseolus vulgaris L.) cultivar Alessa, respectively, using as antago [...] nistic agents 10 Trichoderma spp. isolates selected from in vitro tests. Inoculants were prepared with rice previously colonized by Trichoderma spp. and subsequently ground. For the tests, the antagonists were previously inoculated at a ratio of 10(9) conidia mL-1 on commercial substrate for seedling production. Following seven days, the pathogens were separately introduced at two different concentrations: R. solani at a ratio of 144 mg rice medium per kg of substrate and F oxysporum f.sp. phaseoli inoculated as a suspension containing 4.75 x 10(6) conidia mL-1. The influence of antagonists on % post-emergence damping-off in lettuce and the severity of wilt in common beans were evaluated. The biopreparation with T-03 isolate was most effective in controlling R. solani in lettuce cultivar Regina, for having reduced the incidence of post-emergence damping-off in this culture. On the other hand, none of the biopreparations showed satisfactory antagonistic effect on F. oxysporum f.sp. phaseoli in common bean plants.

Pedro Paulo, Dias; Ricardo Luis Louro, Berbara; Maria do Carmo de Araújo, Fernandes.

2013-12-01

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Efecto diferencial de seis aislamientos de trichoderma sobre la severidad de Rhizoctonia solani, desarrollo radical y crecimiento de plantas de maíz Differential effect of six Trichoderma isolates on root development, plant growth and severity of Rhizoctonia solani on mayze  

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Full Text Available La mancha bandeada de la hoja en maíz, Rhizoctonia solani Kuhn, ha incrementado su incidencia en Venezuela y ocasiona considerables pérdidas en la producción. En muchos casos la microbiota del suelo sirve para proteger a la planta del ataque de patógenos y contribuye a su mayor desarrollo. Para estudiar medidas de biocontrol de R. solani se seleccionaron seis aislamientos de Trichoderma provenientes de la rizósfera de plantas de maíz colectadas en varias localidades de los estados Portuguesa y Yaracuy, las cuales fueron utilizadas en pruebas de antagonismo en vivero con un sustrato esterilizado. En el sustrato se hicieron dos hoyos y en ellos se colocaron dos granos de arroz esterilizados y 2 mL de solución de esporas del antagonista a 3-7x10(6 conidios·mL-1. Luego se colocó una semilla de maíz híbrido D2000 en cada hoyo y dos esclerocios de R. solani, se adicionaron 3 mL de la solución del antagonista y se cubrió con suelo esterilizado. Con relación a la sobrevivencia de plantas, hubo un efecto positivo en los tratamientos donde se utilizaron las cepas de Trichoderma, obteniéndose valores entre 70 y 90 %. En cuanto a la severidad de la enfermedad en la planta hasta los 60 días, se obtuvieron valores de 82,5 % en el testigo y 16,2 % en el mejor tratamiento con Trichoderma. Para un aislamiento proveniente de Píritu-estado Portuguesa se produjo el avance de la enfermedad fue el menor. Este aislamiento, seguido por el procedente de Yaritagua-estado Yaracuy, propiciaron un mayor crecimiento de la planta y mayor desarrollo radical.The banded leaf spot disease on maize, Rhizoctonia solani Kuhn, has increased its incidence in Venezuela, causing considerable damages and yield reduction. In many cases, soil microbiota can protect the plant from the pathogen attack and contributes to better plant development. In order to study forms of biocontrol of R. solani, six isolations of Trichoderma obtained from maize plant rizosphere were collected in several localities of Portuguesa and Yaracuy States; the isolations were used in antagonism tests on a sterilized substrate in nursery. Two orifices were made in the substrate and sterilized grains of rice were placed on them, covering with 2 mL of spore solution of the antagonist (3-7x10(6 conidia mL-1. Later, one maize of seed hybrid D2000 and two esclerotia of R. solani was placed in each hole and added 3 mL of the solution of the antagonist, covering with sterilized soil. In relation to plant survival, there was a positive effect of the treatments where Trichoderma was used, obtaining values between 70 and 90 %. As far as plant disease severity up to 60 days, it was obtained a value of 82.5 % in the control and 16.2 % in the best treatment with Trichoderma. For the isolation coming from Píritu-Portuguesa State, the advance of the disease was the smallest. This isolation, followed by the one coming from Yaritagua-Yaracuy State, promoted a greater plant growth and better root development.

Yuleidy López

2010-04-01

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Molecular identification of thirteen isolates of Trichoderma spp. and evaluation of their pathogenicity towards Rhizoctonia solani Kühn / Identificación molecular y evaluación patogénica de trece aislamientos de Trichoderma spp. frente a Rhizoctonia solani Kühn  

Scientific Electronic Library Online (English)

Full Text Available La incidencia de las enfermedades causadas por Rhizoctonia solani Kühn en las plantas aumenta cada año. Su control es fundamentalmente con productos químicos, en su mayoría muy tóxicos. Por tal razón, se investigan alternativas bioplaguicidas. Trichoderma spp. es uno de los hongos más utilizados par [...] a el control biológico de plagas, por sus propiedades y mecanismos de acción: competencia por el sustrato, antibiosis y micoparasitismo. Este trabajo tuvo como objetivos la identifi cación molecular y evaluación patogénica de 13 aislamientos del género Trichoderma frente a aislamientos de R. solani. Se evaluó su efecto antibiótico sobre aislamientos de 3 grupos de anastomosis de R. solani (AG-2.1, AG-5, AG-8) por el método de celofán. La identificación molecular partió de la secuenciación del espaciador interno del transcrito de la región del ADN ribosomal y del factor de elongación de la traducción EF1A. Más del 70 % de los aislamientos evaluados ejerció un efecto fungistático; mientras que el resto actuó como fungicida. La evaluación de la eficacia técnica en condiciones de campo corroboró estos resultados. A partir de la secuenciación y comparación de los datos de las secuencias depositadas en TrichoBLAST/GenBank, se comprobó que todos los aislamientos tenían el 100 % de identidad con la especie Trichoderma asperellum Samuels. Se seleccionaron los aislamientos 3, 13, 17, 75, 78, 85 y 90 como promisorios agentes de control biológico, por su alto potencial antibiótico y eficacia técnica en condiciones de campo. Abstract in english Disease caused by Rhizoctonia solani Kühn infestations has become a growing problem for commercially important crops. Although this fungus is usually controlled through the application of chemicals, the heavy ecological and financial toll of the latter has prompted for research on biopesticides as a [...] viable alternative. Trichoderma spp. is a well-known fungus often used for the biological control of crop pests, whose anti-fungal mechanisms include competition for the substrate, antibiosis and/or mycoparasitism. In the present work, we have used molecular techniques (sequencing of amplicons from the internal transcribed spacer of ribosomal DNA and the EF1A translation elongation factor) for the taxonomic identification of 13 Trichoderma spp. isolates in our collection, also evaluating their antibiotic effect on strains from three anastomosis groups of R. solani (AG-2.1, AG-5, AG-8) by the cellophane method. The sequences obtained from all isolates exhibited 100 % identity with deposited T. asperellum Samuels sequences in TrichoBLAST/GenBank, enabling their taxonomic assignment to this species. When analyzed by in vitro tests, over 70 % of the isolates exhibited a fungistatic effect towards R. solani, with the remaining strains exhibiting fungicidal activity; these results were later corroborated by technical efficacy tests under field conditions. Isolates 3, 13, 17, 75, 78, 85 and 90 were selected as potential biocontrol agents due to their high antibiotic activity and technical efficacy under field conditions.

Danay, Infante; Benedicto, Martínez; Belkis, Peteira; Yusimy, Reyes; Alfredo, Herrera.

2013-03-01

89

The impact of the pathogen Rhizoctonia solani and its beneficial counterpart Bacillus amyloliquefaciens on the indigenous lettuce microbiome  

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Full Text Available Lettuce belongs to the most commonly raw eaten food worldwide and its microbiome plays an important role for both human and plant health. Yet, little is known about the impact of potentially occurring pathogens and beneficial inoculants of the indigenous microorganisms associated with lettuce. To address this question we studied the impact of the phytopathogenic fungus Rhizoctonia solani and the biological control agent Bacillus amyloliquefaciens FZB42 on the indigenous rhizosphere and phyllosphere community of greenhouse-grown lettuce at two plant stages. The rhizosphere and phyllosphere gammaproteobacterial microbiomes of lettuce plants showed clear differences in their overall and core microbiome composition as well as in corresponding diversity indices. The rhizosphere was dominated by Xanthomonadaceae (48% and Pseudomonadaceae (37% with Rhodanobacter, Pseudoxanthomonas, Dokdonella, Luteimonas, Steroidobacter, Thermomonas as core inhabitants, while the dominating taxa associated to phyllosphere were Pseudomonadaceae (54%, Moraxellaceae (16% and Enterobacteriaceae (25% with Alkanindiges, Pantoea and a group of Enterobacteriaceae unclassified at genus level. The preferential occurrence of enterics in the phyllosphere was the most significant difference between both habitats. Additional enhancement of enterics on the phyllosphere was observed in bottom rot diseased lettuce plants, while Acinetobacter and Alkanindiges were identified as indicators of healthy plants. Interestingly, the microbial diversity was enhanced by treatment with both the pathogen, and the co-inoculated biological control agent. The highest impact and bacterial diversity was found by Rhizoctonia inoculation, but FZB42 lowered the impact of Rhizoctonia on the microbiome. This study shows that the indigenous microbiome shifts as a consequence to pathogen attack but FZB42 can compensate these effects, which supports their role as biocontrol agent and suggests a novel mode of action.

GabrieleBerg

2014-04-01

90

Potential for the integration of biological and chemical control of sheath blight disease caused by Rhizoctonia solani on rice.  

Science.gov (United States)

Biological control using antagonistic microbes to minimize the use of chemical pesticides has recently become more prevalent. In an attempt to find an integrated control system for sheath blight, caused by Rhizoctonia solani in rice, Streptomyces philanthi RM-1-138, commercial formulations of Bacillus subtilis as Larminar® and B. subtilis strain NSRS 89-24+MK-007 as Biobest® and chemical fungicides including carbendazim®, validamycin®, propiconazole® and mancozeb® were applied alone and in combination with S. philanthi RM-1-138. In vitro experiments showed that all treatments tested did provide some control against mycelial growth and sclerotia production by R. solani PTRRS-9. In addition, the four chemical fungicides had no detrimental effects on S. philanthi RM-1-138 even at high concentrations (up to 100 ?g/ml). The efficacy of S. philanthi RM-1-138, the commercial formulations of B. subtilis, chemical fungicides alone or in combination with S. philanthi RM-1-138 was also tested in a greenhouse experiment against sheath blight disease on rice plants. All treatments showed some protection of rice for sheath blight by 47-60 % when carbendazim® was applied alone and up to 74 % when combined with S. philanthi RM-1-138. PMID:23653261

Boukaew, Sawai; Klinmanee, Chanasirin; Prasertsan, Poonsuk

2013-10-01

91

Efecto de algunos fungicidas sobre la interacción Rhizoctonia solani Kuhn-Micorriza vesículo arbuscular en soya, Glycine max Merril  

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Full Text Available En el campo se dispuso de dos preparaciones de suelo: natural y desinfectado químicamente (Ditrapex-CE y en el invernadero de suelo esterilizado con vapor. Se utilizaron los fungicidas Propamocarb, SN-84364, PCNB y Vitavax-300. Se contó con la flora micorrizógena natural y una cepa introducida, Glomus manihotis. R. solani disminuyó en un 50 % la emergencia de la soya, comportándose más agresivo en suelo desinfectado. En los primeros 15 días su ataque se incrementó y redujo el desarrollo de MVA en suelo natural. Al avanzar la edad de la planta decreció su infección. Con relación a la MVA la tendencia es contraria. La presencia de la MVA, incluyendo G. manihotis no incrementó significativamente la materia seca y el rendimiento de la soya. Al desinfectar el suelo los fungicidas afectaron negativamente la infección micorrizógena, mientras que en suelo natural no sucedió este fenómeno, al contrario SN-84364 incrementó su presencia. Este producto es el que menos afecta la simbiosis en el suelo desinfectado. Los fungicidas SN-84364 y PCNB mostraron gran especificidad contra R. solani y Vitavax-300 mayor espectro de acción.With the object to evaluate in the soybeans crop behavior in the interaction of Rhizoctonia solani, vesicular-arbuscular mycorrhizae (VAM and fungicides used to treatment of seed, two different soil preparations were used in the field trials: natural and chemically disinfected (Ditrapex-CE and under greenhouse: using vapor- sterilized. Was utilized the fungicides Propamocarb, SN-84364, PCNB y Vitavax- 300. Be had into account the natural mycorrhizal flora and a source of Glomus manihotis introduced. R. solani reduced the emergence of soybean by 50%, the above-metioned pathogen was more agressive in disinfected soil. In the 15 days first the attack increased and reduced the VAM development in the natural soil. With the age of the plant the pathogen infection decreased. With relation by VAM is contrary the tendency. The presence of VAM, G. manihotis including, not increased significantly the dry mass and yield of the soybean. The fungicides diminished the VAM infection in both chemically and physically disinfected soil, whereas this does not ocurr in natural soil,SN-84364, on the other hand, increased the VAM infection. This product affected least the simbiosis in the disinfected soil. SN-84364 and PCNB exhibitited their great especifity against R. solani and Vitavax-300 a greater spectrum of action.

Sánchez de Prager Marina

1987-09-01

92

Caracterización de aislamientos de Rhizoctonia Solani Kühn que inducen pudriciones radicales en cultivares de caraota (Phaseolus Vulgaris L.  

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Full Text Available Plántulas sintomáticas de caraota (Phaseolus vulgaris L. fueron analizadas con objetivo de estudiar las pudriciones radicales inducidas por Rhizoctonia solani. Tres aislamientos identificados con las siglas CRH-V, CRH-F y CRH-558, que presentaban diferencias morfológicas entre sí, fueron utilizados. Se evaluaron 18 cultivares de caraota. Se caracterizaron los grupos de anastomosis de R. solani asociados al cultivo y se determinó su patogenicidad. Los tres aislamientos sobre presentaron diferencias significativas con relación al crecimiento. Los aislamientos CRH-F y CRH-558 mostraron zonación. El aislamiento CRH-F formó esclerocios bajo luz artificial. Todos los aislamientos produjeron esclerocios bajo luz natural. En las reacciones hifales, los aislamientos CRH-F y CRH-558 produjeron solo contacto hifal con el patrón AG-1-1 y AG-4, respectivamente, y en el CRH-V no hubo interacción. Se detectaron diferencias significativas para el peso seco de las raíces y parte aérea entre cultivares, aislamientos e interacciones cultivar x aislamiento. Todos los aislamientos afectaron tanto el desarrollo radical como el aéreo en los cultivares evaluados. El aislamiento CRH-558 causó mayor disminución al peso seco en raíces y parte aérea. En las interacciones entre aislamientos y cultivares: MEX-E-62, Tacarigua y Victoria presentaron mayor peso seco de las raíces.Symptomatic black bean seedlings (Phaseolus vulgaris L were analized in order to determine the root rot induced by R. solani. Three isolates of R. solani, which showed morphological differences were labeled with the acronyms CRH-V, CRH-F and CRH-558 and utilized. Eighteen beans cultivars were evaluated. Anastomosis groups of R. solani associated to the crop were characterized and their pathogenicity was determined. Significant differences in growth rate were found among the three isolates on PDA. The isolates CRH-F and CRH-558 showed zonation. The isolate CRH-F produced sclerotia under artificial light. Under natural light, all the isolates produced sclerotia. In hyphal reactions, the isolates CRH-F and CRH-558 showed only hyphal contact with AG-1-1 and AG-4, respectively. The isolate CRH-V showed no reaction. There were significant differences for the root and aerial part dry weight among cultivars, isolates and the interactions cultivars by isolates. The isolate CRH-558 caused higher reduction on dry weight and aerial part. In the interaction among isolates and cultivars, MEX -62, Tacarigua and Victoria showed higher root dry weight.

Bárbara Gutiérrez

2006-01-01

93

Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences Identificação de Rhizoctonia solani associada à soja no Brasil através de seqüências da região rDNA-ITS  

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Full Text Available The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp was highly conserved among all isolates but differences in length and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.O objetivo deste estudo foi identificar, através da seqüência de nucleotídeos das regiões ITS-5.8S do rDNA, isolados de Rhizoctonia solani causadores de podridão de hipocótilos e de queima foliar em soja (Glycine max, no Brasil. A seqüência do gene 5.8S do rDNA (155 bp foi altamente conservada entre todos os isolados, mas foram observadas diferenças no tamanho e na seqüência de nucleotídeos nas regiões ITS1 e ITS2 entre os isolados obtidos de soja e os padrões de grupos de anastomose (AGs. A similaridade na seqüência de nucleotídeos entre os isolados do AG-1 IA, causadores de queima foliar, foi 95,1-100% na região ITS1 e 98,5-100% na região ITS2. A similaridade na seqüência de nucleotídeos entre os subgrupos IA, IB e IC variaram de 84,3 a 89% no ITS1 e de 93,3 a 95,6% no ITS2. Entre os isolados obtidos de soja pertencentes ao AG-4 e o padrão AG-4 HGI foram observadas 99,1% e 99,3-100% de similaridades para ITS1 e ITS2, respectivamente. Foi possível confirmar através da análise das regiões ITS-5.8S do rDNA que os isolados de R. solani brasileiros, causadores de queima foliar são pertencentes ao AG-1 IA e que, os isolados causadores de podridão de hipocótilos pertencem ao AG-4 HGI. A análise das regiões ITS-5.8S do rDNA não foi determinante na identificação do isolado AG-2-2 IIIB obtido de soja.

Roseli C. Fenille

2003-08-01

94

Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences / Identificação de Rhizoctonia solani associada à soja no Brasil através de seqüências da região rDNA-ITS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste estudo foi identificar, através da seqüência de nucleotídeos das regiões ITS-5.8S do rDNA, isolados de Rhizoctonia solani causadores de podridão de hipocótilos e de queima foliar em soja (Glycine max), no Brasil. A seqüência do gene 5.8S do rDNA (155 bp) foi altamente conservada ent [...] re todos os isolados, mas foram observadas diferenças no tamanho e na seqüência de nucleotídeos nas regiões ITS1 e ITS2 entre os isolados obtidos de soja e os padrões de grupos de anastomose (AGs). A similaridade na seqüência de nucleotídeos entre os isolados do AG-1 IA, causadores de queima foliar, foi 95,1-100% na região ITS1 e 98,5-100% na região ITS2. A similaridade na seqüência de nucleotídeos entre os subgrupos IA, IB e IC variaram de 84,3 a 89% no ITS1 e de 93,3 a 95,6% no ITS2. Entre os isolados obtidos de soja pertencentes ao AG-4 e o padrão AG-4 HGI foram observadas 99,1% e 99,3-100% de similaridades para ITS1 e ITS2, respectivamente. Foi possível confirmar através da análise das regiões ITS-5.8S do rDNA que os isolados de R. solani brasileiros, causadores de queima foliar são pertencentes ao AG-1 IA e que, os isolados causadores de podridão de hipocótilos pertencem ao AG-4 HGI. A análise das regiões ITS-5.8S do rDNA não foi determinante na identificação do isolado AG-2-2 IIIB obtido de soja. Abstract in english The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max) in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp) was highly conserved among all isolates but differences in len [...] gth and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.

Roseli C., Fenille; Maísa B., Ciampi; Eiko E., Kuramae; Nilton L., Souza.

2003-08-01

95

EFFECT OF LABEL AND SUBLABEL RATES OF METAM SODIUM IN COMBINATION WITH TRICHODERMA HAMATUM, T. HARZIANUM, T. VIRENS, T. VIRIDE ON SURVIVAL AND SAPROPHYTIC ACTIVITY OF RHIZOCTONIA SOLANI IN SOIL  

Science.gov (United States)

This work was undertaken to determine the effects of Trichoderma spp. combined with label and sublabel rates of metam sodium on survival and saprophytic activity of Rhizoctonia solani in soil. To study survival, sterile beet seed were colonized with R. solani and used to infest soil. Soils were al...

96

Polymorphism of genes coding for nuclear 18S rRNA indicates genetic distinctiveness of anastomosis group 10 from other groups in the Rhizoctonia solani species complex.  

OpenAIRE

DNA polymorphism in the 18S nuclear rRNA gene region was investigated by using 11 restriction endonucleases for 161 isolates of 25 intraspecific groups (ISGs) representing 11 reported anastomosis groups (AGs) of Rhizoctonia solani. A PCR-based restriction mapping method in which enzymatically amplified DNA fragments and subfragments were digested with one or two restriction enzymes was employed. Four types of DNA restriction maps of this region were constructed for these 25 ISGs. Map type I o...

Liu, Z. L.; Domier, L. L.; Sinclair, J. B.

1995-01-01

97

Effect of Combined Use of Bacillus subtilis CA32 and Trichoderma harzianum RU01 on Biological Control of Rhizoctonia solani on Solanum melongena and Capsicum annuum  

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Full Text Available A combination of two compatible biological control agents, Bacillus subtilis CA32 and Trichoderma harzianum RU01, both antagonistic to the pathogen Rhizoctonia solani, was used to control damping-off in Solanum melongena and Capsicum annuum. Radial growth of the mycelium of R. solani was inhibited by T. harzianum RU01 in dual Petri plate assay. T. harzianum RU01 was capable to invading the whole surface of the pathogen colony, sporulating on it and suppress the production of sclerotia of R. solani. Microscopic studies showed the hyphae of R. solani surrounded by the T. harzianum RU01 and subsequent disintegration. B. subtilis CA32 produced a zone of inhibition only with the pathogen and no sings of antagonism between the bacteria and T. harzianum RU01 on dual Petri plate assay. Significant plant protection was achieved when either B. subtilis added to the seeds or T. harzianum added to soil. However, when combine application of biocontrol agents, seed bacterization and T. harzianum application to soil, significantly enhanced the plant protection from R. solani. Soil application of B. subtilis and seed application of T. harzianum either singly or in combination did not protect from R. solani infection indicating that the importance of mode of application of biocontrol agents.

S. Abeysinghe

2009-01-01

98

Use of Pseudomonas aeruginosa in the control od root-knot disease complex in tomato: the effects of different inoculum levels of Meloidogyne javanica and Rhizoctonia solani  

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Full Text Available The potential impact of Pseudomons aeruginosa strain IE-6 as a biological control agent against Meloidogyne javanica at four inoculum densities (0, 250, 500 and 1000 eggs/plant and Rhizoctonia solani at three inoeulum levels (0, 1 and 3 ml culture suspension/kg of soil was examined on tomato in the greenhouse experiments. The biocontrol bacterium suppressed root infection caused by R. solani and M. javanica on tomato in both sterilized and non-sterilized soils. Root-rot infection increased with the increase in pathogen(s concentration. P. aeruginosa showed better biocontrol effects at low population levels of M.javanica and R. solani than at higher population densities of the pathogen(s. Root-rot disease severity was more pronounced in sterilized soil compared to the non-sterilized one. Soil infested with high population densities ofR. solani (3 ml /kg of soil and M. javanica (2000 eggs/pot resulted in complete mortality of tomato seedlings in sterilized soil, whereas some plants were found to survive in non-stenlized soil. There seems to be a correlation between population density of M. javanica and root colonization by R. solani. Root colonization by other three root-infecting fungi including Macrophomina phaseolina, Fusarium oxysporum and Fusarium solani was also lower in the presence of P. aeruginosa in non-sterilized soil. P. aeruginosa enhanced plant growth in both types of soil.

I. A. Siddiqui

2001-06-01

99

Characterization of antagonistic-potential of two Bacillus strains and their biocontrol activity against Rhizoctonia solani in tomato.  

Science.gov (United States)

To investigate the biocontrol mechanism of two antagonistic Bacillus strains (Bacillus subtilis MB14 and Bacillus amyloliquefaciens MB101), three in vitro antagonism assays were screened and the results were concluded that both strains inhibited Rhizoctonia solani growth in a similar manner by dual culture assay, but the maximum percent of inhibition only resulted with MB101 by volatile and diffusible metabolite assays. Moreover, cell free supernatant (CFS) of MB101 also showed significant (p?>?0.05) growth inhibition as compared to MB14, when 10 and 20% CFS mix with the growth medium of R. solani. After in vitro-validation, both strains were evaluated under greenhouse and the results concluded that strain MB101 had significant biocontrol potential as compared to MB14. Strain MB101 was enhanced the plant height, biomass and chlorophyll content of tomato plant through a higher degree of root colonization. In field trials, strain MB101 showed higher lessening in root rot symptoms with significant fruit yield as compare to strain MB14 and infected control. Next to the field study, the presence of four antibiotic genes (srfAA, fenD, ituC, and bmyB) also concluded the antifungal nature of both Bacillus strains. Phylogenetic analysis of protein sequences revealed a close relatedness of three genes (srfAA, fenD, and ituC) with earlier reported sequences of B. subtilis and B. amyloliquefaciens. However, bmyB showed heterogeneity in among both strains (MB14 and MB101) and it may be concluded that higher degree of antagonism, root colonization and different antibiotic producing genes may play an important role in biocontrol mechanism of strain MB101. PMID:24277414

Solanki, Manoj Kumar; Singh, Rajesh Kumar; Srivastava, Supriya; Kumar, Sudheer; Kashyap, Prem Lal; Srivastava, Alok K

2015-01-01

100

Suscetibilidade de cultivares de algodoeiro a Rhizoctonia solani e benefícios do tratamento de sementes com fungicidas / Susceptibility of cotton cultivars to Rhizoctonia solani and benefits of fungicide seed treatment  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho teve por objetivo avaliar o comportamento de seis cultivares de algodoeiro (BRS-Ipê, BRS-Aroeira, BRS-Cedro, Fibermax 966, DeltaOpal e CNPA Ita 90-II) ao fungo Rhizoctonia solani AG-4 e os benefícios do tratamento de sementes de algodoeiro com fungicidas para cada cultivar em estudo, e [...] m relação à densidade de inóculo deste fungo. O ensaio foi conduzido na casa de vegetação da Embrapa Agropecuária Oeste, em Dourados, MS. Foram definidas quatro densidades populacionais do fungo (0; 1; 2 e 3g de inóculo do fungo/bandeja plástica de 56x35x10cm) para a realização do ensaio. As avaliações foram realizadas com base no desenvolvimento de sintomas e sobrevivência das plântulas, utilizando os dados de emergência inicial e final e de tombamento de pós-emergência. Sementes não tratadas e tratadas com a mistura fungicida tolylfluanid + pencycuron + triadimenol (30+50+50g do i.a./100kg de sementes) foram semeadas em areia contida em bandejas plásticas, dispostas em orifícios individuais, eqüidistantes e a 3cm de profundidade. A inoculação com R. solani foi feita pela distribuição homogênea do inóculo do fungo na superfície do substrato. O fungo foi cultivado por 35 dias em sementes de aveia preta autoclavadas e trituradas em moinho (1mm). Houve efeito significativo das interações cultivares x níveis de inóculo, cultivares x fungicidas e níveis de inóculo x fungicidas. O comportamento das cultivares foi significativamente influenciado pelas diferentes populações de R. solani, sendo que, a medida que se aumentou a densidade de inóculo do patógeno, menores índices de emergência e maiores índices de doença foram observados. Ficou claramente demonstrada também a importância do tratamento das sementes de algodoeiro com fungicidas, sendo que as melhores emergências e os menores índices de doença (tombamento e plântulas lesionadas), independente da cultivar testada, foram obtidos quando as sementes foram tratadas com a mistura tolylfluanid + pencycuron + triadimenol. Observou-se ainda que as populações do patógeno influenciaram significativamente nos benefícios do tratamento de sementes, demonstrando que a performance da mistura fungicida testada (tolylfluanid + pencycuron + triadimenol) foi melhor na presença dos níveis mais baixos de inóculo do fungo. Com relação as cultivares avaliadas e na ausência do tratamento da sementes com fungicidas, observou-se comportamento diferenciado de alguns materiais com relação ao ataque do fungo R. solani, merecendo destaque os genótipos CNPA ITA 90 II E BRS Aroeira, seguidas de BRS Cedro e BRS Ipê, demonstrando uma maior tolerância destas cultivares ao ataque de R. solani em comparação às demais. Abstract in english The objective of this work was to evaluate the behavior of six cotton cultivars (BRS-Ipê, BRS-Aroeira, BRS-Cedro, Fibermax 966, DeltaOpal and CNPA Ita 90-II) in relation to Rhizoctonia solani AG-4 and the benefits of cotton seed treatment with fungicides, for each tested cultivar, for the control of [...] damping-off in relation to inoculum densities of this fungus. This experiment was carried out at greenhouse conditions at Embrapa Agropecuária Oeste, in Dourados, MS. Four inoculum densities were tested (0; 1; 2 and 3g of fungus inoculum/plastic tray with dimensions of 56x35x10cm) in the trial. The evaluations were done based on symptoms development and seedling survival, using initial and final emergence and pre and pos damping-off data. Treated and untreated seeds with fungicides mixture tolylfluanid + pencycuron + triadimenol (30+50+50g a.i./100kg of seeds) were sowed in sand contained in plastic trays, by placing in equidistant 3-cm-deep wells. The inoculation with R. solani AG-4 was done by the homogeneous distribution of the fungus inoculum onto the substrate. The fungus was grown for 35 days on autoclaved oat seeds and then ground to powder using a mill (1mm). Significant effect of the interactions cultivars x inocul

Augusto César Pereira, Goulart.

2007-09-01

101

Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn  

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Full Text Available Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter, water and ethanol against R. solani in order to determine the Inhibitory Concentration (IC50 of each extract. Results: The results showed that extracts of both L. graveolens and C. illinoensis obtained with lanolin and ethanol (200 and 3000 ppm of total tannins, respectively inhibited at 100% growth of R. solani. The IC50 for each extract was highly variable, low IC50 values were obtained with L. graveolens (4.50×101 and C. illinoensis (4.33×102 extract using lanolin and ethanol respectively. Tannins extraction was strongly dependent on plant species and in the solvent used. Conclusion: The alternative organic solvents lanolin and cocoa butter allowed the recovery of polyphenols compounds with antifungal activity against R. solani.

Francisco D. Hernandez-Castillo

2010-01-01

102

Caracterização citomorfológica, cultural, molecular e patogênica de Rhizoctonia solani Kühn associado ao arroz em Tocantins, Brasil / Citomorphological, cultural, molecular and pathogenical characterization of Rhizoctonia solani Kühn associated with rice in Tocantins, Brazil  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese No Estado do Tocantins, no Norte do Brasil, a incidência de rizoctoniose no arroz é importante, causando danos significativos em lavouras de arroz irrigado. O principal objetivo deste trabalho foi determinar o grupo de anastomose (AG) de isolados de R. solani associados ao arroz naquela região, test [...] ando a hipótese de que esses isolados pertencem ao grupo padrão de anastomose AG-1 IA, que também é o agente causal da mela em soja em áreas úmidas do Norte do Brasil. Todos os quatro isolados de arroz foram caracterizados, através de fusão de hifas, como AG-1 IA. A caracterização cultural, em função das temperaturas basais (mínimas, máximas e ótimas), evidenciou que os isolados de R. solani de arroz apresentaram perfis semelhantes aos padrões AG-1 IA, AG-1 IB e AG-1 IC. Os isolados de arroz foram caracterizados como autotróficos para tiamina assim como os isolados padrões AG-1 IA, IB, IC, AG-4 HGI e o isolado da mela da soja. O teste de patogenicidade em plantas de arroz cultivar IRGA-409 e de patogenicidade cruzada à cultivar IAC-18 de soja (suscetível à mela), indicou que além de causar a queima da bainha em arroz, esses isolados causam mela em soja. Da mesma forma, o isolado SJ-047 foi patogênico ao arroz. As seqüências de bases de DNA da região ITS-5.8S do rDNA dos isolados do arroz foram similares às seqüências do AG-1 IA, depositadas no GenBank® - NCBI. A filogenia do ITS-rDNA indicou um grupo filogenético comum formado pelos isolados do arroz, o isolado da soja e o isolado teste do AG-1 IA. Assim, com base em características citomorfológicas, culturais, filogenéticas e patogênicas, foi confirmada a hipótese de que os isolados de R. solani patógenos de arroz do Estado do Tocantins pertencem ao grupo de anastomose AG-1 IA, além da indicação de que esses isolados podem também causar a mela em soja. Abstract in english In Tocantins State, Northern Brazil, the incidence of Rhizoctonia sheath blight on rice is important, causing significant yield losses on rice crops under irrigation. The main objective of this research was to determine the anastomosis group (AG) of R. solani associated with rice in that area, testi [...] ng the hypothesis that these isolates are from the AG-1 IA, which is also associated with the soybean leaf blight occurring in wet areas of Northern Brazil. All the four rice isolates were characterized, by hyphal fusion, as AG-1 IA. By cultural characterization, based on basal temperatures for mycelial growth (minimum, optimum and maximum), the rice isolates had growth profile similar to the tester isolates AG-1 IA, AG-1 IB and AG-1 IC. The rice isolates were characterized as autotrophic for thiamine, as well as the AG testers AG-1 IA, IB, IC, AG-4 HGI and the soybean leaf blight isolate SJ-047. The pathogenicity test on rice IRGA-409 and the cross pathogenicity on soybean IAC-18 (susceptible to the leaf blight disease) indicated that, besides causing sheath blight, these rice isolates also cause leaf blight on soybean. Similarly, the soybean isolates SJ-047 was pathogenic to rice. The sequences from the ITS-5.8S region of rDNA from the rice isolates were similar to sequences of AG-1 IA deposited at GenBank® - NCBI. The ITS-rDNA phylogeny indicated a common phylogenetic group formed by these rice isolates, the isolate SJ-047 and the tester AG-1 IA. Thus, based on cytomorphological, cultural, phylogenetics and pathogenic attributes, the hypothesis that the rice isolates of R. solani from Tocantins all belong to the AG-1 IA was confirmed, besides the indication that these isolates can also cause soybean foliar blight.

Elaine Costa, Souza; Eiko Eurya, Kuramae; Andreia Kazumi, Nakatani; Marco Antonio, Basseto; Anne Sitarana, Prabhu; Paulo Cezar, Ceresini.

2007-06-01

103

Caracterização citomorfológica, cultural, molecular e patogênica de Rhizoctonia solani Kühn associado ao arroz em Tocantins, Brasil Citomorphological, cultural, molecular and pathogenical characterization of Rhizoctonia solani Kühn associated with rice in Tocantins, Brazil  

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Full Text Available No Estado do Tocantins, no Norte do Brasil, a incidência de rizoctoniose no arroz é importante, causando danos significativos em lavouras de arroz irrigado. O principal objetivo deste trabalho foi determinar o grupo de anastomose (AG de isolados de R. solani associados ao arroz naquela região, testando a hipótese de que esses isolados pertencem ao grupo padrão de anastomose AG-1 IA, que também é o agente causal da mela em soja em áreas úmidas do Norte do Brasil. Todos os quatro isolados de arroz foram caracterizados, através de fusão de hifas, como AG-1 IA. A caracterização cultural, em função das temperaturas basais (mínimas, máximas e ótimas, evidenciou que os isolados de R. solani de arroz apresentaram perfis semelhantes aos padrões AG-1 IA, AG-1 IB e AG-1 IC. Os isolados de arroz foram caracterizados como autotróficos para tiamina assim como os isolados padrões AG-1 IA, IB, IC, AG-4 HGI e o isolado da mela da soja. O teste de patogenicidade em plantas de arroz cultivar IRGA-409 e de patogenicidade cruzada à cultivar IAC-18 de soja (suscetível à mela, indicou que além de causar a queima da bainha em arroz, esses isolados causam mela em soja. Da mesma forma, o isolado SJ-047 foi patogênico ao arroz. As seqüências de bases de DNA da região ITS-5.8S do rDNA dos isolados do arroz foram similares às seqüências do AG-1 IA, depositadas no GenBank® - NCBI. A filogenia do ITS-rDNA indicou um grupo filogenético comum formado pelos isolados do arroz, o isolado da soja e o isolado teste do AG-1 IA. Assim, com base em características citomorfológicas, culturais, filogenéticas e patogênicas, foi confirmada a hipótese de que os isolados de R. solani patógenos de arroz do Estado do Tocantins pertencem ao grupo de anastomose AG-1 IA, além da indicação de que esses isolados podem também causar a mela em soja.In Tocantins State, Northern Brazil, the incidence of Rhizoctonia sheath blight on rice is important, causing significant yield losses on rice crops under irrigation. The main objective of this research was to determine the anastomosis group (AG of R. solani associated with rice in that area, testing the hypothesis that these isolates are from the AG-1 IA, which is also associated with the soybean leaf blight occurring in wet areas of Northern Brazil. All the four rice isolates were characterized, by hyphal fusion, as AG-1 IA. By cultural characterization, based on basal temperatures for mycelial growth (minimum, optimum and maximum, the rice isolates had growth profile similar to the tester isolates AG-1 IA, AG-1 IB and AG-1 IC. The rice isolates were characterized as autotrophic for thiamine, as well as the AG testers AG-1 IA, IB, IC, AG-4 HGI and the soybean leaf blight isolate SJ-047. The pathogenicity test on rice IRGA-409 and the cross pathogenicity on soybean IAC-18 (susceptible to the leaf blight disease indicated that, besides causing sheath blight, these rice isolates also cause leaf blight on soybean. Similarly, the soybean isolates SJ-047 was pathogenic to rice. The sequences from the ITS-5.8S region of rDNA from the rice isolates were similar to sequences of AG-1 IA deposited at GenBank® - NCBI. The ITS-rDNA phylogeny indicated a common phylogenetic group formed by these rice isolates, the isolate SJ-047 and the tester AG-1 IA. Thus, based on cytomorphological, cultural, phylogenetics and pathogenic attributes, the hypothesis that the rice isolates of R. solani from Tocantins all belong to the AG-1 IA was confirmed, besides the indication that these isolates can also cause soybean foliar blight.

Elaine Costa Souza

2007-06-01

104

FT-ICR/MS and GC-EI/MS metabolomics networking unravels global potato sprout's responses to Rhizoctonia solani infection.  

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The complexity of plant-pathogen interactions makes their dissection a challenging task for metabolomics studies. Here we are reporting on an integrated metabolomics networking approach combining gas chromatography/mass spectrometry (GC/MS) with Fourier transform ion cyclotron resonance/mass spectrometry (FT-ICR/MS) and bioinformatics analyses for the study of interactions in the potato sprout-Rhizoctonia solani pathosystem and the fluctuations in the global metabolome of sprouts. The developed bioanalytical and bioinformatics protocols provided a snapshot of the sprout's global metabolic network and its perturbations as a result of pathogen invasion. Mevalonic acid and deoxy-xylulose pathways were substantially up-regulated leading to the biosynthesis of sesquiterpene alkaloids such as the phytoalexins phytuberin, rishitin, and solavetivone, and steroidal alkaloids having solasodine and solanidine as their common aglycons. Additionally, the perturbation of the sprout's metabolism was depicted in fluctuations of the content of their amino acids pool and that of carboxylic and fatty acids. Components of the systemic acquired resistance (SAR) and hypersensitive reaction (HR) such as azelaic and oxalic acids were detected in increased levels in infected sprouts and strategies of the pathogen to overcome plant defense were proposed. Our metabolic approach has not only greatly expanded the multitude of metabolites previously reported in potato in response to pathogen invasion, but also enabled the identification of bioactive plant-derived metabolites providing valuable information that could be exploited in biotechnology, biomarker-assisted plant breeding, and crop protection for the development of new crop protection agents. PMID:22880040

Aliferis, Konstantinos A; Jabaji, Suha

2012-01-01

105

Silício alterando compostos derivados da pirólise de bainhas foliares de plantas de arroz infectadas por Rhizoctonia solani / Silicon altering compounds derived from the pyrolyses of leaf sheaths of rice plants infected with Rhizoctonia solani  

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Full Text Available Este trabalho teve como objetivo elucidar, por meio da pirólise analítica acoplada à cromatografia gasosa e espectrometria de massa, alterações na composição química da lignina nas bainhas de plantas de arroz das cultivares BR-Irga 409 e Labelle supridas ou não com silício (Si) e infectadas por Rhiz [...] octonia solani. A concentração de Si nas bainhas das plantas supridas com esse elemento foi significativamente maior (2,7 dag kg-1) em comparação com as plantas não supridas (0,45 dag kg-1). Na presença de Si, a área abaixo da curva do progresso da queima das bainhas foi significativamente reduzida em 19 e 25%, respectivamente, para as plantas das cultivares BR-Irga-409 e Labelle em relação à ausência desse elemento na solução nutritiva. Com base nos espectros de massas obtidos, foram identificados 33 compostos, dos quais 10 foram produtos da degradação de carboidratos e 23 derivados da lignina. Dentre os derivados da lignina, oito compostos eram do tipo p-hidroxifenila, 11 compostos do tipo guaiacila e quatro compostos do tipo siringila. Nas bainhas das plantas das duas cultivares de arroz, supridas ou não com Si, a concentração de lignina (p-hidroxifenila, siringila (S) e guaiacila (G)) foi de, aproximadamente, 15%. Houve aumento na relação S/G apenas nas bainhas das plantas da cultivar BR-Irga 409 supridas com Si e infectadas por R. solani. A maior concentração de Si nas bainhas das plantas de arroz das duas cultivares, que por sua vez resultou em aumento na relação S/G, contribuiu para reduzir os sintomas da queima das bainhas. Abstract in english This study elucidated, through analytical pyrolysis coupled to gas chromatography and mass spectrometry, changes in the chemical composition of lignin on leaf sheaths of rice plants of cultivars BR-Irga 409 and Labelle supplied or non-supplied with silicon (Si) and infected with Rhizoctonia solani. [...] The Si concentration on leaf sheaths of plants supplied with this element was significatively higher (2.7 dag kg-1) as compared to non-supplied plants (0.45 dag kg-1). In the presence of Si, the area under leaf sheath blight progress curve was significantly reduced by 19 and 25% for plants from cultivars BR-Irga 409 and Labelle, respectively, in comparison to the absence of Si. Based on the mass spectra obtained, 33 compounds were identified, 10 of which were products from the degradation of carbohydrates and 23 derivate from lignin. From lignin derivatives, eight compounds were p-hydroxiphenil type, eleven compounds were guaiacyl type and four compounds were syringyl type. On leaf sheaths of both cultivars, the concentration of lignin (p-hydroxiphenil, syringyl (S) and guaiacyl (G)) was around 15%, regardless of Si. There was no increase in the S/G ratio only for the leaf sheaths of BR-Irga 409 supplied with Si and infected with R. solani. High Si concentration on leaf sheaths of both cultivars, which in turn resulted in an increase in the S/G ratio, contributed to reduce leaf sheath blight symptoms.

Daniel Augusto, Schurt; Fabrício Ávila, Rodrigues; Vivian, Carré-Missio; Nilda Fátima Ferreira, Soares.

2013-03-01

106

Phylogeography of the Solanaceae-infecting Basidiomycota fungus Rhizoctonia solani AG-3 based on sequence analysis of two nuclear DNA loci  

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Full Text Available Abstract Background The soil fungus Rhizoctonia solani anastomosis group 3 (AG-3 is an important pathogen of cultivated plants in the family Solanaceae. Isolates of R. solani AG-3 are taxonomically related based on the composition of cellular fatty acids, phylogenetic analysis of nuclear ribosomal DNA (rDNA and beta-tubulin gene sequences, and somatic hyphal interactions. Despite the close genetic relationship among isolates of R. solani AG-3, field populations from potato and tobacco exhibit comparative differences in their disease biology, dispersal ecology, host specialization, genetic diversity and population structure. However, little information is available on how field populations of R. solani AG-3 on potato and tobacco are shaped by population genetic processes. In this study, two field populations of R. solani AG-3 from potato in North Carolina (NC and the Northern USA; and two field populations from tobacco in NC and Southern Brazil were examined using sequence analysis of two cloned regions of nuclear DNA (pP42F and pP89. Results Populations of R. solani AG-3 from potato were genetically diverse with a high frequency of heterozygosity, while limited or no genetic diversity was observed within the highly homozygous tobacco populations from NC and Brazil. Except for one isolate (TBR24, all NC and Brazilian isolates from tobacco shared the same alleles. No alleles were shared between potato and tobacco populations of R. solani AG-3, indicating no gene flow between them. To infer historical events that influenced current geographical patterns observed for populations of R. solani AG-3 from potato, we performed an analysis of molecular variance (AMOVA and a nested clade analysis (NCA. Population differentiation was detected for locus pP89 (?ST = 0.257, significant at P ST = 0.034, not significant. Results based on NCA of the pP89 locus suggest that historical restricted gene flow is a plausible explanation for the geographical association of clades. Coalescent-based simulations of genealogical relationships between populations of R. solani AG-3 from potato and tobacco were used to estimate the amount and directionality of historical migration patterns in time, and the ages of mutations of populations. Low rates of historical movement of genes were observed between the potato and tobacco populations of R. solani AG-3. Conclusion The two sisters populations of the basidiomycete fungus R. solani AG-3 from potato and tobacco represent two genetically distinct and historically divergent lineages that have probably evolved within the range of their particular related Solanaceae hosts as sympatric species.

Vilgalys Rytas J

2007-09-01

107

Control del mal de los almácigos causado por Rhizoctonia solani y Sclerotium rolfsii con caldos de cebolla / Control of seedling damping off caused by Rhizoctonia solani and Sclerotium rolfsii using onion broths  

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Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish El mal de los almácigos causa muerte de plántulas. Los controles cultural y biológico constituyen las únicas herramientas orgánicas para su manejo. Acerca de la eficiencia de preparaciones vegetales, sólo se encuentra información de divulgación. Este trabajo evalúa el efecto de caldos fermentados de [...] cebolla sobre el crecimiento de Rhizoctonia solani y Sclerotium rolfsii y la incidencia de la enfermedad. Se obtuvieron caldo (B) y caldo esterilizado (SB), respectivamente, mediante hervido de trozos de cebollas y fermentación a temperatura ambiente, con o sin esterilización posterior. Se cultivaron los patógenos en APG suplementado con B y SB diluidos 1,7; 3,3; 8,3; 16,7 y 25%. Su crecimiento decreció con B al 8,3, 16,7 y 25%. La producción de esclerocios por S. rolfsii disminuyó con B, pero aumentó con SB. Penicillium purpurogenum, P. simplicissimum y Aspergillus niger aislados de B evidenciaron antibiosis, competencia e hiperparasitismo respecto de ambos patógenos. B y SB diluidos 10 y 50% fueron aplicados en almácigos de acelga (Beta vulgaris), tomate (Solanum lycopersicum), pimiento (Capsicum annuum) y berenjena (Solanum melongena) infestados. La pérdida de plántulas fue menor en el tratamiento con B al 50%, en relación al tratamiento con SB. Se concluye que la actividad antifúngica de B depende de su dilución y de su micota. La utilización de caldos de cebolla debería ser contemplada como alternativa para el manejo fitosanitario de bajo impacto ambiental. Se requiere continuar los estudios para completar el conocimiento acerca de los componentes químicos y microbiológicos de los caldos, y sus posibles cambios durante la fermentación. Abstract in english Damping off is a frequent disease that kills seedlings. Cultural and biological controls are the only tools in organic crops to manage this disease, and only empirical information is available on the eficiency of plant preparations. This work evaluates the effects of fermented onion decoctions on th [...] e growth of Rhizoctonia solani and Sclerotium rolfsii and disease incidence. Broth (B) and sterilized broth (SB) were respectively obtained by boiling chopped yellow onions in water, and incubating for 14 days at room temperature, with or without subsequent sterilization. The pathogens were grown on potato dextrose agar supplemented with B and SB, diluted at 1.7, 3.3, 8.3, 16.7 and 25% (v/v). Their growth was reduced by B at 8.3, 16.7 and 25%. Production of sclerotia by S. rolfsii was diminished by B, but stimulated by SB. Penicillium purpurogenum, P. simplicissimum and Aspergillus niger obtained from B behaved as antagonistic against both pathogens, showing antibiosis, competition and hyperparasitism in dual confrontations with them. Broth and SB at 10 and 50% dilutions were sprayed on chard (Beta vulgaris), tomato (Solanum lycopersicum), pepper (Capsicum annuum) and eggplant (Solanum melongena) seedlings cultivated in pathogen-colonized soil. Damping of incidence in the B treatment at 50% dilution was markedly lower than that in SB. It is concluded that B antifungal activity depends on its dilution and mycota. Broth sprays should be considered as a tool to control damping of in low-environment-impact crop production. Further studies are needed for a complete understanding of B chemical and microbiological components, as well as their changes during fermentation.

MC, Rivera; ER, Wright; MC, Fabrizio; G, Freixá; R, Cabalini; SE, Lopez.

2013-12-01

108

Bioprospecção de isolados de Trichoderma spp. para o controle de Rhizoctonia solani na produção de mudas de pepino / Bioprospection of Trichoderma spp. isolates to control Rhizoctonia solani on cucumber seedling production  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi selecionar e identificar isolados de Trichoderma spp. para o controle do tombamento causado por Rhizoctonia solani (AG-4) em plântulas de pepino (Cucumis sativus L.), além de avaliar o efeito de concentrações crescentes e de combinações dos isolados mais eficientes no c [...] ontrole da doença. Os experimentos foram conduzidos em casa de vegetação, com 490 isolados. O tombamento das mudas foi avaliado uma semana após a aplicação à base das plântulas de substrato infestado com antagonista (1%) e patógeno (1%). Os doze isolados que proporcionaram mais de 85% de redução da doença foram testados em concentrações crescentes para o controle do patógeno (1%): 0,5, 1, 2, 3 e 4%. Também foi avaliado o efeito das combinações dos cinco isolados mais promissores. Os isolados mais efetivos foram identificados pelo sequenciamento da região espaçadores internos transcritos (ITS) do DNA ribossômico. Dos 490 isolados testados 44 (9%) reduziram o tombamento. As concentrações de antagonistas superiores a 2% foram as mais efetivas no controle da doença. Apenas duas combinações resultaram no aumento do controle da doença. Os isolados mais efetivos foram identificados como T. hamatum (IB08, IB30, IB60), T. harzianum (IB34, IB35), T. atroviride (IB13), T. spirale (IB16, IB24) e T. asperellum (IB44). Não foi possível a identificação da espécie de três isolados. Abstract in english The objective of this work was to select and identify Trichoderma spp. isolates for the control of Rhizoctonia solani (AG-4) damping-off on cucumber (Cucumis sativus L.) seedlings, as well as to evaluate the effects of increasing concentrations and different combinations of the most efficient isolat [...] es in the disease control. The experiments were carried out in a greenhouse with 490 isolates. The disease on cucumber seedlings was evaluated one week after the application of a commercial substrate infested with both antagonist (1%) and pathogen (1%) to the seedlings' root collar. The twelve isolates that conferred more than 85% of disease reduction were further evaluated in pathogen control (1%) at the concentrations 0.5, 1, 2, 3 and 4%. The effect of combining five of the most promising isolates in disease control was also evaluated. The most effective isolates were identified through the sequencing of the ribosomal internal transcribed spacers (ITS) region. Out of the 490 isolates tested 44 (9%) caused reduction of damping-off. Antagonist concentrations higher than 2% conferred the most effective disease control. Only two combinations of isolates resulted in increased disease control. The most effective isolates were identified as T. hamatum (IB08, IB30, IB60), T. harzianum (IB34, IB35), T. atroviride (IB13), T. spirale (IB16, IB24) and T. asperellum (IB44). Three isolates could not be identified at species level.

Cleusa Maria Mantovanello, Lucon; Claudia Mitsue, Koike; Alice Ishida, Ishikawa; Flávia Rodrigues Alves, Patrício; Ricardo, Harakava.

2009-03-01

109

Evaluation of chitinase activity in biological control process of rhizoctonia solani y fusarium oxysporum f. sp. lycopersici in tomate, by using seed priming in the presence of trichoderma koningii Evaluación de la actividad quitinasa en procesos de control biológico de rhizoctonia solani y fusarium oxysporum f. sp. lycopersici en tomate, mediante fitoinvigorización de semillas en presencia de trichoderma koningii  

OpenAIRE

The present work intended to establish in a control model, the possible role of chitinases by using seed priming in the presence of Trichoderma koningii. This method showed to be efficient to control Rhizoctonia solani and Fusarium oxysporum in tomato. The analysis of seed extracts and exudates, and soil extracts from soil seeded with seeds primed in the presence of T. koningii showed high endochitinase activity in the samples. This activity was higher than that exhibited by samples from prim...

Cotes A. M.; Clavijo A.

1998-01-01

110

Effect of Trichoderma harzianum biomass and Bradyrhizobium sp. strain NC 92 to control leaf blight disease of bambara groundnut (Vigna subterranea caused by Rhizoctonia solani in the field  

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Full Text Available Four hundred and sixty two strains of Trichoderma spp. were isolated from 23 soil samples in which groundnut (Arachis hypogaea L. and bambara groundnut (Vigna subterranea L. had been planted in Songkhla, Phattalung, Nakhon Si Thammarat, Narathiwat and Yala provinces. These fungi were tested against Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut, using dual culture technique on PDA medium. Among 462 isolates tested, 226 isolates had an ability to overgrow R. solani completely. Further testing found 13 isolates having the ability to parasitize mycelia of R. solani. Among these isolates, ThB-1-54 produced a cellulolytic enzyme on congo-red agar. This isolate was later identified as T. harzianum Rifai. In the field test, applying biomass of the isolate ThB-1-54 cultured on ground mesocarp fiber of oil palm, the combination of the isolate ThB-1-54 on ground mesocarp fiber of oil palm and Bradyrhizobium sp. (strain NC 92, or fungicide (iprodione had no effect on disease severity, yield, or the amount of total nitrogen content in stems or seeds of bambara groundnut plant.

Mana Kanjanamaneesathian

2007-01-01

111

Suppression subtractive hybridization and comparative expression of a pore-forming toxin and glycosyl hydrolase genes in Rhizoctonia solani during potato sprout infection.  

Science.gov (United States)

Rhizoctonia solani is a plant pathogenic fungus that causes black scurf on tubers and stem and stolon canker on underground parts of potato plant. Early in the season, the fungus attacks germinating sprouts underground before they emerge from the soil. Damage at this stage results in delayed emergence of weakened plants with poor and uneven stands. The mechanism underlying this phenomenon has been investigated in this study by coupling a cDNA-suppression subtractive hybridization (SSH) library to differential screening to identify transcripts of R. solani that are down-regulated during infection of potato sprouts. We report on the identification of 33 unique genes with functions related to carbohydrate binding, vitamin synthesis, pathogenicity, translation, ATP and nucleic acid binding and other categories. RACE-PCR was used to clone and characterize the first full-length cDNA clones, RSENDO1 and RSGLYC1 that encode for an eukaryotic delta-endotoxin CytB protein and an intracellular glycosyl hydrolase, respectively. Quantitative real-time PCR revealed the down-regulation of RSENDO1 during infection of potato sprouts and the up-regulation of RSGLYC1 when the fungus was grown on a cellulose-based nutrient medium. In contrast, additional experiments have highlighted the down-regulation of RSENDO1 when R. solani was co-cultured with the mycoparasite Stachybotrys elegans and the bacterial antagonist Bacillus subtilis B26. These results advance our understanding of R. solani-potato interaction in subterranean parts of the plant. Such approaches could be considered in building an efficient integrated potato disease management program. PMID:25472038

Chamoun, Rony; Samsatly, Jamil; Pakala, Suman B; Cubeta, Marc A; Jabaji, Suha

2014-12-01

112

Evaluación de la actividad quitinasa en procesos de control biológico de rhizoctonia solani y fusarium oxysporum f. sp. lycopersici en tomate, mediante fitoinvigorización de semillas en presencia de trichoderma koningii Evaluation of chitinase activity in biological control process of rhizoctonia solani y fusarium oxysporum f. sp. lycopersici in tomate, by using seed priming in the presence of trichoderma koningii  

OpenAIRE

El propósito del presente trabajo fue el de establecer el posible papel de las quitinasas en un modelo de control, utilizando pregerminación controlada de semillas en presencia de Trichoderma koningii. Este método mostró ser eficiente para el control de Rhizoctonia solani y de Fusarium oxysporum en tomate. Al analizar los extractos y exudados de semillas y los extractos de suel...

Cotes A. M.; Clavijo A.

1998-01-01

113

Associação de Rhizoctonia solani Grupo de Anastomose 4 (AG-4 HGI e HGIII à espécies de plantas invasoras de área de cultivo de batata Rhizoctonia solani anastomosis group 4 (AG-4 HGI and HGIII associated with weed species from a potato cropping area  

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Full Text Available Os grupos 3 e 4 de anastomose (AG-3 e AG-4 do fungo Rhizoctonia solani são importantes grupos associados à batata no mundo. No Brasil, o AG-3 é relatado afetando principalmente batata e fumo. Já o AG-4 causa perdas consideráveis em culturas de importância econômica, como a soja, o feijão e o amendoim, podendo ocorrer também em hortaliças como o espinafre, o pimentão, o brócolis, o tomate, a batata e frutíferas como o melão. Recentemente foi constatada, em Brasília-DF, a associação de R. solani a plantas invasoras em áreas de cultivo de batata. Entretanto, não há informação a respeito da etiologia do patógeno bem como do papel de espécies invasoras como outras hospedeiras no ciclo do patógeno. Objetivou-se com esse estudo caracterizar isolados de R. solani obtidos de batata e de outras três espécies de plantas invasoras associadas a áreas de cultivo da cultura: juá-de-capote [Nicandra physaloides (L. Pers., Solanaceae], beldroega (Portulaca oleracea L., Portulacaceae, e caruru (Amaranthus deflexus L., Amaranthaceae. Foi confirmada a hipótese de que os isolados obtidos de R. solani de beldroega, caruru e juá-de-capote pertencem ao grupo 4 de anastomose e são patogênicos à batata, exceto o isolado de beldroega. Estes isolados apresentaram patogenicidade cruzada às três espécies e também patogênicos à maria-pretinha (Solanum americanum Mill., uma outra espécie de Solanaceae invasora. A classificação dos isolados no grupo AG-4 HGI ou no grupo AG-4 HGIII (isolado de caruru foi confirmada através de características culturais e moleculares (seqüenciamento da região ITS-5.8S do rDNA. Os resultados deste trabalho trazem implicações importantes para o manejo das podridões radiculares de Rhizoctonia em batata.The anastomosis groups 3 and 4 (AG-3 and AG-4 of the fungus Rhizoctonia solani are important groups associated with potatoes worldwide. In Brazil, the AG-3 is reported affecting mainly potatoes and tobacco. The AG-4 cause considerable losses in crops of economic importance, such as soybean, beans and peanuts and may also occur in vegetables such as spinach, pepper, broccoli, tomatoes, potatoes and fruit such as melons. The association of R. solani with invasive plants was recently established in potato production areas from Brasília, DF. However, there is no information about the etiology of the pathogen as well as the role of invasive species as alternative hosts in the life cycle of the pathogen. The objective of this study was to characterize isolates of R. solani obtained from potatoes and three other invasive plant species associated with areas of potato production: Shoo-fly plant [Nicandra physaloides (L. Pers., Solanaceae], pigweed (Portulaca oleracea L., Portulacaceae, and low-amaranth (Amaranthus deflexus L., Amaranthaceae. It was confirmed the hypothesis that the R. solani isolates obtained from pigweed, low-amaranth and Shoo-fly plant belong to the anastomosis group 4 and, except for the isolate from pigweed, are pathogenic to potatoes. These isolates were cross pathogencic to all the three weed species tested and also to American nightshade (Solanum americanum Mill., another Solanaceae invasive of potato fields. The placement of the isolates in the group AG-4 HGI or in the group AG-4 HGIII (isolate from caruru was confirmed by cultural and molecular characteristics (sequencing of the ITS-5.8S region of rDNA. The results of this study provide important implications for the management of the Rhizoctonia root rot in potatoes.

Fátima Aparecida da Silva-Barreto

2010-06-01

114

Associação de Rhizoctonia solani Grupo de Anastomose 4 (AG-4 HGI e HGIII) à espécies de plantas invasoras de área de cultivo de batata / Rhizoctonia solani anastomosis group 4 (AG-4 HGI and HGIII) associated with weed species from a potato cropping area  

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Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Os grupos 3 e 4 de anastomose (AG-3 e AG-4) do fungo Rhizoctonia solani são importantes grupos associados à batata no mundo. No Brasil, o AG-3 é relatado afetando principalmente batata e fumo. Já o AG-4 causa perdas consideráveis em culturas de importância econômica, como a soja, o feijão e o amendo [...] im, podendo ocorrer também em hortaliças como o espinafre, o pimentão, o brócolis, o tomate, a batata e frutíferas como o melão. Recentemente foi constatada, em Brasília-DF, a associação de R. solani a plantas invasoras em áreas de cultivo de batata. Entretanto, não há informação a respeito da etiologia do patógeno bem como do papel de espécies invasoras como outras hospedeiras no ciclo do patógeno. Objetivou-se com esse estudo caracterizar isolados de R. solani obtidos de batata e de outras três espécies de plantas invasoras associadas a áreas de cultivo da cultura: juá-de-capote [Nicandra physaloides (L.) Pers., Solanaceae], beldroega (Portulaca oleracea L., Portulacaceae), e caruru (Amaranthus deflexus L., Amaranthaceae). Foi confirmada a hipótese de que os isolados obtidos de R. solani de beldroega, caruru e juá-de-capote pertencem ao grupo 4 de anastomose e são patogênicos à batata, exceto o isolado de beldroega. Estes isolados apresentaram patogenicidade cruzada às três espécies e também patogênicos à maria-pretinha (Solanum americanum Mill.), uma outra espécie de Solanaceae invasora. A classificação dos isolados no grupo AG-4 HGI ou no grupo AG-4 HGIII (isolado de caruru) foi confirmada através de características culturais e moleculares (seqüenciamento da região ITS-5.8S do rDNA). Os resultados deste trabalho trazem implicações importantes para o manejo das podridões radiculares de Rhizoctonia em batata. Abstract in english The anastomosis groups 3 and 4 (AG-3 and AG-4) of the fungus Rhizoctonia solani are important groups associated with potatoes worldwide. In Brazil, the AG-3 is reported affecting mainly potatoes and tobacco. The AG-4 cause considerable losses in crops of economic importance, such as soybean, beans a [...] nd peanuts and may also occur in vegetables such as spinach, pepper, broccoli, tomatoes, potatoes and fruit such as melons. The association of R. solani with invasive plants was recently established in potato production areas from Brasília, DF. However, there is no information about the etiology of the pathogen as well as the role of invasive species as alternative hosts in the life cycle of the pathogen. The objective of this study was to characterize isolates of R. solani obtained from potatoes and three other invasive plant species associated with areas of potato production: Shoo-fly plant [Nicandra physaloides (L.) Pers., Solanaceae], pigweed (Portulaca oleracea L., Portulacaceae), and low-amaranth (Amaranthus deflexus L., Amaranthaceae). It was confirmed the hypothesis that the R. solani isolates obtained from pigweed, low-amaranth and Shoo-fly plant belong to the anastomosis group 4 and, except for the isolate from pigweed, are pathogenic to potatoes. These isolates were cross pathogencic to all the three weed species tested and also to American nightshade (Solanum americanum Mill.), another Solanaceae invasive of potato fields. The placement of the isolates in the group AG-4 HGI or in the group AG-4 HGIII (isolate from caruru) was confirmed by cultural and molecular characteristics (sequencing of the ITS-5.8S region of rDNA). The results of this study provide important implications for the management of the Rhizoctonia root rot in potatoes.

Fátima Aparecida da, Silva-Barreto; Wagner Vicente, Pereira; Maisa Boff, Ciampi; Marcos Paz Saraiva, Câmara; Paulo Cezar, Ceresini.

2010-06-01

115

Potencial antifúngico de cepas de Bacillusspp. y extracto de Larrea tridentatacontra Rhizoctonia solanien el cultivo de la papa (Solanum tuberosum L.) / Antifungal potential of Bacillus spp. strains and Larrea tridentata extract against Rhizoctonia solani on potato (Solanum tuberosum L.) crop  

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Full Text Available El cultivo de papa en México es el que más funguicidas requiere para prevenir y controlar diversas enfermedades, estimándose que en este cultivo se aplican el 21,3% del total de los funguicidas disponibles. Los pesticidas sintéticos se destinan principalmente para combatir los hongos Phytophthora in [...] festans y Rhizoctonia solani. Esto trae como consecuencia severos daños a la salud y a los ecosistemas; es por eso que existe la necesidad de encontrar nuevas opciones para el manejo sustentable de los patógenos que atacan a este cultivo. Se realizaron investigaciones en condiciones de laboratorio, invernadero y campo con los siguientes objetivos (1) analizar el efecto antifúngico de tres cepas de bacterias del género Bacillus (B3, B9 y B15) contra R. solani, así como su efecto promotor del crecimiento en plantas de papa, (2) determinar el efecto de un extracto resinoso obtenido de hojas de Larrea tridentata contra el hongo R. solani, y (3) establecer si existe un efecto sinérgico al mezclar las cepas de Bacillus con el extracto de L. tridentata. Los resultados indicaron que las cepas bacterianas tuvieron una clara actividad antifúngica, al igual que el extracto de L. tridentata. Las cepas de Bacillus sobresalieron además por su efecto estimulador del crecimiento de las plantas y del rendimiento de papa, así como por el efecto sinérgico al mezclar las bacterias con el extracto de Larrea; un efecto potenciador similar se observó al aplicar la mezcla de las cepas. Los resultados obtenidos con las cepas de Bacillus, así como su mezcla con el extracto de L. tridentata son alentadores. Los mismos sugieren que podrían ser utilizados para apoyar programas de control biológico contra R. solani. Sin embargo, es necesario continuar con más trabajos in vivo para validar estos resultados. Abstract in english Potato crop requires more fungicides than any other crop in Mexico to prevent and control several diseases. More than 21,3% of the total available fungicides are required for cropping potato. High quantities of synthetic pesticides are intended to control Phytophthora infestans and Rhizoctonia solan [...] i fungi. As a result, this produces severe health problems and ecosystem disturbances. There is then an urgent need for finding new options for sustainable management of potato crop diseases. Several experiments were conducted under laboratory, greenhouse, and field conditions, to: (1) analyze the antifungal effect of bacteria strains of the genus Bacillus, and their effect on potato plant growth; (2) determine the effect of a resinous extract from Larrea tridentata leaves against the fungus R. solani, and (3) establish if there is a synergic effect when Bacillus spp. are mixed with L. tridentata extract. Results indicate an antifungal effect of bacterial strains and Larrea extract. Bacillus strains also stimulated plant growth and yield increase. A synergic effect was detected when Bacillus spp. were mixed with Larrea extract; a similar outcome occurred with the mixture of B3, B9 and B15 strains. Results obtained with Bacillus and Larrea, as well as with their mixture are encouraging since they could be used as an organic option for biological control programs against the fungus R. solani. However, more in vivo research is necessary to validate these results.

FD, Hernández-Castillo; RH, Lira-Saldivar; L, Cruz-Chávez; G, Gallegos-Morales; Me, Galindo-Cepeda; E, Padrón-Corral; M, Hernández-Suárez.

2008-12-01

116

Impact of Gamma Irradiation Stresses II. Control of Sugarbeet Pathogens Rhizoctonia solani Kuhn and Sclerotium rolfsii Sacc.  

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Full Text Available To control the fungal pathogens attacked sugarbeet plant, we subjected R. solani and S. rolfsii to different gamma irradiation doses (0.0, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 7.0 kGy for R. solani and 0.0, 0.5, 1.0, 2.0, 3.0 and 4.0 kGy for S. rolfsii. The growth activities of R. solani were completely inhibited at dose 7.0 kGy, while S. rolfsii at 4.0 kGy. The infection percentage was inhibited with gamma irradiation doses increased for both R. solani and S. rolfsii. This was confirmed by the SDS-PAGE for cellular proteins of both R. solani and S. rolfsii, which showed a great variation in protein bands for the same fungus at different gamma irradiation doses. Finally, we can conclude that the gamma irradiation dose to control pathogenic fungi varies with different pathogenic fungi to control the pathogenicity of R. solani, we irradiate it at 7.0 kGy dose while at 4.0 kGy for S. rolfsii.

Tarek A. A. Moussa

2003-01-01

117

Eficiência de diferentes moléculas na redução dos sintomas da queima das bainhas em arroz e no crescimento de Rhizoctonia solani in vitro / Efficiency of different molecules on the reduction of sheath blight symptoms in rice and on Rhizoctonia solani growth in vitro  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este estudo verificou a eficiência da aplicação de diferentes moléculas em reduzir o comprimento relativo da lesão (CRL) da queima das bainhas em arroz. Plantas dos cultivares BR-Irga 409 e Labelle foram cultivadas em solução nutritiva e inoculadas com Rhizoctonia solani, no estádio de máximo perfil [...] hamento. Às 24 horas antes da inoculação, as bainhas das plantas foram pulverizadas com soluções de silicato de potássio (SP), silicato de potássio + fósforo (SP+F), Acibenzolar-S-Metil (ASM), fungicida Carbendazim, quitosana desacetilada (QD), etileno (ET) e fosfito de potássio (FP). Plantas cujas bainhas foram pulverizadas com água destilada serviram como testemunhas. O efeito das moléculas contidas nesses produtos no crescimento micelial de R. solani foi testado in vitro. Para BR-Irga 409, o CRL foi menor com a aplicação do FP, em relação aos demais tratamentos, exceto o Carbendazim. A aplicação do Carbendazim reduziu em 86,1% o CRL, em relação à testemunha. O CRL foi significativamente menor no cultivar BR-Irga 409 do que no 'Labelle', com aplicação do FP. O crescimento micelial de R. solani foi reduzido apenas pelo FP e Carbendazim, em comparação com os demais tratamentos. Não houve diferença significativa entre os tratamentos testemunha, SP e SP+F para a concentração de Si nas bainhas das plantas dos dois cultivares. Abstract in english This study aimed to test the efficiency of different molecules on the reduction of the relative lesion extension (RLE) of sheath blight in rice. Plants of cultivars BR-Irga 409 and Labelle were grown in nutrient solution and inoculated with Rhizoctonia solani at the maximum tillering stage. At 24 ho [...] urs before inoculation, sheaths of plants were sprayed with solutions of potassium silicate (PS), potassium silicate + phosphorus (PS+P), Acibenzolar-S-Methyl (ASM), Carbendazim fungicide, deacetylated chitosan (DC), ethylene (ET) and potassium phosphite (PP). Sheaths from plants sprayed with water served as the control treatment. The effect of these products on R. solani mycelia growth was also studied in vitro. For BR-Irga 409, the RLE was lower with the application of PP compared with the other treatments, except the Carbendazim. The application of Carbendazim reduced in 86.1% the RLE in comparison with the control. The RLE was lower for BR-Irga 409 than for Labell with the application of PP. Mycelia growth of R. solani was inhibited only by PP and Carbendazim in comparison with the other treatments. There was no significant difference among the treatments control, PS, and PS+P for silicon concentration on sheaths of plants of the two cultivars.

Daniel Augusto, Schurt; Fabrício Ávila, Rodrigues; Naiara Fernandes Abreu, Souza; Ricardo Dutra, Reis.

2013-04-01

118

Efeitos de materiais orgânicos e da umidade do solo na patogenicidade de Rhizoctonia solani Kühn GA-4 HGI ao feijoeiro The role of the organic material amended and the soil moisture on the pathogenicity of Rhizoctonia solani Kühn AG-4 HGI in snap bean  

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Full Text Available Foram avaliados, em casa de vegetação, os efeitos das seguintes variáveis sobre a patogenicidade de Rhizoctonia solani GA-4 HGI a plantas de feijão (Phaseolus vulgaris L., em solo artificialmente infestado: presença de materiais orgânicos com diferentes relações C:N (torta de mamona e bagaço de cana; níveis de decomposição da matéria orgânica, e condições de umidade do solo incorporado. A umidade do solo até o momento da semeadura foi mantida sob duas condições: 20% ou acima de 80% da capacidade de campo. Foram realizadas semeaduras aos 0, 7, 14, 21, 28 e 35 dias após inoculação e incorporação. As avaliações foram realizadas 14 dias após cada semeadura. O material com baixa relação C:N propiciou o aumento da incidência de R. solani no feijoeiro, enquanto o material com alta relação C:N não interferiu na incidência do patógeno. A incidência de R. solani no feijoeiro, em solo incorporado, foi independente da condição de umidade.The pathogenicity of Rhizoctonia solani AG-4 HGI on bean (Phaseolus vulgaris L. plants was evaluated, in artificially infested soil under greenhouse conditions, when submitted to the following treatments: amendments with different C:N ratios (castor-oil cake and sugar-cane bagasse; different organic matter decomposition levels; different moisture contents of the amended soil. Until the moment of sowing the soil moisture was maintained at 20% of the moisture-holding capacity or above 80%. The sowings were made at 0, 7, 14, 21, 28 and 35 days after the inoculation and amendments incorporation. Evaluations were carried out 14 days after each sowing date. The amendment with low C:N ratio increased the incidence of R. solani on bean plants, in any decomposition level, whereas the amendment with high C:N ratio did not interfere on the incidence of the pathogen. The incidence of R. solani on bean plants, in a soil amended with both castor-oil cake or sugar-cane bagasse, was independent of the soil moisture condition.

Roseli Chela Fenille

1999-10-01

119

Efeitos de materiais orgânicos e da umidade do solo na patogenicidade de Rhizoctonia solani Kühn GA-4 HGI ao feijoeiro / The role of the organic material amended and the soil moisture on the pathogenicity of Rhizoctonia solani Kühn AG-4 HGI in snap bean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Foram avaliados, em casa de vegetação, os efeitos das seguintes variáveis sobre a patogenicidade de Rhizoctonia solani GA-4 HGI a plantas de feijão (Phaseolus vulgaris L.), em solo artificialmente infestado: presença de materiais orgânicos com diferentes relações C:N (torta de mamona e bagaço de can [...] a); níveis de decomposição da matéria orgânica, e condições de umidade do solo incorporado. A umidade do solo até o momento da semeadura foi mantida sob duas condições: 20% ou acima de 80% da capacidade de campo. Foram realizadas semeaduras aos 0, 7, 14, 21, 28 e 35 dias após inoculação e incorporação. As avaliações foram realizadas 14 dias após cada semeadura. O material com baixa relação C:N propiciou o aumento da incidência de R. solani no feijoeiro, enquanto o material com alta relação C:N não interferiu na incidência do patógeno. A incidência de R. solani no feijoeiro, em solo incorporado, foi independente da condição de umidade. Abstract in english The pathogenicity of Rhizoctonia solani AG-4 HGI on bean (Phaseolus vulgaris L.) plants was evaluated, in artificially infested soil under greenhouse conditions, when submitted to the following treatments: amendments with different C:N ratios (castor-oil cake and sugar-cane bagasse); different organ [...] ic matter decomposition levels; different moisture contents of the amended soil. Until the moment of sowing the soil moisture was maintained at 20% of the moisture-holding capacity or above 80%. The sowings were made at 0, 7, 14, 21, 28 and 35 days after the inoculation and amendments incorporation. Evaluations were carried out 14 days after each sowing date. The amendment with low C:N ratio increased the incidence of R. solani on bean plants, in any decomposition level, whereas the amendment with high C:N ratio did not interfere on the incidence of the pathogen. The incidence of R. solani on bean plants, in a soil amended with both castor-oil cake or sugar-cane bagasse, was independent of the soil moisture condition.

Roseli Chela, Fenille; Nilton Luiz de, Souza.

1959-19-01

120

Eficiência de diferentes moléculas na redução dos sintomas da queima das bainhas em arroz e no crescimento de Rhizoctonia solani in vitro Efficiency of different molecules on the reduction of sheath blight symptoms in rice and on Rhizoctonia solani growth in vitro  

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Full Text Available Este estudo verificou a eficiência da aplicação de diferentes moléculas em reduzir o comprimento relativo da lesão (CRL da queima das bainhas em arroz. Plantas dos cultivares BR-Irga 409 e Labelle foram cultivadas em solução nutritiva e inoculadas com Rhizoctonia solani, no estádio de máximo perfilhamento. Às 24 horas antes da inoculação, as bainhas das plantas foram pulverizadas com soluções de silicato de potássio (SP, silicato de potássio + fósforo (SP+F, Acibenzolar-S-Metil (ASM, fungicida Carbendazim, quitosana desacetilada (QD, etileno (ET e fosfito de potássio (FP. Plantas cujas bainhas foram pulverizadas com água destilada serviram como testemunhas. O efeito das moléculas contidas nesses produtos no crescimento micelial de R. solani foi testado in vitro. Para BR-Irga 409, o CRL foi menor com a aplicação do FP, em relação aos demais tratamentos, exceto o Carbendazim. A aplicação do Carbendazim reduziu em 86,1% o CRL, em relação à testemunha. O CRL foi significativamente menor no cultivar BR-Irga 409 do que no 'Labelle', com aplicação do FP. O crescimento micelial de R. solani foi reduzido apenas pelo FP e Carbendazim, em comparação com os demais tratamentos. Não houve diferença significativa entre os tratamentos testemunha, SP e SP+F para a concentração de Si nas bainhas das plantas dos dois cultivares.This study aimed to test the efficiency of different molecules on the reduction of the relative lesion extension (RLE of sheath blight in rice. Plants of cultivars BR-Irga 409 and Labelle were grown in nutrient solution and inoculated with Rhizoctonia solani at the maximum tillering stage. At 24 hours before inoculation, sheaths of plants were sprayed with solutions of potassium silicate (PS, potassium silicate + phosphorus (PS+P, Acibenzolar-S-Methyl (ASM, Carbendazim fungicide, deacetylated chitosan (DC, ethylene (ET and potassium phosphite (PP. Sheaths from plants sprayed with water served as the control treatment. The effect of these products on R. solani mycelia growth was also studied in vitro. For BR-Irga 409, the RLE was lower with the application of PP compared with the other treatments, except the Carbendazim. The application of Carbendazim reduced in 86.1% the RLE in comparison with the control. The RLE was lower for BR-Irga 409 than for Labell with the application of PP. Mycelia growth of R. solani was inhibited only by PP and Carbendazim in comparison with the other treatments. There was no significant difference among the treatments control, PS, and PS+P for silicon concentration on sheaths of plants of the two cultivars.

Daniel Augusto Schurt

2013-04-01

121

Distinctively variable sequence-based nuclear DNA markers for multilocus phylogeography of the soybean- and rice-infecting fungal pathogen Rhizoctonia solani AG-1 IA  

Scientific Electronic Library Online (English)

Full Text Available A series of multilocus sequence-based nuclear DNA markers was developed to infer the phylogeographical history of the Basidiomycetous fungal pathogen Rhizoctonia solani AG-1 IA infecting rice and soybean worldwide. The strategy was based on sequencing of cloned genomic DNA fragments (previously used [...] as RFLP probes) and subsequent screening of fungal isolates to detect single nucleotide polymorphisms (SNPs). Ten primer pairs were designed based on these sequences, which resulted in PCR amplification of 200-320 bp size products and polymorphic sequences in all markers analyzed. By direct sequencing we identified both homokaryon and heterokaryon (i.e. dikaryon) isolates at each marker. Cloning the PCR products effectively estimated the allelic phase from heterokaryotic isolates. Information content varied among markers from 0.5 to 5.9 mutations per 100 bp. Thus, the former RFLP codominant probes were successfully converted into six distinctively variable sequence-based nuclear DNA markers. Rather than discarding low polymorphism loci, the combination of these distinctively variable anonymous nuclear markers would constitute an asset for the unbiased estimate of the phylogeographical parameters such as population sizes and divergent times, providing a more reliable species history that shaped the current population structure of R. solani AG-1 IA.

Maisa B., Ciampi; Liane Rosewich, Gale; Eliana G. de Macedo, Lemos; Paulo C., Ceresini.

122

Transgenic rice with inducible ethylene production exhibits broad-spectrum disease resistance to the fungal pathogens Magnaporthe oryzae and Rhizoctonia solani.  

Science.gov (United States)

Rice blast (Magnaporthe oryzae) and sheath blight (Rhizoctonia solani) are the two most devastating diseases of rice (Oryza sativa), and have severe impacts on crop yield and grain quality. Recent evidence suggests that ethylene (ET) may play a more prominent role than salicylic acid and jasmonic acid in mediating rice disease resistance. In this study, we attempt to genetically manipulate endogenous ET levels in rice for enhancing resistance to rice blast and sheath blight diseases. Transgenic lines with inducible production of ET were generated by expressing the rice ACS2 (1-aminocyclopropane-1-carboxylic acid synthase, a key enzyme of ET biosynthesis) transgene under control of a strong pathogen-inducible promoter. In comparison with the wild-type plant, the OsACS2-overexpression lines showed significantly increased levels of the OsACS2 transcripts, endogenous ET and defence gene expression, especially in response to pathogen infection. More importantly, the transgenic lines exhibited increased resistance to a field isolate of R. solani, as well as different races of M. oryzae. Assessment of the growth rate, generational time and seed production revealed little or no differences between wild type and transgenic lines. These results suggest that pathogen-inducible production of ET in transgenic rice can enhance resistance to necrotrophic and hemibiotrophic fungal pathogens without negatively impacting crop productivity. PMID:23031077

Helliwell, Emily E; Wang, Qin; Yang, Yinong

2013-01-01

123

In vitro antifungal activities of extracts of fruits and other morphological parts of xanthium strumarium against the plant pathogen, rhizoctonia solani  

International Nuclear Information System (INIS)

In vitro antifungal activity of different plant parts of Xanthium strumarium (Compositae) was investigated against Rhizoctonia solani to seek safe natural alternatives to the harmful synthetic fungicides. The most active plant parts of X. strumarium were seeds, extracted with n-hexane and the leaves, extracted with absolute ethanol. The two treatments resulted in growth inhibition diameters of 45 mm and 47 mm, respectively. The value of MIC lied between 350.0 and 175.0 mg of Xanthium oil/mL. Gas liquid chromatography of the seed oil of X. strumarium revealed the presence of the usual fatty acids, palmitoleic (7.6%), oleic (21.6%) and linoleic (70.4%). The oil was separated into free fatty acids fraction and unsaponifiable matter fraction. The unsaponifiable matter fraction was separated on TLC, out of six separated compounds, two were active against R. solani. The infrared spectra (FTIR) of these two purified compounds pointed to a long chain hydrocarbon back-bone for both, one of them possessing in addition, an alcoholic moiety. (author)

124

Compositional variability and antifungal potentials of ocimum basilicum, O. tenuiflorum, O. gratissimum and O. kilimandscharicum essential oils against Rhizoctonia solani and Choanephora cucurbitarum.  

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The composition of hydrodistilled essential oils of Ocimum basilicum L. (four chemovariants), O. tenuiflorum L., O. gratissimum L., and O. kilimandscharicum Guerke were analyzed and compared by using capillary gas chromatography (GC/FID) and GC-mass spectrometry (GC/MS). Phenyl propanoids (upto 87.0%) and monoterpenoids (upto 83.3%) were prevalent constituents distributed in the studied Ocimum taxa. The major constituents of the four distinct chemovariants of O. basilicum were methyl chavicol (86.3%), methyl chavicol (61.5%)/linalool (28.6%), citral (65.9%); and linalool (36.1%)/citral (28.8%). Eugenol (66.5% and 78.0%) was the major constituent of O. tenuiflorum and O. gratissimum. Eugenol (34.0%), ?-bisabolene (15.4%), (E)-?-bisabolene (10.9%), methyl chavicol (10.2%) and 1,8-cineole (8.2%) were the major constituents of O. kilimandscharicum. In order to explore the potential for industrial use, the extracted essential oils were assessed for their antifungal potential through poison food technique against two phytopathogens, Rhizoctonia solani and Choanephora cucurbitarum, which cause root and wet rot diseases in various crops. O. tenuiflorum, O. gratissimum, and O. kilimandscharicum exhibited complete growth inhibition against R. solani and C. cucurbitarum after 24 and 48 h of treatment. O. basilicum chemotypes showed variable levels of growth inhibition (63.0%-100%) against these two phytopathogens. PMID:25522548

Padalia, Rajendra C; Verma, Ram S; Chauhan, Amit; Goswami, Prakash; Chanotiya, Chandan S; Saroj, Arvind; Samad, Abdul; Khaliq, Abdul

2014-10-01

125

Antagonistic Potentials of Rhizosphere-associated Bacterial Isolates Against Soil-borne Diseases of Tomato and Pepper Caused by Sclerotinia sclerotiorum and Rhizoctonia solani  

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Full Text Available By use of selective media, putative antagonist bacterial isolates were isolated from rhizosphere-associated soils from different parts of the Amik plain. Isolates to be tested were chosen in approximate proportion to their abundance on the plates. Selected 113 bacterial isolates were screened for in vitro antagonism towards two important soil-borne root infecting plant pathogens, Sclerotinia sclerotiorum and Rhizoctonia solani by using dual culture test. From this test, significant numbers of bacterial isolates, but not the yeast, were found to produce inhibition zones by inhibiting the hyphal growth of fungal pathogens to a varying degree. On the basis of the result obtained from the preliminary screening test, isolates belonging to Bacillus spp. and Pseudomonas spp. found to be highly efficient against fungal pathogens used in the experiment. Among the inhibitory isolates, bacterial isolates AKB50 and AFP104 significantly suppressed hyphal growth of S. sclerotiorum and R. solani by 75.3 and 83.3%, respectively. This study indicates that selected bacterial strain have potential for controlling of soil-borne disease agents.

Soner Soylu

2005-01-01

126

Rhizoctonia solani AG-3PT is the major pathogen associated with potato stem canker and black scurf in Colombia / Rhizoctonia solani GA-3PT es el principal patógeno asociado con el chancro del tallo y la sarna negra de la papa en Colombia  

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Full Text Available SciELO Colombia | Language: English Abstract in spanish El chancro del tallo y la sarna negra de la papa son ocasionados por el hongo basidiomicete Thanatephorus cucumeris (especie anamórfica compleja Rhizoctonia solani). Estas dos enfermedades tienen una distribución global en los cultivos de papa, pero su etiología local es variable, dependiendo de la [...] predominancia de diferentes grupos de anastomosis (GA s) en una localidad dada. Al interior de esta especie compleja se han encontrado varios GA s asociados con el chancro del tallo y la sarna negra, como GA -1, GA -2-1, GA -2-2, GA -3, GA -4, GA -5 y GA -9. Este artículo presenta el estudio más exhaustivo a nivel poblacional realizado en Colombia sobre la distribución de los GA s de R. solani en lotes comerciales de papa. Se examinaron 433 aislamientos colectados entre 2005 y 2009 en las regiones paperas más importantes del país. Los aislamientos fueron asignados a los GA s por PCR usando cebadores específicos para el GA -3 y secuenciamiento del ITS -ADNr e interacciones hifales. El GA -3PT cubrió la mayoría de los aislamientos (88.45%), el GA -2-1 tuvo el 2.54% y los aislamientos restantes correspondieron a cepas binucleadas de R. solani (GA -A, -E, y -I). Las pruebas de patogenicidad sobre diferentes especies de plantas, incluida la papa, evidenciaron que el GA -3PT afecta los tallos de las plantas de la familia Solanácea; en otros hospedantes evaluados el daño fue severo en las raíces pero no en los tallos; el GA -2-1 ocasionó chancros en tallos de plántulas de Solanum tuberosum cv. Capiro y R. raphanistrumi and B. campestris subsp. Rapa, y pudrición de raíces en otras plantas. Los resultados de nuestro estudio indican que el GA -3PT de R. solani es el principal patógeno asociado con las enfermedades del chancro del tallo y la sarna negra de la papa en Colombia Abstract in english Stem canker and black scurf diseases of potatoes are caused by the basidiomycetous fungus Thanatephorus cucumeris (anamorphic species complex Rhizoctonia solani). These diseases have worldwide distribution wherever potato is grown but their etiology varies depending on the predominance of distinct R [...] . solani anastomosis groups (AG s) in a particular area. Within the species complex, several AG s have been associated with stem canker or black scurf diseases, including AG -1, AG -2-1, AG -2-2, AG -3, AG -4, AG -5 and AG -9. This article reports on the most comprehensive population-based study, providing evidence on the distribution of R. solani AG s in Colombian potato fields. A total of 433 isolates were sampled from the main potato cropping areas in Colombia from 2005 to 2009. Isolates were assigned to AG s by conventional PCR assays using specific primers for AG -3, sequencing of the ITS -rDNA and hyphal interactions. Most of the isolates evaluated were assigned to AG -3PT (88.45%), and a few to AG -2-1 (2.54%). The remaining isolates were binucleate Rhizoctonia (AG -A, E, and I). Pathogenicity tests on the stems and roots of different plant species, including the potato, showed that AG -3PT affects the stems of solanaceous plants. In other plant species, damage was severe in the roots, but not the stems. AG -2-1 caused stem canker of Solanum tuberosum cv. Capiro and in R. raphanistrumi and B.campestris subsp. Rapa plantlets and root rot in other plants. The results of our study indicated that R. solani AG -3PT was the principal pathogen associated with potato stem canker and black scurf diseases of potatoes in Colombia

Rosa Lilia, Ferrucho; Johan Manuel, Cifuentes; Paulo, Ceresini; Celsa, García-Domínguez.

2012-08-01

127

Efeito da solarização do solo, seguida pela aplicação de Trichoderma spp: ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4 Effect of soil solarization, followed or not by the application of Trichoderma spp: or fungicides for the control of Pythium aphanidermatum and Rhizoctonia solani AG-4  

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Full Text Available O presente trabalho foi realizado com o objetivo de estudar alternativas para a desinfestação de solos, especialmente considerando a retirada do brometo de metila do mercado. Avaliou-se o efeito da solarização do solo, seguida ou não pela aplicação de isolados de Trichoderma spp. ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4, responsáveis por tombamento e podridão de raízes em várias culturas. Dois experimentos foram realizados em Piracicaba, SP (latitude 22º 42' e longitude 47º38', um em campo aberto e outro no interior de uma casa-de-vegetação vedada, em delineamento em blocos casualizados, em esquema fatorial (2x3, tendo como fatores a solarização (com e sem e os tratamentos (com fungicida, um isolado de Trichoderma sp. e uma testemunha. Bolsas de náilon contendo solo naturalmente infestado com P. aphanidermatum ou solo contendo propágulos de R. solani AG-4 foram enterradas a 10 cm de profundidade, em parcelas solarizadas ou não, nos dois ambientes. Após 30 dias de solarização, as bolsas foram coletadas e o solo infestado com P. aphanidermatum recebeu os tratamentos: o isolado de Trichoderma sp. IB-26 ou o fungicida metalaxyl + mancozeb. O solo contendo propágulos de R. solani foi tratado com o isolado de Trichoderma sp. IB-17 ou o fungicida pencycuron. As soluções dos fungicidas foram aplicadas na forma de rega. Também foram mantidas testemunhas para ambos os patógenos. Avaliou-se a viabilidade de P. aphanidermatum pelo tombamento de pós-emergência de plântulas de pepino e de R. solani pelo número de plântulas de rabanete sobreviventes ao tombamento de pré e pós-emergência. A solarização, o controle biológico e a solarização seguida pelo controle biológico não promoveram o controle de P. aphanidermatum, obtido apenas com metalaxyl + mancozeb, nos solos solarizados ou não. A solarização aplicada nos dois ambientes controlou R. solani, assim como o fungicida pencycuron, mas não houve efeito sinérgico na associação entre as técnicas. A aplicação do isolado de Trichoderma sp. IB-17 não proporcionou o controle desse patógeno nos solos solarizados ou não.The development of alternative strategies for soil desinfestation with methyl bromide is necessary since the use of this compound faces increasing restrictions worldwide. Therefore the effect of soil solarization, followed by the application of isolates of Trichoderma spp. or fungicides, was evaluated for the control of Pythium aphanidermatum and Rhizoctonia solani, both can cause damping-off and root rots of several crops. Two experiments were carried out, one under greenhouse conditions and the other one under field conditions, both in a randomized block design, in factorial scheme (2x3, involving the combination of soil solarization (solarized and non-solarized soils and the application of chemical or biological treatments, plus controls. Nylon bags containing soil naturally infested with P. aphanidermatum or soil with propagules of R. solani AG-4 were buried at 10 cm soil depth in plots solarized or non-solarized. After 30 days of solarization the bags were collected and the soil infested with P. aphanidermatum was treated with Trichoderma sp. (isolate IB-26 or with the fungicide metalaxyl + mancozeb, whereas the soil containing propagules of R. solani received an isolate of Trichoderma sp. (isolate IB-17 or the fungicide pencycuron. Fungicide suspensions were irrigated over the soil. A control was maintained for the soils infested with both pathogens. Viability of P. aphanidermatum and R. solani was evaluated by post-emergence damping-off of cucumber seedlings and by pre and post-emergence damping-off of radish seedling, respectively. Soil solarization, the biological treatment and the association of both treatments had no effect on the control of P. aphanidermatum, which was achieved only by the treatment with metalaxyl + mancozeb in the solarized and non-solarized soil. Soil solarization applied in both environments as well as the fungicide pencycu

Flávia Rodrigues Alves Patrício

2007-06-01

128

Efeito da solarização do solo, seguida pela aplicação de Trichoderma spp: ou de fungicidas, sobre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4 / Effect of soil solarization, followed or not by the application of Trichoderma spp: or fungicides for the control of Pythium aphanidermatum and Rhizoctonia solani AG-4  

Scientific Electronic Library Online (English)

Full Text Available O presente trabalho foi realizado com o objetivo de estudar alternativas para a desinfestação de solos, especialmente considerando a retirada do brometo de metila do mercado. Avaliou-se o efeito da solarização do solo, seguida ou não pela aplicação de isolados de Trichoderma spp. ou de fungicidas, s [...] obre o controle de Pythium aphanidermatum e de Rhizoctonia solani AG-4, responsáveis por tombamento e podridão de raízes em várias culturas. Dois experimentos foram realizados em Piracicaba, SP (latitude 22º 42' e longitude 47º38'), um em campo aberto e outro no interior de uma casa-de-vegetação vedada, em delineamento em blocos casualizados, em esquema fatorial (2x3), tendo como fatores a solarização (com e sem) e os tratamentos (com fungicida, um isolado de Trichoderma sp. e uma testemunha). Bolsas de náilon contendo solo naturalmente infestado com P. aphanidermatum ou solo contendo propágulos de R. solani AG-4 foram enterradas a 10 cm de profundidade, em parcelas solarizadas ou não, nos dois ambientes. Após 30 dias de solarização, as bolsas foram coletadas e o solo infestado com P. aphanidermatum recebeu os tratamentos: o isolado de Trichoderma sp. IB-26 ou o fungicida metalaxyl + mancozeb. O solo contendo propágulos de R. solani foi tratado com o isolado de Trichoderma sp. IB-17 ou o fungicida pencycuron. As soluções dos fungicidas foram aplicadas na forma de rega. Também foram mantidas testemunhas para ambos os patógenos. Avaliou-se a viabilidade de P. aphanidermatum pelo tombamento de pós-emergência de plântulas de pepino e de R. solani pelo número de plântulas de rabanete sobreviventes ao tombamento de pré e pós-emergência. A solarização, o controle biológico e a solarização seguida pelo controle biológico não promoveram o controle de P. aphanidermatum, obtido apenas com metalaxyl + mancozeb, nos solos solarizados ou não. A solarização aplicada nos dois ambientes controlou R. solani, assim como o fungicida pencycuron, mas não houve efeito sinérgico na associação entre as técnicas. A aplicação do isolado de Trichoderma sp. IB-17 não proporcionou o controle desse patógeno nos solos solarizados ou não. Abstract in english The development of alternative strategies for soil desinfestation with methyl bromide is necessary since the use of this compound faces increasing restrictions worldwide. Therefore the effect of soil solarization, followed by the application of isolates of Trichoderma spp. or fungicides, was evaluat [...] ed for the control of Pythium aphanidermatum and Rhizoctonia solani, both can cause damping-off and root rots of several crops. Two experiments were carried out, one under greenhouse conditions and the other one under field conditions, both in a randomized block design, in factorial scheme (2x3), involving the combination of soil solarization (solarized and non-solarized soils) and the application of chemical or biological treatments, plus controls. Nylon bags containing soil naturally infested with P. aphanidermatum or soil with propagules of R. solani AG-4 were buried at 10 cm soil depth in plots solarized or non-solarized. After 30 days of solarization the bags were collected and the soil infested with P. aphanidermatum was treated with Trichoderma sp. (isolate IB-26) or with the fungicide metalaxyl + mancozeb, whereas the soil containing propagules of R. solani received an isolate of Trichoderma sp. (isolate IB-17) or the fungicide pencycuron. Fungicide suspensions were irrigated over the soil. A control was maintained for the soils infested with both pathogens. Viability of P. aphanidermatum and R. solani was evaluated by post-emergence damping-off of cucumber seedlings and by pre and post-emergence damping-off of radish seedling, respectively. Soil solarization, the biological treatment and the association of both treatments had no effect on the control of P. aphanidermatum, which was achieved only by the treatment with metalaxyl + mancozeb in the solarized and non-solarized soil. Soil solarization applied in both en

Flávia Rodrigues Alves, Patrício; Hiroshi, Kimati; João, Tessarioli Neto; Ademir, Petenatti; Benedito Camargo, Barros.

2007-06-01

129

Antagonistic Potentials of Rhizosphere-associated Bacterial Isolates Against Soil-borne Diseases of Tomato and Pepper Caused by Sclerotinia sclerotiorum and Rhizoctonia solani  

OpenAIRE

By use of selective media, putative antagonist bacterial isolates were isolated from rhizosphere-associated soils from different parts of the Amik plain. Isolates to be tested were chosen in approximate proportion to their abundance on the plates. Selected 113 bacterial isolates were screened for in vitro antagonism towards two important soil-borne root infecting plant pathogens, Sclerotinia sclerotiorum and Rhizoctonia solani by using dual culture test. From this test, significant numbers of...

Soner Soylu; Mine Soylu, E.; Sener Kurt; Ekici, Ozlem K.

2005-01-01

130

Evaluation of chitinase activity in biological control process of rhizoctonia solani y fusarium oxysporum f. sp. lycopersici in tomate, by using seed priming in the presence of trichoderma koningii  

OpenAIRE

The present work intended to establish in a control model, the possible role of chitinases by using seed priming in the presence of Trichoderma koningii. This method showed to be efficient to control Rhizoctonia solani and Fusarium oxysporum in tomato. The analysis of seed extracts and exudates, and soil extracts from soil seeded with seeds primed in the presence of T. koningii showed high endochitinase activity in the samples. This activity was higher than that exhibited by samples from prim...

Clavijo, A.; Cotes, A. M.

2012-01-01

131

Reacción de genotipos de frijol a Fusarium spp. y Rhizoctonia solani bajo condiciones de campo e invernadero / Reaction of common bean genotypes to Fusarium spp. y Rhizoctonia solani under field and greenhose conditions  

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Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Las pudriciones de raíz inducidas por R. solani y Fusarium spp. afectan al cultivo de frijol (Phaseolus vulgaris L.) en el altiplano de México. Para identificar genotipos de frijol resistentes a ambos hongos bajo condiciones de invernadero y campo, se realizaron dos experimentos en 2001. En campo, b [...] ajo condiciones de temporal, se sembraron 15 genotipos el 24 de julio, en suelo naturalmente infestado con hongos inductores de pudriciones de raíz, en Texcoco, Estado de México. Durante el ciclo del cultivo se determinó la incidencia y severidad de la enfermedad en las etapas fenológicas V3, R5, R7 y R8; además, se registraron temperatura ambiente y precipitación pluvial diaria. Los mismos genotipos se sembraron en invernadero el 27 de julio de 2001 en macetas con suelo del mismo sitio, las determinaciones realizadas en ambos ensayos fueron similares. Se tomaron muestras de tejido vegetal para el aislamiento e identificación de los hongos causantes de pudriciones de raíz; ambos, R. solani y Fusarium spp. se recuperaron. En campo, se observaron pudriciones de raíz durante todo el ciclo, con la mayor severidad en las etapas R5 y R7, sin que se observaran genotipos inmunes. Negro Tacaná mostró resistencia intermedia a Fusarium spp. y G 12729 (genotipo silvestre) fue resistente en las primeras etapas fenológicas. En invernadero, ningún genotipo mostró un patrón de resistencia durante el ciclo. En campo, el ataque de R. solani fue menos severo que el de Fusarium spp., mientras que en invernadero el ataque de R. solani fue más alto. En campo, los genotipos Pinto Villa, Wisc RRR, PI 203958 y BAT 477 mostraron resistencia intermedia y fueron consistentes en su respuesta a ambos hongos, pero en invernadero mostraron susceptibilidad. La incidencia y la severidad de los patógenos mostraron diferencias relacionadas con las condiciones climáticas registradas durante el ciclo del cultivo. Abstract in english The root rot induced damage caused by R. solani and Fusarium spp. affects common bean (Phaseolus vulgaris L.) production at the highlands of Mexico. To identify bean genotypes resistant to both fungi, two experiments were conductedunderfieldand greenhouse conditions. In the field, under rainfed cond [...] itions, 15 bean genotypes were planted on July 24 2001, at Texcoco, state of Mexico. Incidence and attack severity were determined at the phenological stages V3, R5, R7 and R8; also, daily temperature and precipitation were recorded. The same genotypes were planted under greenhouse conditions on July 27th, 2001 in pots with soil from the same site. Plant samples were collected from all genotypes for isolation and identification of fungi causing root rots. Both,R. solani and Fusarium spp. were recovered. Under field conditions, root rots were observed throughout the cycle, with the greatest severity at the R5 and R7 stages, no immune genotypes were observed. Cultivar Negro Tacana showed intermediate resistance to Fusarium spp. and G 12729 (a wild genotype) was resistant during the early phenological stages. Under greenhouse conditions, any genotype showed a consistent resistance pattern during the cycle. Atthe field, the attack by R. solani was less severe than that of Fusarium spp., whereas in the greenhouse the attack R. solani was severe. Atthe field, cultivars Pinto Villa, Wisc RRR, PI 203,958 and BAT 477 were intermediate and consistent in its response to both fungi; however, were susceptible in the greenhouse. The disease incidence and severity on the genotypes showed differences related to climatic conditions registered during the growth cycle.

Rosa, Navarrete-Maya; Evangelina, Trejo-Albarrán; Jorge, Navarrete-Maya; José Manuel, Prudencio-Sains; Jorge Alberto, Acosta Gallegos.

2009-12-01

132

Evaluación del método de conservación en papel de filtro en dos cepas de Bacillus subtilis Cohn mediante la actividad antagónica frente a Rhizoctonia solani Kühn / Evaluation of Filter Paper Disks Preserving Method in Two Bacillus subtilis Cohn. Strains by Antagonistic Activity on Rhizoctonia solani Kühn  

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Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish Se evaluó la actividad antagónica de dos cepas de Bacillus subtilis conservadas en discos de papel de filtro a 4°C por un período de tres años. Se escogieron las cepas del género B. subtilis: Bs-21 y Bs-42, aisladas del suelo, autóctonas de Cuba, y antagónicas de la cepa Rs-10 de Rhizoctonia solani. [...] Se determinó la viabilidad, pureza y actividad antagónica de cinco colonias de Bs-42 y una de Bs-21, escogidas al azar y cultivadas en agar nutriente. Las colonias seleccionadas se evaluaron por el método de enfrentamiento dual en papa dextrosa agar, después de 96 h de incubación a 30°C. Ambas cepas presentaron una viabilidad de 108 UFC/mL. Los cultivos mantuvieron la pureza, las características morfológicas y respuesta positiva a la tinción de Gram, comparadas con la cepa de B. subtilis ATCC 6633. Todas las colonias seleccionadas inhibieron el crecimiento micelial de la cepa Rs-10 de R. solani, no así la de referencia. El análisis de varianza realizado mostró diferencias significativas en el porcentaje de inhibición de las colonias ensayadas. La cepa Bs-21 resultó ser la de menor inhibición con el 78%, y Bs-421 y Bs-422 las de mayor porcentaje con el 98%. Abstract in english Antagonistic activity of two Bacillus subtilis strains preserved in filter paper disks at 4°C for a period of three years was evaluated. Strains Bs-21 and Bs-42, isolated from Cuban soil and antagonists to Rhizoctonia solani Rs-10 were choiced. Five colonies from Bs-42 and one from Bs-21, randomly s [...] elected were growth in nutrient agar. The antagonism was compared by dual culture method in PDA after 96 h at 30°C. Viability of both strains was 108 CFU/mL. Selected colonies kept purity, morphological characteristics and positive response to Gram stain compared with B. subtilis ATCC 6633. All selected colonies inhibited mycelial growth of R. solani Rs-10, but not the reference strain. Strain Bs-21 had the lower inhibition (78%) while Bs-421 and Bs-422 had the higher percent (98%). Variance analysis showed significant differences in the percentage of inhibition exhibited by tested colonies.

Acenet I, Sosa López; Victoria, Pazos Álvarez-Rivera; Giovanni, Borges Marín; Marleny, González García; Enrique, Ponce Grijuela.

2011-03-01

133

SENSIBILIDADE DE Rhizoctonia solani Kuhn, A FUNGICIDAS “IN VITRO” E EM PLÂNTULAS DE ALGODOEIRO (Gossypium hirsutum L., EM CONDIÇÕES DE CASA DE VEGETAÇÃO SENSIBILITY OF Rhizoctonia solani Kuhn TO FUNGICIDES “IN VITRO” AND IN COTTON PLANTULES (Gossypium hirsutum L AT GREENHOUSE CONDITIONS  

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Full Text Available

Foram instalados nas dependências do Departamento Fitossanitário da Escola de Agronomia - UFG, ensaio “in vitro”, em BDA2 e a nível de Casa de Vegetação, objetivando testar a eficiência de diferentes dosagens de Iprodione + Thiran (Rovrin em comparação com PCNB (Brassicol 75 BR, TMTD (Rhodiauran 70 e Captan + Pencycuron (Monceren para o controle de Rhizoctonia solani Kuhn, na cultura do algodoeiro, através do tratamento de sementes. Os resultados obtidos, nas condições de realização dos ensaios, permitem concluir que os fungicidas Rovrin - 320 g.i.a., Monceren - 210 g.i.a., Rovrin - 240 g.i.a., Rovrin - 200 g.i.a., PCNB - 450 g.i.a./100 litros de água ou 100 kg de sementes mostraram-se eficientes e não diferiram estatisticamente entre si no controle de R. solani, enquanto que o produto TMTD (Rhodiauran 70 na dosagem de 280 g.i.a./100 litros de água ou 100 kg de sementes de algodoeiro não se mostrou eficiente no controle deste agente causal.

Aiming to test the efficiency of different dosages of Iprodione + Thiram (Rovrin in comparison with PCNB (Brassicol 75 BR, TMTD (Rhodiauran 70 and Captan + Pencycuron (Monceren for controlling Rhizoctonia solani Kuhn, in cotton plantation, through seeds treatment, was mounted essays “in vitro” at greenhouse level and BDA, in the Phytosanitary Department annexes of School of Agronomy-UFG. The results obtained, at essays conditions, permit to conclude that fungicides Rovrin - 320 g.i.a., Monceren - 210 g.i.a., Rovrin - 240 g.i.a., Rovrin - 200 g.i.a., PCNB - 450 g.i.a./l00 liters of water or 100kg of seeds, were efficient and statistically had no variation among them, in controlling R. solani, while chemical product TMTD (Rhodiauran 70, at dosage of 280 g.i.a./100 liters of water or 100 kg of cotton seeds, was not efficient in controlling this causal agent.

Wilson Ferreira de Oliveira

2007-09-01

134

Evaluation of chitinase activity in biological control process of rhizoctonia solani y fusarium oxysporum f. sp. lycopersici in tomate, by using seed priming in the presence of trichoderma koningii Evaluación de la actividad quitinasa en procesos de control biológico de rhizoctonia solani y fusarium oxysporum f. sp. lycopersici en tomate, mediante fitoinvigorización de semillas en presencia de trichoderma koningii  

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Full Text Available The present work intended to establish in a control model, the possible role of chitinases by using seed priming in the presence of Trichoderma koningii. This method showed to be efficient to control Rhizoctonia solani and Fusarium oxysporum in tomato. The analysis of seed extracts and exudates, and soil extracts from soil seeded with seeds primed in the presence of T. koningii showed high endochitinase activity in the samples. This activity was higher than that exhibited by samples from primed seeds without antagonist and unprimed seeds.   In vitro evaluation of the hydrolytic activity of the extracts and exudates were performed using F. oxysporum and R. solani cell walls. The results also showed that the samples from seeds primed in the presence of T. koningii exhibited higher endochitinase activity than the others. These data allowed us to conclude that seed priming in the presence of T. koningii promotes endochinolytic activity in seeds. It was also concluded that this chitinase activity is related with the protection previously observed.El propósito del presente trabajo fue el de establecer el posible papel de las quitinasas en un modelo de control, utilizando pregerminación controlada de semillas en presencia de Trichoderma koningii. Este método mostró ser eficiente para el control de Rhizoctonia solani y de Fusarium oxysporum en tomate. Al analizar los extractos y exudados de semillas y los extractos de suelo sembrado con semillas pregerminadas en presencia de T. koningii, se encontró que éstos presentaron niveles significativamente mayores de actividad endoquitinasa que los provenientes de semillas pregerminadas en ausencia del antagonista y que los provenientes de semillas no pregerminadas. Al evaluar in-vitro la actividad hidrolítica de dichos extractos y exudados, utilizando paredes celulares de R. solani y de Fusarium oxysporum, los provenientes de semillas pregerminadas en presencia de T. koningii también mostraron significativamente mayor actividad endoquitinasa que la presentada en los otros tratamientos. Se pudo concluir que la pregerminación controlada de semillas en presencia de T. koningii estimula la actividad endoquitinolítica de las semillas y que esta actividad quitinasa estuvo relacionada con la protección previamente obtenida. 

Cotes A. M.

1998-12-01

135

Influence of Weather and Soil Parameters on Development of Wet Root Rot in Pulse Crops and Virulence Analysis of Rhizoctonia solani Isolates  

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Full Text Available Wet root rot caused by Rhizoctonia solani Kühn in pulse crops was favored by wide range of soil parameters like temperature, humidity, pH, electric conductivity and soil texture. The areas surveyed for the collection of the isolates showing variable atmospheric temperature and relative humidity and low to medium levels of soil organic carbon and high level of available phosphorus influenced the development of the disease incidence from 2-48%. Seventy three cultivars of mungbean, twenty eight cultivars of urdbean and eight cultivars of cowpea were evaluated against virulent isolate of R. solani (RASC 30 to design a set of differential cultivars for virulence analysis. Two cultivars of urdbean, namely, NDU3-4 and IPU2-14, one cultivar of mungbean, namely, HUM 1 and three cultivars of cowpea, namely, V240, V585 and DCP7 showed resistant reactions. Four cultivars of urdbean, namely, TU94-2, KU323, KUG216 and B3-8-8, one cultivar of mungbean, namely, PDM54 and two cultivars of cowpea, namely, V578 and DCP13 were moderately resistant against the pathogen. The virulence analysis of 90 isolates of the pathogen representing 7 anastomosis groups (AGs isolated from pulse crops of 16 agro-ecological regions of India on a set of differential cultivars, namely, HUM 1, PDM 54 and Pusa Vishal of mungbean, NDU 3-4, KU 323, Uttara of urdbean and V 240, V 578 and Pusa Sukomal of cowpea grouped the isolates into five pathotypes. The differential cultivar for each pathotype was identified. The pathotypes were not corresponding to the AG type of the isolates. Except one pathotype (isolate RMPG28 belonging to AG2-3, each pathotype had the isolates from different AGs.

S. C. Dubey

2012-10-01

136

Métodos de evaluación y reacción de cultivares para resistencia al añublo de la vaina del arroz causado por Rhizoctonia solani AG-1 IA / Evaluation methods and cultivars reaction for resistance to the rice sheath blight caused by Rhizoctonia solani AG-1 IA  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish El arroz (Oryza sativa L.) en Venezuela, es afectado por el añublo de la vaina causado por Rhizoctonia solani (Teleomorfo = Thanatephorus cucumeris). No existe resistencia completa ante esta enfermedad. Por ello, los programas de mejoramiento genético deben evaluar un alto número de cultivares para [...] seleccionar aquellos cuantitativamente mejores en resistencia. Los objetivos fueron comparar métodos de evaluación de resistencia y la reacción de cultivares para resistencia al añublo de la vaina del arroz causado por R. solani AG-1 IA. Los métodos de evaluación usados fueron microcámaras y bola de micelio en umbráculo, la prueba de cinetina en laboratorio y la infestación con arroz colonizado bajo condiciones de campo. Se evaluaron 23 genotipos de arroz, incluyendo variedades testigo. Tres haplotipos de R. solani, previamente caracterizados, fueron utilizados para las inoculaciones. Los ensayos fueron de bloques completos al azar con tres repeticiones. La efectividad de los ensayos se determinó con base a la discriminación de los testigos de reacción conocida y a la mejor correlación de los métodos de laboratorio y umbráculo con los resultados de campo. El método de microcámaras, combinado con el aislado de R. solani A5B4 (64), presentó la mejor correlación con los resultados de campo (r = 0,50 en promedio), seguido por el método de bola de micelio (r = 0,49, promedio). Los cultivares testigo ‘Tetep’ (resistente) y ‘Lemont’ (susceptible) fueron consistentes en los ensayos. El análisis de componentes principales identificó los genotipos CT15150-M-11-4-3-2-M (derivado de un cruce con O. glaberrima), ‘SD20A’ y ‘D-Sativa’ con los mejores niveles de resistencia. Estos resultados indican la existencia de métodos confiables para evaluar el añublo de la vaina y de cultivares adaptados con resistencia a la enfermedad. Abstract in english The rice (Oryza sativa L.), in Venezuela, is affected by sheath blight caused by Rhizoctonia solani (teleomorph = Thanatephorus cucumeris). No complete resistance has been found in the world. In consequence, breeding programs should evaluate many cultivars for selecting those with the best quantitat [...] ive level of resistance. The objectives were to compare methods of evaluation and cultivars reaction for resistance to the sheath blight caused by R. solani AG-1 IA. The evaluation methods were microchamber and mycelium ball in greenhouse conditions, kinetin test in laboratory and colonized rice infestation under field conditions. The cultivars were 23 genotypes of rice, including control varieties. Three haplotypes of R. solani, previously characterized, were used for the inoculations. The experimental designs were randomized complete block with three replications. The effectiveness of the trials was determined based on the discrimination of controls with well-known reaction and the best correlation of the laboratory and greenhouse methods with the field results. The method of microchamber using the isolate A5B4 (64) had the best correlation with field results (r = 0.50 on average), followed by the method of ball mycelium (r = 0.49, on average). The control cultivars 'Tetep' (resistant) and 'Lemont' (susceptible) were consistent across the experiments. The principal component analysis identified the genotypes CT15150-M-11-4-3-2-M (derived from a cross with O. glaberrima), 'SD20A' and 'D-Sativa' with the best levels of resistance. These results indicate the existence of reliable methods to evaluate this disease and adapted cultivars with resistance to rice sheath blight.

Alex, González-Vera; Eduardo, Graterol; Brígida, Borges; Francis, Hernández.

2011-04-01

137

Características de aislamientos de Rhizoctonia solani Huhn y su importancia como patógenos de Stylosanthes guianensis (Aubl. Sw.  

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Full Text Available Se encontró considerable variación en el crecimiento, color, zonificación, esclerocios, textura del micelio y en la virulencia de siete aislamientos de R. solani. Como seis aislamientos fueron multinucleados y uno binucleado, se demostró que es indispensable determinar ésta característica en ensayos con R. solani. Los aislamientos se ubicaron en los grupos de anastomosis AG -1, AG-2, AG-4; pero en los ensayos con electroforesis de isoenzirnas los modelos de bandas para los a islamientos probadores de los AG y los probados en éste estudio fueron diferentes, lo que llevó a cuestionar la importancia de los AG. Los ecotípos de Centrosema spp y P. phaseoloides fueron más afectados que los de S. guianensis, D. ovalifolium y S. capitata. La reacción al daño de R. solani fue diferencial en los ecotipos CIAT 1283 (tardío y 184 (común y tuvo mucha relación con la edad; en general, la enfermedad se incrementó con la edad en el eco tipo tardío y disminuyó con ésta o fue independiente en el ecotipo común; el ecotipo más fectado fue el tardío; las pérdidas de forraje no fueron considerables, pero el efecto en la digestibilidad fue notorio; la capacidad de rebrote fue buena en 184. Se observó un estímulo en el crecimiento de las plantas de S.guianensis y D. ovalifolium.Considerable variation was found in the growth, color, zonation, sclerotia, mycelial texture and virulence of seven isolates of R. solani. Six multinuclease and one binuclease isolates were determined, demonstrating that it is indispensable to determine this characteristic in trials with this pathogen. The isolates were placed in three anastomosis group AG -1, AG -2 and AG -4; but with electrophoresis of isoenzymes it was found that the band models were different for the known rest AG iso lates and those isolates proven in this study which questions the importance of anastomosis qroups. Ecotypes of Centrosema spp. and P. phaseoloides were more affected than those of S. guianensis, D. ovalifolium and S. capitata. The reaction on damage by R. solani was differencial for ecotypes C IAT 1283 (tardío and 184 (comrno n and was related to age. In general, the disease increased with age in the tardio and decreased or was independent of age in the cornrnon: the tardio was more affected; forage losses were not cosiderable but the effect on the digestibility was noted; the regrowth capacity was good in the cornrnon. A stimulus in the growth of plants of S. guianensis and D. ovalifolium was observed.

Lenne Jilliam M.

1986-06-01

138

Detection of trypsin inhibitor in seeds of Eucalyptus urophylla and its influence on the in vitro growth of the fungi Pisolithus tinctorius and Rhizoctonia solani  

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Full Text Available Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two proteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds and fractions partially purified by gel filtration, with inhibitory activity against trypsin, inhibited in vitro the mycelial growth of a compatible isolate of the ectomycorrhizal fungus Pisolithus tinctorius and allowed an unsatisfactory growth of another isolate from Pinus taeda, considered incompatible for this eucalyptus species. The same amounts of inhibitory proteins, when tested in vitro on the pathogen Rhizoctonia solani, did not exhibit any effect on the growth of the pathogen. These results indicate the existence of proteases inhibitors in seeds of E. urophylla which could influence the complex biochemical system that differentiates mechanisms of symbiosis and pathogenicity between plants and microorganisms.

Tremacoldi Célia Regina

2002-01-01

139

Co-expression of RCH10 and AGLU1 confers rice resistance to fungal sheath blight Rhizoctonia solani and blast Magnorpathe oryzae and reveals impact on seed germination.  

Science.gov (United States)

Rice sheath blight and blast caused by Rhizoctonia solani Kühn and Magnorpathe oryzae respectively, are the two most destructive fungal diseases in rice. With no genetic natural traits conferring resistance to sheath blight, transgenic manipulation provides an obvious approach. In this study, the rice basic chitinase gene (RCH10) and the alfalfa ?-1,3-glucanase gene (AGLU1) were tandemly inserted into transformation vector pBI101 under the control of 35S promoter with its enhancer sequence to generate a double-defense gene expression cassette pZ100. The pZ100 cassette was transformed into rice (cv. Taipei 309) by Agrobacterium-mediated transformation. More than 160 independent transformants were obtained and confirmed by PCR. Northern analysis of inheritable progenies revealed similar levels of both RCH10 and AGLU1 transcripts in the same individuals. Disease resistance to both sheath blight and blast was challenged in open field inoculation. Immunogold detection revealed that RCH10 and AGLU1 proteins were initially located mainly in the chloroplasts and were delivered to the vacuole and cell wall upon infection, suggesting that these subcellular compartments act as the gathering and execution site for these anti-fungal proteins. We also observed that transgenic seeds display lower germination rate and seedling vigor, indicating that defense enhancement might be achieved at the expense of development. PMID:24197785

Mao, Bizeng; Liu, Xuehui; Hu, Dongwei; Li, Debao

2014-04-01

140

Characterization of genes involved in biosynthesis of a novel antibiotic from Burkholderia cepacia BC11 and their role in biological control of Rhizoctonia solani  

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Genetic manipulation of fluorescent pseudomonads has provided major insight into their production of antifungal molecules and their role in biological control of plant disease. Burkholderia cepacia also produces antifungal activities, but its biological control activity is much less well characterized, in part due to difficulties in applying genetic tools. Here the authors report genetic and biochemical characterization of a soil isolate of B. cepacia relating to its production of an unusual antibiotic that is very active against a variety of soil fungi. Purification and preliminary structural analyses suggest that this antibiotic (called AFC-BC11) is a novel lipopeptide associated largely with the cell membrane. Analysis of conditions for optimal production of AFC-BC11 indicated stringent environmental regulation of its synthesis. Furthermore, the authors show that production of AFC-BC11 is largely responsible for the ability of B. cepacia BC11 to effectively control the damping-Off of cotton caused by the fungal pathogen Rhizoctonia solani in a gnotobiotic system. Using Tn5 mutagenesis, they identified, cloned, and characterized a region of the genome of strain BC11 that is required for production of this antifungal metabolite. DNA sequence analysis suggested that this region encodes proteins directly involved in the production of a nonribosomally synthesized lipopeptide.

Kang, Y.; Carlson, R.; Tharpe, W.; Schell, M.A. [Univ. of Georgia, Athens, GA (United States)

1998-10-01

141

Liquid culture production of microsclerotia and submerged conidia by Trichoderma harzianum active against damping-off disease caused by Rhizoctonia solani.  

Science.gov (United States)

Media and culturing protocols were identified that supported the formation of submerged conidia and microsclerotia (MS) by Trichoderma harzianum Rifai strain T-22 using liquid culture fermentation. Liquid media with a higher carbon concentration (36 g L(-1)) promoted MS formation at all C:N ratios tested. Hyphae aggregated to form MS after 2 d growth and after 7 d MS were fully melanized. This is the first report of MS formation by T. harzianum or any species of Trichoderma. Furthermore, submerged conidia formation was induced by liquid culture media, but yields, desiccation tolerance, and storage stability varied with C:N ratio and carbon rate. Air-dried MS granules (<4 % moisture) retained excellent shelf life under cool and unrefrigerated storage conditions with no loss in conidial production. A low-cost complex nitrogen source based on cottonseed flour effectively supported high MS yields. Amending potting mix with dried MS formulations reduced or eliminated damping-off of melon seedlings caused by Rhizoctonia solani. Together, the results provide insights into the liquid culture production, stabilization process, and bioefficacy of the hitherto unreported MS of T. harzianum as a potential biofungicide for use in integrated management programs against soilborne diseases. PMID:25813507

Kobori, Nilce N; Mascarin, Gabriel M; Jackson, Mark A; Schisler, David A

2015-04-01

142

Interaction of Collimonas strain IS343 with Rhizoctonia solani at low carbon availability in vitro and in soil (online first)  

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Collimonas sp. IS343, isolated from an organically-farmed arable soil and characterized as a broad-range oligotrophic bacterium, was shown to degrade chitin and to suppress R. solani mycelium growth under in vitro conditions at high and low carbon availabilities. In contrast to C. fungivorans Ter331, strain IS343 did not respond with an increase in growth rate to higher carbon levels in liquid medium, it reached higher cell numbers in carbon-poor media and it showed better survival in bulk so...

Senechkin, I. V.; Overbeek, L. S.; Er, H. L.; Vos, O. J.; Bruggen, A. H. C.

2013-01-01

143

Importancia del método estadístico para el cálculo de la CE50 y CE95 de algunos isotiocianatos evaluados contra Rhizoctonia solani Kühn / Importance of the statistical method applied to calculate the EC50 and EC95 of some isothiocyanates evaluated against Rhizoctonia solani Kühn  

Scientific Electronic Library Online (English)

Full Text Available En el marco de la evaluación del efecto de algunos isotiocianatos (ITC) sobre el crecimiento de Rhizoctonia solani Kühn, la presente investigación establece también si el método estadístico utilizado determina diferencias considerables en los valores de la concentración efectiva media (CE50) y la co [...] ncentración efectiva 95 (CE95) de estos compuestos. Para ello se realizó un experimento in vitro, y se estimaron dichos valores mediante regresiones lineales y no lineales. Los compuestos evaluados contra R. solani AG-3 fueron: alil isotiocianato (AITC), bencil isotiocianato (BITC), fenil isotiocianato (PITC), fenetil isotiocianato (PEITC) y metil isotiocianato (MITC). El ensayo se llevó a cabo en el Laboratorio de Biotecnología de la Facultad de Agronomía de la Universidad Nacional de Colombia, sede Bogotá. Manteniendo agitación constante, se prepararon diluciones de los ITC utilizando metanol como solvente, para obtener las concentraciones 0,0; 0,01; 0,1; 1,0 y 10,0%, que correspondieron a los distintos tratamientos evaluados. En cada uno de ellos se agregaron 50 mL de una de estas soluciones a las unidades experimentales, consistentes en cajas de petri con medio PDA y micelio de R. solani AG-3, selladas herméticamente y almacenadas a temperatura ambiente. Pasadas 72 y 144 horas después de la aplicación de los tratamientos (hdt), se tomaron fotografías digitales para calcular el área de crecimiento micelial con el software MapMaker® 3.5. Esto permitió obtener la Concentración Efectiva Media (CE50) y la Concentración Efectiva 95 (CE95) mediante regresiones lineales, no lineales (modelos Gompertz, logístico y polinómico) y análisis Probit. Los valores obtenidos a partir de este último distan bastante de lo observado, que a su vez coincide con los valores encontrados por regresión lineal. A la concentración del 10%, todos los ITC, excepto PEITC, mostraron un efecto inhibitorio total. Por su parte, BITC mantuvo su efecto fungistático hasta 21 días después de aplicados los tratamientos, mientras que PITC, AITC y MITC mantuvieron un efecto fungistático más prolongado, inclusive hasta un año después de iniciados los tratamientos. Abstract in english Framed in the evaluation of the effect of some isothiocyanates (ITC) on the growth of Rhizoctonia solani Kühn, the present research also studied whether the applied statistical method determines significant differences in the values of the Median (EC50) and 95 (EC95) effective concentrations of thes [...] e compounds. For this purpose, we conducted an in vitro experiment in which said values were calculated by different statistical methods. In vitro efficacy against R. solani AG-3 was tested of allyl isothiocyanate (AITC), benzyl isothiocyanate (BITC), phenyl isothiocyanate (PITC), phenethyl isothiocyanate (PEITC) and methyl isothiocyanate (MITC). Under constant shaking we prepared stock solutions by mixing ITC with methanol as solvent, to get concentrations of 0.0, 0.01, 0.1, 1.0, and 10%, corresponding to the different studied treatments; each of which consisted in the addition of 50 mL of one of these solutions to the experimental units. The latter were Petri dishes containing potato-dextrose-agar medium (PDA) and mycelium of R. solani AG-3. These containers were then sealed with two layers of parafilm and incubated at room temperature. Digital pictures were taken to obtain the colony areas using MapMaker 3.5® software, 72 and 144 hours after the treatments were applied. The Median (EC50) and 95 (EC95) effective concentrations were calculated through linear and non-linear (Gompertz, logistic, and polynomial models) regressions, as well as probit analysis. The values obtained through the latter were found to be considerably different from the actual ones, which in turn coincided with those found by means of linear regressions. All of ITC at 10% concentration were completely inhibitory, with the exception of PEITC. Whereas BITC was fungistatic up to twenty one days after the treatments were applied, PITC, AITC, and MITC h

Luis Federico, Molina-Vargas; Sandra Esperanza, Melo-Martínez.

2010-08-01

144

Identificación y caracterización de seis aislados pertenecientes al género Bacillus promisorios para el control de Rhizoctonia solani Künh y Sclerotium rolfsii Sacc. / Identification and Characterization of Six Isolates from Genera Bacillus with Antagonistic Capacity against Rhizoctonia solani Künh and Sclerotium rolfsii Sacc. Control  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: Spanish Abstract in spanish En la actualidad la identificación de los microorganismos se realiza por varios métodos. Existen métodos clásicos que utilizan como criterios de diferenciación los caracteres fenotípicos morfológicos y fisiológicos. Los kits miniaturizados, como los API 50CHB para Bacillusayudan a caracterizar la fi [...] siología de las bacterias pertenecientes a este grupo, de manera fácil y rápida; además, resultan muy útiles para la identificación hasta el nivel de especie por su elevada precisión. La observación de la morfología y esporulación, la respuesta a la tinción de Gram y algunas pruebas bioquímicas permiten, en el caso de Bacillus spp., ubicarlos dentro de su género. El objetivo de esta investigación fue caracterizar morfológica, bioquímica y fisiológicamente seis aislados de suelo y rizosfera pertenecientes al género Bacillus con capacidad antagónica frente a Rhizoctonia solani y Sclerotium rolfsii (Sr.), con la utilización del API 50 CHB.Tres de los aislados resultaron pertenecer a la especie de Bacillus subtilisy otro a B. megateriumcon más del 95% de confiabilidad, además un aislado de B. licheniformis y otro de B. circulans, ambos con el 82,7%. Abstract in english Microorganism identification is realized by several methods, currently. Classical methods utilize phenotypic, morphologic and physiological characters as differentiation criteria. Commercial miniaturized kits as API 50CHB for Bacillus, helps to characterize physiology of this kind of bacteria in an [...] easy and fast way; furthermore they are useful for identification until species level due to their high precision. Observation of morphology and sporulation, the answer to Gram tinction and some biochemical tests permit, in the case of Bacillus spp., put them within they genera. The objective of this investigation was to characterize morphologic, biochemical and physiologically six isolated of genera Bacillusfrom soil and rhizosphere with antagonistic capability in front of Rhizoctonia solani and Sclerotium rolfsii(Sr.), with the utilization of the API 50 CHB. Three of the isolated proved to belong to species Bacillus subtilis and another one to B. megaterium with over than 95% of reliability, also one isolated of B. licheniformis and another one of B. circulans, both with 82.7%.

Acenet I., Sosa López; Victoria, Pazos Álvarez-Rivera; Dania, Torres Campos; Luis, Casadesús Romero.

2011-03-01

145

Detection of trypsin inhibitor in seeds of Eucalyptus urophylla and its influence on the in vitro growth of the fungi Pisolithus tinctorius and Rhizoctonia solani / Descoberta de inibidor de tripsina em sementes de Eucalyptus urophylla e sua influência sobre o crescimento in vitro dos fungos Pisolithus tinctorius e Rhizoctonia solani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Os inibidores de proteases de plantas podem regular a hidrólise de proteínas no interior celular e também participar de seus mecanismos de defesa contra insetos herbívoros e patógenos. No presente trabalho, nós demonstramos que sementes de Eucalyptus urophylla apresentam atividades de inibidores de [...] tripsina e papaína, duas proteases comumente encontradas em seres vivos. Pequenas quantidades de proteínas do extrato protéico bruto de sementes e de frações parcialmente purificadas por filtração em gel, com atividade inibitória de tripsina, inibiram o crescimento micelial in vitro de um isolado compatível do fungo ectomicorrízico Pisolithus tinctorius e permitiram um crescimento insatisfatório de outro isolado de Pinus taeda, considerado compatível para esta espécie de eucalipto. As mesmas concentrações de proteínas, quando testadas in vitro sobre o patógeno Rhizoctonia solani, não demonstraram qualquer efeito sobre seu crescimento. Estes resultados indicam a existência de inibidores de proteases em sementes de E. urophylla, os quais poderiam influenciar o complexo sistema bioquímico que diferencia mecanismos de simbiose e patogenicidade entre plantas e microrganismos. Abstract in english Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two pr [...] oteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds and fractions partially purified by gel filtration, with inhibitory activity against trypsin, inhibited in vitro the mycelial growth of a compatible isolate of the ectomycorrhizal fungus Pisolithus tinctorius and allowed an unsatisfactory growth of another isolate from Pinus taeda, considered incompatible for this eucalyptus species. The same amounts of inhibitory proteins, when tested in vitro on the pathogen Rhizoctonia solani, did not exhibit any effect on the growth of the pathogen. These results indicate the existence of proteases inhibitors in seeds of E. urophylla which could influence the complex biochemical system that differentiates mechanisms of symbiosis and pathogenicity between plants and microorganisms.

Célia Regina, Tremacoldi; Sérgio Florentino, Pascholati.

2002-12-01

146

Efecto inhibitorio in vitro de cinco monoterpenos de aceites esenciales sobre un aislado de Rhizoctonia solani en papa (Solanum tuberosum L.) / Inhibitory Effect in vitro of Five Monoterpens from Essentials Oils on a Rhizoctonia solani Isolate in Potato (Solanum tuberosum L.)  

Scientific Electronic Library Online (English)

Full Text Available En los últimos años la sociedad mundial ha priorizado los aspectos ambientales, y ha conducido un grupo de investigaciones hacia el descubrimiento de nuevas alternativas para el manejo integrado de plagas y enfermedades, con menos efectos negativos al ambiente. Los aceites esenciales, que hasta hace [...] poco eran empleados solamente en la industria farmacéutica y cosmética, en la actualidad tienen gran importancia por su efecto en el control de plagas y enfermedades de las plantas. Basado en este criterio, se evaluó la actividad fungicida de cinco monoterpenos (mentol, timol, alcanfor, citronelal y 1,8 cineol) comúnmente encontrados en aceites esenciales. Se empleó el método de envenenamiento del medio de cultivo a concentraciones de 0,5; 0,1 y el 0,05% p/v para evaluar el efecto inhibitorio de cada uno sobre un aislado de Rhizoctonia solani, causante de la rizoctoniasis en papa. Se calculó el porcentaje de inhibición y los resultados se analizaron estadísticamente. Se obtuvo que timol, mentol y citronelal tuvieron el 100% de inhibición al 0,1 y el 0,5%; Por otra parte, alcanfor y 1,8 cineol mostraron resultados por debajo del 100%; pero se valorarán para posteriores estudios, donde el rango de concentración sea mayor. Abstract in english The looking for new alternative to chemical control for integrated pest management to reduce the environmental impact has received attention internationally in last decades. Essentials oils have been using in pharmaceutical and cosmetic industry, recently they have become in an interesting possibili [...] ty for pest and disease control. The fungicide activity of five monoterpens (menthol, thymol, camphor, citronellal and 1,8 cineol), commonly found in essentials oils was evaluated. The method of culture media poisoning was used with concentration of 0,5; 0,1 y 0,05% w/v. The inhibitory effect was evaluated on a Rhizoctonia solani isolate, pathogen which causes rizoctoniasis in potato crops. The inhibition percentage was calculated and the results were statistically analyzed. Thymol, menthol and citronellal showed 100% of inhibition at 0,5 and 0,1%. The monoterpens camphor and 1, 8 cineol showed lower values of inhibition percentage, but they will taking into account for future studies with a wider range of concentration.

Daymara, Vaillant Flores; Carlos, Romeu Carballo; Elda, Ramos Ramos; Marleny, González García; Rebeca, Ramírez Ochoa; Johan, González Pentón.

2009-09-01

147

EFFECT OF THE TREATMENT OF SEEDS WITH FUNGICIDES IN CONTROLLING DAMPING OFF OF THE BEAN (Phaseolus vulgaris L CAUSED BY Rhizoctonia solani Kuhn EFEITO DO TRATAMENTO DE SEMENTES COM FUNGICIDAS NO CONTROLE DO TOMBAMENTO EM FEIJOEIRO (Phaseolus vulgaris L. CAUSADO POR Rhizoctonia solani Kuhn  

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Some fungicides were tested in control of Rhizoctonia solani in bean (Phaseolus vulgaris planted in soil inoculated with this fungus. The evaluations were made at 10, 20 and 30 days after sowing, observing germination and damping-off. The results showed that the fungicides thiram (280g. a.i./ 100kg seeds have no increased plant stand in Phaseolus vulgaris, in relation to the non treated control. Seed treatments with PCNB (450g a.i./ 100kg seeds, iprodione + thiram (200g a.i/l00kg seeds and iprodione + thirarn (240g a.i./100kg seeds, increased plant stand in percentages varying from 65 to 73%, respectively in relation to non treated control, but the best treatment was with iprodione + thiram (320g a.i./l00kg seeds, presenting an increase around 83%.

Foram testados alguns fungicidas no controle de Rhizoctonia solani em feijoeiro (Phaseolus vulgaris L., semeado em vasos com solo previamente inoculado por este fungo. As avaliações foram feitas aos 10, 20 e 30 dias após o plantio, levando-se em consideração ausência de germinação e plântulas tombadas. Os resultados mostraram que o fungicida thiram (280g i.a./100kg de sementes, não aumentou o stand de plantas em relação à testemunha. Sementes tratadas com PCNB (450g i.a./l00kg de sementes, com iprodione + thiram (200g i.a./l00kg de sementes e com iprodione + thiram (240g i.a./l00kg de sementes aumentaram o stand em percentagens que variaram de 65 a 73%, em relação à testemunha, mas o melhor resultado foi obtido com iprodione + thiram na concentração de 320g i.a./ 100kg de sementes, que promoveu aumento do stand em cerca de 83%.

Rosângela Vera

2007-09-01

148

Evaluación in vitro de aislamientos de Trichoderma harzianum para el control de Rhizoctonia solani, Sclerotium rolfsii y Fusarium oxysporum en plantas de tomate / In vitro evaluation of Trichoderma harzianum for control of Rhizoctonia solani, Sclerotium rolfsii, and Fusarium oxysporum in tomato plants  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in spanish En este estudio se determinó la capacidad antagónica de aislamientos de T. harzianum para el control de Rhizoctonia solani, Sclerotium rolfsii y Fusarium oxysporum en raíces de plantas de tomate. Se obtuvieron 6 aislamientos de T. harzianum de 6 municipios del estado Trujillo, empleando la técnica d [...] e siembra directa de raíces en agar agua acidificada. El antagonismo se realizó en cultivos duales utilizando agar papa dextrosa, incubados a 25 ºC, bajo un diseño al azar, con 18 tratamientos conformados por cada aislamiento de T. harzianum y cada patógeno, 3 tratamientos testigos correspondientes a cada patógeno y 3 repeticiones por tratamiento, evaluándose el modo de acción e inhibición del crecimiento radial al tercer día. Todos los aislamientos de T. harzianum mostraron un rápido crecimiento sin diferencias significativas entre ellos (p>0,05), aún cuando se observó que el T121 fue más eficaz como controlador. Al comparar el crecimiento de los aislamientos de T. harzianum con el de los hongos patógenos, se obtuvieron diferencias significativas (p Abstract in english This study determined the antagonistic capacity of T. harzianum isolates for control of Rhizoctonia solani, Sclerotium rolfsii, and Fusarium oxysporum in the roots of tomato plants. Six T. harzianum isolates were obtained from 6 municipalities of Trujillo State, using the direct inoculation of roots [...] in acidified water agar technique. The antagonism was carried out in dual cultures using potato dextrose agar, incubated at 25 ºC, under a random design, with 18 treatments conformed for each T. harzianum isolate and each pathogen, 3 control treatments corresponding to each pathogen, and 3 repetitions per treatment, evaluating the mode of action and inhibition of radial growth at the third day. All the T. harzianum isolates showed rapid growth without significant differences among them (p>0.05), even though it was observed that T121 was more efficient as controller. When comparing the growth of the T. harzianum isolates with that of the pathogenic fungi, there were significant differences (p

Clemencia, Guédez; Luis, Cañizalez; Carmen, Castillo; Rafael, Olivar.

2012-06-01

149

Impact of Gamma Irradiation Stresses II. Control of Sugarbeet Pathogens Rhizoctonia solani Kuhn and Sclerotium rolfsii Sacc.  

OpenAIRE

To control the fungal pathogens attacked sugarbeet plant, we subjected R. solani and S. rolfsii to different gamma irradiation doses (0.0, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 7.0 kGy for R. solani and 0.0, 0.5, 1.0, 2.0, 3.0 and 4.0 kGy for S. rolfsii). The growth activities of R. solani were completely inhibited at dose 7.0 kGy, while S. rolfsii at 4.0 kGy. The infection percentage was inhibited with gamma irradiation doses increased for both R. solani and S. rolfsii. This was confirmed by...

Moussa, Tarek A. A.; Rizk, Mohamed A.

2003-01-01

150

Evaluación de aislamientos de Trichoderma spp. contra Rhizoctonia solani y Sclerotium rolfsii bajo condiciones in vitro y de invernadero  

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Se evaluó la eficacia biológica de ocho aislamientos de Trichoderma spp. provenientes de suelos de Colombia para el control de los agentes causales de volcamiento, Sclerotium rolfsii y Rhizoctonia solani, bajo condiciones in vitro y de invernadero. Los análisis in vitro mostraron la capacidad antagónica de todos los aislamientos evaluados. En condiciones de invernadero, cuatro aislamientos fueron altamente eficaces contra S. rolfsii en plantas de fríjol en semillero (>90% de reducción de la enfermedad y dos aislamientos fueron eficaces contra R. solani en plantas de algodón en semillero (58 y 61% de reducción de la enfermedad. El análisis UP-PCR y DS-PCR permitió determinar tres grupos de aislamientos; dentro de estas asociaciones formadas no se encontró ninguna relación evidente entre la posición en el dendrograma y la actividad antagónica, pero sí permitió separar las especies de Trichoderma por grupos, e incluso encontrar diferencias dentro de aislamientos de una misma especie. Los resultados muestran que el comportamiento micoparasítico de los aislamientos de Trichoderma spp. varía según el hongo fitopatógeno, evidenciando una amplia especificidad del antagonista por su sustrato, es decir por el hongo atacado; por lo tanto es necesario realizar cuidadosas selecciones del aislamiento de Trichoderma que se utilice en programas de control de fitopatógenos.

Hoyos-Carvajal Liliana

2008-12-01

151

Lippia graveolens and Carya illinoensis Organic Extracts and there in vitro Effect Against Rhizoctonia Solani Kuhn  

OpenAIRE

Problem statement: Plant extracts with polyphenolic compounds obtained with different solvents have been evaluated against plant pathogens. However, most of these extract have been obtained using solvents no allowed under an organic production context. Approach: In the present research was to evaluate the inhibitory effect of polyphenolic extracts from L. graveolens and C. illinoensis, obtained with alternative organic solvents (lanolin and cocoa butter), water and ethanol against R. solani i...

Hernandez-castillo, Francisco D.; Francisco Castillo-Reyes; Gabriel Gallegos-Morales; Raul Rodriguez-Herrera; Aguilar-gonzalez, Cristobal N.

2010-01-01

152

The Use of Antioxidants and Microelements for Controlling Damping-Off Caused by Rhizoctonia solani and Charcoal Rot Caused by Macrophomina phasoliana on Sunflower  

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Full Text Available Seed soaking method or foliar spray of antioxidants (citric acid and salicylic acid at 10 mM and microelements (manganese and zinc at 2 g L-1 were tested to control of the damping-off and charcoal rot diseases of sunflower (varieties Sakha 53 and Giza 102. Field treatments in two different localities i.e., Tag El-Ezz, Dakahlia province and El-Serow, Damietta province were carried out. The high frequency isolated fungi (M. phaseolina and R. solani presented in Tag El-Ezz location. On the other hand, M. phaseolina was isolated at a high frequency compared with R. solani in both locations. Sakha 53 was highly susceptible compered with Giza 102 when artificially infected with both M. phaseolina and R. solani. Laboratory results showed that salicylic acid alone or in combination with citric acid completely inhibited the linear growth of both pathogens i.e., M. phasoliana and R. solani in vitro. A positive correlation between the concentrations of Rizolex-T 50 and its effect on the fungal growth were recorded. The dose of 3 g L-1 prevented the growth of R. solani linear growth in vitro. The greenhouse results revealed that Giza 102 variety was highly susceptible to the infection by R. solani. M. phasoliana showed severe symptoms in both sunflower varieties. On contrary, Giza 102 variety was tolerant to damping-off and charcoal rot diseases than Sakha 53 under field conditions. The application of Rizolex-T 50 followed by citric acid showed a highest percentage of healthy plants followed by the combination of citric acid and salicylic acid. The application of manganese combined with zinc was more effective than the microelements alone. All treatments of antioxidants and microelements significantly reduced the incidence of charcoal rot disease. On the other hand, no significant differences between Rizolex-T 50 and salicylic acid treatments was shown. Sakha 53 variety gave the highest values of plant height and number of leaves plant-1 while Giza 102 recorded the highest values of stem diameter and flower head diameter. The application of citric acid combined with salicylic acid maximized the plant height followed by the mixture of manganese and zinc. Manganese treatment followed by the mixture of citric acid and salicylic acid then zinc were the most effective in increasing the number of leaves plant-1. While, Rizolex-T 50 had no significant effect on plant height and number of leaves plant-1. Microelements were more effective than antioxidants on enhancing the stem and flower head diameters. The combination between manganese and zinc followed by Rizolex-T 50 recorded the maximum values of the stem and flower head diameters. Giza 102 variety recorded the highest values of 100 seeds weight, total phenols, photosynthetic pigments and the percentage of seed oil when the above applications were carried out. Sakha 53 variety showed the highest plant yield under the above treatment. The mixtures of citric and salicylic acids were highly effective in increasing plant yield. The highest values of photosynthetic pigments were shown in salicylic acid treatment followed by Rizolex-T 50. Total phenols content was highest due to Rizolex-T 50 application followed by salicylic acid. Except zinc, seed oil concentration increased significantly in both antioxidants and microelements treatments on oil concentration.

K.M. Abd El-Hai

2009-01-01

153

A New Disease of Gladiolus Caused by Binucleate Rhizoctonia sp.  

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Full Text Available Fungi with Rhizoctonia-like mycelia were isolated from root and stem of Gladiolus (Gladiolus hybrida L. grown in commercial glasshouse in Mahallat, Iran, during the summer and fall of 2003. Isolated fungi were identified as either binucleate or multi nucleate Rhizoctonia sp. On the basis of hyphal characteristics and nuclear number, twenty three isolates of Rhizoctonia sp. were obtained from infected corms and stems. Of the 23 isolate, 9 had binucleate and 14 had multinucleate vegetative hyphal cells. Representative isolates of binucleate Rhizoctonia sp. were characterized for anastomosis, optimum temperature in vitro and virulence on Gladiolus. Isolates of binucleate Rhizoctonia failed to anastomose with tester isolates of Anastomosis Groups (AG-A throug-S (not including AG-J and AG-M. The optimum temperature range for growth rate of binucleate Rhizoctonia sp. was 24-28?C. Growth rate of binucleate Rhizoctonia sp. was more rapid than R. solani. Five isolates from each group caused severe corm rot and mortality of plant during rooting. Isolates of binucleate Rhizoctonia caused corm and stem rot and mortality only on 35-day-old plants. This is the first detailed report of corm and stem rot disease of Gladiolus caused by binucleate Rhizoctonia. Further field studies are needed on the ecology and pathogenicity of Rhizoctonia sp. to formulate steps for controlling corm and stem rot of Gladiolus.

Mohammad Javad Soleimani

2005-01-01

154

Interactions between cauliflower and Rhizoctonia anastomosis groups with different levels of aggressiveness  

OpenAIRE

Abstract Background The soil borne fungus Rhizoctonia is one of the most important plant pathogenic fungi, with a wide host range and worldwide distribution. In cauliflower (Brassica oleracea var. botrytis), several anastomosis groups (AGs) including both multinucleate R. solani and binucleate Rhizoctonia species have been identified showing different levels of aggressiveness. The infection and colonization process of Rhizoctonia during pathogenic interactions is well described. In contrast, ...

Höfte Monica; Pannecoucque Joke

2009-01-01

155

Cropping Systems and Cultural Practices Determine the Rhizoctonia Anastomosis Groups Associated with Brassica spp. in Vietnam  

OpenAIRE

Ninety seven Rhizoctonia isolates were collected from different Brassica species with typical Rhizoctonia symptoms in different provinces of Vietnam. The isolates were identified using staining of nuclei and sequencing of the rDNA-ITS barcoding gene. The majority of the isolates were multinucleate R. solani and four isolates were binucleate Rhizoctonia belonging to anastomosis groups (AGs) AG-A and a new subgroup of A-F that we introduce here as AG-Fc on the basis of differences in rDNA-ITS s...

Hua, Gia Khuong Hoang; Bertier, Lien; Soltaninejad, Saman; Ho?fte, Monica

2014-01-01

156

Postharvest respiration rate and sucrose content of Rhizoctonia-infected sugarbeet roots  

Science.gov (United States)

Rhizotonia crown and root rot of sugarbeet (Beta vulgaris L), caused by Rhizoctonia solani AG 2-2, is increasing in Minnesota and North Dakota. As the disease increases in prevalence and severity, more diseased roots are being stored in piles where they affect storability and postharvest quality. T...

157

Determination of the Anastomosis Grouping and Virulence of Rhizoctonia spp. Associated with Potato Tubers Grown in Lincoln, New Zealand  

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Full Text Available A total of 58 isolates of Rhizoctonia spp. (46 R. solani and 12 binucleate Rhizoctonia were recovered from potato tubers showing black scurf disease symptom during the 2004 growing season in Lincoln, New Zealand. The isolates were assigned to 5 Anastomosis Groups (AG of R. solani AG-3 (54.34%, AG-5 (28.26%, AG-8 (8.69%, AG-4 (6.52% and AG-2-2 IIIB (2.17% and six anastomosis groups of binucleate Rhizoctonia, AG-K (25%, AG-Bi (25%, AG-Ba (8.33%, AG-C (8.33%, AG-D (8.33% and AG-E (8.33%. Two isolates of BNR did not anastomose with any of the tester strains and remain unidentified. In pathogenicity tests that were carried out on radish, carrot, lettuce, onion, tomato and hemp, it was found that all the isolates of both R. solani and binucleate Rhizoctonia to be virulent at varying degrees to these 6 plants species from different families. In these tests, isolates of AG-3 and AG-8 from R. solani population caused the highest and lowest disease severity on all 6 plant species, respectively. In population of binucleate Rhizoctonia, on the other hand, the highest and lowest disease severities were caused by the isolates of AG-D and AG-Ba on all test plants, respectively. When the results of the pathogenicity tests were examined in terms of the susceptibility levels of the plants, the most resistant plant was tomato against different AGs of R. solani and BNR. On the other hand, radish was the most susceptible plant species tested in this study against both R. solani and BNR isolates.

Reza Farrokhi-Nejad

2007-01-01

158

Nonpathogenic Binucleate Rhizoctonia spp. and Benzothiadiazole Protect Cotton Seedlings Against Rhizoctonia Damping-Off and Alternaria Leaf Spot in Cotton.  

Science.gov (United States)

ABSTRACT Recent reports have shown induction of resistance to Rhizoctonia root rot using nonpathogenic strains of binucleate Rhizoctonia spp. (np-BNR). This study evaluates the biocontrol ability of several np-BNR isolates against root and foliar diseases of cotton in greenhouse trials, provides evidence for induced systemic resistance (ISR) as a mechanism in this biocontrol, and compares the disease control provided by np-BNR with that provided by the chemical inducer benzothiadiazole (BTH). Pretreatment of cotton seedlings with np-BNR isolates provided good protection against pre- and post-emergence damping-off caused by a virulent strain of Rhizoctonia solani (AG-4). Seedling stand of protected cotton was significantly higher (P leaf spot in cotton; however, the degree of disease reduction was comparable to that obtained with np-BNR treatment alone. Significant reduction in leaf spot symptoms caused by Alternaria macrospora occurred on cotyledons pretreated with np-BNR or sprayed with BTH, and the np- BNR-treated seedlings had significantly less leaf spot than BTH-treated seedlings. The results demonstrate that np-BNR isolates can protect cotton from infections caused by both root and leaf pathogens and that disease control was superior to that observed with a chemical inducer. PMID:18943300

Jabaji-Hare, Suha; Neate, Stephen M

2005-09-01

159

Método fácil y confiable para teñir núcleos en hongos del complejo Rhizoctonia / Easy and reliable method for nuclei staining of Rhizoctonia complex fungi  

Scientific Electronic Library Online (English)

Full Text Available En el complejo Rhizoctonia la morfología hifal y configuración del septo permiten diferenciar los géneros, mientras que las especies pueden ser distinguidas por la condición nuclear y el grosor de hifas “guías” ó la morfometría del teleomorfo. Para caracterizar las especies en uni, bi y multinuclead [...] as se han desarrollado varios métodos de tinción nuclear con acridina naranja, azules de anilina y tripano, diamina fenil indol (DAPI), giemsa, hematoxilina, orceina y safranina O. Algunos de esos procedimientos son rápidos, pero otros requieren técnicas especiales (fluorescencia) o consumen mucho tiempo y limitan la cantidad de muestras a procesar. Un nuevo método fue desarrollado durante análisis de anastomosis (AGs) en aislamientos de R. solani que atacan la papa cultivada en Mérida, Venezuela. El procedimiento es rápido, fácil, confiable y permite la manipulación simultánea de un número considerable de especimenes, y tanto el núcleo como el nucléolo conservan su integridad. El método fue probado exitosamente en 10 patrones de AGs de R. solani, y permitió separar 173 cepas multinucleadas y 3 binucleadas, todas del género Rhizoctonia. El método fue efectivo utilizando sustrato de agua-agar 2,4 % más PDA 0,39 %, en cultivos de 18 a 48 h fijado con formaldehído 4 % y coloreado con fucsina ácida 0,025 en ácido láctico 50 %. Abstract in english Hyphal morphology and septal structure configuration of the fungi included in Rhizoctonia complex allows for differentiation of genus, while species may be distinguished by nuclear condition and thickness of the runner hyphae, or teleomorph morphometry. For characterization of species in uni, bi, an [...] d multinucleate diverse methods of staining have been developed using acridine orange, aniline and trypan blue, diamine phenyl indole (DAPI), giemsa, hematoxiline, orcein and saphranin O. Some of these procedures are quick to perform, while others require special techniques (fluorescence) or are time consuming, which impose a limit on the number of samples that can be processed at a time. A new method of nuclei staining was developed during the analysis of anastomosis groups (AGs) of R. solani strains isolated from potato plants cultivated in Mérida, Venezuela. The procedure is quick, easy, and reliable, and allows for simultaneous manipulation of a significant number of samples, and both nucleus and nucleolus maintain their integrity. The method was successfully assayed in 10 different AGs testers of R. solani, and allowed separation of 173 multinucleate and 3 binucleate Rhizoctonia strains. Method effectiveness depends upon growth medium (water agar 2.4 % plus PDA 0.39 %), culture age (18-48 h), fixing agent (formaldehyde 4 %), and stain (fuchsin acid 0.025 % in lactic acid 50 %).

Luis, Cedeño.

2008-12-01

160

Método fácil y confiable para teñir núcleos en hongos del complejo Rhizoctonia Easy and reliable method for nuclei staining of Rhizoctonia complex fungi  

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Full Text Available En el complejo Rhizoctonia la morfología hifal y configuración del septo permiten diferenciar los géneros, mientras que las especies pueden ser distinguidas por la condición nuclear y el grosor de hifas “guías” ó la morfometría del teleomorfo. Para caracterizar las especies en uni, bi y multinucleadas se han desarrollado varios métodos de tinción nuclear con acridina naranja, azules de anilina y tripano, diamina fenil indol (DAPI, giemsa, hematoxilina, orceina y safranina O. Algunos de esos procedimientos son rápidos, pero otros requieren técnicas especiales (fluorescencia o consumen mucho tiempo y limitan la cantidad de muestras a procesar. Un nuevo método fue desarrollado durante análisis de anastomosis (AGs en aislamientos de R. solani que atacan la papa cultivada en Mérida, Venezuela. El procedimiento es rápido, fácil, confiable y permite la manipulación simultánea de un número considerable de especimenes, y tanto el núcleo como el nucléolo conservan su integridad. El método fue probado exitosamente en 10 patrones de AGs de R. solani, y permitió separar 173 cepas multinucleadas y 3 binucleadas, todas del género Rhizoctonia. El método fue efectivo utilizando sustrato de agua-agar 2,4 % más PDA 0,39 %, en cultivos de 18 a 48 h fijado con formaldehído 4 % y coloreado con fucsina ácida 0,025 en ácido láctico 50 %.Hyphal morphology and septal structure configuration of the fungi included in Rhizoctonia complex allows for differentiation of genus, while species may be distinguished by nuclear condition and thickness of the runner hyphae, or teleomorph morphometry. For characterization of species in uni, bi, and multinucleate diverse methods of staining have been developed using acridine orange, aniline and trypan blue, diamine phenyl indole (DAPI, giemsa, hematoxiline, orcein and saphranin O. Some of these procedures are quick to perform, while others require special techniques (fluorescence or are time consuming, which impose a limit on the number of samples that can be processed at a time. A new method of nuclei staining was developed during the analysis of anastomosis groups (AGs of R. solani strains isolated from potato plants cultivated in Mérida, Venezuela. The procedure is quick, easy, and reliable, and allows for simultaneous manipulation of a significant number of samples, and both nucleus and nucleolus maintain their integrity. The method was successfully assayed in 10 different AGs testers of R. solani, and allowed separation of 173 multinucleate and 3 binucleate Rhizoctonia strains. Method effectiveness depends upon growth medium (water agar 2.4 % plus PDA 0.39 %, culture age (18-48 h, fixing agent (formaldehyde 4 %, and stain (fuchsin acid 0.025 % in lactic acid 50 %.

Luis Cedeño

2008-12-01

161

Fusarium solani breast abscess  

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Full Text Available An unusual manifestation of breast fusariosis was encountered in a 55-year-old female diabetic patient. Two fine needle aspirates (FNA from the abscess were done at three days interval and they showed hyaline, septate, branched, fungal hypahe in 10% potassium hydroxide mount. Fungal infection was confirmed by demonstrating the fungal hyphae in the midst of lymphocytes, macrophages and neutrophils in Leishman stained smears. Culture of both FNAs yielded a heavy and pure growth of Fusarium solani . The patient responded to oral ketoconazole 200 mg once daily for 3 weeks. The breast fusariosis reported here is presumably the first case in India.

Anandi V

2005-01-01

162

Caracterização de isolados de Rhizoctonia spp. e identificação de novos grupos de anastomose em jardim clonal de eucalipto Characterization of isolates of Rhizoctonia spp. and identification of new anastomosis groups in eucalyptus clonal nurseries  

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Full Text Available Espécies de Rhizoctonia causam queima foliar em brotações de jardim clonal e podridão de estacas durante o enraizamento, que podem limitar a clonagem do eucalipto, por estaquia. Diante da importância do patógeno para a cultura e da falta de estudos sobre a diversidade de isolados, esse trabalho objetivou caracterizar isolados e relatar novos grupos de anastomose de Rhizoctonia spp. em jardim clonal de eucalipto. Os isolados obtidos nas diferentes fases de propagação por estaquia foram caracterizados quanto ao número de núcleos nas células vegetativas, agrupados segundo as características morfológicas das colônias e identificados quanto aos grupos de anastomose, incluindo auxotrofia por tiamina. Avaliou-se, também, a virulência ao eucalipto e o efeito da temperatura no crescimento micelial dos isolados. Não se detectou correlação entre os agrupamentos morfológicos e reações de anastomose. Constatou-se, também, que a população de Rhizoctonia spp., nos solos de jardins clonais, é constituída por ampla gama de isolados, predominantemente binucleados, com diferentes graus de virulência a eucalipto. Os isolados binucleados e os multinucleados, tiveram a mesma tendência de crescimento em relação à temperatura, com ótimo para a taxa de crescimento entre 25-30 ºC. Observou-se, pela primeira vez, isolados de R. solani AG2-2 IIIB e os binucleados de Rhizoctonia spp., AG-P e AG-O, como agentes etiológicos da podridão de estacas em casa de vegetação, e os isolados binucleados AG-A e AG-L em solo de jardim clonal de eucalipto.Rhizoctonia spp. cause shoot and leaf blight of eucalyptus in clonal hedges as well as cuttings. Despite the importance of Rhizoctonia spp. to eucalyptus, little is known about their diversity. Thus, we characterized isolates and report new anastomosis groups in a eucalyptus clonal hedge. Isolates obtained at different stages of cutting propagation were characterized according to the number of nuclei in vegetative cells, grouped by morphological characteristics of the colony, anastomosis group, and thiamine auxotrophism. The isolates were also evaluated for virulence on eucalyptus and effect of temperature on their mycelial growth. No correlation between morphological grouping and anastomosis reaction was detected. A wide range of isolates, predominantly binucleate, forms the population of Rhizoctonia spp. present in the soil of clonal hedges, which differed in virulence to eucalyptus. Binucleate and multinucleate isolates had similar growth features at different temperatures, with an optimum growth rate between 25-30 ºC. Isolates of R. solani AG2-2 IIIB and binucleate isolates of Rhizoctonia spp., AG-P and AG-O, as agents of cutting rot, and binucleate isolates AG-A and AG-L in the soil of eucalyptus clonal hedge are reported for the first time.

Eugenio Sanfuentes

2007-06-01

163

Rhizoctonia wilt suppression of brinjal (Solanum melongena L) and plant growth activity by Bacillus BS2.  

Science.gov (United States)

An antibiotic-producing and hydrogen-cyanide-producing rhizobacteria strain Bacillus BS2 showed a wide range of antifungal activity against many Fusarium sp. and brinjal wilt disease pathogen Rhizoctonia solani. Seed bacterization with the strain BS2 promoted seed germination and plant growth in leguminous plants Phaseolus vulgaris and non-leguminous plants Solanum melongena L, Brassica oleracea var. capitata, B. oleraceae var. gongylodes and Lycopersicon esculentum Mill in terms of relative growth rate, shoot height, root length, total biomass production and total chlorophyll content of leaves. Yield of bacterized plants were increased by 10 to 49% compared to uninoculated control plants. Brinjal sapling raised through seed bacterization by the strain BS2 showed a significantly reduced wilt syndrome of brinjal caused by Rhizoctonia solani. Control of wilt disease by the bacterium was clue to the production of antibiotic-like substances, whereas plant growth-promotion was due to the activity of hydrogen cyanide. Root colonization study confirmed that the introduced bacteria colonized the roots and occupied 23-25% of total aerobic bacteria, which was confirmed using dual antibiotic (nalidixic acid and streptomycin sulphate) resistant mutant strain. The results obtained through this investigation suggested the potentiality of the strain BS2 to be used as a plant growth promoter and suppressor of wilt pathogen. PMID:15266911

Boruah, H P Deka; Kumar, B S Dileep

2003-06-01

164

Caracterização de isolados de Rhizoctonia spp., associados à mela do feijão-caupi (Vigna unguiculata), coletados em Roraima / Characterization of Rhizoctonia spp. associated with cowpea web (Vigna unguiculata) blight in Roraima, Brazil  

Scientific Electronic Library Online (English)

Full Text Available A mela causada pelo fungo Rhizoctonia solani (teleomorfo Thanatephorus cucumeris) é a principal doença que afeta a cultura do feijão-caupi (Vigna unguiculata) no Estado de Roraima. Este trabalho teve como objetivo caracterizar 28 isolados de Rhizoctonia spp. obtidos de plantas de feijão-caupi com si [...] ntoma de mela, coletados em ecossistemas de mata e de cerrado em Roraima. Foram avaliados o número de núcleos, a taxa de crescimento micelial, a formação e o tamanho de microescleródios, o grupo de anastomose e realizado teste de patogenicidade. Um isolado proveniente do cerrado foi identificado como binucleado e os demais isolados, de mata e de cerrado, como multinucleados. A taxa de crescimento micelial, em meio batata-dextrose-agar a 25 ºC e escuro contínuo, variou de 2,1-5,3 cm.dia-1 para os isolados de mata e de 2,7-5,8 cm.dia-1 para os isolados de cerrado. Nestas mesmas condições, após três a quatro dias foi observada a formação de microescleródios. Dois grupos foram diferenciados: um grupo com formação de 10-50 microescleródios.placa-1, em forma de tufos, inicialmente brancos e tornando-se marrom claro, de 1-2 mm (maioria dos isolados de mata) e outro grupo com mais de 100 microescleródios.placa-1, de coloração marrom e 68-541 µm (maioria dos isolados de cerrado). Dos 28 isolados coletados, 24 foram identificados como pertencentes ao grupo de anastomose GA1-1A de Rhizoctonia solani. Abstract in english The web blight caused by the fungus Rhizoctonia solani (teleomorph Thanatephorus cucumeris) is an important disease of cowpea [Vigna unguiculata (L.) Walp.] in Roraima state, Brazil. The aim of this work was to characterize 28 Rhizoctonia spp. isolates from cowpea plants with web blight, collected i [...] n two ecosystems (savannah and forest) in Roraima state. The characteristics evaluated were nuclear number, radial growth rate, the presence and morphology of microsclerotia, anastomosis group (AG) and pathogenicity test. One savannah isolate was binucleate and the others, savannah and forest isolates, were multinucleate. The radial growth rate on potato-dextrose-aga, at 25 ºC in the dark, was 2.1 to 5.3 cm.day-1 for forest isolates and 2.7 to 5.8 cm.day-1 for savannah isolates. In these conditions, after three to four days, microsclerotia formation was observed. Two types of microsclerotia were differentiated: one type of 10 to 50 microsclerotia.Petri dish-1, formed as flat sclerotia mass, which was white when young and pale brown at maturity, 1 to 2 mm in diameter (most forest isolates) and another type of 100 microsclerotia.Petri dish-1, brown color, 68 to 541 µm in diameter (most savannah isolates). Among 28 Rhizoctonia isolates collected in Roraima state, 24 anastomosed with AG1-1A of Rhizoctonia solani.

Kátia L., Nechet; Bernardo A., Halfeld-Vieira.

2006-10-01

165

Cropping systems and cultural practices determine the Rhizoctonia anastomosis groups associated with Brassica spp. in Vietnam.  

Science.gov (United States)

Ninety seven Rhizoctonia isolates were collected from different Brassica species with typical Rhizoctonia symptoms in different provinces of Vietnam. The isolates were identified using staining of nuclei and sequencing of the rDNA-ITS barcoding gene. The majority of the isolates were multinucleate R. solani and four isolates were binucleate Rhizoctonia belonging to anastomosis groups (AGs) AG-A and a new subgroup of A-F that we introduce here as AG-Fc on the basis of differences in rDNA-ITS sequence. The most prevalent multinucleate AG was AG 1-IA (45.4% of isolates), followed by AG 1-ID (17.5%), AG 1-IB (13.4%), AG 4-HGI (12.4%), AG 2-2 (5.2%), AG 7 (1.0%) and an unknown AG related to AG 1-IA and AG 1-IE that we introduce here as AG 1-IG (1.0%) on the basis of differences in rDNA-ITS sequence. AG 1-IA and AG 1-ID have not been reported before on Brassica spp. Pathogenicity tests revealed that isolates from all AGs, except AG-A, induced symptoms on detached leaves of several cabbage species. In in vitro tests on white cabbage and Chinese cabbage, both hosts were severely infected by AG 1-IB, AG 2-2, AG 4-HGI, AG 1-IG and AG-Fc isolates, while under greenhouse conditions, only AG 4-HGI, AG 2-2 and AG-Fc isolates could cause severe disease symptoms. The occurrence of the different AGs seems to be correlated with the cropping systems and cultural practices in different sampling areas suggesting that agricultural practices determine the AGs associated with Brassica plants in Vietnam. PMID:25372406

Hua, Gia Khuong Hoang; Bertier, Lien; Soltaninejad, Saman; Höfte, Monica

2014-01-01

166

Caracterização de isolados de Rhizoctonia spp. e identificação de novos grupos de anastomose em jardim clonal de eucalipto / Characterization of isolates of Rhizoctonia spp. and identification of new anastomosis groups in eucalyptus clonal nurseries  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Espécies de Rhizoctonia causam queima foliar em brotações de jardim clonal e podridão de estacas durante o enraizamento, que podem limitar a clonagem do eucalipto, por estaquia. Diante da importância do patógeno para a cultura e da falta de estudos sobre a diversidade de isolados, esse trabalho obje [...] tivou caracterizar isolados e relatar novos grupos de anastomose de Rhizoctonia spp. em jardim clonal de eucalipto. Os isolados obtidos nas diferentes fases de propagação por estaquia foram caracterizados quanto ao número de núcleos nas células vegetativas, agrupados segundo as características morfológicas das colônias e identificados quanto aos grupos de anastomose, incluindo auxotrofia por tiamina. Avaliou-se, também, a virulência ao eucalipto e o efeito da temperatura no crescimento micelial dos isolados. Não se detectou correlação entre os agrupamentos morfológicos e reações de anastomose. Constatou-se, também, que a população de Rhizoctonia spp., nos solos de jardins clonais, é constituída por ampla gama de isolados, predominantemente binucleados, com diferentes graus de virulência a eucalipto. Os isolados binucleados e os multinucleados, tiveram a mesma tendência de crescimento em relação à temperatura, com ótimo para a taxa de crescimento entre 25-30 ºC. Observou-se, pela primeira vez, isolados de R. solani AG2-2 IIIB e os binucleados de Rhizoctonia spp., AG-P e AG-O, como agentes etiológicos da podridão de estacas em casa de vegetação, e os isolados binucleados AG-A e AG-L em solo de jardim clonal de eucalipto. Abstract in english Rhizoctonia spp. cause shoot and leaf blight of eucalyptus in clonal hedges as well as cuttings. Despite the importance of Rhizoctonia spp. to eucalyptus, little is known about their diversity. Thus, we characterized isolates and report new anastomosis groups in a eucalyptus clonal hedge. Isolates o [...] btained at different stages of cutting propagation were characterized according to the number of nuclei in vegetative cells, grouped by morphological characteristics of the colony, anastomosis group, and thiamine auxotrophism. The isolates were also evaluated for virulence on eucalyptus and effect of temperature on their mycelial growth. No correlation between morphological grouping and anastomosis reaction was detected. A wide range of isolates, predominantly binucleate, forms the population of Rhizoctonia spp. present in the soil of clonal hedges, which differed in virulence to eucalyptus. Binucleate and multinucleate isolates had similar growth features at different temperatures, with an optimum growth rate between 25-30 ºC. Isolates of R. solani AG2-2 IIIB and binucleate isolates of Rhizoctonia spp., AG-P and AG-O, as agents of cutting rot, and binucleate isolates AG-A and AG-L in the soil of eucalyptus clonal hedge are reported for the first time.

Eugenio, Sanfuentes; Acelino C., Alfenas; Luiz A., Maffia; Reginaldo G., Mafia.

2007-06-01

167

Extracellular mycosynthesis of gold nanoparticles using Fusarium solani  

Science.gov (United States)

The development of eco-friendly methods for the synthesis of nanomaterial shape and size is an important area of research in the field of nanotechnology. The present investigation deals with the extracellular rapid biosynthesis of gold nanoparticles using Fusarium solani culture filtrate. The UV-vis spectra of the fungal culture filtrate medium containing gold ion showed peak at 527 nm corresponding to the plasmon absorbance of gold nanoparticles. FTIR spectra provide an evidence for the presence of heterocyclic compound in the culture filtrate, which increases the stability of the synthesized gold nanoparticles. The X-ray analysis respects the Bragg's law and confirmed the crystalline nature of the gold nanoparticles. AFM analysis showed the results of particle sizes (41 nm). Transmission electron microscopy (TEM) showed that the gold nanoparticles are spherical in shape with the size range from 20 to 50 nm. The use of F. solani will offer several advantages since it is considered as a non-human pathogenic organism. The fungus F. solani has a fast growth rate, rapid capacity of metallic ions reduction, NPs stabilization and facile and economical biomass handling. Extracellular biosynthesis of gold nanoparticles could be highly advantageous from the point of view of synthesis in large quantities, time consumption, eco-friendly, non-toxic and easy downstream processing.

Gopinath, K.; Arumugam, A.

2014-08-01

168

Histologia da interação Stemphylium solani e tomateiro / Histology of Stemphylium solani and tomato interaction  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Estudou-se a infecção de Stemphylium solani Weber em folíolos de tomateiros (Lycopersicon esculentum) resistente (Motelle) e suscetível (Moneymaker), usando-se técnicas histológicas e de microscopia eletrônica de varredura e transmissão. Inicialmente, foram quantificados os eventos de pré-penetração [...] nas duas cultivares, os quais não diferiram significativamente entre si (teste F a 5%), indicando que a resistência é exercida em pós-penetração. A penetração ocorreu principalmente via estômatos e a hifa diferenciou-se na cavidade subestomática formando uma vesícula globosa ou irregular; a qual ramificou-se em hifas secundárias. Tanto a colonização intra quanto intercelular ocorreram no período de 24 e 36 h após a inoculação nas duas cultivares estudadas. Aposições foram observadas na parede das células do mesofilo resistente e, na maioria das células examinadas, aparentemente restringiram a colonização intracelular. Abstract in english The infection process of Stemphylium solani on resistant (Motelle) and susceptible (Moneymaker) tomato (Lycopersicon esculentum) leaflets was studied using histochemical, scanning and transmission electron microscopy techniques. No quantitative differences were found in the pre-penetration conidial [...] events on resistant and susceptible tomatoes, indicating that resistance results from post-penetration responses. The histological studies showed that the initial infection events were similar in resistant and susceptible plants. The pathogen invaded the tomato leaf primarily through stomates and a vesicle developed inside the substomatal cavity. Secondary hyphae originated from the vesicle and within 24 and 36 h after inoculation had branched inter and intracellularly in both cultivars. Cell wall appositions in the mesophyll of resistant tomato prevented intracellular colonization.

Jânia L.S., Bentes; Kiyoshi, Matsuoka.

2005-06-01

169

Characteristics and diversity of Rhizoctonia spp. population in soil of selected forest bare-root nurseries in Poland  

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Full Text Available Fourty three Rhizoctonia isolates obtained from four forest nurseries situated in the Wielkopolska region (central-western Poland has been proved as multinucleate (anamorph – R. solani. They represented four anastomosis groups (AG: AG1-IC, AG-5, AG4-HG2 and AG2-1. Three AGs were found in Jarocin nursery (AG-5, AG4-HG2 and AG2-1, two in ?opuchówko (AG-5 and AG4-HG2 and one in Konstantynowo (AG1-IC and Pniewy (AG-5. All isolates were highly pathogenic to Scots pine (Pinus sylvestris seedlings and pose a large damping-off threat to the seedlings in the nurseries with single AG and in those where more AGs exists.

Marta Be?ka

2014-12-01

170

Controle químico da queima de folhas e da mela de estacas de eucalipto, causadas por Rhizoctonia spp. / Chemical control of leaf scorch and web blight of eucalypt cuttings, caused by Rhizoctonia spp.  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Visando ao controle químico da queima de folhas e mela de estacas de eucalipto (Eucalyptus spp.) em viveiros florestais, avaliou-se a eficiência de 12 fungicidas em inibir in vitro o crescimento micelial de um isolado epifítico de Rhizoctonia solani AG1-IB (RH-2). Sete fungicidas que inibiram totalm [...] ente o crescimento micelial do fungo, a concentrações inferiores a 100 ppm, foram pré-selecionados: methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol, thiram e captan. Avaliou-se, ainda, a sensibilidade (EC50 = dose provável que inibe o crescimento micelial em 50%) aos fungicidas methyl-tolclophos, benomyl, iprodione e pencycuron de mais oito isolados patogênicos ao eucalipto, que diferem entre si quanto a virulência, morfologia, grupo de anastomose, número de núcleos por célula vegetativa e padrões eletroforéticos de proteínas e isoenzimas. Embora variações nos valores de EC50 entre algumas combinações de fungicidas e isolados tenham ocorrido, todos os isolados foram sensíveis aos quatro fungicidas testados (EC50 Abstract in english To achieve the chemical control of leaf scorch and web blight of eucalyptus (Eucalyptus spp.) cuttings in forest nurseries, 12 fungicides were assayed against one isolate of Rhizoctonia solani AG1-IB (RH-2). Seven fungicides (methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol and captan [...] ) completely inhibited mycelial growth under concentrations lower than 100 ppm of active ingredient on PDA culture. Additionally, the sensibility (EC50 = estimated dose for 50% inhibition of mycelial growth) to methyl-tolclophos, benomyl, pencycuron and iprodione of another eight isolates differing in virulence, morphology, anastomosis groups, and proteins and isozyme profiles was evaluated. Little differences in sensitivity was observed in some combinations of fungicides-isolates. However, the eight isolates were sensitive to the four tested fungicides (EC50

Silvaldo Felipe da, Silveira; Acelino Couto, Alfenas; Luís Antônio, Maffia; Márcio Shiguero, Suzuki.

2003-12-01

171

Immobilization of lipase from Fusarium solani FS1 Imobilização de lipase de Fusarium solani FS1  

OpenAIRE

Lipase from Fusarium solani FS1 was immobilized by covalent attachment to polyacrylamide beads and onto magnetized Dacron, retaining 12% and 97% of activity, respectively. Lipase was also entrapped within polyacrylamide beads, retaining 53% of activity. Investigations of the kinetic characteristics of the immobilized derivatives using triolein as substrate showed that lipase immobilized onto polyacrilamide beads and Dacron did not follow Michaelis-Menten kinetics.Lipase de Fusarium solani FS1...

Kirsty Knight; Maria do Carmo Barros Pimentel; Marcia Maria Camargo de Morais; Ledingham, William M.; José Luiz de Lima Filho; Maria de Mascena Diniz Maia

2000-01-01

172

Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions  

Energy Technology Data Exchange (ETDEWEB)

The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

2010-07-01

173

In vitro selection of beans (Phaseolus vulgaris) from Costa Rica for resistance to fungal pathogen Thanatephorus cucumeris (Rhizoctonia solani)  

International Nuclear Information System (INIS)

The research has been realized in the Laboratory of Plant Pathology and Laboratory of Plant Tissue Cultures of the Department of Botany in the Palacky University, Olomouc during the period 3 September - 21 December 2007. In vitro cultivation of beans seeds.The culture medium AC agar (Sigma) was used for Thanatephorus cucumeris. The next three isolates from Costa Rica were tested: 007-3242, 007-3241, 007-3077. For each pathogen isolate three different doses were evaluated: 1%, 5% and 10%. The medium was added before it was autoclaved. Two bean varieties (Brunca /black color/ and Bribri /red color/) were used during this procedure. In order to cultivate the bean seeds the Murashige/Skoog (MS) (Duchefa) culture medium was used. The bean seeds were sterilized with Chloramine B (2.5%) for 30 min, washing them three times with distilled sterile water and then leaving the seeds into distilled sterile water for 24 hours. The seed coat was eliminated, and then the embryos were extirpated, and placed in Petri dishes for two days, after two days of incubation the roots were cut and transferred to Erlenmeyer flasks. They were cultivated in the growth chamber at a temperature of 24 + 2 deg. C and a photoperiod of 16 hours /8 day/night. The evaluations were made during the 30, 40 and 50 days of incubation. The spray method was used in order to inoculate Thanatephorus cucumeris from the in vitro bean seedlings. After three weeks of incubation the seedlings were inoculated (by using n the seedlings were inoculated (by using a glass sprayer) with T. cucumeris (treatments of 1%, 5%, 10%, 2 ml per/ Erlenmeyer flask) in aseptic conditions. The evaluation was made 12 days after the inoculation. The results obtained so far are preliminary, the collected data needs to be analyzed statistically, so it can be published this year. (author)

174

Compost Tea and Poultry Litter Extract: Alternative Organic Management Approaches for Stem Canker of Potato Caused by Rhizoctonia solani  

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Full Text Available An experiment was conducted in the field laboratory, Department of Plant pathology, Bangladesh Agricultural University, Mymensingh to know the efficacy of compost tea and poultry litter extract in controlling stem canker of potato under natural infection condition. Significant effect of different treatments was observed on the incidence of stem canker of potato as compared to control. The results evidently showed the lowest stem canker incidence recorded in plots when IPM Lab Biopesticde was applied followed by foliar spray of Ridomil, compost tea, and BAU-Biofungicide while the highest stem canker incidence was recorded in untreated control plot. However, the soil drenching of compost tea and poultry litter extract also performed better as compared to control in reducing the incidence of stem canker. Significant effect of the treatments was observed on the plant height and yield except number of plant raised per tuber. Foliar and soil application of compost tea, poultry litter and mustard oil cake showed better performance in increasing the plant height and yield as compared to all other treatments. Benefit cost analyses of the treatments revealed that foliar application of compost tea showed highest BCR (65.20 followed by Soil application of IPM Lab Biopesticide with BCR 54.38. The treatments viz. foliar spray of Ridomil and BAU-Biofungicide resulted 35.31 and 38.88 BCR, respectively which were the second best treatments as compared to untreated control. The results indicated that an investment of Tk. 1.00 may lead to a profit up to Tk. 65.20 by foliar application of compost tea which shows the maximum profit in the present study. Therefore, compost tea as foliar spray may be used as an alternative environment-friendly approach to control stem canker of potato along with other biological means with maximum economic return.

Md. Rashidul Islam

2013-09-01

175

Ribosome Inactivating Protein of barley enhanced resistance to Rhizoctonia solani in transgenic potato cultivar 'Desirée' in greenhouse conditions  

OpenAIRE

In the present study, the potato cultivar 'Desirée' was transformed via Agrobacterium tumefaciens strain LBA4404 containing the plasmid pBIN19 which harbors the Ribosome Inactivating Protein (rip30). The potato leaf discs were used as an explant for transformation. The in vitro regeneration parameters (percentage of callus regenerated, number of shoots per callus, percentage of regenerated roots and percentage of the transgenic plants) were evaluated. The PCR technique was used for identific...

M Hamdi, M.; Chikh-rouhou, H.; Boughalleb, N.; Ruiz Galarreta, Ji

2013-01-01

176

FIRST REPORT OF DAMPING-OFF OF CANOLA CAUSED BY RHIZOCTONIA SOLANI AG 2-1 IN WASHINGTON STATE  

Science.gov (United States)

In early Sept. 2003, winter canola (Brassica napus) cv. Inca was direct-seeded into plots previously cropped with spring barley, as part of a long-term irrigated cropping systems experiment at the WSU Dryland Research Station at Lind, WA. Before planting, the plots received 80 mm of water by sprinkl...

177

Compost Tea and Poultry Litter Extract: Alternative Organic Management Approaches for Stem Canker of Potato Caused by Rhizoctonia solani  

OpenAIRE

An experiment was conducted in the field laboratory, Department of Plant pathology, Bangladesh Agricultural University, Mymensingh to know the efficacy of compost tea and poultry litter extract in controlling stem canker of potato under natural infection condition. Significant effect of different treatments was observed on the incidence of stem canker of potato as compared to control. The results evidently showed the lowest stem canker incidence recorded in plots when IPM Lab Biopesticde was ...

Md. Rashidul Islam; Chhoa Mondal; Ismail Hossain; Bahadur Meah, M.

2013-01-01

178

Controle químico da queima de folhas e da mela de estacas de eucalipto, causadas por Rhizoctonia spp. Chemical control of leaf scorch and web blight of eucalypt cuttings, caused by Rhizoctonia spp.  

Directory of Open Access Journals (Sweden)

Full Text Available Visando ao controle químico da queima de folhas e mela de estacas de eucalipto (Eucalyptus spp. em viveiros florestais, avaliou-se a eficiência de 12 fungicidas em inibir in vitro o crescimento micelial de um isolado epifítico de Rhizoctonia solani AG1-IB (RH-2. Sete fungicidas que inibiram totalmente o crescimento micelial do fungo, a concentrações inferiores a 100 ppm, foram pré-selecionados: methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol, thiram e captan. Avaliou-se, ainda, a sensibilidade (EC50 = dose provável que inibe o crescimento micelial em 50% aos fungicidas methyl-tolclophos, benomyl, iprodione e pencycuron de mais oito isolados patogênicos ao eucalipto, que diferem entre si quanto a virulência, morfologia, grupo de anastomose, número de núcleos por célula vegetativa e padrões eletroforéticos de proteínas e isoenzimas. Embora variações nos valores de EC50 entre algumas combinações de fungicidas e isolados tenham ocorrido, todos os isolados foram sensíveis aos quatro fungicidas testados (EC50 To achieve the chemical control of leaf scorch and web blight of eucalyptus (Eucalyptus spp. cuttings in forest nurseries, 12 fungicides were assayed against one isolate of Rhizoctonia solani AG1-IB (RH-2. Seven fungicides (methyl-tolclophos, benomyl, pencycuron, iprodione, thiabendazol and captan completely inhibited mycelial growth under concentrations lower than 100 ppm of active ingredient on PDA culture. Additionally, the sensibility (EC50 = estimated dose for 50% inhibition of mycelial growth to methyl-tolclophos, benomyl, pencycuron and iprodione of another eight isolates differing in virulence, morphology, anastomosis groups, and proteins and isozyme profiles was evaluated. Little differences in sensitivity was observed in some combinations of fungicides-isolates. However, the eight isolates were sensitive to the four tested fungicides (EC50 < 11 ppm. Under artificial conditions of inoculations, sprays of iprodione (1,5 g/l, benomyl (1 g/l, methyl-tolclophos (1,5 g/l, thiram (2,1 g/l, captan (2 g/l, and pencycuron (2 g/l significantly (alpha=5% reduced the incidence of leaf scorch on shoots of plants in vessels. Pruning of diseased shoots in clonal gardens (field associated with weekly sprays of iprodione (1 g/l or mixtures of benomyl (0,5 g/l + captan (1 g/l alternating with benomyl (0,5 g/l + thiram (1 g/l, reduced the incidence of web blight on cuttings under shade house conditions (alpha=5%.

Silvaldo Felipe da Silveira

2003-12-01

179

Immobilization of lipase from Fusarium solani FS1 Imobilização de lipase de Fusarium solani FS1  

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Full Text Available Lipase from Fusarium solani FS1 was immobilized by covalent attachment to polyacrylamide beads and onto magnetized Dacron, retaining 12% and 97% of activity, respectively. Lipase was also entrapped within polyacrylamide beads, retaining 53% of activity. Investigations of the kinetic characteristics of the immobilized derivatives using triolein as substrate showed that lipase immobilized onto polyacrilamide beads and Dacron did not follow Michaelis-Menten kinetics.Lipase de Fusarium solani FS1 foi imobilizada por ligação covalente usando esferas de poliacrilamida e Dacron magnetizado, retendo 12%, e 97% de atividade, respectivamente. A lipase foi também enclausurada em esferas de poliacrilamida e reteve 53% de sua atividade específica. Investigações sobre o comportamento cinético usando trioleína como substrato mostraram que as lipases imobilizadas não seguem a cinética de Michaelis-Menten.

Kirsty Knight

2000-09-01

180

Immobilization of lipase from Fusarium solani FS1 / Imobilização de lipase de Fusarium solani FS1  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Lipase de Fusarium solani FS1 foi imobilizada por ligação covalente usando esferas de poliacrilamida e Dacron magnetizado, retendo 12%, e 97% de atividade, respectivamente. A lipase foi também enclausurada em esferas de poliacrilamida e reteve 53% de sua atividade específica. Investigações sobre o c [...] omportamento cinético usando trioleína como substrato mostraram que as lipases imobilizadas não seguem a cinética de Michaelis-Menten. Abstract in english Lipase from Fusarium solani FS1 was immobilized by covalent attachment to polyacrylamide beads and onto magnetized Dacron, retaining 12% and 97% of activity, respectively. Lipase was also entrapped within polyacrylamide beads, retaining 53% of activity. Investigations of the kinetic characteristics [...] of the immobilized derivatives using triolein as substrate showed that lipase immobilized onto polyacrilamide beads and Dacron did not follow Michaelis-Menten kinetics.

Kirsty, Knight; Maria do Carmo Barros, Pimentel; Marcia Maria Camargo de, Morais; William M., Ledingham; José Luiz de, Lima Filho; Maria de Mascena Diniz, Maia.

2000-09-01

181

In vitro production of conidia of Alternaria solani / Produção in vitro de conídios de Alternaria solani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A esporulação de Alternaria solani in vitro pode ser escassa e tende a reduzir após sucessivas repicagens. Conduziram-se vários experimentos para avaliar o efeito da umidade, injúria da colônia, qualidade de luz e fotoperíodo, bem como do meio de cultura na produção de conídios. Adaptou-se a técnica [...] bifásica para induzir esporulação, por meio de injúria de micélio e desidratação do meio de cultura. Obtiveram-se melhores resultados quando colônias cresceram em meio V8 a 25ºC, no escuro, sob agitação durante sete dias; a massa de micélio foi triturada e a suspensão depositada em meio BDA (pH 6,5) em placas de Petri, incubando-se a 25 ± 2ºC, sob luz negra com 12 h de fotoperíodo. Validou-se o protocolo para 30 isolados de A. solani distintos quanto ao hospedeiro, local de origem, idade e forma de armazenamento. Quantificaram-se a produção, germinação e infectividade de conídios. Dos 30 isolados, 75% esporularam e a germinação mínima de conídios foi de 68%. Todos os isolados foram patogênicos em seus respectivos hospedeiros. Avaliou-se, também, o efeito de repicagens sucessivas na esporulação. Todos os isolados produziram conídios após seis repicagens sucessivas. Abstract in english Sporulation of Alternaria solani can be scarce and is often reduced when the fungus is cultivated in vitro. A series of experiments were conducted to assess the effects of moisture, mycelial wounding, light quality and photoperiod, and culture media on conidial production. A procedure to induce spor [...] ulation based on mycelial wounding and dehydration was adapted and validated. Best results were obtained when fungal colonies were grown in V8 medium at 25ºC in the dark with agitation for seven days; the mycelium mass was ground, poured into potato dextrose agar (pH 6.5) in plates, and incubated at 25 ± 2ºC under near ultraviolet light and 12 h-photoperiod. The procedure was validated with 30 isolates of A. solani from different hosts, sampling locations, ages, and storage conditions. Conidial production, germination, and infectivity were quantified. Seventy-five percent of the isolates sporulated and the lowest germination rate was 68%. Inoculations of conidial suspension of all isolates resulted in lesions on tomato and potato plants. The effect of subculturing on A. solani sporulation was also assessed. After six subcultures, every seven days, there was no reduction in sporulation of colonies that were induced with the protocol.

Tatiana T.M.S, Rodrigues; Luiz A, Maffia; Onkar D, Dhingra; Eduardo S.G, Mizubuti.

2010-08-01

182

In vitro production of conidia of Alternaria solani Produção in vitro de conídios de Alternaria solani  

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Full Text Available Sporulation of Alternaria solani can be scarce and is often reduced when the fungus is cultivated in vitro. A series of experiments were conducted to assess the effects of moisture, mycelial wounding, light quality and photoperiod, and culture media on conidial production. A procedure to induce sporulation based on mycelial wounding and dehydration was adapted and validated. Best results were obtained when fungal colonies were grown in V8 medium at 25ºC in the dark with agitation for seven days; the mycelium mass was ground, poured into potato dextrose agar (pH 6.5 in plates, and incubated at 25 ± 2ºC under near ultraviolet light and 12 h-photoperiod. The procedure was validated with 30 isolates of A. solani from different hosts, sampling locations, ages, and storage conditions. Conidial production, germination, and infectivity were quantified. Seventy-five percent of the isolates sporulated and the lowest germination rate was 68%. Inoculations of conidial suspension of all isolates resulted in lesions on tomato and potato plants. The effect of subculturing on A. solani sporulation was also assessed. After six subcultures, every seven days, there was no reduction in sporulation of colonies that were induced with the protocol.A esporulação de Alternaria solani in vitro pode ser escassa e tende a reduzir após sucessivas repicagens. Conduziram-se vários experimentos para avaliar o efeito da umidade, injúria da colônia, qualidade de luz e fotoperíodo, bem como do meio de cultura na produção de conídios. Adaptou-se a técnica bifásica para induzir esporulação, por meio de injúria de micélio e desidratação do meio de cultura. Obtiveram-se melhores resultados quando colônias cresceram em meio V8 a 25ºC, no escuro, sob agitação durante sete dias; a massa de micélio foi triturada e a suspensão depositada em meio BDA (pH 6,5 em placas de Petri, incubando-se a 25 ± 2ºC, sob luz negra com 12 h de fotoperíodo. Validou-se o protocolo para 30 isolados de A. solani distintos quanto ao hospedeiro, local de origem, idade e forma de armazenamento. Quantificaram-se a produção, germinação e infectividade de conídios. Dos 30 isolados, 75% esporularam e a germinação mínima de conídios foi de 68%. Todos os isolados foram patogênicos em seus respectivos hospedeiros. Avaliou-se, também, o efeito de repicagens sucessivas na esporulação. Todos os isolados produziram conídios após seis repicagens sucessivas.

Tatiana T.M.S Rodrigues

2010-08-01

183

Fusarium solani: An Emerging Fungus in Chronic Diabetic Ulcer  

OpenAIRE

Fusarium species, a mold which causes disease mainly in plants has emerged as pathogen in immunocompromised patients. Fusarium is known to cause keratitis, onychomycosis, and endophthalmitis. Fusarium solani, is the most common isolate from clinical specimen. Here is a case, a 65-year-old male with type II diabetes mellitus since 10 years presented with a large ulcer on the left leg since 8 months following trauma. The fungal culture of the escar of the ulcer isolated a mold, Fusarium solani....

Pai, Ramakrishna; Boloor, Rekha; Shreevidya, K.; Shenoy, Divakar

2010-01-01

184

Chemical disinfectants can reduce potato blackleg caused by ‘Dickeya solani  

OpenAIRE

Treatments of tubers with chemical disinfectants (70 % ethanol, 1 % sodium hypochlorite, 2 % copper sulphate, 5 % peracetic acid, 10 % hydrogen peroxide, 1 % MennoClean (benzoic acid), 5 % trisodium phosphate and 0.2 % caffeine) were evaluated for control of blackleg caused by ‘D. solani’. All disinfectants effectively killed bacteria in axenic cultures within 5 min and all, except hydrogen peroxide and trisodium phosphate, were able to kill ‘D. solani’ in spiked potato extracts. Trea...

Czajkowski, R. L.; Boer, W. J.; Wolf, J. M.

2013-01-01

185

Histopatologia da interação Alternaria solani e tomateiros resistente e suscetível / Histopathology of the interaction between Alternaria solani and resistant and susceptible tomato plants  

Scientific Electronic Library Online (English)

Full Text Available Para esclarecer a natureza da resistência à pinta-preta (Alternaria solani) em tomateiro resistente (Lycopersicon hirsutum var. glabratum) cv. CNPH 417 e suscetível (L. esculentum) cv. Miller, avaliou-se o processo de infecção, através da histopatologia. Às 6, 12, 24, 36, 48 e 72 h após as inoculaçõ [...] es (h.a.i.) de suspensões de conídios, coletaram-se amostras de tecidos foliares que foram submetidas ao clareamento, à inclusão em resina para confecção de cortes semifinos e ao processamento para microscopia eletrônica de varredura (MEV). Pela análise das amostras clareadas, observou-se que a germinação de conídios completou-se em 24 h.a.i. O crescimento de tubos germinativos foi similar na superfície de ambos os genótipos. Entretanto, os números de apressórios formados, de penetrações nos tecidos e de lesões foram inferiores no genótipo resistente. Com relação aos eventos pós-penetração, o desenvolvimento inicial de hifas primárias e secundárias, processos posteriores de colonização e desenvolvimento de lesões, bem como a ocorrência de formação de papilas sob apressórios e de reações de hipersensibilidade foram similares em ambos os genótipos. Para a maioria dos aspectos da patogênese de A. solani, portanto, o genótipo resistente CNPH 417 comportou-se de modo similar ao suscetível, cv. Miller, exceto quanto aos números de apressórios, de penetrações e de lesões. Assim, ficou evidenciado que a resistência de L. hirsutum var. glabratum (CNPH 417) a A. solani é expressa na fase de pré-penetração, principalmente pelo baixo número de apressórios formados. Abstract in english Light and scanning electron microscopy (SEM) were used to follow the infection process of Alternaria solani on leaves of resistant tomato (Lycopersicon hirsutum var. glabratum) cv. CNPH 417 and susceptible tomato (L. esculentum) cv. Miller. Conidial germination was completed 24 h after inoculation ( [...] h.a.i) and growth of germ tubes was similar on the leaf surfaces of both genotypes. However, on the resistant genotype the quantity of appressoria, tissue penetration and lesions were significantly less. The events after penetration were similar in both genotypes and included the initial development of primary and secondary hyphae, colonization processes and lesion development, frequency of formation of papilla and hypersensitive reactions. Although papilla production and hypersensitive reaction are considered as resistant reactions, they seem to have not contributed to the resistance of L. hirsutum var. glabratum to A. solani in this study. The resistant tomato genotype was similar to the susceptible one according to the aspects of pathogenesis studied, except regarding the number of appressoria, penetrations and lesions. Therefore, it was concluded that the resistance of L. hirsutum var. glabratum (CNPH 417) to A. solani is expressed during the pre-penetration phase of the fungus, mainly due to the low number of appressoria formed.

José Cristino A. de, Araujo; Kiyoshi, Matsuoka.

2004-06-01

186

Genetic diversity among isolates of stemphylium solani from cotton Diversidade genética entre isolados de Stemphylium solani de algodoeiro  

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Full Text Available The fungus Stemphylium solani causes leaf blight of tomato (Lycopersicon esculentum in Brazil. In recent years, severe epidemics of a new leaf blight of cotton (Gossipium hyrsutum caused by S. solani occurred in three major cotton-growing Brazilian states (PR, MT and GO. Molecular analysis was performed to assess the genetic diversity among the S. solani isolates from cotton, and to verify their relationship with representative S. solani isolates from tomato. Random amplified polymorphic DNA (RAPD markers and internal transcribed spacers of ribosomal DNA (rDNA were used to compare 33 monosporic isolates of S. solani (28 from cotton and five from tomato. An isolate of Alternaria macrospora from cotton was also used for comparison. RAPD analysis showed the presence of polymorphism between the genera and the species. The A. macrospora and the S. solani isolates from cotton and tomato were distinct from each other, and fell into separate groups. Variation by geographic region was observed for the tomato isolates but not for the cotton isolates. Amplifications of the ITS region using the primer pair ITS4/ITS5 resulted in a single PCR product of approximately 600 bp for all the isolates. Similarly, when amplified fragments were digested with eight restriction enzymes, identical banding patterns were observed for all the isolates. Hence, rDNA analysis revealed no inter-generic or intra-specific variation. The genetic difference observed between the cotton and the tomato isolates provides evidence that S. solani attacking cotton in Brazil belongs to a distinct genotype.Stemphylium solani causa manchas foliares em tomateiro (Lycopersicon esculentum. Em anos recentes, epifitias severas de uma nova doença do algodoeiro (Gossipium hirsutum causada por S. solani ocorreu em três estados brasileiros (PR, MT e GO. Análise molecular foi realizada para verificar variabilidade entre os isolados de S. solani de algodoeiro e ao mesmo tempo verificar sua relação com isolados representativos de S. solani de tomateiro. Ensaios de polimorfismo de DNA amplificado ao acaso (RAPD e regiões internamente transcritas de DNA ribossomal (rDNA foram utilizados para analisar 33 isolados monosporicos de S. solani (28 de algodoeiro e cinco de tomateiro. Um isolado de Alternaria macrospora de algodoeiro também foi incluido para comparação. Análise de RAPD demonstrou a presença de polimorfismo entre os gêneros e espécies. Os isolados de A. macrospora e S. solani de algodoeiro e tomateiro eram distintos, e formaram grupos separados. Variação de acordo com a região geográfica foi encontrada para os isolados de tomateiro, mas não para os isolados de algodoeiro. A amplificação da região de ITS utilizando-se o par de primers ITS4/ITS5 resultou num produto de PCR de aproximadamente 600 pb para todos os isolados. Da mesma forma, quando os fragmentos amplificados foram digeridos com oito enzimas de restrição, padrões idênticos de bandas foram observados para todos os isolados. Desta forma, a análise de rDNA não revelou diferença intergenérica ou intra-específica. A separação de isolados de algodoeiro com os isolados de tomateiro sugere que eles pertencem a um genótipo diferente de S. solani atacando algodoeiro no Brasil.

Y.R. MEHTA

2001-12-01

187

Genetic diversity among isolates of stemphylium solani from cotton / Diversidade genética entre isolados de Stemphylium solani de algodoeiro  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Stemphylium solani causa manchas foliares em tomateiro (Lycopersicon esculentum). Em anos recentes, epifitias severas de uma nova doença do algodoeiro (Gossipium hirsutum) causada por S. solani ocorreu em três estados brasileiros (PR, MT e GO). Análise molecular foi realizada para verificar variabil [...] idade entre os isolados de S. solani de algodoeiro e ao mesmo tempo verificar sua relação com isolados representativos de S. solani de tomateiro. Ensaios de polimorfismo de DNA amplificado ao acaso (RAPD) e regiões internamente transcritas de DNA ribossomal (rDNA) foram utilizados para analisar 33 isolados monosporicos de S. solani (28 de algodoeiro e cinco de tomateiro). Um isolado de Alternaria macrospora de algodoeiro também foi incluido para comparação. Análise de RAPD demonstrou a presença de polimorfismo entre os gêneros e espécies. Os isolados de A. macrospora e S. solani de algodoeiro e tomateiro eram distintos, e formaram grupos separados. Variação de acordo com a região geográfica foi encontrada para os isolados de tomateiro, mas não para os isolados de algodoeiro. A amplificação da região de ITS utilizando-se o par de primers ITS4/ITS5 resultou num produto de PCR de aproximadamente 600 pb para todos os isolados. Da mesma forma, quando os fragmentos amplificados foram digeridos com oito enzimas de restrição, padrões idênticos de bandas foram observados para todos os isolados. Desta forma, a análise de rDNA não revelou diferença intergenérica ou intra-específica. A separação de isolados de algodoeiro com os isolados de tomateiro sugere que eles pertencem a um genótipo diferente de S. solani atacando algodoeiro no Brasil. Abstract in english The fungus Stemphylium solani causes leaf blight of tomato (Lycopersicon esculentum) in Brazil. In recent years, severe epidemics of a new leaf blight of cotton (Gossipium hyrsutum) caused by S. solani occurred in three major cotton-growing Brazilian states (PR, MT and GO). Molecular analysis was pe [...] rformed to assess the genetic diversity among the S. solani isolates from cotton, and to verify their relationship with representative S. solani isolates from tomato. Random amplified polymorphic DNA (RAPD) markers and internal transcribed spacers of ribosomal DNA (rDNA) were used to compare 33 monosporic isolates of S. solani (28 from cotton and five from tomato). An isolate of Alternaria macrospora from cotton was also used for comparison. RAPD analysis showed the presence of polymorphism between the genera and the species. The A. macrospora and the S. solani isolates from cotton and tomato were distinct from each other, and fell into separate groups. Variation by geographic region was observed for the tomato isolates but not for the cotton isolates. Amplifications of the ITS region using the primer pair ITS4/ITS5 resulted in a single PCR product of approximately 600 bp for all the isolates. Similarly, when amplified fragments were digested with eight restriction enzymes, identical banding patterns were observed for all the isolates. Hence, rDNA analysis revealed no inter-generic or intra-specific variation. The genetic difference observed between the cotton and the tomato isolates provides evidence that S. solani attacking cotton in Brazil belongs to a distinct genotype.

Y.R., MEHTA.

2001-12-01

188

A New Disease of Gladiolus Caused by Binucleate Rhizoctonia sp.  

OpenAIRE

Fungi with Rhizoctonia-like mycelia were isolated from root and stem of Gladiolus (Gladiolus hybrida L.) grown in commercial glasshouse in Mahallat, Iran, during the summer and fall of 2003. Isolated fungi were identified as either binucleate or multi nucleate Rhizoctonia sp. On the basis of hyphal characteristics and nuclear number, twenty three isolates of Rhizoctonia sp. were obtained from infected corms and stems. Of the 23 isolate, 9 had binucleate and 14 had multinucleate vegetative hyp...

Mohammad Javad Soleimani; Leila Kashi

2005-01-01

189

Synthesis of Silver Nanoparticles by a Bryophilous Rhizoctonia species  

OpenAIRE

We demonstrate the synthesis of silver nanoparticles by a potentially benign species of bryophilous Rhizoctonia in two different media. The first medium supports fungal growth and the up?regulation of nitrate reductase, while the second medium supports fungal growth and the repression of nitrate reductase. For both media, the resulting silver nanoparticles were ca. 25? 50nm and were subglobose to broadly ellipsoidal in shape. The optical analysis of the silver nano...

Raudabaugh, Daniel B.; Tzolov, Marian B.; Calabrese, Joseph P.; Overton, Barrie E.

2013-01-01

190

Studies of genetic polymorphism in the isolates of Fusarium solani  

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Full Text Available Fusarium solani is the important pathogen causing wilt disease of guava in India. In the present investigation six representative isolate of Fusarium solani, collected from different places of India were subjected to analysis of genetic variability in terms of Carboxylesterases isozyme pattern and DNA polymorphism using RAPD-PCR. Pattern of Carboxylesterase revealed a similar isozyme cluster in the isolate namely, Allahabad (isolate-3, Faizabad, (isolate-4, Unnao (isolate-5 and Lucknow (isolate-6. Similar results were obtained when 10 randomly amplified polymorphic DNA markers (OPA1-OPA10 tested in the genome of Fusarium solani and grouped on basis of obtained allelic data. This pattern of genetic variability in the isolate was also supported by the analysis of the similarity indices and UPGMA dendrogram.

Vijai K. Gupta

2009-03-01

191

Flutuação populacional de Rhizoctonia spp. em jardim clonal de Eucalyptus spp / Population fluctuation of Rhizoctonia spp. in clonal nurseries of Eucalyptus spp  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A queima de folhas em brotações em jardim clonal e a mela de estacas na fase de enraizamento, causadas por espécies de Rhizoctonia, podem limitar a produção de mudas de eucalipto por estaquia. Apesar de sua importância, pouco se conhece sobre essas doenças. Assim, visando otimizar as estratégias de [...] controle dessas doenças, nesse trabalho objetivou-se elucidar aspectos da dinâmica populacional de Rhizoctonia spp. no solo e em brotações, a fim de estabelecer, correlações com a incidência da doença, bem como determinar a distribuição do patógeno em jardim clonal de eucalipto. Conclui-se que há flutuação populacional de Rhizoctonia spp. em jardim clonal de eucalipto, sendo observado um padrão de distribuição espacial agregado do inóculo no solo. A dinâmica populacional de Rhizoctonia spp. foi correlacionada à temperatura, mas não à precipitação pluviométrica. Abstract in english Leaf blight in shoots of clonal hedges and web blight of cuttings for rooting, caused by Rhizoctonia species, may be limiting to the production of eucalyptus seedlings by cuttings. Despite their importance, there have been few etiological and epidemiological studies of these diseases. To optimize di [...] sease management strategies, this research aimed to evaluate population dynamics of Rhizoctonia spp. in soil and eucalyptus cuttings to correlate with disease incidence, and to determine spatial distribution of Rhizoctonia spp. inoculum in a clonal nursery of eucalyptus cuttings. Population fluctuation of Rhizoctonia spp. was detected throughout the year. Pathogen distribution in soil was found to have an aggregated pattern. Temperature, but not rainfall, was correlated to population levels of Rhizoctonia spp in soil samples.

Eugenio, Sanfuentes; Acelino C., Alfenas; Luiz A., Maffia; Reginaldo G., Mafia.

2007-04-01

192

Production of paclitaxel by Fusarium solani isolated from Taxus celebica.  

Science.gov (United States)

A fungus was isolated from the stem cuttings of Taxus celebica, which produced paclitaxel in liquid-grown cultures. The fungus was identified as Fusarium solani based on colony characteristics, morphology of conidia and the 26S rDNA sequence. Paclitaxel was identified by chromatographic and spectroscopic comparison with authentic paclitaxel and its cytotoxic activity towards Jurkat cells in vitro. PMID:18535360

Chakravarthi, B V S K; Das, Prasanta; Surendranath, Kalpana; Karande, Anjali A; Jayabaskaran, Chelliah

2008-06-01

193

Fusarium solani infection in a kidney transplant recipient  

OpenAIRE

Hyalo hypho mycosis due to Fusarium species mainly occurs in immunocompromised hosts. The clinical presentation varies from localized to disseminated involvement. A case of localized cutaneous fusariosis caused by Fusarium solani in a renal transplant patient is described and the skin manifestations of the disease are discussed.

Mohanty, N. K.; Sahu, S.

2014-01-01

194

Enhanced amylase production by fusarium solani in solid state fermentation  

International Nuclear Information System (INIS)

The present study illustrates the investigation carried out on the production of amylase by Fusarium species under solid state fermentation. All the tested Fusarium species were capable of producing amylase. A selected F. solani isolate SY7, showed the highest amylase production in solid state fermentation. Different substrates were screened for enzyme production. Among the several agronomic wastes, wheat bran supported the highest yield of amylase (141.18 U/g of dry substrate) after 3 days of incubation. Optimisation of the physical parameters revealed the optimum pH, temperature and moisture level for amylase production by the isolate as 8.0, 25 C and 70%, respectively. The above results indicate that the production of amylase by F. solani isolate SY7 could be improved by a further optimisation of the medium and culture conditions. (author)

195

Immobilization of lipase from Fusarium solani FS1  

OpenAIRE

Lipase from Fusarium solani FS1 was immobilized by covalent attachment to polyacrylamide beads and onto magnetized Dacron, retaining 12% and 97% of activity, respectively. Lipase was also entrapped within polyacrylamide beads, retaining 53% of activity. Investigations of the kinetic characteristics of the immobilized derivatives using triolein as substrate showed that lipase immobilized onto polyacrilamide beads and Dacron did not follow Michaelis-Menten kinetics.

Knight Kirsty; Pimentel Maria do Carmo Barros; Morais Marcia Maria Camargo de; Ledingham William M.; Lima Filho José Luiz de; Maia Maria de Mascena Diniz

2000-01-01

196

Tratamentos biológico e químico em sementes de Cedrela fissilis para controle de Rhizoctonia sp. / Biological and chemical treatment of Cedrela fissilis seeds for controlling Rhizoctonia sp.  

Scientific Electronic Library Online (English)

Full Text Available Neste trabalho, objetivou-se avaliar o efeito de um fungicida protetor e de um produto biológico, utilizados isoladamente e combinados, no controle de patógenos presentes em sementes de cedro (Cedrela fissilis), especialmente de Rhizoctonia sp. Anteriormente ao tratamento das sementes, parte das sem [...] entes foi previamente inoculada com Rhizoctonia sp., isolado de sementes de cedro, e parte recebeu os tratamentos sem a inoculação. Após, as sementes foram submetidas a tratamentos com produto biológico em pó à base de Trichoderma spp. (aplicado isoladamente), fungicida Captan em pó (também aplicado isoladamente), combinação dos dois produtos aplicados em uma dose considerada máxima (100%) e combinação de metade da dose de ambos os produtos (50%) e ainda a testemunha. As avaliações constaram dos testes de germinação, sanidade em papel-filtro, emergência e das avaliações de mudas. Nenhum tratamento conseguiu erradicar Rhizoctonia sp. das sementes inoculadas, porém o tratamento com 100% da dose de ambos os produtos reduziu sua incidência. A combinação de produto químico e biológico, apresenta-se como uma alternativa viável para o tratamento de sementes de cedro, especialmente no controle de Rhizoctonia sp. Abstract in english This research evaluated the effect of a fungicide and a biological product, singly and combined, for the control of pathogens, especially Rhizoctonia sp., in seeds of Cedrela fissilis. Before the seeds treatment, the inoculation of Rhizoctonia sp., isolated from C. fissilis seeds in blotter-test and [...] considered pathogenic for the specie, was done on half of the seeds used. After, the seeds were subjected to treatments with powder organic product based on Trichoderma spp. (singly), powder fungicide Captan (also singly), combination of two products in a maximum dose considered (100%) and combination of half dose of both products, besides the control. After the seeds treatments the following tests were done: germination, emergence in vermiculite, with evaluations of seedlings and sanitary by blotter-test. No treatment could eradicate Rhizoctonia sp. inoculated seed, but the treatment with 100% of the dose of both products reduced its incidence. The combination of chemical and biological products can be a viable alternative for the treatment of C. fissililis seeds, especially in the control of Rhizoctonia sp.

Marília, Lazarotto; Marlove Fátima Brião, Muniz; Rafael, Beltrame; Álvaro Figueredo dos, Santos; Jucéli, Müller; Maristela Machado, Araújo.

2013-03-01

197

ANTIFUNGAL ACTIVITY OF SOME PLANT EXTRACT S AGAINST FUSARIUM SOLANI  

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Full Text Available The aqueous extracts of twenty plants were screened for their antifungal activity Fusarium solani, causal organism if Sudden Death Syndrome (SDS of Soybean (Glycine max wilt diseases, soft rot of potato. The maximum inhibitory effect was shown by leaf extracts of Camellia sinensis (67.17%, root extracts of Asparagus racemosus (54.43%. Some of the other plants showed moderate to intermediate inhibition against the mycelium growth of test fungi whcih varied in the following range Callistemon lanceolatus> Agegle marmelos> Azadirachta> Acacia catechu> Aloevera.

S.K. BHARADWAJ

2007-01-01

198

Detection of trypsin inhibitor in seeds of Eucalyptus urophylla and its influence on the in vitro growth of the fungi Pisolithus tinctorius and Rhizoctonia solani  

OpenAIRE

Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two proteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds and fractions partially purified by gel filtration, with inhibitory activity against trypsin, i...

Tremacoldi Célia Regina; Pascholati Sérgio Florentino

2002-01-01

199

Temperature and dosage dependent suppression of damping-off caused by Rhizoctonia solani in vermicompost amended nurseries of white pumpkin: (with 3 tables & 2 figures)  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in english It is generally accepted that composts have the potential to provide biological control of plant diseases. However, there has been little research on the use of vermicomposts for the same purpose. The aim of this paper was to evaluate a vermicompost suppressiveness in nurseries of white pumpkin infe [...] sted with Rhizoctoniasolani. Two assays were carried out at 22 ± 2 °Cand 15 ± 3 °C, with increasing proportions of compost in the substratum. Seedlings with damping-off or incipient crown rot, as well as those that did not emerge as expected for the germination power, were considered diseased. Vermicompost's effectiveness in suppressing the disease depended on dosage and temperature.

MC, Rivera; Eduardo R, Wright; MV, López; MC, Fabrizio.

2004-12-01

200

In vitro effect of essential oils on Alternaria solani Sorauer / Efecto in vitro de aceites esenciales sobre Alternaria solani Sorauer  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: English Abstract in spanish Este trabajo tuvo como objetivo determinar la actividad antifúngica in vitro de diez aceites esenciales sobre Alternaria solani Sorauer, importante patógeno de las solanáceas. Se evaluó el efecto por contacto directo y por exposición a los vapores. Los bioensayos se realizaron según diseño completam [...] ente aleatorizado, se utilizó el método de discos de papel inoculados con los aceites, enfrentados a discos del fitopatógeno y se evaluó el crecimiento radial del hongo. Todos los aceites, excepto Citrus sinensis (L.) Osbeck (naranjo dulce), inhibieron el crecimiento micelial hasta los 7 días. A los 14 días se observó inhibición total en los tratamientos con los aceites de Pimpinella anisum L. (anís), Ocimum basilicum L. (albahaca blanca), Ocimum basilicum L. variedad genovese (albahaca genovesa) y Piper auritum Kunth (caisimón de anís). Los metabolitos volátiles de los aceites no mostraron efecto fungicida; no obstante se observó inhibición del crecimiento micelial de A. solani en los tratamientos con los extractos de Ruta chalepensis L. (ruda) y Piper auritum. Los resultados abren nuevas perspectivas para el control de este patógeno. Abstract in english The aim of this work was to determine the in vitro antifungal activity of ten essential oils on Alternaria solani SORAUER. The effect by direct contact and exposure to vapors was evaluated. The bioassays were performed using a completely randomized design and the method of paper discs inoculated wit [...] h the oils facing phytopathogen discs; the fungal radial growth was evaluated. All the oils, except those from Citrus sinensis (L.) Osbeck (sweet orange), inhibited the mycelial growth until the seventh day. At day 14, a total inhibition was observed in the treatments with the oils from Pimpinella anisum L. (anise), Ocimum basilicum L. (white basil), Ocinum basilicum L. var. genovese (Genovese basil), and Piper auritum Kunth (anise caisimon). No fungicidal effect was shown by the volatile metabolites of the oils; however, the inhibition of A. solani mycelial growth was observed in the treatments with the extracts of Ruta chalepensis L. (ruda) and P. auritum. These results open new perspectives for the control of this pathogen.

Yanisia, Duarte; Oriela, Pino; Danay, Infante; Yaima, Sánchez; María del Carmen, Travieso; B, Martínez.

2013-04-01

201

Efficacy of Posaconazole as Treatment and Prophylaxis against Fusarium solani?  

Science.gov (United States)

Invasive fusariosis is a highly aggressive fungal infection associated with high mortality in heavily immunocompromised patients. Although posaconazole is efficacious as salvage therapy against infections caused by Fusarium species, concerns remain regarding this agent in the setting of reduced potency. To evaluate the efficacy of posaconazole as treatment or prophylaxis against invasive fusariosis caused by Fusarium solani, we utilized a neutropenic murine model of disseminated disease. ICR mice were administered escalating doses of posaconazole (6.25, 12.5, 25, or 50 mg/kg of body weight twice daily [BID]) by oral gavage beginning 2 days prior to inoculation in the prophylaxis studies or beginning 12 h after inoculation as treatment. Therapy was continued until day 9 postinoculation, and animals were monitored off therapy until day 15 for survival. Fungal burden was assessed as CFU in the kidneys. A clear dose-response relationship was observed, as the highest dose of posaconazole (50 mg/kg) was the most effective in prolonging survival and reducing tissue fungal burden both as prophylaxis and as treatment. This dose response was associated with high posaconazole serum concentrations as measured by bioassay. However, the extent of efficacy was also dependent on the infecting inoculum, as greater increases in survival and reductions in fungal burden were observed with the lower inocula tested. In this model high dosages of posaconazole were effective as treatment and prophylaxis against disseminated fusariosis caused by F. solani. PMID:20065054

Wiederhold, Nathan P.; Najvar, Laura K.; Bocanegra, Rosie; Graybill, John R.; Patterson, Thomas F.

2010-01-01

202

Efficacy of posaconazole as treatment and prophylaxis against Fusarium solani.  

Science.gov (United States)

Invasive fusariosis is a highly aggressive fungal infection associated with high mortality in heavily immunocompromised patients. Although posaconazole is efficacious as salvage therapy against infections caused by Fusarium species, concerns remain regarding this agent in the setting of reduced potency. To evaluate the efficacy of posaconazole as treatment or prophylaxis against invasive fusariosis caused by Fusarium solani, we utilized a neutropenic murine model of disseminated disease. ICR mice were administered escalating doses of posaconazole (6.25, 12.5, 25, or 50 mg/kg of body weight twice daily [BID]) by oral gavage beginning 2 days prior to inoculation in the prophylaxis studies or beginning 12 h after inoculation as treatment. Therapy was continued until day 9 postinoculation, and animals were monitored off therapy until day 15 for survival. Fungal burden was assessed as CFU in the kidneys. A clear dose-response relationship was observed, as the highest dose of posaconazole (50 mg/kg) was the most effective in prolonging survival and reducing tissue fungal burden both as prophylaxis and as treatment. This dose response was associated with high posaconazole serum concentrations as measured by bioassay. However, the extent of efficacy was also dependent on the infecting inoculum, as greater increases in survival and reductions in fungal burden were observed with the lower inocula tested. In this model high dosages of posaconazole were effective as treatment and prophylaxis against disseminated fusariosis caused by F. solani. PMID:20065054

Wiederhold, Nathan P; Najvar, Laura K; Bocanegra, Rosie; Graybill, John R; Patterson, Thomas F

2010-03-01

203

Phylogenetic Analysis of Fusarium solani Associated with the Asian Longhorned Beetle, Anoplophora glabripennis  

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Full Text Available Culture-independent analysis of the gut of a wood-boring insect, Anoplophora glabripennis (Coleoptera: Cerambycidae, revealed a consistent association between members of the fungal Fusarium solani species complex and the larval stage of both colony-derived and wild A. glabripennis populations. Using the translation elongation factor 1-alpha region for culture-independent phylogenetic and operational taxonomic unit (OTU-based analyses, only two OTUs were detected, suggesting that genetic variance at this locus was low among A. glabripennis-associated isolates. To better survey the genetic variation of F. solani associated with A. glabripennis, and establish its phylogenetic relationship with other members of the F. solani species complex, single spore isolates were created from different populations and multi-locus phylogenetic analysis was performed using a combination of the translation elongation factor alpha-1, internal transcribed spacer, and large subunit rDNA regions. These analyses revealed that colony-derived larvae reared in three different tree species or on artificial diet, as well as larvae from wild populations collected from three additional tree species in New York City and from a single tree species in Worcester, MA, consistently harbored F. solani within their guts. While there is some genetic variation in the F. solani carried between populations, within-population variation is low. We speculate that F. solani is able to fill a broad niche in the A. glabripennis gut, providing it with fungal lignocellulases to allow the larvae to grow and develop on woody tissue. However, it is likely that many F. solani genotypes could potentially fill this niche, so the relationship may not be limited to a single member of the F. solani species complex. While little is known about the role of filamentous fungi and their symbiotic associations with insects, this report suggests that larval A. glabripennis has developed an intimate relationship with F. solani that is not limited by geographic location or host tree.

Kelli Hoover

2012-02-01

204

Óleo essencial de Baccharis tridentata Vahl: composição química, atividade antioxidante e fungitóxica, e caracterização morfológica das estruturas secretoras por microscopia eletrônica de varredura / Baccharis tridentata Vahl essential oil: chemical composition, and antioxidant and fungitoxic activities and morphological characterization of secretory structures by scanning electron microscopy  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho teve como objetivos avaliar a composição química do óleo essencial de Baccharis tridentata Vahl, as atividades antioxidante e fungitóxica, e estudar a morfologia das estruturas secretoras do óleo essencial presentes na superfície foliar por meio de microscopia eletrônica de varredura ( [...] MEV). A extração do óleo essencial foi realizada por hidrodestilação, as análises quantitativas e qualitativas foram executadas por meio de cromatografia em fase gasosa com detector de ionização de chamas (FID) e acoplada à espectrometria de massas, respectivamente. A atividade antioxidante foi realizada empregando-se os métodos de redução do radical estável DPPH e o ensaio de oxidação do sistema ?-caroteno/ácido linoleico. As atividades fungitóxicas foram avaliadas utilizando o teste bioanalítico in vitro, sobre a inibição do crescimento micelial dos fitopatógenos Fusarium oxysporum, Colletotrichum gloeosporioides e Rhizoctonia solani. A composição química revelou a presença de 28 compostos, sendo o ?-tujeno (22,93%) o constituinte majoritário; não foi observada atividade antioxidante por meio dos ensaios utilizados, no entanto, observou-se atividade fungitóxica sobre o crescimento micelial dos fitopatógenos estudados. Já os estudos da superfície foliar por MEV revelaram a presença de tricomas glandulares em ambas as superfícies abaxial e adaxial. Abstract in english This study aimed to evaluate the chemical composition and the antioxidant and fungitoxic activities of Baccharis tridentata essential oil, as well as to study the morphology of its secretory structures present on the leaf surface by scanning electron microscopy (SEM). The essential oil was extracted [...] by hydrodistillation; the quantitative and qualitative analyses were performed on a gas chromatograph equipped with a flame ionization detector (FID) and coupled to a mass spectrometer, respectively. The antioxidant activity was determined by the methods of reduction of the DPPH stable radical and oxidation of the ?-carotene/linoleic acid system. Fungitoxic activities were assessed by the in vitro bioanalytical test on the inhibition of the mycelial growth of the plant pathogens Fusarium oxysporum, Colletotrichum gloeosporioides and Rhizoctonia solani. The chemical composition revealed the presence of 28 compounds, with ?-thujene (22.93%) as the major constituent. No antioxidant activity was observed in the tests used; however, there was fungitoxic activity against the mycelial growth of plant pathogens. Leaf surface studies by SEM revealed the presence of glandular trichomes on both abaxial and adaxial surfaces.

S.P., Souza; M.G., Cardoso; P.E., Souza; L.G.L., Guimarães; J., Andrade; A.C.T., Mallet; D.L., Nelson.

205

Atividade alelopática do filtrado de cultura produzido por Fusarium solani / Allelopathic activity of culture filtrate produced by Fusarium solani  

Scientific Electronic Library Online (English)

Full Text Available As plantas daninhas se constituem no principal problema a impor limitação à exploração da agropecuária nas áreas tropicais. Entretanto, o controle químico dessas plantas tem gerado insatisfações de ordem social, quer porque contaminam as fontes de recursos naturais ou por comprometerem a qualidade d [...] os alimentos da dieta dos animais, em geral, e dos humanos, em particular. Os objetivos deste trabalho foram identificar e caracterizar a atividade alelopática do filtrado de cultura produzido pelo fungo Fusarium solani f. sp. pipers. Foram avaliados os efeitos das toxinas, nas concentrações de 1,0 e 4,0%, sobre a germinação de sementes e o desenvolvimento da radícula e do hipocótilo das plantas daninhas malícia (Mimosa pudica) e mata-pasto (Senna obtusifolia). Os resultados mostraram presença de atividade alelopática inibitória, com variações de acordo com a concentração e a planta receptora. A intensidade dos efeitos inibitórios induzidos pelo extrato esteve positivamente associada à concentração, com efeitos mais intensos verificados a 4,0%. Independentemente da concentração e do bioensaio, a espécie malícia se mostrou mais sensível aos efeitos do filtrado da cultura. O desenvolvimento da radícula foi o fator da planta mais intensamente inibido. Os resultados indicam a existência de potencial de utilização da toxina produzida pelo fungo, como fonte alternativa no controle de plantas daninhas, o que justifica estudos mais avançados. Abstract in english Weeds are a major problem limiting agriculture and cattle raising activities in the tropics. Current chemical control measures have raised environmental concerns due to their potential of contaminating natural resources and compromising the quality of animal feed. The objective of this paper was to [...] identify and characterize the potential allelopathic activity of Fusarium solani f. sp. pipers culture filtrate. The effects of the toxin were analyzed at 1% and 4% concentration, on seed germination and radicle and hypocotyl elongation of the weeds Mimosa pudica and Senna obtusifolia. The results showed potential inhibitory allelopathic activity of the Fusarium culture filtrate, varying according to concentration and receiving plants. The intensity of the inhibition effects promoted by the extracts was clearly associated to concentration, with the major effect being observed at 4%. Regardless of concentration and bioassays, Mimosa pudica was more sensitive to the toxin effects of the culture filtrate. Radicle elongation was more intensely inhibited by the culture filtrate toxins. The results showed potential for the use of the toxins produced by Fusarium solani f. sp. pipers, as an alternative source to control weeds. However, further studies should be carried out.

A.P.S., Souza Filho; M.L.R., Duarte.

2007-03-01

206

Secondary metabolite profiling of Alternaria dauci, A. porri, A. solani, and A. tomatophila  

DEFF Research Database (Denmark)

Chemotaxonomy (secondary metabolite profiling) has been shown to be of great value in the classification and differentiation in Ascomycota. However, few studies have investigated the use of metabolite production for classification and identification purposes of plant pathogenic Alternaria species. The purpose of the present study was to describe the methodology behind metabolite profiling in chemotaxonomy using A. dauci, A. porri, A. solani, and A. tomatophila strains as examples of the group. The results confirmed that A. dauci, A. solani, and A. tomatophila are three distinct species each with their own specific metabolite profiles, and that A. solani and A. tomatophila both produce altersolanol A, altertoxin 1, and macrosporin. By using automated chemical image analysis and other multivariate statistic analyses, three sets of species-specific metabolites could be selected, one each for A. dauci, A. solani, and A. tomatophila.

Andersen, Birgitte; Dongo, Anita

2008-01-01

207

Bilateral endogenous Fusarium solani endophthalmitis in a liver-transplanted patient : a case report  

DEFF Research Database (Denmark)

Endogenous Fusarium endophthalmitis is a rare disease predominantly described in immunocompromised patients often due to leukemia. We report a case of bilateral endogenous Fusarium solani endophthalmitis in a liver-transplanted patient.

JØrgensen, Jesper Skovlund; Prause, Jan Ulrik

2014-01-01

208

Effect of potting mix microbial carrying capacity on biological control of rhizoctonia damping-off of radish and rhizoctonia crown and root rot of poinsettia.  

Science.gov (United States)

ABSTRACT Potting mixes prepared with dark, highly decomposed Sphagnum peat, with light, less decomposed Sphagnum peat, or with composted pine bark, all three of which were colonized by indigenous microorganisms, failed to consistently suppress Rhizoctonia damping-off of radish or Rhizoctonia crown and root rot of poinsettia. Inoculation of these mixes with Chryseobacterium gleum (C(299)R(2)) and Trichoderma hamatum 382 (T(382)) significantly reduced the severity of both diseases in the composted pine bark mix in which both biocontrol agents maintained high populations over 90 days. These microorganisms were less effective against damping-off in the light and dark peat mixes, respectively, in which populations of C(299)R(2) declined. In contrast, crown and root rot, a disease that is severe late in the crop, was suppressed in all three types of mixes. High populations of T(382) in all three mixes late during the cropping cycle may have contributed to control of this disease. PMID:18943449

Krause, M S; Madden, L V; Hoitink, H A

2001-11-01

209

C-20 Ketone reduction of hydrocortisone by Fusarium solani and Aspergillus ochraceus.  

Science.gov (United States)

The biotransformation of hydrocortisone (1) by Fusarium solani and Aspergillus ochraceus was investigated for the first time. After 10 days at 30 °C, just one metabolite was produced by both fungi: 11?, 17?, 20?, 21-tetrahydroxypregn-4-en-3-one (2) established on the basis of spectroscopic data. The reaction was reduction of the 20-carbonyl group. Time course study determined by HPLC showed 60 and 45 % yield for the metabolite by F. solani and A. ochraceus, respectively. PMID:25048228

Gandomkar, Somayyeh; Hosseinzadeh, Leila; Habibi, Zohreh

2014-11-01

210

Produção de enzimas extracelulares por Fusarium solani de maracujazeiro amarelo Production of extracellular enzymes by Fusarium solani from yellow passion fruit  

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Full Text Available Uma das principais doenças do maracujazeiro, na maioria dos estados produtores do Brasil, é a podridão do colo, causada por Fusarium solani. Pouco se sabe a respeito da fisiologia deste patógeno do maracujazeiro amarelo, principalmente quanto à produção de enzimas extracelulares. O objetivo do presente trabalho foi verificar, em meios de cultura individuais e apropriados, a produção das enzimas extracelulares amilase, lipase, celulase, proteases (caseinase e gelatinase, lacase (oxidase e catalase por isolados de F. solani, provenientes de maracujazeiro amarelo. O delineamento experimental adotado foi o inteiramente casualizado, em esquema de dois fatores (nove isolados versus sete enzimas, com três repetições. Todos os isolados de F. solani produziram, de maneira semiquantitativa, as enzimas extracelulares amilase, lipase, celulase, caseinase (protease e lacase (oxidase. No entanto, a quantidade produzida de cada enzima foi significativamente diferente entre os isolados. As enzimas extracelulares gelatinase (protease e catalase foram produzidas em pouca quantidade e de maneira igual por todos os isolados do fungo.In most Brazilian producer states, one of the main diseases of the passion fruit is collar rot caused by Fusarium solani. Little is known about the physiology of this pathogen from yellow passion fruit, which mainly involves the production of extracellular enzymes. The objective of this work was to verify, in individual and appropriate culture media, the production of the extracellular enzymes amylase, lipase, cellulase, proteases (caseinase and gelatinase, lacase (oxydase and catalase by isolates of F. solani from yellow passion fruit. The experimental design adopted was an entirely randomized two-factor scheme (nine isolates and seven enzymes with three repetitions. All the isolates of F. solani produced, in a semi-quantitative manner, the extracellular enzymes amylase, lipase, cellulase, caseinase (protease and lacase. However, the amount of each enzyme produced was significantly different among the isolates. The extracellular enzymes gelatinase (protease and catalase were produced in a small amount and in an equal manner by all the isolates of the fungus.

César Júnior Bueno

2009-10-01

211

Regulators involved in Dickeya solani virulence, genetic conservation, and functional variability.  

Science.gov (United States)

Bacteria from the genus Dickeya (formerly Erwinia chrysanthemi) are plant pathogens causing severe diseases in many economically important crops. A majority of the strains responsible for potato disease in Europe belong to a newly identified Dickeya solani species. Although some ecological and epidemiological studies have been carried out, little is known about the regulation of D. solani virulence. The characterization of four D. solani strains indicates significant differences in their virulence on potato, although they are genetically similar based on genomic fingerprinting profiles. A phenotypic examination included an analysis of virulence on potato; growth rate in culture; motility; Fe3+ chelation; and pectate lyase, cellulase, protease, biosurfactant, and blue pigment production. Mutants of four D. solani strains were constructed by inactivating the genes coding either for one of the main negative regulators of D. dadantii virulence (kdgR, pecS, and pecT) or for the synthesis and perception of signaling molecules (expI and expR). Analysis of these mutants indicated that PecS, PecT, and KdgR play a similar role in both species, repressing, to different degrees, the synthesis of virulence factors. The thermoregulator PecT seems to be a major regulator of D. solani virulence. This work also reveals the role of quorum sensing mediated by ExpI and ExpR in D. solani virulence on potato. PMID:24625032

Potrykus, Marta; Golanowska, Ma?gorzata; Hugouvieux-Cotte-Pattat, Nicole; Lojkowska, Ewa

2014-07-01

212

CHARACTERIZATION OF RHIZOCTONIA SPP. FROM CROPPING SYSTEMS IN THE WESTERN CAPE PROVINCE OF SOUTH AFRICA  

Science.gov (United States)

Rhizoctonia spp. are important pathogens of a broad range of crop plants that are economically important to the farm economy of the Western Cape region of South Africa. However, there is little information concerning the identity and relative importance of these fungal pathogens. Isolates of Rhizo...

213

Postharvet losses associated with Rhizoctonia crown and root rot of sugarbeet  

Science.gov (United States)

As the prevalence of Rhizoctonia crown and root rot (RCRR) increases, more diseased sugarbeet (Beta vulgaris L.) roots are destined for storage piles. To investigate the effect of RCRR on storage properties, roots with similar symptoms were grouped and extractable sucrose, invert sugar, and respirat...

214

Análise de restrição de DNA ribossomal amplificado (ARDRA pode diferenciar Fusarium solani f. sp. phaseoli de F. solani f. sp. glycines Restriction analysis of rDNA (ARDRA can differentiate Fusarium solani f. sp. phaseoli from F. solani f. sp. glycines  

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Full Text Available Métodos moleculares têm sido utilizados para caracterizar a diversidade entre isolados de Fusarium spp. patogênicos e não patogênicos a uma cultura e, para determinar relações genéticas entre formae speciales. Testes de patogenicidade realizados em soja (Glycine max e feijoeiro (Phaseolus vulgaris com 17 isolados de Fusarium solani não demonstraram especificidade de hospedeiros. Utilizou-se a técnica ARDRA (Amplified Ribosomal DNA Restriction Analysis para analisar a região ITS1 - 5,8S rDNA - ITS2, amplificada com os primers ITS5 e ITS4. Os produtos amplificados foram digeridos com as enzimas de restrição Hae III e Msp I. Os padrões de bandas gerados pela digestão com a enzima Hae III permitiram diferenciar três grupos entre os isolados de F. solani, sendo um grupo específico para isolados de F. solani f. sp. phaseoli com 100% de similaridade entre os 11 isolados. Entre os isolados de F. solani f. sp glycines foram observados dois padrões distintos de restrição. A técnica de ARDRA utilizando a enzima Hae III apresenta, portanto, potencial para utilização como um marcador para diferenciação entre as formae specialesphaseoli e glycines, dentro do complexo F. solani.Molecular methods have been used to characterize diversity among pathogenic and non pathogenic isolates of Fusarium spp. and to determine genetic relationships among formae speciales. Pathogenicity tests performed on dry beans (Phaseolus vulgaris and soybeans (Glycine maxwith 17 isolates of Fusarium solani did not demonstrate host specificity. Amplified Ribosomal DNA Restriction Analysis (ARDRA was used to analyze the ITS1 - 5,8S rDNA - ITS2 region, amplified with primers ITS4 and ITS5. The amplified products were digested with the restriction enzymes Hae III and Msp I. Banding patterns generated by the enzyme Hae III enabled the differentiation of three groups within F. solani, one specific for isolates of F. solani f. sp. phaseoli and the other two for F. solani f. sp. glycines. The ARDRA technique, using the enzyme Hae III, is a promising marker to differentiate the formae specialesphaseoli from glycines within the F. solani complex.

VIRGÍNIA C. de OLIVEIRA

2002-11-01

215

Análise de restrição de DNA ribossomal amplificado (ARDRA) pode diferenciar Fusarium solani f. sp. phaseoli de F. solani f. sp. glycines / Restriction analysis of rDNA (ARDRA) can differentiate Fusarium solani f. sp. phaseoli from F. solani f. sp. glycines  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Métodos moleculares têm sido utilizados para caracterizar a diversidade entre isolados de Fusarium spp. patogênicos e não patogênicos a uma cultura e, para determinar relações genéticas entre formae speciales. Testes de patogenicidade realizados em soja (Glycine max) e feijoeiro (Phaseolus vulgaris) [...] com 17 isolados de Fusarium solani não demonstraram especificidade de hospedeiros. Utilizou-se a técnica ARDRA (Amplified Ribosomal DNA Restriction Analysis) para analisar a região ITS1 - 5,8S rDNA - ITS2, amplificada com os primers ITS5 e ITS4. Os produtos amplificados foram digeridos com as enzimas de restrição Hae III e Msp I. Os padrões de bandas gerados pela digestão com a enzima Hae III permitiram diferenciar três grupos entre os isolados de F. solani, sendo um grupo específico para isolados de F. solani f. sp. phaseoli com 100% de similaridade entre os 11 isolados. Entre os isolados de F. solani f. sp glycines foram observados dois padrões distintos de restrição. A técnica de ARDRA utilizando a enzima Hae III apresenta, portanto, potencial para utilização como um marcador para diferenciação entre as formae specialesphaseoli e glycines, dentro do complexo F. solani. Abstract in english Molecular methods have been used to characterize diversity among pathogenic and non pathogenic isolates of Fusarium spp. and to determine genetic relationships among formae speciales. Pathogenicity tests performed on dry beans (Phaseolus vulgaris) and soybeans (Glycine max)with 17 isolates of Fusari [...] um solani did not demonstrate host specificity. Amplified Ribosomal DNA Restriction Analysis (ARDRA) was used to analyze the ITS1 - 5,8S rDNA - ITS2 region, amplified with primers ITS4 and ITS5. The amplified products were digested with the restriction enzymes Hae III and Msp I. Banding patterns generated by the enzyme Hae III enabled the differentiation of three groups within F. solani, one specific for isolates of F. solani f. sp. phaseoli and the other two for F. solani f. sp. glycines. The ARDRA technique, using the enzyme Hae III, is a promising marker to differentiate the formae specialesphaseoli from glycines within the F. solani complex.

VIRGÍNIA C. de, OLIVEIRA; JEFFERSON L. S. da, COSTA.

2002-11-01

216

CONTROLE DE ALTERNARIA SOLANI COM FUNGICIDAS NA CULTURA DO TOMATEIRO / CONTROL OF ALTERNARIA SOLANI WITH FUNGICIDES IN TOMATO PLANTS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Portuguese Abstract in portuguese A pinta-preta, causada pelo fungo Alternaria solani, caracteriza-se por ser uma importante e destrutiva doença da cultura do tomate, sob condições de alta temperatura e umidade. Objetivou-se avaliar a eficiência de diferentes fungicidas no controle da Alternaria solani na cultura do tomateiro na reg [...] ião de Lavras (MG). O experimento foi desenvolvido na Universidade Federal de Lavras - Departamento de Agricultura, no período de novembro de 2004 a janeiro de 2005. O delineamento experimental foi o de blocos casualizados com 10 tratamentos e quatro repetições. Cada parcela composta por 12 plantas. As aplicações foram realizadas com um pulverizador costal manual (45 lbf/pol2), volume de aplicação de 800 L•ha-1, totalizando sete aplicações, com intervalos de sete dias. Foram realizadas cinco avaliações para a severidade foliar da doença com o uso de escala diagramática. Todos os fungicidas apresentaram potencial de controle da pinta-preta dentro das características inerentes ao seu grupo químico. Os melhores níveis de controle foram obtidos com os tratamentos Chlorothalonil 500 g•L-1 + Tetraconazole 20 g•L-1 (dosagem 200 mL•100 L-1), Chlorothalonil 400 g•L-1+ Oxicloreto de Cobre 420 g•kg-1 e Chlorothalonil 750 g•kg-1 + Tetraconazole 20 g•kg-1 (dosagem 150 g•100 L-1). Tetraconazole 100 g•L-1 proporcionou os menores níveis de controle. Abstract in english The early blight disease on tomato, caused by the fungus Alternaria solani, is referred to in importance due its destructive power, under conditions of high temperature and humidity. This study aimed to evaluate the effectiveness of various fungicides in your control in the region of Lavras-MG, Braz [...] il. The experiment was conducted at the Federal University of Lavras, Department of Agriculture in the period from November 2004 to January 2005. The experimental design was randomized blocks with 10 treatments and four replications, each plot comprise 12 plants. The applications were made with a manual spray costal (45 lbf/pol2), volume for the application of 800 L•ha-1 and seven applications in an interval of seven days. Five evaluations were accomplished for the leaf severity of the disease with the use of a diagrammatic scale. All the fungicides presented potential for the control of early blight inside of the inherent characteristics in their chemical group. The best control levels were obtained with the treatments Chlorothalonyl 500 g•L-1 + Tetraconazol 20 g•L-1 (dosage 200 mL•100 L-1), Chlorothalonyl 400 g•L-1 + Copper oxychloride 420 g•kg-1 and Chlorothalonyl 750 g•kg-1 + Tetraconazol 20 g•kg-1 (dosage 150 g•100 L-1). Tetraconazol 100 g•L-1 provided the smallest control levels.

Fabrício, Silva Coelho; Marco Antônio, Rezende Alvarenga; Armindo, Bezerra Leão; Leandro, Rodrigues.

2011-06-01

217

CONTROLE DE ALTERNARIA SOLANI COM FUNGICIDAS NA CULTURA DO TOMATEIRO CONTROL OF ALTERNARIA SOLANI WITH FUNGICIDES IN TOMATO PLANTS  

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Full Text Available A pinta-preta, causada pelo fungo Alternaria solani, caracteriza-se por ser uma importante e destrutiva doença da cultura do tomate, sob condições de alta temperatura e umidade. Objetivou-se avaliar a eficiência de diferentes fungicidas no controle da Alternaria solani na cultura do tomateiro na região de Lavras (MG. O experimento foi desenvolvido na Universidade Federal de Lavras - Departamento de Agricultura, no período de novembro de 2004 a janeiro de 2005. O delineamento experimental foi o de blocos casualizados com 10 tratamentos e quatro repetições. Cada parcela composta por 12 plantas. As aplicações foram realizadas com um pulverizador costal manual (45 lbf/pol2, volume de aplicação de 800 L•ha-1, totalizando sete aplicações, com intervalos de sete dias. Foram realizadas cinco avaliações para a severidade foliar da doença com o uso de escala diagramática. Todos os fungicidas apresentaram potencial de controle da pinta-preta dentro das características inerentes ao seu grupo químico. Os melhores níveis de controle foram obtidos com os tratamentos Chlorothalonil 500 g•L-1 + Tetraconazole 20 g•L-1 (dosagem 200 mL•100 L-1, Chlorothalonil 400 g•L-1+ Oxicloreto de Cobre 420 g•kg-1 e Chlorothalonil 750 g•kg-1 + Tetraconazole 20 g•kg-1 (dosagem 150 g•100 L-1. Tetraconazole 100 g•L-1 proporcionou os menores níveis de controle.The early blight disease on tomato, caused by the fungus Alternaria solani, is referred to in importance due its destructive power, under conditions of high temperature and humidity. This study aimed to evaluate the effectiveness of various fungicides in your control in the region of Lavras-MG, Brazil. The experiment was conducted at the Federal University of Lavras, Department of Agriculture in the period from November 2004 to January 2005. The experimental design was randomized blocks with 10 treatments and four replications, each plot comprise 12 plants. The applications were made with a manual spray costal (45 lbf/pol2, volume for the application of 800 L•ha-1 and seven applications in an interval of seven days. Five evaluations were accomplished for the leaf severity of the disease with the use of a diagrammatic scale. All the fungicides presented potential for the control of early blight inside of the inherent characteristics in their chemical group. The best control levels were obtained with the treatments Chlorothalonyl 500 g•L-1 + Tetraconazol 20 g•L-1 (dosage 200 mL•100 L-1, Chlorothalonyl 400 g•L-1 + Copper oxychloride 420 g•kg-1 and Chlorothalonyl 750 g•kg-1 + Tetraconazol 20 g•kg-1 (dosage 150 g•100 L-1. Tetraconazol 100 g•L-1 provided the smallest control levels.

Fabrício Silva Coelho

2011-06-01

218

Cutinase of Fusarium solani F. sp. pisi: mechanism of induction and relatedness to other Fusarium species  

International Nuclear Information System (INIS)

Three studies were made on the extracellular cutinase of the phytopathogenic fungus Fusarium solani f. sp. pisi. I. The production of cutinase was found to be induced in spores of F. solani f. sp. pisi, strain T-8, by cutin and cutin hydrolysate. Fractionation and analysis of the cutin hydrolysate indicated that dihydroxy-C16 acid and trihydroxy-C18 acid were the cutin monomers most active for inducing cutinase. Measurement of cutinase-specific RNA levels by dot-blot hybridization with a [32P]-labeled cutinase cDNA showed that the cutinase gene transcripts could be detected within 15 min after addition of the inducers. The results indicated that the fungal spores have the capacity to recognize the unique monomer components of the plant cuticle and rapidly respond by the synthesis of cutinase. II. Analysis of the genomic DNA's of seven strains of F. solani f. sp. pisi indicated that both high and low cutinase-producing strains contain at least one copy of the cutinase structural gene and a homologous promoter region. The data suggest a different promoter sequence exists in these additional copies. III. Relatedness of five phytopathogenic Fusarium species to F. solani f. sp. pisi was determined by their cutinase antigenic properties and gene homologies of cutinase cDNA from F. solani f. sp. pisi. The results suggest that formae specialis of F. solani are phylogenetically identical and that F. solani is quite distinct from the other Fusarani is quite distinct from the other Fusarium species tested

219

The galactolipase activity of Fusarium solani (phospho)lipase.  

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The purified (phospho)lipase of Fusarium solani (FSL), was known to be active on both triglycerides and phospholipids. This study aimed at assessing the potential of this enzyme in hydrolyzing galactolipids. FSL was found to hydrolyze at high rates of synthetic medium chains monogalactosyldiacylglycerol (4658±146U/mg on DiC8-MGDG) and digalactosyldiacylglycerol (3785±83U/mg on DiC8-DGDG) and natural long chain monogalactosyldiacylglycerol extracted from leek leaves (991±85U/mg). It is the microbial enzyme with the highest activity on galactolipids identified so far with a level of activity comparable to that of pancreatic lipase-related protein 2. FSL maximum activity on galactolipids was measured at pH8. The analysis of the hydrolysis product of natural MGDG from leek showed that FSL hydrolyzes preferentially the ester bond at the sn-1 position of galactolipids. To investigate the structure-activity relationships of FSL, a 3D model of this enzyme was built. In silico docking of medium chains MGDG and DGDG and phospholipid in the active site of FSL reveals structural solutions which are in concordance with in vitro tests. PMID:25529980

Jallouli, Raida; Othman, Houcemeddine; Amara, Sawsan; Parsiegla, Goetz; Carriere, Frédéric; Srairi-Abid, Najet; Gargouri, Youssef; Bezzine, Sofiane

2015-03-01

220

Detection of trypsin inhibitor in seeds of Eucalyptus urophylla and its influence on the in vitro growth of the fungi Pisolithus tinctorius and Rhizoctonia solani Descoberta de inibidor de tripsina em sementes de Eucalyptus urophylla e sua influência sobre o crescimento in vitro dos fungos Pisolithus tinctorius e Rhizoctonia solani  

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Inhibitors of plant proteases can regulate the hydrolysis of proteins inside the cells and also participate in the mechanisms of plant defense against herbivore insects and pathogens. Here, we demonstrated that seeds of Eucalyptus urophylla exhibit activities of trypsin and papain inhibitors, two proteases commonly found in living cells. Low amounts of proteins of the crude protein extract of seeds and fractions partially purified by gel filtration, with inhibitory activity against trypsin, i...

Célia Regina Tremacoldi; Sérgio Florentino Pascholati

2002-01-01

221

Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles  

International Nuclear Information System (INIS)

Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities

222

Polycyclic aromatic hydrocarbons storage by Fusarium solani in intracellular lipid vesicles  

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Accumulation and elimination of polycyclic aromatic hydrocarbons (PAHs) were studied in the fungus Fusarium solani. When the fungus was grown on a synthetic medium containing benzo[a]pyrene, hyphae of F. solani contained numerous lipid vesicles which could be stained by the lipid-specific dyes: Sudan III and Rhodamine B. The fluorescence produced by Rhodamine B and PAH benzo[a]pyrene were at the same locations in the fungal hyphae, indicating that F. solani stored PAH in pre-existing lipid vesicles. A passive temperature-independent process is involved in the benzo[a]pyrene uptake and storage. Sodium azide, a cytochrome c oxidation inhibitor, and the two cytoskeleton inhibitors colchicine and cytochalasin did not prevent the transport and accumulation of PAH in lipid vesicles of F. solani hyphae. F. solani degraded a large range of PAHs at different rates. PAH intracellular storage in lipid vesicles was not necessarily accompanied by degradation and was common to numerous other fungi. - Fungi can store PAHs intracellularly in lipid vesicles independently of their PAH degradation abilities.

Verdin, Anthony [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France); Lounes-Hadj Sahraoui, Anissa [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)]. E-mail: lounes@univ-littoral.fr; Newsam, Ray [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Robinson, Gary [Department of Biosciences, University of Kent, Canterbury CT2 7NJ (United Kingdom); Durand, Roger [Laboratoire de Mycologie/Phytopathologie/Environnement, Universite du Littoral-Cote d' Opale, 17 avenue Bleriot, BP 699, 62228 Calais Cedex (France)

2005-01-01

223

Produção de enzimas extracelulares por Fusarium solani de maracujazeiro amarelo / Production of extracellular enzymes by Fusarium solani from yellow passion fruit  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Uma das principais doenças do maracujazeiro, na maioria dos estados produtores do Brasil, é a podridão do colo, causada por Fusarium solani. Pouco se sabe a respeito da fisiologia deste patógeno do maracujazeiro amarelo, principalmente quanto à produção de enzimas extracelulares. O objetivo do prese [...] nte trabalho foi verificar, em meios de cultura individuais e apropriados, a produção das enzimas extracelulares amilase, lipase, celulase, proteases (caseinase e gelatinase), lacase (oxidase) e catalase por isolados de F. solani, provenientes de maracujazeiro amarelo. O delineamento experimental adotado foi o inteiramente casualizado, em esquema de dois fatores (nove isolados versus sete enzimas), com três repetições. Todos os isolados de F. solani produziram, de maneira semiquantitativa, as enzimas extracelulares amilase, lipase, celulase, caseinase (protease) e lacase (oxidase). No entanto, a quantidade produzida de cada enzima foi significativamente diferente entre os isolados. As enzimas extracelulares gelatinase (protease) e catalase foram produzidas em pouca quantidade e de maneira igual por todos os isolados do fungo. Abstract in english In most Brazilian producer states, one of the main diseases of the passion fruit is collar rot caused by Fusarium solani. Little is known about the physiology of this pathogen from yellow passion fruit, which mainly involves the production of extracellular enzymes. The objective of this work was to [...] verify, in individual and appropriate culture media, the production of the extracellular enzymes amylase, lipase, cellulase, proteases (caseinase and gelatinase), lacase (oxydase) and catalase by isolates of F. solani from yellow passion fruit. The experimental design adopted was an entirely randomized two-factor scheme (nine isolates and seven enzymes) with three repetitions. All the isolates of F. solani produced, in a semi-quantitative manner, the extracellular enzymes amylase, lipase, cellulase, caseinase (protease) and lacase. However, the amount of each enzyme produced was significantly different among the isolates. The extracellular enzymes gelatinase (protease) and catalase were produced in a small amount and in an equal manner by all the isolates of the fungus.

César Júnior, Bueno; Ivan Herman, Fischer; Daniel Dias, Rosa; Edson Luiz, Furtado.

2009-10-01

224

Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola  

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An experiment on the metabolite [salicylic acid (SA), jasmonic acid (JA), hydrocyanic acid (HCN) and chitinase activity] changes owing to seed treatn1ent with pathogen, plant growth pron1oting rhizobacteria (PGPRs) - (P. maltophilia, P. fluorescens and Bacillus subtilis) alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola) treated seeds ...

Surender Kumar; Sushil Sharma

2013-01-01

225

Interaction of Pratylenchus penetrans and Rhizoctonia fragariae in Strawberry Black Root Rot  

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A split-root technique was used to examine the interaction between Pratylenchus penetrans and the cortical root-rotting pathogen Rhizoctonia fragariae in strawberry black root rot. Plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. Isolation of R. fragariae from field-grown roots differed with root type and time of sampling. Fungal infection of structural roots was low unt...

Lamondia, J. A.

2003-01-01

226

Natural occurrence of the Fusarium solani on Tityus stigmurus (Thorell, 1876) (Scorpiones: Buthidae) Ocorrência natural de Fusarium solani em Tityus stigmurus (Thorell, 1876) (Scorpions: Buthidae)  

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Members of the Fusarium solani species complex are agents of human mycoses, also affecting plants and other animals. Nevertheless, this fungus has not been reported on scorpions. Ten specimens of Tityus stigmurus collected in the field and showing their surface covered by white mycelia were used to assess fungus presence in the animal after its death. Identification of the fungi was based upon the cultural and morphological characteristics. The fungus was isolated from chelicerae and interseg...

Pl, Santana-neto; Cmr, Albuquerque; App, Silva; Vm, Svedese; Eala, Lima

2010-01-01

227

Ecological distribution of Fusarium solani and its opportunistic action related to mycotic keratitis in Cali, Colombia.  

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Corneal ulcera in patients treated at the University Hospital Cali, Colombia have been attributed to the fungus Fusarium solani, which was isolated from patients' eyes by deep scraping. The fungus, which was characterized by culture and morphology, was found to grow well at 37 degrees C in Sabouraud and potato dextrose agars and in liquid asparagine medium, in which it produced very few spores; at 40 degrees C, it survived for 3 weeks. Different levels of pathogenicity were shown by the fungus when 3-week-old bean, corn, and tomato plants were inoculated. Controlled experiments in which an inoculum of F. solani was instilled in rabbit eyes were also carried out; it evoked a clinical reaction producing irritation and erythema. The F. solani isolated from eyes was the same species as that isolated by an agar plate method with Fusarium-selective medium from sugar cane, bean, tomato, or corn fields throughout December 1976 to November 1977. Nonfarming areas and urban sites were also air sampled, but only a few (less than 1%) colonies of F. solani were isolated at one of four sites. A preliminary attempt to identify the physiologically active substance of the fungus was carried out through chemical extraction, thin-layer chromatography, and ultraviolet and infrared spectra analysis. PMID:7217337

Cuero, R G

1980-09-01

228

OPTIMIZATION OF XYLANASE PRODUCTION FROM FREE AND IMMOBILIZED CELLS OF FUSARIUM SOLANI F7  

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Full Text Available The aim of the present investigation was to characterize a xylanase-producing Fusarium solani isolate and to optimize cultural conditions for xylanase enzyme production from free and immobilized cells. Screening of Fusarium solani isolate was based on the diameter of the clear zone formation in oat spelt xylan agar plates. Fusarium solani isolate F7 was selected and optimized for xylanase enzyme production using cheaper substrates such as wheat straw, rice straw, rice bran, and wood husk. Maximum enzyme activity was observed in wheat straw (78.32 U ml-1 for free cells and 94.68 U ml-1 for immobilized cells. Optimum pH and temperature for xylanase activity were found to be 5.5 and 30°C at 3% substrate concentration for free cells and 5.0 and 30°C at 3% substrate concentration for immobilized cells. In the purification step, 75% ammonium sulphate saturation was found to be suitable, giving maximum xylanase activity. Production of xylanase was greater from immobilized cells than from free cells. Purified xylanase from free cells yielded a single band with a molecular weight of 89kDa, while it was 92.8kDa for immobilized cells. The use of wheat straw as a major carbon source is particularly valuable, because oat spelt xylan is very expensive. The Fusarium solani F7 isolate proved to be a promising microorganism for xylanase production.

Vijai Kumar Gupta

2009-08-01

229

In Vitro and In Vivo Experimental Activities of Antifungal Agents against Fusarium solani  

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In the treatment of disseminated Fusarium infections, amphotericin B either alone or in combination with flucytosine and rifampin is the drug therapy most frequently used. The efficacy of these antifungal drugs was evaluated in a murine disseminated-infection model, with five strains of Fusarium solani. All the treatments were clearly ineffective.

Guarro, J.; Pujol, I.; Mayayo, E.

1999-01-01

230

Resistance to alternaria solani in hybrids between a Solanum tuberosum haploid and S. raphanifolium  

Science.gov (United States)

Early blight of potato (Solanum tuberosum L.), caused by the foliar fungal pathogen Alternaria solani is a major cause of economic loss in many potato growing regions. Genetic resistance offers an opportunity to decrease fungicide usage while maintaining yield and quality. In this study, an early bl...

231

In-vineyard population structure of 'Candidatus Phytoplasma solani' using multilocus sequence typing analysis.  

Science.gov (United States)

'Candidatus Phytoplasma solani' is a phytoplasma of the stolbur group (16SrXII subgroup A) that is associated with 'Bois noir' and causes heavy damage to the quality and quantity of grapevine yields in several European countries, and particularly in the Mediterranean area. Analysis of 'Ca. P. solani' genetic diversity was carried out for strains infecting a cv. 'Chardonnay' vineyard, through multilocus sequence typing analysis for the vmp1, stamp and secY genes. Several types per gene were detected: seven out of 20 types for vmp1, six out of 17 for stamp, and four out of 16 for secY. High correlations were seen among the vmp1, stamp and secY typing with the tuf typing. However, no correlations were seen among the tuf and vmp1 types and the Bois noir severity in the surveyed grapevines. Grouping the 'Ca. P. solani' sequences on the basis of their origins (i.e., study vineyard, Italian regions, Euro-Mediterranean countries), dN/dS ratio analysis revealed overall positive selection for stamp (3.99, P=0.019) and vmp1 (2.28, P=0.001). For secY, the dN/dS ratio was 1.02 (P=0.841), showing neutral selection across this gene. Using analysis of the nucleotide sequencing by a Bayesian approach, we determined the population structure of 'Ca. P. solani', which appears to be structured in 3, 5 and 6 subpopulations, according to the secY, stamp and vmp1 genes, respectively. The high genetic diversity of 'Ca. P. solani' from a single vineyard reflects the population structure across wider geographical scales. This information is useful to trace inoculum source and movement of pathogen strains at the local level and over long distances. PMID:25660034

Murolo, Sergio; Romanazzi, Gianfranco

2015-04-01

232

Pathogenicity and Antimicrobial Activity of Seed-before Fusarium solani (Mart. Appel and Wollenw. Emend. Snyd and Hans Strains  

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Full Text Available Eight strain/isolates of seed-borne Fusarium solani tested for pathogenicity on sunflower, sesame, tomato, wheat and millet showed variations in pathogenicity in in vitro on test host. Some strains were found pahtogen in their original host while some isolates showed pathogenicity on other host with out causing rot on roots of their original host. Culture filtrates of these eight strains of F. solani also showed variation in antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Fusarium solani (roots isolates.

Shamim A. Qureshi

2003-01-01

233

Herança da resistência a stemphylium solani e insensibilidade a sua fitotoxina em cultivares de algodoeiro / Inheritance of resistance to Stemphylium solani and to its phytotoxin in cotton cultivars  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A mancha preta do algodoeiro (Gossypium hirsutum) causada por Stemphylium solani ocorre em várias regiões produtoras de algodão do Brasil, causando severos prejuízos em rendimento especialmente no Estado do Paraná. Estudou-se a herança da resistência a S. solani e sua fitotoxina, em três cultivares [...] de algodoeiro. As cultivares de algodoeiro PR 94-82, PR 94-215 e CNPA Precoce 2 identificadas como resistentes foram cruzadas com a cultivar suscetível IAPAR 71, inclusive cruzamentos recíprocos. Aos 30 dias de idade, duas folhas de cada planta foram inoculadas com um isolado agressivo de S. solani, e outras duas da mesma planta foram infiltradas com seu filtrado contendo fitotoxina(s) na diluição de 1:1. A severidade da área foliar infetada (AFI) pelo patógeno e a área foliar necrosada pelo filtrado (AFN) foram avaliadas sete dias após a inoculação/infiltração. Considerando as reações de 740 plantas segregantes, o coeficiente de correlação entre AFI e AFN foi alto (r = 0,70). Os modelos de média e de variância confirmaram a predominância de efeitos genéticos aditivos para AFI e AFN. O modelo de segregação simples incluindo um único gene na determinação do caráter produzindo uma proporção de 1:2:1 foi aceito pelo teste de qui-quadrado para os cruzamentos IAPAR 71 x PR94-82 e IAPAR 71 x CNPA-PRECOCE 2. Para o cruzamento IAPAR 71 x PR94-215, o padrão de segregação incluindo dois genes e epistasia (9:6:1) foi aceito pelo teste de qui-quadrado. Abstract in english Leaf blight of cotton (Gossypium hirsutum) caused by Stemphylium solani occurs in several cotton growing areas of Brazil, and causes severe yield losses especially in the State of Paraná. The inheritance of resistance to S. solani and to its phytotoxin was investigated in three cotton cultivars. Cro [...] sses including reciprocals were made between the cotton cultivars PR 94-82, PR 94-215 and CNPA Precoce 2, identified as resistant, and cv. IAPAR 71 as susceptible. Thirty days after sowing, two leaves of each plant were inoculated with S. solani, and the other two leaves of the same plant were infiltrated with the toxin containing culture filtrate of the same isolate at a dilution of 1:1. The percent of leaf area infected by the pathogen (LAI) and the percent of necrotic leaf area caused by the culture filtrate (LAN) were evaluated seven days after inoculation. Considering the reactions of 740 segreganting plants, the coefficient of correlation between the LAI and LAN was high (r=0.70). The segregating populations of the three crosses showed significant additive genetic variation for LAI and LAN. A F3 based chi-square (c2) testing for the 1:2:1 ratio for a single non-dominant gene segregation was not rejected (P=0.001) for the crosses IAPAR 71 x PR94-82 and IAPAR 71 x CNPA-PRECOCE 2. For the cross IAPAR 71 x PR94-215, the pattern of segregation including two genes and epistasis (9:6:1) was accepted by the chi2 test.

YESHWANT R., MEHTA; CARLOS A.A., ARIAS.

2001-12-01

234

Role for Fks1 in the Intrinsic Echinocandin Resistance of Fusarium solani as Evidenced by Hybrid Expression in Saccharomyces cerevisiae?  

OpenAIRE

The opportunistic mold Fusarium solani is intrinsically resistant to cell wall synthesis-inhibiting echinocandins (ECs), including caspofungin and micafungin. Mutations that confer acquired EC resistance in Saccharomyces cerevisiae and other normally susceptible yeast species have been mapped to the Fks1 gene; among these is the mutation of residue 639 from Phe to Tyr (F639Y) within a region designated hot spot 1. Fks1 sequence analysis identified the equivalent of Y639 in F. solani as well a...

Katiyar, Santosh K.; Edlind, Thomas D.

2009-01-01

235

In vitro Susceptibility of Alternaria solani to Several Iranian Soil Actinomycetes  

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Full Text Available Streptomyces sp. are of the most attractive sources of biologically active compounds. In the recent decades, they have attracted high interests as biocontrol agents. In search of finding such principles, in vitro suppression of Alternaria solani was studied by use of Streptomyces antagonists. A. solani was sensitive to several species mainly Streptomyces plicatus, S. olivaceus and two unidentified actinomycetes. Activity versus time was monitored in S. olivaceus in solid and shaked cultures. Ongoing goals of this research include isolation, characterization and identification of the active metabolites. Future goals include identification of active genes for use in development of recombinant DNAs in transgenic hosts bearing elevated resistance to infections by Alternaria sp.

F. Sharifi

2006-01-01

236

Compatibilidade vegetativa de nit-mutantes de Fusarium solani patogênicos e não-patogênicos ao feijoeiro e à soja / Nit-mutant vegetative compatibility of Fusarium solani pathogenic and non pathogenic to dry-bean and soybean  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho objetivou determinar o grau de relacionamento entre 18 isolados de Fusarium solani f. sp. phaseoli e F. solani f. sp. glycines. A maioria destes isolados (14) demonstrou inespecificidade de hospedeiro sendo patogênicos ao feijoeiro (Phaseolus vulgaris) e a soja (Glycine max). Grupos de [...] compatibilidade vegetativa de nit-mutantes destes isolados foram então determinados. Utilizou-se, como indutor de mutação, o clorato de potássio (KClO3), sendo estes nit-mutantes justapostos sobre meio mínimo contendo NAN0(3) para verificar a formação de heterocariose. Dos 18 isolados de F. solani, 13 foram reunidos em um único GCV. Neste grupo os isolados nit-mutantes F42, f. sp. phaseoli e F46, f. sp. glycines, foram compatíveis entre si. Três isolados constituíram em membros únicos de GCVs diferentes, sendo um destes isolados considerado auto-incompatível. Encontrou-se, portanto, compatibilidade vegetativa entre isolados de F. solani f. sp. phaseoli e F. solani f. sp. glycines. Esta compatibilidade pode ser uma justificativa para existência de isolados patogênicos a ambas culturas. Abstract in english The purpose of this study was to determine the relatedness 18 isolates of Fusarium solani f. sp. phaseoli and F. solani f. sp. glycines. The majority of these isolates have shown host un-especificity and were pathogenic to dry-bean (Phaseolus vulgaris) and soybean (Glycine max). The vegetative compa [...] tibility groups (VCG) of these isolates were determined. The nit-mutants (KClO3) of each isolate were paired on a NAN0(3) minimal media to verify the heterocariosis formation. Among the 18 isolates of F. solani, 13 were gathered in a single VCG. The nit-mutants strains of isolate F42, f. sp. phaseoli and isolate F46, f. sp. glycines were compatible to each other. Three isolates consisted of single members of different VCGs and one of these isolates was not even incompatible with itself. Vegetative compatibility, therefore, was found among isolates of F. solani f. sp. phaseoli and F. solani f. sp. glycines. This compatibility could be a reason for the existence of isolates pathogenic to both crops.

Virgínia C. de, Oliveira; Jefferson L. S. da, Costa.

2003-01-01

237

Use of molecular and conventional techniques to identify and analyze genetic variability of Rhizoctonia spp. isolates  

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Full Text Available In this study the pathogenicity of Rhizoctonia spp. isolates towards wheat seedlings in laboratory and greenhouse conditions was evaluated. In both experiments seven features were examined: plant height, roots weight, the percentage of infected stems and leaf sheaths and also the degree of stem and leaf sheaths infection. Isolates R1, R29, R39 and R59 were the most pathogenic. Percentage of infected stems ranged from 25.3 to 82.5 and roots from 35 to 82.3. The amplification of internal transcribed spacer regions (ITS1 and ITS2 between 18S, 5.8S and 28S rRNA genes and sequence analysis of these regions have been shown to be sufficiently variable to resolve two Rhizoctonia species. Random amplified polymorphic DNA (RAPD was used to assess genetic variability among isolates. The suitability of RAPD method for isolates differentiation at intraspecific level was shown. Using seven arbitrary primers in polymerase chain reaction (PCR thirty-three RAPD markers were generated. Clustering analysis from RAPD data resolved two groups of R. cerealis isolates at the 36% similarity level. Moreover, significant associations between molecular markers and pathogenicity of R. cerealis isolates were found.

Lidia Irzykowska

2005-12-01

238

Phylogenetic Analysis of Fusarium solani Associated with the Asian Longhorned Beetle, Anoplophora glabripennis  

OpenAIRE

Culture-independent analysis of the gut of a wood-boring insect, Anoplophora glabripennis (Coleoptera: Cerambycidae), revealed a consistent association between members of the fungal Fusarium solani species complex and the larval stage of both colony-derived and wild A. glabripennis populations. Using the translation elongation factor 1-alpha region for culture-independent phylogenetic and operational taxonomic unit (OTU)-based analyses, only two OTUs were detected, suggesting that genetic var...

Kelli Hoover; Ming Tien; Scully, Erin D.; Maria del Mar Jimenez-Gasco; Carlson, John E.; Geib, Scott M.

2012-01-01

239

Ecological distribution of Fusarium solani and its opportunistic action related to mycotic keratitis in Cali, Colombia.  

OpenAIRE

Corneal ulcera in patients treated at the University Hospital Cali, Colombia have been attributed to the fungus Fusarium solani, which was isolated from patients' eyes by deep scraping. The fungus, which was characterized by culture and morphology, was found to grow well at 37 degrees C in Sabouraud and potato dextrose agars and in liquid asparagine medium, in which it produced very few spores; at 40 degrees C, it survived for 3 weeks. Different levels of pathogenicity were shown by the fungu...

Cuero, R. G.

1980-01-01

240

UV-B-irradiation effect on growth reactions of phytopathogenic fungus fusarium solani  

International Nuclear Information System (INIS)

The UV-B irradiation effect on spore germination and hyphae growth of phythopathogenic fungus Fusarium solani was studied. Spores irradiation by small doses of 0,1 - 1,0 kJ/m2 results in growth stimulation of primary hyphae. Adaptive effect of UV-B small doses for fungi was shown. Preliminary irradiation in doses of 0,1 - 0,5 kJ/m2 increased spore radioresistance and diminished the effect of the next damaging dose

241

In silico analysis and prioritization of drug targets in Fusarium solani.  

Science.gov (United States)

Mycotic keratitis has emerged as a major ophthalmic problem and a leading cause of blindness, since its recognition in 1879. Filamentous fungi are major causative of mycotic keratitis. In India, the main etiological organism responsible for mycotic keratitis is Aspergillus species followed by Fusarium species. In South India, Fusarium based keratitis scales up to 43%. Nearly one-third of mycotic keratitis treatment results in failure, as fungal infections are highly resistant to antibiotic therapies. Therefore, there is need to determine novel and specific targets to constrain Fusarium infections in human eye. In this study, we implemented subtractive proteomics coupled with in silico functional annotation to prioritize potential and specific drug targets which can be used to modulate the virulence of Fusarium solani subsp.pisi (Nectria haematococca MPVI). The results infer that Thiamine thiazole synthase (Thi4), an intracellular membrane bound protein as the potential target, which is a core protein in biological and metabolic process of this pathogen. Moreover, this protein occurs in the thiamine thiazole biosynthesis pathway which is unique to F.solani and devoid in human. Hence, we predicted a plausible structure for this protein and also performed ligand-binding cavity analysis which can be for a strong base for drug designing studies. This study will pave way in better understanding of potential drug targets in F.solani and also leading to therapeutic interventions of fungal keratitis. PMID:25555413

Sivashanmugam, Muthukumaran; Nagarajan, Hemavathy; Vetrivel, Umashankar; Ramasubban, Gayathri; Therese, Kulandai Lily; Narahari, Madhavan Hajib

2015-02-01

242

Impact of water potential on growth and germination of Fusarium solani soilborne pathogen of peanut  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Studies were conducted to determine the effect of osmotic and matric stress on germination and growth of two Fusarium solani strains, the etiological agent responsible of peanut brown root rot. Both strains had similar osmotic and matric potential ranges that allowed growth, being the latter one nar [...] rower. F. solani showed the ability to grow down to -14 MPa at 25 °C in non-ionic modified osmotic medium, while under matric stress this was limited to -8.4 MPa at 25 °C. However, both strains were seen to respond differently to decreasing osmotic and matric potentials, during early stages of germination. One strain (RC 338) showed to be more sensitive to matric than osmotic (non ionic) and the other one (RC 386) showed to be more sensitive to osmotic than matric imposed water stress. After 24 h of incubation, both isolates behaved similarly. The minimum water potential for germination was -8.4 MPa on glycerol amended media and -5.6 MPa for NaCl and PEG amended media, respectively. The knowledge of the water potential range which allow mycelia growth and spore germination of F. solani provides an inside to the likely behaviour of this devastating soilborne plant pathogen in nature and has important practical implications.

Sofia, Palacios; Francisco, Casasnovas; María L., Ramirez; María. M., Reynoso; Adriana M., Torres.

1105-11-01

243

Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a  

Science.gov (United States)

Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two ...

244

Characterization of fungi (Fusarium and Rhizoctonia) and oomycetes (Phytophthora and Pythium) associated with apple orchards in South Africa.  

Science.gov (United States)

Several species of fungi and oomycetes including Fusarium, Rhizoctonia, Phytophthora and Pythium have been reported as root pathogens of apple where they contribute to a phenomenon known as apple replant disease. In South Africa, very little is known about the specific species in these genera and th...

245

Description of Quinisulcius solani n.sp. (Nematoda: Tylenchorhynchidae) with a Key to the Species and Data on Scutylenchus koreanus from Pakistan  

OpenAIRE

A new species. Quinisulcius solani, is described and illustrated from specimens on Solanum tuberosum from Murree Hills, Pakistan. Q. solani n.sp. differs from its closest relative, Q. acutus (Allen, 1955) Siddiqi, 1971, by its spiral to open 'C' shaped body and stylet length of 19 ?n, vs. 17 ?m in Q. acutus. In Q. acutus the stylet knobs project anteriorly but slope posteriorly in Q. solani n.sp. Tail annules number 17 in Q. acutus but 38 in Q. solani n.sp.; also the phasmids in the former ...

Maqbool, M. A.

1982-01-01

246

RESISTÊNCIA DE TOMATEIRO (Lycopersicon esculentum Mill. A Stemphylium solani Weber RESISTANCE OF TOMATO (Lycopersicon esculentum Mill. TO THE Stemphylium solani Weber  

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Full Text Available

Na Região Centro-Oeste, dadas as condições climáticas, o tomateiro pode ser cultivado o ano inteiro. A produção, no entanto, é baixa e bastante onerosa, em função de diferentes fatores dentre os quais incluem-se as doenças de diferentes etiologias, com destaque para a fúngica provocada por Stemphylium solani, responsável por danos de natureza qualitativa e quantitativa no tomate. Conduziram-se experimentos na Escola de Agronomia da Universidade Federal de Goiás, Goiânia - GO, a uma altitude de 730 m, latitude de 16° 41’S e longitude de 49° 17’W, com temperatura, umidade relativa e precipitação pluviométrica (médias de 23ºC, 82,7 e 62,7mm, respectivamente. O objetivo principal era testar níveis de resistência de variedades comerciais, genótipos pertencentes ao banco de germoplasma da Embrapa-CNPH e geração F1 de tomateiro, em condições de campo a S. solani. As avaliações foram realizadas aos 36, 43, 50, 57, 64, 71, 78 e 85 dias, após o transplantio, combinando escala diagramática e de notas. A diferenciação dos genótipos foi feita através da análise de variância dos valores da área abaixo da curva de progresso de doença, pelo teste de Tukey a 5% de probabilidade e pelo modelo logístico. Dentre as cultivares avaliadas quanto à resistência e/ou à suscetibilidade a S. solani, Ohio 4013, Yoshimatusu e TSW-10 comportaram-se como resistentes, entre os tutorados. Entre os rasteiros, verificou-se este fato na geração F1 (Hawaii 7998 x Monense. Os genótipos Ohio 4013 e o F1 (Hawaii 7998 x Monense foram os que mais se destacaram para resistência a este patógeno, podendo ser indicados para futuros programas de melhoramento.

PALAVRAS-CHAVE: Tomateiro; resistência; Stemphylium solani.

In the climate conditions of the Brazilian central west regions, tomato can be cultivated the whole year. However, the production is low and quite onerous in function of different factors Besides, different diseases affect the crop. Among the most being the fungal important is the fungi Stemphylium solani, responsible for damages of qualitative and quantitative nature in tomato. With the objective of finding a way to minimize the effect of these pathogen, an experiment was conduced at the experimental fields of the Federal University of Goiás, Goiânia-GO, Brazil. It is located at an altitude of 730 m, latitude of 16° 41’S and longitude of 49° 17’W, with temperature varying among 20 to for 40ºC, relative humidity (average of the month of 80% in August, 83% in September and 85% in October. Precipitation in August, September and October of 1999 was respectively 0.0 mm, 69.6 mm, and 118.4 mm. The main objectives were to test levels of resistance of commercial varieties, genotypes belonging to the bank of germoplasm of Embrapa-CNPH and F1 generations of tomato Lycopersicon esculentum in field conditions to S. solani. The evaluations were accomplished at the 36, 43, 50, 57, 64, 71, 78 and 85 days after the seedlings planting combining diagramatic scale and grades. Was considered the percentage of infected area on the leaf (PIAL and the also grades: 1 – without symptoms; 2 – spraid lesions; 3 – gathering lesions; 4 – partial dryness of the leaf; 5 – death of the leaf and 6 – death of the plant. The differentiation among genotypes was made through analysis of variance of the values of area under disease progress curve and by of Tukey’s test at the level of 5% of probability and also the logistic model. Regarding resistance to S. solani, Ohio 4013, Yoshimatusu and TSW-10 behaved as resistant, among the indeterminate. Among the determined ones, F1 (Hawaii 7998 x Monense

Reinaldo Soares de Paula

2007-09-01

247

Herança da resistência a stemphylium solani e insensibilidade a sua fitotoxina em cultivares de algodoeiro  

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Full Text Available A mancha preta do algodoeiro (Gossypium hirsutum causada por Stemphylium solani ocorre em várias regiões produtoras de algodão do Brasil, causando severos prejuízos em rendimento especialmente no Estado do Paraná. Estudou-se a herança da resistência a S. solani e sua fitotoxina, em três cultivares de algodoeiro. As cultivares de algodoeiro PR 94-82, PR 94-215 e CNPA Precoce 2 identificadas como resistentes foram cruzadas com a cultivar suscetível IAPAR 71, inclusive cruzamentos recíprocos. Aos 30 dias de idade, duas folhas de cada planta foram inoculadas com um isolado agressivo de S. solani, e outras duas da mesma planta foram infiltradas com seu filtrado contendo fitotoxina(s na diluição de 1:1. A severidade da área foliar infetada (AFI pelo patógeno e a área foliar necrosada pelo filtrado (AFN foram avaliadas sete dias após a inoculação/infiltração. Considerando as reações de 740 plantas segregantes, o coeficiente de correlação entre AFI e AFN foi alto (r = 0,70. Os modelos de média e de variância confirmaram a predominância de efeitos genéticos aditivos para AFI e AFN. O modelo de segregação simples incluindo um único gene na determinação do caráter produzindo uma proporção de 1:2:1 foi aceito pelo teste de qui-quadrado para os cruzamentos IAPAR 71 x PR94-82 e IAPAR 71 x CNPA-PRECOCE 2. Para o cruzamento IAPAR 71 x PR94-215, o padrão de segregação incluindo dois genes e epistasia (9:6:1 foi aceito pelo teste de qui-quadrado.

MEHTA YESHWANT R.

2001-01-01

248

Cyanide Degradation under Alkaline Conditions by a Strain of Fusarium solani Isolated from Contaminated Soils  

OpenAIRE

Several cyanide-tolerant microorganisms have been selected from alkaline wastes and soils contaminated with cyanide. Among them, a fungus identified as Fusarium solani IHEM 8026 shows a good potential for cyanide biodegradation under alkaline conditions (pH 9.2 to 10.7). Results of K(sup14)CN biodegradation studies show that fungal metabolism seems to proceed by a two-step hydrolytic mechanism: (i) the first reaction involves the conversion of cyanide to formamide by a cyanide-hydrolyzing enz...

Dumestre, A.; Chone, T.; Portal, J.; Gerard, M.; Berthelin, J.

1997-01-01

249

Natural occurrence of the Fusarium solani on Tityus stigmurus (Thorell, 1876) (Scorpiones: Buthidae).  

Science.gov (United States)

Members of the Fusarium solani species complex are agents of human mycoses, also affecting plants and other animals. Nevertheless, this fungus has not been reported on scorpions. Ten specimens of Tityus stigmurus collected in the field and showing their surface covered by white mycelia were used to assess fungus presence in the animal after its death. Identification of the fungi was based upon the cultural and morphological characteristics. The fungus was isolated from chelicerae and intersegmental regions. Infected individuals had their behaviour modified by reducing feeding and locomotion. None of the infected individuals survived. It is likely that this fungus may have a role in the regulation of field scorpion populations. PMID:20231972

Santana-Neto, P L; Albuquerque, C M R; Silva, A P P; Svedese, V M; Lima, E A L A

2010-02-01

250

Analysis of Growth and Resistance to Different Population of Fusarium Solani in Soybean Legume Plant  

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Full Text Available Experiment was conducted to study the effect of different concentrations (10,000, 100,000 and 1000, 000 cfu of Fusariumsolani on growth and resistance to soybean (Glycine max(L. Merr leguminous plant. Sterilized seeds of Glycine max were sown in 350g of acid washed sand. The plants were regularly watered with complete Nutrient Hoagland solution. Leaves samples were weekly collected for analysis of biochemical tests. The growth and morphology of G. max were adversely affected with F.solani which show damping of fseedling root rot. The symptom was first appearing in root. Infected seedling of G. max showed a marked decreased in root, shoot length and discoloration and decay in roots. Stem diameter was also decreased in infected plants as compared with the control plants. There were not marked differences occurring in leaf area but the color of leaves turn yellowish green in infected plants. The infected tissues of soybean with different colonies of F.solani showed the highest level of total phenolic content as compared to healthy tissues.

N. H amid

2014-03-01

251

Production of extracellular lipase by the phytopathogenic fungus Fusarium solani FS1 Produção de lipase extracelular pelo fungo fitopatogênico Fusarium solani FS1  

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Full Text Available A Brazilian strain of Fusarium solani was tested for extracellular lipase production in peptone-olive oil medium. The fungus produced 10,500 U.l-1 of lipase after 72 hours of cultivation at 25oC in shake-flask at 120 rpm in a medium containing 3% (w/v peptone plus 0.5% (v/v olive oil. Glucose (1% w/v was found to inhibit the inductive effect of olive oil. Peptone concentrations below 3% (w/v resulted in a reduced lipase production while increased olive oil concentration (above 0.5% did not further stimulate lipase production. The optimum lipase activity was achieved at pH 8.6 and 30oC and a good enzyme stability (80% activity retention was observed at pH ranging from 7.6 to 8.6, and the activity rapidly dropped at temperatures above 50oC. Lipase activity was stimulated by the addition of n-hexane to the culture medium supernatants, in contrast to incubation with water-soluble solvents.

Maria de Mascena Diniz Maia

1999-12-01

252

Biocontrol potential of soybean bacterial endophytes against charcoal rot fungus, Rhizoctonia bataticola.  

Science.gov (United States)

A total of 137 bacterial isolates from surface sterilized root, stem, and nodule tissues of soybean were screened for their antifungal activity against major phytopathogens like Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium udam, and Sclerotium rolfsii. Nine bacterial endophytes suppressed the pathogens under in vitro plate assay. These were characterized biochemically and identified at the genus level based on their partial sequence analysis of 16S rDNA. Eight of the isolates belonged to Bacillus and one to Paenibacillus. The phylogenetic relationship among the selected isolates was studied and phylogenetic trees were generated. The selected isolates were screened for biocontrol traits like production of hydrogen cyanide (HCN), siderophore, hydrolytic enzymes, antibiotics, and plant growth promoting traits like indole 3-acetic acid production, phosphate solubilization, and nitrogen fixation. A modified assessment scheme was used to select the most efficient biocontrol isolates Paenibacillus sp. HKA-15 (HKA-15) and Bacillus sp. HKA-121 (HKA-121) as potential candidates for charcoal rot biocontrol as well as soybean plant growth promotion. PMID:19067044

Senthilkumar, M; Swarnalakshmi, K; Govindasamy, V; Lee, Young Keun; Annapurna, K

2009-04-01

253

Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola  

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Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonicacid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatment with pathogen, plant growth promoting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinaseactivity in both the cases alone as well as in integration with pathogen, however, maximum increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 ?g g-1 over control (24 ?g g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 ?g g-1 at 10 DPI. The co-seed inoculation elicited 68 units at 10 DPI whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declinedslightly or sharply with age of the plant irrespective of inoculations.

Surender Kumar

2013-11-01

254

Screening of peas for resistance to Fusarium wilt and root rot (Fusarium oxysporum, Fusarium solani)  

International Nuclear Information System (INIS)

In the introduction to this chapter, two fungal pathogens (Fusarium solani and F. oxysporum) are reviewed from the viewpoint of their incidence, importance, symptoms, mode of infection, harmfullness for peas, and known resistance resources. Further, this chapter gives detailed information about the screening of germplasm and plant breeding material, including the methods of pathogen isolation, cultivation and maintenance, preparation of plant material for screening and inoculum preparation. Three types of laboratory screening methods (tube tests, seed soaking test, root submersion test) are described. The results of testing are assessed via root and shoot symptom expression and further evaluated as a degree of infection. In F. oxysporum f. sp. pisi, six races are described, including the reaction to them on a set of differential genotypes. Finally, practical applications of these screening methods are summarised. (author)

255

Optimization of culture conditions of Fusarium solani for the production of neoN-methylsansalvamide.  

Science.gov (United States)

The aim of this study was to optimize the culture conditions of Fusarium solani KCCM90040 on cereal grain for the production of neoN-methylsansalvamide, a novel low-molecular-weight cyclic pentadepsipeptide exhibiting cytotoxic and multidrug resistance reversal effects. From the analysis of variance results using response surface methodology, temperature, initial moisture content, and growth time were shown to be important parameters for the production of neoN-methylsansalvamide on cereal grain. A model was established in the present study to describe the relationship between environmental conditions and the production of neoN-methylsansalvamide on rice, the selected cereal grain. The optimal culture conditions were determined at 25.79?°C with the initial moisture content of 40.79%, and 16.19?days of growth time. This report will give important information concerning the optimization of environmental conditions using statistic methodology for the production of a new cyclic pentadepsipeptide from fungi. PMID:25130748

Lee, Hee-Seok; Phat, Chanvorleak; Nam, Woo-Seon; Lee, Chan

2014-01-01

256

Potencial antifúngico de extratos de plantas e de basidiomicetos nativos sobre Colletotrichum acutatum, Alternaria solani e Sclerotium rolfsii / Antifungal potential of extracts of native plants and basidiomycetes on Colletotrichum acutatum, Alternaria solani and Sclerotium rolfsii  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O emprego de fungicidas na agricultura, principalmente quando utilizados de forma inadequada, tem provocado danos tanto ao homem como ao ambiente. O presente trabalho teve por objetivo o estudo in vitro da eficácia de extratos de três plantas e de dois basidiomicetos nativos do Brasil no controle do [...] s fungos Alternaria solani e Colletotrichum acutatum, causadores de graves prejuízos às culturas de tomate e morango, respectivamente, além de Sclerotium rolfsii, considerado como patógeno polífago. No trabalho foram avaliados: a) a inibição de crescimento micelial dos três fitopatógenos, b) inibição da germinação de conídios de A. solani e C. acutatum e c) inibição da germinação de escleródios de S. rolfsii. Os melhores resultados foram obtidos com o extrato de Oudemansiella canarii, que proporcionou os menores valores de crescimento micelial dos três patógenos, além inibir totalmente a germinação de conídios de A. solani e C. acutatum e de escleródios de S. rolfsii. O extrato de Irpex lacteus inibiu parcialmente o crescimento micelial dos patógenos estudados e o extrato de Avicennia schaueriana promoveu apenas 16 % de inibição do crescimento micelial de S. rolfsii. Nenhum efeito sobre os patógenos foi verificado com os extratos de Senna spectabilis e Senna multijuga nas condições em que foram realizados os experimentos. Abstract in english The use of fungicides in agriculture, especially when inadequate, has caused damages to both the environment and humans. The present study aimed to investigate in vitro the efficacy of extracts of three plants and two basidiomycetes of the Brazilian flora in controlling Alternaria solani and Colleto [...] trichum acutatum, which causes serious damages to tomato and strawberry crops, respectively, and Sclerotium rolfsii, considered as non-specific pathogen. This work evaluated: a) mycelial growth inhibition for the three phytopathogens, b) conidial germination inhibition (A. solani and C. acutatum) and c) sclerotial germination inhibition for S. rolfsii. The best results were obtained with Oudemansiella canarii extract, which provided the lowest mycelial growth values for the three pathogens, besides totally inhibiting A. solani and C. acutatum conidial germination and S. rolfsii sclerotial germination. I. lacteus extract partially inhibited the mycelial growth of the pathogens and Avicennia schaueriana promoted only 16% inhibition in S. rolfsii mycelial growth. Senna spectabilis and Senna multijuga extracts had no effect on the pathogens under the conditions of the present experiments.

Ricardo José, Domingues; Maria Cláudia Marx, Young; Jesus Guerino, Töfoli; Dácio Roberto, Matheus.

2011-09-01

257

Antagonismo in vitro de Trichoderma harzianum Rifai sobre Fusarium solani (Mart.) Sacc., asociado a la marchitez en maracuyá / Trichoderma harzianum Rifai in vitro antagonism against Fusarium solani (Mart.) Sacc., associated to withering in passion fruit  

Scientific Electronic Library Online (English)

Full Text Available Cultivos de maracuyá de la región Caribe colombiana presentan problemas de marchitez y el hongo Fusarium solani (Mart.) Sacc., está asociado a esta patología. Plantas de maracuyá de la Estación Experimental (E.E Caribia de Corpoica) poseen este problema y por tal razón se determinó el antagonismo in [...] vitro de aislamientos de Trichoderma harzianum Rifai, frente a F. solani, aislado de plantas enfermas de maracuyá (Passiflora edulis). Utilizando la técnica de cultivo dual en platos Petri con Agar Sabouraud, se evaluaron competencia por nutrientes y espacio, micoparasitismo y porcentaje de inhibición del crecimiento radial (PICR), empleando un diseño estadístico factorial 2x6x1 con arreglo completamente aleatorio. Se obtuvieron tres aislamientos nativos de T. harzianum (TCN-009, TCN-010, TCN-014) de suelo de Palma de Aceite (Elaeis guineensis) de la E.E Caribia, y se compararon con tres aislamientos comerciales (TCC-001, TCC-005, TCC-006). TCC-001 y TCN-014, reportaron ser más competentes por nutrientes y espacio, con el mayor radio de crecimiento de 7,50 y 7,32 cm el día 10, comparado a FSM-011 en el cual solo fue de 2,30 cm. Aunque, TCN-014 mostró micoparasitismo grado 4 con ambos aislamientos de F. solani y TCC-005 únicamente con FSM-012, el cual fue más susceptible a ser micoparasitado. En cuanto al PICR, los tratamientos con mejores porcentajes de inhibición fueron TA-9, TA-12 y TA-6 con valores de 70,56, 68,52 y 65,32% respectivamente. El aislamiento del patógeno mayormente inhibido fue FSM-011. Todos estos resultados demuestran que hubo antagonismo in vitro al utilizar los aislamientos nativos y comerciales de T. harzianum sobre F. solani. Abstract in english Passion fruit cultivation of the Colombian Caribbean region presents problems withering and the fungus Fusarium solani (Mart.) Sacc., this associated with this pathology. Plant of passion fruit of the experimental station of Corpoica Caribia EE. presented this problem and for that reason it was dete [...] rmined the antagonism in Vitro of isolations of Trichoderma harzianum Rifai, compared with F. solani, isolated from diseased plant of passion fruit (Passiflora edulis). Using the technique of cultivation dual petri dishes with Sabouraud agar was evaluated competition for space and nutrients, mycoparasitism and percentage of inhibition of radial growth (PICR), using a factorial design 2x6x1 under completely random. Three native isolations of T. harzianum were obtained (TCN-009, TCN-010, TCN-014) in soil of oil palm (Elaeis guineensis) in Caribia EE and were compared with three commercial isolations (TCC-001, TCC-005, TCC-006). TCC- 001 and TCN-014 resulting be more competent for nutrients and space, the native isolations with the highest growth of 7.50 and 7.32 radius of centimeters the day 10, compared to FSM-011 in which was only 2.30cm. Although, TCN-014 showed mycoparasitism degree 4 with both isolations of F. solani and TCC-005 only with FSM-012 which was more susceptible to micoparasitism. As for the PICR, treatments with better percentages of inhibition were TA-9, TA-12 and TA-6 with values of 70.56%, 68.52% and 65.32% respectively. The pathogenic isolation largely inhibited was FSM-011. All these results demonstrate that there was antagonism in Vitro to use the native and commercial isolations of T. harzianum on F. solani.

Carol Libeth, Suárez Meza; Reinel José, Fernández Barbosa; Nelson Osvaldo, Valero; Rocío Margarita, Gámez Carrillo; Alberto Rafael, Páez Redondo.

2008-07-01

258

Enanismo y podredumbre basal de eustoma grandiflorum y su relación con la densidad de fusarium solani en el suelo / Stunt and basal rot of Eustoma grandiflorum and its relationship with Fusarium solani density in the soil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Spanish Abstract in spanish En cultivos comerciales de lisianthus de La Plata y alrededores (Argentina), se observó que Fusarium solani afecta al 100% de los establecimientos productivos provocando enanismo y podredumbre basal. Se realizó un ensayo para analizar la densidad de F. solani del suelo bajo el efecto de distintos tr [...] atamientos y relacionarla con la evolución de ambas patologías. Los análisis del suelo se hicieron en 3 épocas: antes del transplante (octubre), al inicio (enero) y al final (marzo) de la floración. En enero y marzo se evaluó la incidencia de cada enfermedad y se cuantificaron las plantas cosechadas. La población de F. solani no varió en las 3 épocas y se redujo significativamente con los fumigantes y el vapor. Esto determinó una incidencia del enanismo (enero) de 0 a 9,5% con los primeros y de 31,4% con el vapor. Para el testigo y los fungicidas la incidencia varió entre el 87,9 y el 100%, disminuyendo las plantas cosechadas. La podredumbre basal comenzó con el ingreso del patógeno a través de las heridas producidas por la cosecha. Ésta fue significativamente mayor con los fumigantes (90,7 a 99%) y también con el vapor (76,8%), produciéndose la mayor incidencia en marzo (15,7 a 22,2 y 10,1% respectivamente), reduciéndose el período productivo. Se destaca la importancia de disminuir la densidad de F. solani en el momento del transplante. Entre los métodos de control el Metam sodio y Dazomet podrían ser eficaces sustitutos del Bromuro de metilo, seguidos por el vapor. Abstract in english Fusarium solani was recorded in 100% of the commercial crops of lisianthus (Eustoma grandiflorum) located around La Plata (Argentina). The pathogen causes stunt and basal rot. A trial was carried out to analyse the F. solani soil density and its relation to the development of both diseases. Soil sam [...] ples were analysed at three times: before transplant (October), at the beginning of flowering (January) and at the ending of flowering (March) of flowering. The incidence of each disease was evaluated in January and March, and the plants harvested were quantified. The soil density of F. solani was not altered during the three times for each treatment, and fumigants and steam decrease it significantly. In January the stunt incidence reached 0 to 9.5% with the fumigants and 31.4% with the steam treatment. In the control and fungicide plots, the incidence reached 87.9 to 100%, and a consequent reduction of flower production was observed. Stem rot began after the flowers were harvested as a result of pathogen entry through the wounds. The major values of harvested plants were obtained with fumigants (90.7 to 99%) and steam (76.8%), so the greatest stem rot incidence was 15.7 to 22.2 and 10.1%, respectively, in March, and the productive period was shortened. The need of reducing F. solani soil density before lisianthus transplant is emphasized. Among soil control treatments, Metham sodium and Dazomet could be effective substitutes for Methil bromide followed by steam treatment.

SILVIA M., WOLCAN; GLADYS A., LORI; LIA, RONCO; ADRIÁN F., MITIDIERI; ROBERTO, FERNÁNDEZ.

2001-12-01

259

Enanismo y podredumbre basal de eustoma grandiflorum y su relación con la densidad de fusarium solani en el suelo Stunt and basal rot of Eustoma grandiflorum and its relationship with Fusarium solani density in the soil  

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Full Text Available En cultivos comerciales de lisianthus de La Plata y alrededores (Argentina, se observó que Fusarium solani afecta al 100% de los establecimientos productivos provocando enanismo y podredumbre basal. Se realizó un ensayo para analizar la densidad de F. solani del suelo bajo el efecto de distintos tratamientos y relacionarla con la evolución de ambas patologías. Los análisis del suelo se hicieron en 3 épocas: antes del transplante (octubre, al inicio (enero y al final (marzo de la floración. En enero y marzo se evaluó la incidencia de cada enfermedad y se cuantificaron las plantas cosechadas. La población de F. solani no varió en las 3 épocas y se redujo significativamente con los fumigantes y el vapor. Esto determinó una incidencia del enanismo (enero de 0 a 9,5% con los primeros y de 31,4% con el vapor. Para el testigo y los fungicidas la incidencia varió entre el 87,9 y el 100%, disminuyendo las plantas cosechadas. La podredumbre basal comenzó con el ingreso del patógeno a través de las heridas producidas por la cosecha. Ésta fue significativamente mayor con los fumigantes (90,7 a 99% y también con el vapor (76,8%, produciéndose la mayor incidencia en marzo (15,7 a 22,2 y 10,1% respectivamente, reduciéndose el período productivo. Se destaca la importancia de disminuir la densidad de F. solani en el momento del transplante. Entre los métodos de control el Metam sodio y Dazomet podrían ser eficaces sustitutos del Bromuro de metilo, seguidos por el vapor.Fusarium solani was recorded in 100% of the commercial crops of lisianthus (Eustoma grandiflorum located around La Plata (Argentina. The pathogen causes stunt and basal rot. A trial was carried out to analyse the F. solani soil density and its relation to the development of both diseases. Soil samples were analysed at three times: before transplant (October, at the beginning of flowering (January and at the ending of flowering (March of flowering. The incidence of each disease was evaluated in January and March, and the plants harvested were quantified. The soil density of F. solani was not altered during the three times for each treatment, and fumigants and steam decrease it significantly. In January the stunt incidence reached 0 to 9.5% with the fumigants and 31.4% with the steam treatment. In the control and fungicide plots, the incidence reached 87.9 to 100%, and a consequent reduction of flower production was observed. Stem rot began after the flowers were harvested as a result of pathogen entry through the wounds. The major values of harvested plants were obtained with fumigants (90.7 to 99% and steam (76.8%, so the greatest stem rot incidence was 15.7 to 22.2 and 10.1%, respectively, in March, and the productive period was shortened. The need of reducing F. solani soil density before lisianthus transplant is emphasized. Among soil control treatments, Metham sodium and Dazomet could be effective substitutes for Methil bromide followed by steam treatment.

SILVIA M. WOLCAN

2001-12-01

260

Potencial de rizobactérias no controle de Fusarium solani (Mart. Sacc. em pepino (Cucumis sativum L. Potential of rhizobacteria in the control of Fusarium solani (Mart. Sacc. in cucumber (Cucumis sativum L.  

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Full Text Available Rizobactérias, isoladas da rizosfera de diferentes hospedeiros foram selecionadas in vitro quanto ao antagonismo contra Fusarium solam agente causai da podridão radicular. In vitro, foram selecionadas 18 bactérias isoladas da rizosfera de plantas sadias de pepino e, destas, somente três foram eficientes em inibir consideravelmente o crescimento micelial do patógeno. Dois isolados de Bacillus subtilis e dois de Pseudomonas sp., antagônicos a outros fungos fitopatogênicos foram incluidos nos testes, os quais mostraram-se capazes de antagonizar F. solani. Em condições de casa-de-vegetação, B. subtilis, linhagem 0G, controlou totalmente o patógeno em todos os ensaios realizados. Promoção do crescimento de plantas foi verificada pela inoculação com linhagens 0G (B. subtilis, St. Barb. e CBPN (Pseudomonas sp.Rhizobacteria, isolated from the rhizosphere of different hosts were selected in vitro, based on the antagonism against Fusarium solani, agent of root rot. In vitro, 18 bacterias were selected from rhizosphere of healthy plants of cucumber and, from those, only three were efficient in inhibiting the micelial growth of the pathogen. In these tests two isolates of Bacillus subtilis (0G and 5G, and two of Pseudomonas (CBPN and St Barb., antagonistic to some pathogenic fungi, were included. These bolates also inhibited the growth of F solani. The bolate OG of B. subtilis reduced significantly the root rot of cucumber. Beneficial effects were obtained with the bolates St Barb., 0G and CBPN in relation to plant growth.

I S. de Melo

1995-08-01

261

Antagonismo in vitro de Trichoderma harzianum Rifai sobre Fusarium solani (Mart. Sacc., asociado a la marchitez en maracuyá  

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Full Text Available Cultivos de maracuyá de la región Caribe colombiana presentan problemas de marchitez y el hongo Fusarium solani (Mart. Sacc., está asociado a esta patología. Plantas de maracuyá de la Estación Experimental (E.E Caribia de Corpoica poseen este problema y por tal razón se determinó el antagonismo in vitro de aislamientos de Trichoderma harzianum Rifai, frente a F. solani, aislado de plantas enfermas de maracuyá (Passiflora edulis. Utilizando la técnica de cultivo dual en platos Petri con Agar Sabouraud, se evaluaron competencia por nutrientes y espacio, micoparasitismo y porcentaje de inhibición del crecimiento radial (PICR, empleando un diseño estadístico factorial 2x6x1 con arreglo completamente aleatorio. Se obtuvieron tres aislamientos nativos de T. harzianum (TCN-009, TCN-010, TCN-014 de suelo de Palma de Aceite (Elaeis guineensis de la E.E Caribia, y se compararon con tres aislamientos comerciales (TCC-001, TCC-005, TCC-006. TCC-001 y TCN-014, reportaron ser más competentes por nutrientes y espacio, con el mayor radio de crecimiento de 7,50 y 7,32 cm el día 10, comparado a FSM-011 en el cual solo fue de 2,30 cm. Aunque, TCN-014 mostró micoparasitismo grado 4 con ambos aislamientos de F. solani y TCC-005 únicamente con FSM-012, el cual fue más susceptible a ser micoparasitado. En cuanto al PICR, los tratamientos con mejores porcentajes de inhibición fueron TA-9, TA-12 y TA-6 con valores de 70,56, 68,52 y 65,32% respectivamente. El aislamiento del patógeno mayormente inhibido fue FSM-011. Todos estos resultados demuestran que hubo antagonismo in vitro al utilizar los aislamientos nativos y comerciales de T. harzianum sobre F. solani.  Palabras clave: Passiflora, competencia, micoparasitismo, inhibición, antagonismo.

Carol Libeth Suárez Meza

2009-01-01

262

Antifungal Effects of Thyme, Agastache and Satureja Essential Oils on Aspergillus fumigatus, Aspergillus flavus and Fusarium solani  

OpenAIRE

Growth inhibition of Aspergillus fumigatus,Aspergillus flavus and Fusarum solani exposed to the essential oils including Thyme, Agastache and Satureja were studied. Disc Diffusion Method was used to evaluate the fungal growth inhibitory effects of the essential oils. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) of the oils were determined and compared with each other. The results showed that all three essential oils examined, had antifungal effects against...

Karim Mardani; Samira Ebrahimzadeh; Abbas Hasani; Abdulghaffar Ownagh

2010-01-01

263

Antifungal Activity of (KW)n or (RW)n Peptide against Fusarium solani and Fusarium oxysporum  

OpenAIRE

The presence of lysine (Lys) or arginine (Arg) and tryptophan (Trp) are important for the antimicrobial effects of cationic peptides. Therefore, we designed and synthesized a series of antimicrobial peptides with various numbers of Lys (or Arg) and Trp repeats [(KW and RW)n-NH2, where n equals 2, 3, 4, or 5]. Antifungal activities of these peptides increased with chain length. Light microscopy demonstrated that longer peptides (n = 4, 5) strongly inhibited in vitro growth of Fusarium solani, ...

Yoonkyung Park; Chang Ho Seo; Ramamourthy Gopal; Hyungjong Na

2012-01-01

264

Evaluation of the in vitro antimicrobial properties of ultraviolet A/riboflavin mediated crosslinking on Candida albicans and Fusarium solani  

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Full Text Available AIM:To evaluate the antimicrobial properties of ultraviolet A (UVA (365 nm/riboflavin against Candida albicans and Fusarium solani.METHODS:Two fungus isolates were cultured in vitro and prepared with 10-fold serial PBS dilutions of cell concentration. For each dilution of fungus suspension, the concentration (colony-forming units/mL, CFU/mL and the inactivation ratio of fungal cells were evaluated under 4 conditions:no treatment (control, UVA (365 nm/riboflavin, riboflavin, and UVA (365 nm.RESULTS:The cell concentration decreased in UVA (365 nm/riboflavin group for Candida albicans at each dilution and Fusarium solani at dilutions of 104, 103, 102 CFU/mL, when compared with that in control, riboflavin, and UVA (365 nm groups (P<0.01. No difference of cell concentration was detected amongst the culture of control, riboflavin, and UVA (365 nm groups for the two fungus. There is a negative correlation between suspension concentration (log-transformed and the inactivation ratio in UVA (365 nm/riboflavin group for Candida albicans and Fusarium solani (P<0.01.CONCLUSION: According to the standard protocol of corneal collagen cross-linking, UVA (365 nm/riboflavin combination treatment is found to moderately inactivate the viability of Candida albicans and Fusarium solaniin vitro. The inactivation ratio was found to increase with the decrease of cell concentration under UVA (365 nm/riboflavin condition.

Bing Sun

2014-04-01

265

Efficacy of fungicides to manage onion stunting caused by Rhizoctonia spp. in the Columbia Basin of Oregon and Washington, 2011-2012  

Science.gov (United States)

Onion stunting, caused by Rhizoctonia spp., has become a significant soilborne problem of onion bulb crops planted in sandy soils in the semi-arid Columbia Basin of Oregon and Washington following winter cereal cover crops. Research on the epidemiology and management of this disease is in progress. ...

266

Morphological and Phylogenetic Analysis of Fusarium solani Species Complex in Malaysia.  

Science.gov (United States)

Members of Fusarium solani species complex (FSSC) have been known as plant, animal, and human pathogens. Nevertheless, the taxonomic status of such an important group of fungi is still very confusing and many new species as well as lineages have been elucidated recently. Unfortunately, most of the new taxa came from temperate and subtropical regions. Therefore, the objectives of the present study were to identify strains of FSSC recovered from different sources in Malaysia. In the present study, 55 strains belonging to the FSSC were examined and phylogenetically analyzed on the basis of internal transcribed spacer (ITS) regions and partial translation elongation factor-1 (TEF-1?) sequences. Based on morphological features, a total of 55 strains were selected for molecular studies. Based on morphological features, the strains were classified into four described Fusarium species, namely Fusarium keratoplasticum, Fusarium falciforme, FSSC 5, and Fusarium cf. ensiforme, and one unknown phylogenetic species was introduced. Although the data obtained from morphological and molecular studies sufficiently supported each other, the phylogenetic trees based on ITS and TEF-1? dataset clearly distinguished closely related species and distinctly separated all morphological taxa. All members of FSSC in this research were reported for the first time for Malaysian mycoflora. PMID:25238930

Chehri, Khosrow; Salleh, Baharuddin; Zakaria, Latiffah

2015-04-01

267

First Report of Antifungal Spectra of Activity of Iranian Actinomycetes Strains Against Alternaria solani, Alternaria alternate, Fusarium solani, Phytophthora megasperma, Verticillium dahliae and Saccharomyces cerevisiae  

OpenAIRE

This is the first report of antifungal activity of Iranian Actinomycetes isolates against Alternaria solani Sorauer, Alternaria alternata (Fr.) Keissler, Fusarium solani (Mart.) Sacc., Phytophthora megasperma Drechsler, Verticillium dahliae Klebahn and Saccharomyces cerevisiae Meyen ex Hansen. Biological control of plant diseases has received worldwide attention in recent years mainly as a response to public concern about the use of hazardous chemicals in the environment. Soil Actinomycetes p...

Aghighi, S.; Shahidi Bonjar, G. H.; Rawashdeh, R.; Batayneh, S.; Saadoun, I.

2004-01-01

268

Effect of topical 0.5% povidone-iodine compared to 5% natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study Efeito tópico de iodo-povidona 0,5% comparado com natamicina 5% em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto  

OpenAIRE

PURPOSE: To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine) - treated with topical 0.5% povidone-iodine; Group II (natamycin) - treated with topical 5% natamycin; and Group III (control) - treated with topical saline...

Lauro Augusto de Oliveira; Thales Takeo Takata; Alvio Isao Shiguematsu; Luiz Alberto Soares Melo Júnior; Olga Fischman Gompertz; Luciene Barbosa de Sousa; Mannis, Mark J.

2008-01-01

269

Possibilidade de transmissão de Fusarium solani f.sp. glycines, agente causal da podridão vermelha da raiz da soja, através da semente / Possible transmission of Fusarium solani f. sp. glycines, causal agent of Sudden Death Syndrome, through soybean seed  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Um isolado de Fusarium solani f.sp. glycines, coletado em plantas de soja (Glycine max) na região de Cruz Alta - RS, foi utilizado em experimentos conduzidos com o objetivo de avaliar a possibilidade de a semente ser um veículo eficiente de disseminação da podridão vermelha da raiz na cultura da soj [...] a. A transferência de propágulos do patógeno para sementes de soja, armazenada durante um, seis e 12 meses, foi realizada através da mistura de grãos de sorgo (Sorghum bicolor), solo e resíduos de colheita, previamente esterilizados e posteriormente infetados, em condições de laboratório, com F. solani f.sp. glycines. As evidências de que sementes de soja podem ser uma das fontes de inóculo primário de Podridão Vermelha da Raiz relacionaram-se à presença de clamidósporos aderidos externamente às sementes, após seis meses de armazenamento. As sementes apresentando crescimento do fungo após 12 meses de armazenamento, um mínimo de 75 unidades formadoras de colônias/ml removidas do tegumento das sementes de soja e plântulas formadas a partir das sementes infetadas após 12 meses de armazenamento mostrando sintomas da doença. Abstract in english A Fusarium solani f.sp. glycines isolate collected in Cruz Alta RS, Brazil, was utilized in these experiments to evaluate the possibility of the Sudden Death Syndrome (SDS) pathogen being transmitted by soybean (Glycine max) seeds. The seedborne nature of SDS pathogen was demonstrated using infected [...] sorghum (Sorghum bicolor) seeds, infested soil, and infected plant debris as transport vehicles of inoculum. The following evidence of soybean seeds being the primary inoculum of SDS pathogen was chlamidospores were externally adhered to the soybean seeds after six months; soybean seeds had with the fungus mycelium after 12 months of storage; 75 c.f.u./ml were removed from the seed coat after 12 months of storage; and the fungus was transmissible after 12 months of storage.

Clarice R., Balardin; Alisson F., Celmer; Ervandil C., Costa; Rosana C., Meneghetti; Ricardo S., Balardin.

2005-12-01

270

Possibilidade de transmissão de Fusarium solani f.sp. glycines, agente causal da podridão vermelha da raiz da soja, através da semente Possible transmission of Fusarium solani f. sp. glycines, causal agent of Sudden Death Syndrome, through soybean seed  

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Full Text Available Um isolado de Fusarium solani f.sp. glycines, coletado em plantas de soja (Glycine max na região de Cruz Alta - RS, foi utilizado em experimentos conduzidos com o objetivo de avaliar a possibilidade de a semente ser um veículo eficiente de disseminação da podridão vermelha da raiz na cultura da soja. A transferência de propágulos do patógeno para sementes de soja, armazenada durante um, seis e 12 meses, foi realizada através da mistura de grãos de sorgo (Sorghum bicolor, solo e resíduos de colheita, previamente esterilizados e posteriormente infetados, em condições de laboratório, com F. solani f.sp. glycines. As evidências de que sementes de soja podem ser uma das fontes de inóculo primário de Podridão Vermelha da Raiz relacionaram-se à presença de clamidósporos aderidos externamente às sementes, após seis meses de armazenamento. As sementes apresentando crescimento do fungo após 12 meses de armazenamento, um mínimo de 75 unidades formadoras de colônias/ml removidas do tegumento das sementes de soja e plântulas formadas a partir das sementes infetadas após 12 meses de armazenamento mostrando sintomas da doença.A Fusarium solani f.sp. glycines isolate collected in Cruz Alta RS, Brazil, was utilized in these experiments to evaluate the possibility of the Sudden Death Syndrome (SDS pathogen being transmitted by soybean (Glycine max seeds. The seedborne nature of SDS pathogen was demonstrated using infected sorghum (Sorghum bicolor seeds, infested soil, and infected plant debris as transport vehicles of inoculum. The following evidence of soybean seeds being the primary inoculum of SDS pathogen was chlamidospores were externally adhered to the soybean seeds after six months; soybean seeds had with the fungus mycelium after 12 months of storage; 75 c.f.u./ml were removed from the seed coat after 12 months of storage; and the fungus was transmissible after 12 months of storage.

Clarice R. Balardin

2005-12-01

271

Aceites Esenciales y Extractos Acuosos para el Manejo in vitro de Fusarium oxysporum f. sp. lycopersici y F. solani / Essential Oils and Aqueous Extracts for the in vitro Management of Fusarium oxysporum f. sp. lycopersici and F. solani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El uso de fungicidas sintéticos favorece la aparición de hongos fitopatógenos resistentes, por lo que se requieren nuevos productos para el manejo de enfermedades. Una alternativa son los aceites esenciales (AE) y extractos acuosos (EA) de origen vegetal. En este trabajo se evaluaron distintas conce [...] ntraciones de AE y EA de cinco especies de la familia Chenopodiaceae sobre el crecimiento micelial y esporulación de Fusarium oxysporum f. sp. lycopersici (FOL) y F. solani. Se encontró que existe una respuesta diferencial entre las razas 2 y 3 de FOL e incluso entre aislamientos de una misma raza. Los AE de Chenopodium album [0.3 %] y C. ambrosioides [2 %] inhibieron totalmente el crecimiento y esporulación en ambas especies de Fusarium. De los EA probados, el de Beta vulgaris ejerció la mayor reducción del crecimiento micelial (38 %) y esporulación (61 %). Los EA al 5 %, de las cinco especies evaluadas, mostraron una estimulación del 27 al 183 % en el crecimiento micelial en las cuatro cepas empleadas. Al 10 %o, Beta vulgaris, C. album, C. berlandieri subsp. nuttalliae y C. graveolens redujeron entre 11 y 38 % el crecimiento de F. solani y FOL raza 2 (aislamiento Yautepec) con respecto al testigo. Abstract in english The use of synthetic pesticides favors the appearance of resistant pathogens and pest; therefore, new products are needed for disease management. The use of essential oils (EO) and aqueous extracts (AE) are an alternative option. In this work, different concentrations of EO and AE of five Chenopodia [...] ceae species were evaluated on micelial growth and spore production of Fusarium oxysporum f. sp. lycopersici (FOL) and F. solani. It was found that there is a differential response between races 2 and 3 of FOL and even among isolates of the same race. EO of Chenopodium album [0.3 %] and C. ambrosioides [2 %] inhibited micelial growth and spore production on both Fusarium species. Of the EA tested, Beta vulgaris exercised the greatest reduction in mycelial growth (38 %) and sporulation (61 %). The EA 5 %, of the five species tested showed a stimulation by 27 to 183 % in mycelial growth on the four strains used. At 10 %, Beta vulgaris, C. album, C. berlandieri subsp. nuttalliae and C. graveolens reduced between 11 and 38 % growth of F. solani and FOL race 2 (isolate Yautepec) compared with the control.

Daniel Antonio, Vásquez Covarrubias; Roberto, Montes Belmont; Alfredo, Jiménez Pérez; Hilda Elizabet, Flores Moctezuma.

272

Sporulation and mycelial growth of Fusarium solani in different culture media and steady bright = Esporulação e crescimento micelial de Fusarium solani em diferentes meios de cultura e regimes de luminosidade  

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Full Text Available Considering the physiological characterization of Fusarium solani isolated from cassava roots, the objective of this study was to evaluate mycelial growth and sporulation of F. solani in different culture media and lighting regimes. The fungus was grown using five culture media (potato dextrose agar, potato sucrose agar, cassava, agar-agar, and water micophil under three light regimes (continuous darkness, a photoperiod of 12 h, and continuous light during the incubation period of seven day, temperature 25 °C ± 2 °C. The trial was done in completely randomized design with three replications. Discs of 5 mm diameter taken from the edge of the colony grown on PDA medium were transferred to the center of Petri dishes containing 20 mL of each medium. Mycelial growth was determined by measuring the diameter of the colonies in two diametrically opposite directions while sporulation by quantifying conidia by drop method. No significant changes in the production of conidia and mycelial mass in different culture media and lighting regimes tested, and BDA and BSA under the regime of continuous light best sporulation and conidial production were observed. While in the midst AA under continuous darkness was the lowest rates of mycelial growth and sporulation. = Visando a caracterização fisiológica de Fusarium solani isolado de raízes de mandioca, objetivou-se com este trabalho avaliar a esporulação e o crescimento micelial de F. solani em diferentes meios de cultura e regimes de luminosidade. O fungo foi cultivado utilizando cinco meios de cultura (batata dextrose ágar, batata sacarose ágar, mandioca ágar, micophil e ágar-água sob três regimes de luminosidade (escuro contínuo, fotoperíodo de 12 h e luz contínua durante o período de incubação de sete dias, a temperatura de 25 °C ± 2 o C. O ensaio foi conduzido em delineamento inteiramente casualizado, em esquema fatorial (5x3, com três repetições. Discos de 5 mm de diâmetro, retirados da borda da colônia cultivada em meio BDA, foram transferidos para o centro de placas de Petri contendo 20 mL de cada meio. Determinou-se o crescimento micelial por meio da medida do diâmetro das colônias em dois sentidos diametralmente opostos, enquanto a esporulação por meio da quantificação de conídios pelo método da gota. Foram observadas variações significativas na produção de massa micelial e conídios nos diferentes meios de cultura e regimes de luminosidade testados, sendo que BDA e BSA sob regime de luz contínua induziram maior crescimento micelial e produção de conídios. Enquanto que no meio AA sob escuro contínuo ocorreu às menores taxas de esporulação e crescimento micelial.

Jhonata Lemos da Silva

2012-04-01

273

Fontibacillus solani sp. nov. isolated from potato (Solanum tuberosum L.) root.  

Science.gov (United States)

A bacterial strain designated A4STR04(T) was isolated from the inner root tissue of potatoes in Spain. Phylogenetic analysis based on the 16S rRNA gene sequence placed the isolate into the genus Fontibacillus, being most closely related to Fontibacillus panacisegetis KCTC 13564(T) with 99 % identity. The isolate was observed to form Gram-positive, motile and sporulating rods. The catalase test was found to be negative and oxidase positive. Nitrate was found to be reduced to nitrite. ?-Galactosidase and caseinase were observed to be produced but the production of gelatinase, urease, arginine dehydrolase, ornithine and lysine decarboxylase was negative. Aesculin hydrolysis was found to be positive and acetoin production was negative. Growth was found to be supported by many carbohydrates and organic acids as carbon source. MK-7 was the only menaquinone detected and the major fatty acid (61.5 %) was identified as anteiso-C15:0, as occurs in the other species of genus Fontibacillus. The strain A4STR04(T) was found to display a complex lipid profile consisting of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, a glycolipid, two phospholipids, a lipid and two aminophospholipids. Mesodiaminopimelic acid was detected in the peptidoglycan. The G+C content was determined to be 50.5 mol% (Tm). Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain A4STR04(T) (=LMG 28458 (T) = CECT 8693(T)) should be classified as representing a novel species of genus Fontibacillus, for which the name Fontibacillus solani sp. nov. is proposed. PMID:25772303

Ramírez-Bahena, Martha-Helena; Flores-Félix, José David; Cuesta, Maria José; Gil, Carmen Tejedor; Palomo, Jose Luis; Benavides, Pablo García; Igual, Jose Mariano; Pascual, Mercedes Fernández; Velázquez, Encarna; Peix, Alvaro

2015-05-01

274

Isolation of a Fusarium solani mutant reduced in cutinase activity and virulence.  

Science.gov (United States)

Fusarium solani isolate T-8 produces an extracellular enzyme, cutinase, which catalyzes the degradation of cutin in the plant cuticle. Cutinase activity can be measured by the hydrolysis of either the artifical substrate, p-nitrophenylbutyrate (PNB), or radioactive cutin containing [14C]palmitic acid. In the present study, the culture filtrate contained basal levels of cutinase when T-8 was grown on acetate as a sole source of carbon. After mutagenesis, a cutinase-defective mutant (PNB-1) was identified by screening acetate-grown colonies for a loss of PNBase activity. The mutant possessed an 80 to 90% reduction in cutinase activity when grown for 3 to 5 days on acetate- or cutin-containing medium. Induction of cutinase by cutin or hydrolyzed cutin after growth on glucose medium was similarly reduced. Kinetic analysis indicated that cutinase from the mutant possessed a near normal Km for PNB and a 92% reduction in Vmax. Fluorography and Western blotting of 15% sodium dodecyl sulfate-polyacrylamide gels of separated 35S-labeled proteins from cutin induction medium revealed that in the mutant the 22,000-molecular-weight band corresponding to cutinase was reduced approximately 85%. The virulence of the mutant in a pea stem bioassay was decreased by 55% and was restored to nearly the parental level by the addition of purified cutinase. The data suggest that the mutant synthesizes reduced quantities of a functional and immunoreactive cutinase enzyme and that cutinase plays a critical role in infection. The PNB1 mutation may be within a regulatory gene or a promoter for cutinase. PMID:3782031

Dantzig, A H; Zuckerman, S H; Andonov-Roland, M M

1986-11-01

275

An abundant ‘Candidatus Phytoplasma solani’ tuf b strain is associated with grapevine, stinging nettle and Hyalesthes obsoletus  

Science.gov (United States)

Bois noir (BN) associated with ‘Candidatus Phytoplasma solani’ (Stolbur) is regularly found in Austrian vine growing regions. Investigations between 2003 and 2008 indicated sporadic presence of the confirmed disease vector Hyalesthes obsoletus and frequent infections of bindweed and grapevine. Infections of nettles were rare. In contrast present investigations revealed a mass occurrence of H. obsoletus almost exclusively on stinging nettle. The high population densities of H. obsoletus on Urtica dioica were accompanied by frequent occurrence of ‘Ca. P. solani’ in nettles and planthoppers. Sequence analysis of the molecular markers secY, stamp, tuf and vmp1 of stolbur revealed a single genotype named CPsM4_At1 in stinging nettles and more than 64 and 90 % abundance in grapevine and H. obsoletus, respectively. Interestingly, this genotype showed tuf b type restriction pattern previously attributed to bindweed associated ‘Ca. P. solani’ strains, but a different sequence assigned as tuf b2 compared to reference tuf b strains. All other marker genes of CPsM4_At1 clustered with tuf a and nettle derived genotypes verifying distinct nettle phytoplasma genotypes. Transmission experiments with H. obsoletus and Anaceratagallia ribauti resulted in successful transmission of five different strains including the major genotype to Catharanthus roseus and in transmission of the major genotype to U. dioica. Altogether, five nettle and nine bindweed associated genotypes were described. Bindweed types were verified in 34 % of grapevine samples, in few positive Reptalus panzeri, rarely in bindweeds and occasionally in Catharanthus roseus infected by H. obsoletus or A. ribauti. ‘Candidatus Phytoplasma convolvuli’ (bindweed yellows) was ascertained in nettle and bindweed samples. PMID:25309042

Mörtel, J.; Pastar, M.

2014-01-01

276

An abundant 'Candidatus Phytoplasma solani' tuf b strain is associated with grapevine, stinging nettle and Hyalesthes obsoletus.  

Science.gov (United States)

Bois noir (BN) associated with 'Candidatus Phytoplasma solani' (Stolbur) is regularly found in Austrian vine growing regions. Investigations between 2003 and 2008 indicated sporadic presence of the confirmed disease vector Hyalesthes obsoletus and frequent infections of bindweed and grapevine. Infections of nettles were rare. In contrast present investigations revealed a mass occurrence of H. obsoletus almost exclusively on stinging nettle. The high population densities of H. obsoletus on Urtica dioica were accompanied by frequent occurrence of 'Ca. P. solani' in nettles and planthoppers. Sequence analysis of the molecular markers secY, stamp, tuf and vmp1 of stolbur revealed a single genotype named CPsM4_At1 in stinging nettles and more than 64 and 90 % abundance in grapevine and H. obsoletus, respectively. Interestingly, this genotype showed tuf b type restriction pattern previously attributed to bindweed associated 'Ca. P. solani' strains, but a different sequence assigned as tuf b2 compared to reference tuf b strains. All other marker genes of CPsM4_At1 clustered with tuf a and nettle derived genotypes verifying distinct nettle phytoplasma genotypes. Transmission experiments with H. obsoletus and Anaceratagallia ribauti resulted in successful transmission of five different strains including the major genotype to Catharanthus roseus and in transmission of the major genotype to U. dioica. Altogether, five nettle and nine bindweed associated genotypes were described. Bindweed types were verified in 34 % of grapevine samples, in few positive Reptalus panzeri, rarely in bindweeds and occasionally in Catharanthus roseus infected by H. obsoletus or A. ribauti. 'Candidatus Phytoplasma convolvuli' (bindweed yellows) was ascertained in nettle and bindweed samples. PMID:25309042

Aryan, A; Brader, G; Mörtel, J; Pastar, M; Riedle-Bauer, M

2014-10-01

277

Antifungal Effects of Thyme, Agastache and Satureja Essential Oils on Aspergillus fumigatus, Aspergillus flavus and Fusarium solani  

Directory of Open Access Journals (Sweden)

Full Text Available Growth inhibition of Aspergillus fumigatus,Aspergillus flavus and Fusarum solani exposed to the essential oils including Thyme, Agastache and Satureja were studied. Disc Diffusion Method was used to evaluate the fungal growth inhibitory effects of the essential oils. Minimal inhibitory concentration (MIC and minimal fungicidal concentration (MFC of the oils were determined and compared with each other. The results showed that all three essential oils examined, had antifungal effects against three fungi species. The MIC data revealed that Thyme oil was the most effective essential oil with the MIC of 62.5 ?l ml-1.

Karim Mardani

2010-09-01

278

Biodégradation des cyanures libres par le champignon Fusarium solani: relation avec le pH et la distribution des espèces cyanurées en solution  

Science.gov (United States)

Free cyanide biodégradation by Fusarium solani, a fungi isolated from cyanide-contaminated soils. involves a cyanide hydrolyzing enzyme. cyanide hydratase (EC 4.2.1.66). This enzyme specifically seems to convert cyanhydric acid (HCN) to formamide but not the cyanide ion (CN -). Hence. the rate of free cyanide biodégradation is a function of the equilibrium HCN/CN - in solution. A better understanding of cyanide hydratase properties allows the definition of optimal conditions of F.solani biodégradation activity. and the proposition of a biological treatment of cyanide-contaminated alkaline soils and effluents.

Dumestre, Alain; Bousserrhine, Noureddine; Berthelin, Jacques

1997-07-01

279

Evaluación de la capacidad biocontroladora de cepas nativas de Trichoderma spp sobre Rhizoctonia sp y Fusarium sp en café (Coffea arabica) en condiciones experimentales / Evaluation of biocontrol ability of native strains of Trichoderma spp on Rhizoctonia and Fusarium sp in coffee (Coffea arabica) in experimental conditions  

Scientific Electronic Library Online (English)

Full Text Available Debido al uso indiscriminado agroquímicos, en la agricultura convencional, se esta provocando problemas de contaminación del medio ambiente (suelo, aire y agua), de ahí que, la búsqueda de alternativas que contribuyan a una producción agrícola libre de agroquímicos haciendo sostenible la producción. [...] En este trabajo se estudia el control biológico del damping off en café (Coffea arabica) aplicando el hongo antagónico Trichoderma sp., en condiciones experimentales a escala de laboratorio, en instalaciones de la Unidad Académica Campesina Carmen Pampa, comunidad de Carmen Pampa, municipio de Coroico. El objetivo de este trabajo fue controlar biológicamente el “damping off”, se encontraron dos géneros causantes del damping off en almacigo de café: Rhizoctonia sp. y Fusarium sp. Para determinar el porcentaje de crecimiento y control en el medio de cultivo, se utilizó el método de conteo de cuadrantes, donde se obtuvieron los porcentajes del crecimiento micelial del hongo antagónico Trichoderma sp.,y de los hongos fitopatógenos Rhizoctonia sp. y Fusarium sp. Estadísticamente existió una diferencia altamente significativa en la variable porcentaje de crecimiento de Trichoderma sp. sobre los hongos patógenos Rhizoctonia sp. y Fusarium sp. a los 3, 6 y 9 días esto da a conocer que el factor tiempo y los tratamientos son dependientes entre sí. La variable de control mostró una diferencia altamente significativa en el factor tiempo y tratamiento, pero en la interacción no muestra diferencia significativa esto da a conocer que son independientes los factores, por lo que el hongo Trichoderma sp., no depende del tiempo en los tratamientos, así mostrando su poder inhibidor a Rhizoctonia sp. y Fusarium sp.. Esta prueba da referencias de que existe control del hongo antagónico sobre los hongos fitopatógenos Rhizoctonia sp. y Fusarium sp. Abstract in english Due to the indiscriminate use agrochemicals in conventional agriculture, it is causing pollution problems in the environment (soil, air and water), hence the search for alternatives that contribute to agricultural production by agro-chemical free sustainable production. This paper studies the biolog [...] ical control of damping off in coffee (Coffea arabica) by applying antagonistic fungus Trichoderma sp. Under experimental conditions at laboratory facilities of the Academic Unit Carmen Pampa Campesina, a community of Carmen Pampa, Township Coroico. The aim of this study was to biologically control the "damping off", they found two genera that cause damping off in seedbed of coffee: Rhizoctonia sp. and Fusarium sp.To determine the percentage of growth and control in the culture medium, we used the method of counting quarters, where they gave the mycelial growth of antagonistic fungus Trichoderma sp., And the fungal pathogens Rhizoctonia sp. and Fusarium sp. Statistically there was a highly significant difference in the variable growth rate of Trichoderma sp. on pathogenic fungi Rhizoctonia sp. and Fusarium sp. at 3, 6 and 9 days that announces the time factor and treatments are interdependent. The control variable showed a highly significant difference in the time factor and treatment, but the interaction shows no significant difference this makes known factors that are independent, so the fungus Trichoderma sp. not depend on time in treatment, thus showing its inhibitory power to Rhizoctonia sp. and Fusarium sp .. This test gives references that there is antagonistic fungus control on the fungal pathogens Rhizoctonia sp. and Fusarium sp.

Rudy, Nina; Hugh, Smeltekop; JC, Almanza; Manuel, Loza-Murguia.

280

Identificação de genótipos do gênero Solanum (secção Lycopersicon) com resistência a Stemphylium solani e S. lycopersici / Identification of Solanum (section Lycopersicon) accessions with resistance to Stemphylium solani and S. lycopersici  

Scientific Electronic Library Online (English)

Full Text Available A mancha-de-estenfílio do tomateiro, causada pelos fungos Stemphylium solani e S. lycopersici, foi considerada, por muito tempo, como uma doença secundária devido à utilização combinada de fungicidas e variedades resistentes. Recentemente, severas epidemias da mancha-de-estenfilio têm sido relatadas [...] nas várias regiões produtoras sugerindo a necessidade de retomar o emprego de cultivares com resistência a esta enfermidade. O objetivo do presente trabalho foi avaliar a reação de genótipos cultivados e silvestres de tomateiro [Solanum (secção Lycopersicon)] frente a isolados destas duas espécies de Stemphylium. Na primeira etapa do trabalho, 109 genótipos de Solanum (secção Lycopersicon) foram avaliados via inoculação com uma suspensão de 10(4) conídios/mL dos isolados 'EH-1740' (S. solani) e 'EH-1749' (S. lycopersici). As plantas foram transplantadas aos 18 dias da semeadura e inoculadas sete dias depois. A avaliação da resposta dos genótipos foi feita 15 dias após a inoculação. Cinqüenta e oito genótipos considerados promissores foram novamente avaliados (com os mesmos isolados) em um segundo experimento. Neste experimento a reação dos genótipos foi avaliada cada dois dias utilizando como critérios o período de incubação e a severidade da doença através de uma escala de notas de 0 a 5. Com os valores de severidade, nas diferentes leituras, foi calculada a área abaixo da curva de progresso da doença e o índice de doença. Foram identificadas 35 fontes de resistência às duas espécies de Stemphylium em genótipos das espécies S. lycopersicum, S. habrochaites, S. peruvianum e S. pimpinellifolium. Os genótipos de S. lycopersicum e S. pimpinellifolium resistentes possuem, provavelmente, o gene de resistência Sm. No entanto, os genótipos de S. peruvianum e S. habrochaites podem representar fontes de novos genes/alelos que conferem resistência às duas espécies fúngicas. Esta potencial diversidade de fatores de resistência para Stemphylium pode ser útil em futuras ações de pesquisa dentro de programas de melhoramento genético do tomateiro bem como para o manejo integrado da doença. Abstract in english The gray leaf spot disease, caused by the fungi Stemphylium solani and S. lycopersici, has been considered as a minor tomato disease in Brazil due to the use of varieties with genetic resistance in combination with fungicide sprays. However, recent reports of severe epidemics of the gray leaf spot i [...] n the various tomato-producing areas of the country suggest that the employment of resistant cultivars should be re-implemented as a control strategy. In the present study, 109 cultivated and wild Solanum (section Lycopersicon) accessions were evaluated to isolates of both S. solani and S. lycopersici. In the first assay, spore suspension (adjusted to 10(4) conidia/mL) of the isolates 'EH-1740' (S. solani) and 'EH-1749' (S. lycopersici) were employed to inoculate seedlings transplanted 15 days after sowing and kept in a greenhouse. Plants were inoculated 18 days after transplanting and evaluated 15 days after inoculation. Fifty-eight promising accessions identified in the first assay were evaluated again with the same isolates in a second experiment. The reaction of the accessions to the pathogens was evaluated every two days using as assessment criteria the incubation period, the severity of gray leaf spot, and the disease index. Disease severity values over time were used to calculate the area under the disease progress curve. Promising sources of resistance to both pathogens were identified in accessions of S. lycopersicum, S. habrochaites, S. peruvianum and S. pimpinellifolium. The resistant sources identified in S. pimpinellifolium and S. lycopersicum accessions probably have the gene Sm. However, S. habrochaites and S. peruvianum might be potential new sources of gene/alleles that confer resistance to both fungi. This diversity of Stemphylium resistance genes might be useful for tomato breeding programs in the future as well as in integrated

Bruno Eduardo C de, Miranda; Leonardo S, Boiteux; Ailton, Reis.

2010-06-01

281

Isolation and In Vivo and In Vitro Antifungal Activity of Phenylacetic Acid and Sodium Phenylacetate from Streptomyces humidus  

OpenAIRE

The antifungal substances SH-1 and SH-2 were isolated from Streptomyces humidus strain S5-55 cultures by various purification procedures and identified as phenylacetic acid and sodium phenylacetate, respectively, based on the nuclear magnetic resonance, electron ionization mass spectral, and inductively coupled plasma mass spectral data. SH-1 and SH-2 completely inhibited the growth of Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, Saccharomyces cerevisiae, and Pseudomonas syringa...

Hwang, Byung Kook; Lim, Song Won; Kim, Beom Seok; Lee, Jung Yeop; Moon, Surk Sik

2001-01-01

282

A case of mycotic keratitis caused by Fusarium solani / Um caso de ceratite micótica causada por Fusarium sotani  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O caso estudado refere-se a paciente do sexo masculino, 36 anos, feoderma, sem história de doença sistêmica ou trauma ocular, apresentando úlcera corneana no olho esquerdo. Antes do estabelecimento do diagnóstico específico, o paciente foi tratado com antibiótico associado a corticosteróides durante [...] um mês. O exame direto realizado a partir de raspado de córnea tratado com KOH revelou a presença de hifas fúngicas e clamidosporos, e o cultivo do material em ágar Sabouraud dextrose mostrou-se positivo para Fusarium solani. É enfatizada a necessidade do uso cauteloso de antibióticos e corticosteróides no tratamento de infecções da córnea, bem como de se considerar a possibilidade de etiologia fúngica destes quadros. Abstract in english A 36-year-old black man, without history of systemic disease or ocular trauma developed a corneal infection in his left eye. He was treated with antibacterial antibiotic and corticosteroids for one month prior to diagnosis. Fungal hyphae and chlamydospores were found in a KOH preparation of the corn [...] eal scrapings, and positive cultures for Fusarium solani were obtained in Sabouraud dextrose agar. It is emphasized the cautious use of antibiotics and steroids in corneal diseases, and the need of considering the involvement of opportunistic fungi in the etiology of these infections.

Junia Soares, Hamdan; Maria Aparecida de, Resende; Sarah Piancastelli, Franzot; Daniel Vieira, Dias; Evelin Márcia, Viana; Agnes Kiesling, Casali.

1995-04-01

283

The Effect of Endophytic Fungi of Tall and Meadow Fescues on Biological Control of Mealybug (Phenococcus solani Ferris, Hom.:Pseudococcidae  

Directory of Open Access Journals (Sweden)

Full Text Available Endophytic fungi, Neotyphodium spp. symbiotically infect host grasses, Fescue arundinacea Schreb. and F. pratensis Huds. and Mealybug, Phenococcus solani Ferris attacks some forage plants. To evaluate the role of these fungi to control this pest, four genotypes of F. arundinacea and two genotypes of F. pratensis were used. Plant tillers were split into two sections, one section of which was freed from endophyte using a fungicide mixture. The mixture contained 2 grams of active ingredients of Propiconazol and 1 ml of Folicur per liter of water. New tillers from endophyte-infected and endophyte-free plants were transferred into the field. The number of mealybugs was measured after the first visible sign of infestation on roots. To count mealybug, one plant hill of each plot was randomly selected. Hay yield of each plot was measured by clipping the plants 5 cm above ground level. Correlation of hay yield and other growth characteristics with the number of mealybugs on roots as an index for mealybug damage on infested plants was determined. The results indicated that endophyte-free plants were highly infested with mealybug, P. solani compared with endophyte-infected plants that were completely free of P. solani, correlation coefficients showed that there was significant negative correlation between forage yield and mealybug numbers, indicating mealybug damage on infested plants. It seems that endophytic fungi are effective biocontrol factors for some root feeding pest such as mealybug, P. solani.

A.F. Mirlohi

2006-07-01

284

Pathological and molecular identification of Fusarium Solani F.Sp, phaseoli isolates and determination of suitable gamma ray dose rate for mutation induction  

International Nuclear Information System (INIS)

During 1384-1385, the plants showing root and crown rot were collected from 48 bean fields in the Khuzestan and Markazi provinces. Twenty isolates were identified as Fusarium solani based on morphological characteristics. The pathogenicity tests confirmed four isolates as Fusarium solani f.sp. phaseoli. By using specific primers for this specific form, three isolates showed concordant results with pathogenicity tests. As a result three isolates morphologically and molecularly identified as F.solani f.sp. phaseoli. In order to induce mutation, conidia scraped from F.solani f.sp. phaseoli cultures, were counted, diluted and then plated on water agar. The plates containing conidia were irradiated in a 60 Co-gamma cell (with activity of 2500 curi and 0.38 gray per second dose rates) in doses 0, 60, 90,120, 150, 180 Gy. After 18 hours, the percentage germination of spores were scored. The comparison of percentage germination and vegetative growth in different dose rates Showed that spore mutagenesis can be expected in 120-180 Gy.

285

Electronics  

CERN Document Server

Although most people would scarcely be able to make it through the day without using some type of electronic device-computers, televisions, and MP3 players, to name a few-the inner workings of such devices remain a mystery to many. This insightful volume examines various components, such as electron tubes and semiconductors, that have been essential to electronics over the years, as well as the history of the field in general and its applications in everyday life.

Hollar, Sherman

2012-01-01

286

Electronics  

CERN Document Server

Electronics Theory and Practice introduces the key areas of analog electronics through practicals, worked examples and concise explanations. The author is a senior lecturer at De Montfort University and his approach is a proven way of teaching the essentials of electronics to groups with a variety of academic backgrounds. This is an ideal text for first year modules and HNC/D units - comprehensive, concise and affordable.

Mesias, Gerardo

2012-01-01

287

Electrons  

International Nuclear Information System (INIS)

Fast electrons are used to produce isotopes for studying the cooper metabolism: Cu-64 in a cyclotron and Cu-67 in a linear accelerator. Localized electrons are responsible for the chemical and physiological characteristics of the trace elements. Studied are I, Cu, Co, Zn, Mo, Mn, Fe, Se, Mg. The Cu/Mo and Cu/Zn interactions are investigated. The levels of molybdenum, sulfate and zinc in the food are analysed. The role of the electrons in free radicals is discussed. The protection action of peroxidases and super oxidases against electron dangerous effect on normal physiology is also considered. Calculation of radiation damage and radiation protection is made. (author)

288

INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN  

Directory of Open Access Journals (Sweden)

Full Text Available

Foram testadas quatro densidades de inóculo de Fusarium solani, em gramas por litro de solo (1,0; 2,0; 4,0 e 8,0 e um tratamento testemunha, em solo tipo Latossolo Vermelho-Escuro, cultivado e não cultivado, com o objetivo de determinar a densidade mínima de inóculo no solo necessária para a ocorrência de podridão radicular seca do feijoeiro. Como variáveis respostas foram avaliadas: número de microorganismos totais do solo, número de propágulos de F. solani, atividade microbiológica total do solo e severidade da doença em plântulas. Os resultados indicaram que a densidade de inóculo do fungo variou com o tipo de solo. Para um solo não cultivado a densidade necessária para causar a doença esteve acima de 5.127 propágulos por grama de solo, enquanto para o solo cultivado a densidade de inóculo para causar doença foi de 3.701 propágulos por grama de solo. Os índices de doença em plântulas cultivadas sob o solo cultivado foram duas vezes superiores ao índice de doença de plântulas sob o solo não cultivado. A atividade microbiológica total nos solos, determinada pela desidrogenase de fluorescina diacetato, não se correlacionou com a população dos microorganismos, indicando que a simples presença desses não implica em que estejam ativos.

PALAVRAS-CHAVE: Solo supressivo; solo conducivo; Phaseolus vulgaris.

Four densities of Fusarium solani inoculum (1, 2, 4 and 8 g/L of soil were tested for determining the minimum inoculum density for the occurrence of bean dry root rot, in two soil types. The response variables evaluated were the total number of microorganisms in the soil, the number of F. solani f. sp. phaseoli propagules, total soil microbial activity and seedling disease severity. The results indicated that the minimum inoculum density for disease occurrence varied with the soil type. For a non-cultivated soil, the minimum inoculum density was greater than 5,127 propagules per gram of soil, while for cultivated soil, the minimum inoculum density was 3,701 propagules per gram of soil. Disease severity in seedlings grown in cultivated soil was twice as great as for those grown in non-cultivated soil. Total soil microbial activity, as determined by dehydrogenase of fluorescein diacetate, did not correlate with the population of the pathogen, indicating that the mere presence of these organisms in the samesoils does not imply that they are active.

KEY-WORDS: Suppressive soil; conducive soil; Phaseolus vulgaris.

Gesimária Ribeiro Costa

2007-09-01

289

Isolation and characterization of a novel wheat cysteine-rich receptor-like kinase gene induced by Rhizoctonia cerealis  

Science.gov (United States)

Cysteine-rich receptor kinases (CRKs) belong to the receptor-like kinase family. Little is known about CRK genes in wheat. We isolated a wheat CRK gene TaCRK1 from Rhizoctonia cerealis-resistant wheat CI12633 based on a differentially expressed sequence identified by RNA-Sequencing (RNA-Seq) analysis. TaCRK1 was more highly expressed in CI12633 than in susceptible Wenmai 6. Transcription of TaCRK1 in wheat was induced in CI12633 after R. cerealis infection and exogenous abscisic acid (ABA) treatment. The deduced TaCRK1 protein contained a signal peptide, two DUF26 domains, a transmembrane domain, and a serine/threonine protein kinase domain. Transient expression of a green fluorescence protein fused with TaCRK1 in wheat and onion indicated that TaCRK1 may localize to plasma membranes. Characterization of TaCRK1 silencing induced by virus-mediated method in CI12633 showed that the downregulation of TaCRK1 transcript did not obviously impair resistance to R. cerealis. This study paves the way to further CRK research in wheat.

Yang, Kun; Rong, Wei; Qi, Lin; Li, Jiarui; Wei, Xuening; Zhang, Zengyan

2013-10-01

290

Pressure Cycling Technology Sample Preparation System (PCT SPS) Improves Quantification of Pathogen DNA in Plants and Soil  

Science.gov (United States)

Rhizoctonia root rot, bare patch, and damping-off of wheat are yield-limiting diseases caused by Rhizoctonia solani AG-8 and R. oryzae. Detection and quantification of Rhizoctonia spp. are essential for evaluating pathogen distribution and management, but extraction of DNA from these pathogens is ha...

291

Deep granulomatous dermatitis of the fin caused by Fusarium solani in a false killer whale (Pseudorca crassidens).  

Science.gov (United States)

A 10-year-old female false killer whale (Pseudorca crassidens) developed skin lesions in the left breast fin. Histopathologically, the lesions consisted of multiple granulomas spread diffusely into the deep dermis and bone; characteristically, each granuloma had septate, branching fungal hyphae and chlamydospores surrounded by eosinophilic Splendore-Hoeppli materials. Macrophages, epithelioid cells and multinucleated giant cells in the granulomas reacted mainly to anti-SRA-E5 antibody against human macrophage scavenger receptor type I. Fusarium solani was isolated and its gene was detected from the skin samples. Mycotic skin lesions by Fusarium spp. reported so far in marine mammals were regarded as superficial dermatitis; therefore, the present case is very uncommon in that the lesions spread deeper into the skin. PMID:22214860

Tanaka, Miyuu; Izawa, Takeshi; Kuwamura, Mitsuru; Nakao, Tatsuko; Maezono, Yuko; Ito, Shu; Murata, Michiko; Murakami, Masaru; Sano, Ayako; Yamate, Jyoji

2012-06-01

292

Overexpression of a tea flavanone 3-hydroxylase gene confers tolerance to salt stress and Alternaria solani in transgenic tobacco.  

Science.gov (United States)

Flavan-3-ols are the major flavonoids present in tea (Camellia sinensis) leaves. These are known to have antioxidant and free radical scavenging properties in vitro. Flavanone 3-hydroxylase is considered to be an important enzyme of flavonoid pathway leading to accumulation of flavan-3-ols in tea. Expression analysis revealed the upregulation in transcript levels of C. sinensis flavanone 3-hydroxylase (CsF3H) encoding gene under salt stress. In this study, the biotechnological potential of CsF3H was evaluated by gene overexpression in tobacco (Nicotiana tabacum cv. Xanthi). Overexpression of CsF3H cDNA increased the content of flavan-3-ols in tobacco and conferred tolerance to salt stress and fungus Alternaria solani infection. Transgenic tobaccos were observed for increase in primary root length, number of lateral roots, chlorophyll content, antioxidant enzyme expression and their activities. Also, they showed lesser malondialdehyde content and electrolyte leakage compared to control tobacco plants. Further, transgenic plants produced higher degree of pectin methyl esterification via decreasing pectin methyl esterase (PME) activity in roots and leaves under unstressed and salt stressed conditions. The effect of flavan-3-ols on pectin methyl esterification under salt stressed conditions was further validated through in vitro experiments in which non-transgenic (wild) tobacco seedlings were exposed to salt stress in presence of flavan-3-ols, epicatechin and epigallocatechin. The in vitro exposed seedlings showed similar trend of increase in pectin methyl esterification through decreasing PME activity as observed in CsF3H transgenic lines. Taken together, overexpression of CsF3H provided tolerance to salt stress and fungus A. solani infection to transgenic tobacco through improved antioxidant system and enhanced pectin methyl esterification. PMID:24880475

Mahajan, Monika; Yadav, Sudesh Kumar

2014-08-01

293

Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds  

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Full Text Available Abstract Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz, against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 ?g/ml of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100% of spore germination in both the moulds. At 100 ?g/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 ?g/ml of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 ?g/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata.

Sharma Bechan

2009-03-01

294

Inhibitory activity of Indian spice plant Cinnamomum zeylanicum extracts against Alternaria solani and Curvularia lunata, the pathogenic dematiaceous moulds  

Science.gov (United States)

Background Dematiaceous moulds are pathogenic microorganisms and act as etiological agents of mycoses with different degrees of severity in humans and animals. These moulds also cause loss of food crops and storage food products. The information regarding antimicrobial efficacy of the plant preparations on these moulds is scanty. The present study reveals phytochemical characterization and the effect of bark and leaf extracts of Indian spice plant, Cinnamomum zeylanicum (Cz), against the growth of two species of dematiaceous moulds, Alternaria solani and Curvularia lunata. Methods Cz bark and leaf samples were sequentially extracted in different solvents using Soxhlet apparatus. Phytochemical analyses of extracts were done as per standard protocols. The antifungal bioassay of extracts was done by hanging drop technique. The inhibition of fungal spore germination was monitored under influence of three different concentrations of extracts. Results The lowest test concentration (50 ?g/ml) of extracts of Cz bark prepared into acetone and that of Cz leaf into petroleum ether and ethanol exhibited complete inhibition (100%) of spore germination in both the moulds. At 100 ?g/ml concentration all the extracts showed about 50 to 100% inhibition. However, the treatment of the spores of the two fungal species with highest concentration (500 ?g/ml) of bark and leaf extracts in all the solvents showed 100% fungicidal activity as it completely arrested the germination of spores. Relatively lower activity of aqueous extracts at 50 and 100 ?g/ml concentrations suggests that the antifungal ingredients present in Cz bark and leaf are more soluble in organic solvents than water. Conclusion The results demonstrated that the Cz bark and leaves contain certain fungicidal constituents exhibiting potential antimould activity against A. solani and C. lunata. PMID:19267932

Mishra, Ajay K; Mishra, Amita; Kehri, HK; Sharma, Bechan; Pandey, Abhay K

2009-01-01

295

Electronics  

International Nuclear Information System (INIS)

Some of the electronic equipment used in pulse counting and mean current radiation detection systems is described. This includes the high voltage supply, amplifier, amplitude discriminator, scalers or counters, ratemeters, single-channel pulse height analyser, multi-channel pulse height analyser, d.c. amplifiers, coincidence and anticoincidence units and gain stabilisers

296

Functional Analyses of the Diels-Alderase Gene sol5 of Ascochyta rabiei and Alternaria solani Indicate that the Solanapyrone Phytotoxins Are Not Required for Pathogenicity.  

Science.gov (United States)

Ascochyta rabiei and Alternaria solani, the causal agents of Ascochyta blight of chickpea (Cicer arietinum) and early blight of potato (Solanum tuberosum), respectively, produce a set of phytotoxic compounds including solanapyrones A, B, and C. Although both the phytotoxicity of solanapyrones and their universal production among field isolates have been documented, the role of solanapyrones in pathogenicity is not well understood. Here we report the functional characterization of the sol5 gene, which encodes a Diels-Alderase that catalyzes the final step of solanapyrone biosynthesis. Deletion of sol5 in both A. rabiei and Al. solani completely prevented production of solanapyrones and led to accumulation of the immediate precursor compound prosolanapyrone II-diol, which is not toxic to plants. Deletion of sol5 did not negatively affect growth rate or spore production in vitro, and led to overexpression of the other solanapyrone biosynthesis genes, suggesting a possible feedback regulation mechanism. Phytotoxicity tests showed that solanapyrone A is highly toxic to several legume species and Arabidopsis thaliana. Despite the apparent phytotoxicity of solanapyrone A, pathogenicity tests showed that solanapyrone-minus mutants of A. rabiei and Al. solani were equally virulent as their corresponding wild-type progenitors, suggesting that solanapyrones are not required for pathogenicity. PMID:25372118

Kim, Wonyong; Park, Chung-Min; Park, Jeong-Jin; Akamatsu, Hajime O; Peever, Tobin L; Xian, Ming; Gang, David Roger; Vandemark, George; Chen, Weidong

2014-11-01

297

Electronics  

CERN Document Server

Owen Bishop's First Course starts with the basics of electricity and component types, introducing students to practical work almost straight away. No prior knowledge of electronics is required. The approach is student-centred with self-test features to check understanding, including numerous activities suitable for practicals, homework and other assignments. Multiple choice questions are incorporated throughout the text in order to aid student learning. Key facts, formulae and definitions are highlighted to aid revision, and theory is backed up by numerous examp

Bishop, Owen

2010-01-01

298

Comparative metabolite profiling of foxglove aphids (Aulacorthum solani Kaltenbach) on leaves of resistant and susceptible soybean strains.  

Science.gov (United States)

Aphid infestations can cause severe decreases in soybean (Glycine max [L.] Merr.) yield. Since planting aphid-resistant soybean strains is a promising approach for pest control, understanding the resistance mechanisms employed by aphids is of considerable importance. We compared aphid resistance in seven soybean strains and found that strain Tohoku149 was the most resistant to the foxglove aphid, Aulacorthum solani Kaltenbach. We subsequently analyzed the metabolite profiles of aphids cultured on the leaves of resistant and susceptible soybean strains using capillary electrophoresis-time-of-flight mass spectrometry. Our findings showed that the metabolite profiles of several amino acids, glucose 6-phosphate, and components of the tricarboxylic acid cycle were similar in aphids reared on Tohoku149 leaves and in aphids maintained under conditions of starvation, suggesting that Tohoku149 is more resistant to aphid feeding. Compared to susceptible strains, we also found that two methylated metabolites, S-methylmethionine and trigonelline, were either not detected or decreased in aphids reared on Tohoku149 plants. Since these metabolites function as important sulfur transporters in phloem sap and osmoprotectants involved in salt and drought stress, respectively, aphid-resistance is considered to be related to sulfur metabolism and methylation. These results contribute to an increase in our understanding of soybean aphid resistance mechanisms at the molecular level. PMID:24514152

Sato, Dan; Sugimoto, Masahiro; Akashi, Hiromichi; Tomita, Masaru; Soga, Tomoyoshi

2014-04-01

299

Successful treatment of fusarium solani ecthyma gangrenosum in a patient affected by leukocyte adhesion deficiency type 1 with granulocytes transfusions  

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Full Text Available Abstract Background Ecthyma gangrenosum (EG manifests as a skin lesion affecting patients suffering extreme neutropenia and is commonly associated with Pseudomonas aeruginosa in immunocompromised patients. Leukocyte adhesion deficiency I (LAD I which count among primary immunodeficiency syndromes of the innate immunity, is an autosomal recessive disorder characterized in its severe phenotype by a complete defect in CD18 expression on neutrophils, delayed cord separation, chronic skin ulcers mainly due to recurrent bacterial and fungal infections, leucocytosis with high numbers of circulating neutrophils and an accumulation of abnormally low number of neutrophils at sites of infection. Case Presentation We report at our knowledge the first case of a child affected by LAD-1, who experienced during her disease course a multi-bacterial and fungal EG lesion caused by fusarium solani. Despite targeted antibiotics and anti-fungi therapy, the lesion extended for as long as 18 months and only massive granulocytes pockets transfusions in association with G-CSF had the capacity to cure this lesion. Conclusion We propose that granulocytes pockets transfusions will be beneficial to heal EG especially in severely immunocompromised patients.

Hassen Assia

2010-10-01

300

Selection and differentiation of Bacillus spp. Antagonistic to Fusarium oxysporum f.sp. lycopersici and Alternaria solani infecting Tomato.  

Science.gov (United States)

Antagonistic Bacillus spp. displaying in vitro production of siderophore, chitinase, and ?-1,3-glucanase were identified from dual culture assays. In independent greenhouse studies, seed bacterization and soil application of Bacillus atrophaeus S2BC-2 challenge inoculated with Fusarium oxysporum f.sp. lycopersici (FOL) and Alternaria solani (AS) recorded low percent disease index of 25.3 and 28.7, respectively, over nonbacterised pathogen control (44.3 and 56.4). The low disease incidence corroborated with tomato growth promotion with high vigor index (8,041.2) and fresh plant weight (82.5 g) on challenge inoculation with FOL. Analysis of root and leaf samples in rhizobacterial treatment challenged with FOL and AS revealed maximum induction of chitinase (1.9 and 1.7 U/mg of protein, respectively) and ?-1,3-glucanase (23.5 and 19.2 U/mg of protein, respectively). In native gel activity assays, the rhizobacterial treatment on challenge inoculation strongly expressed three high intensity PO isoforms along with one low intensity isoform. In studies on genetic diversity of the Bacillus strains by repetitive extragenomic palindromic-polymerase chain reaction (REP-PCR) and amplified rDNA restriction analysis (ARDRA) patterns, ARDRA was more highly discriminant than REP-PCR and allowed grouping of the strains and differentiation of the antagonistic strains from other isolates. PMID:21503737

Shanmugam, Veerubommu; Atri, Kamini; Gupta, Samriti; Kanoujia, Nandina; Naruka, Digvijay Singh

2011-03-01

301

Purification and characterization of an extracellular laccase from the anthracene-degrading fungus Fusarium solani MAS2.  

Science.gov (United States)

An extracellular laccase was purified from the culture medium of the non-white rot, anthracene-degrading fungal strain Fusarium solani MAS2. Both native PAGE and SDS-PAGE revealed one single band corresponding to a molecular weight of about 72 kDa. Treatment with endoglycosidase H reduced the molecular weight by 12%. The purified laccase maintained stable at pH 3-11 and up to 50 degrees C. The highest activity was detected at pH 3.0 and at 70 degrees C. The enzyme retained 46.2-97.2% of it activity in the presence of 20mM Pb(2+), Ni(2+), Cr(3+), and its activity was enhanced in the presence of 20mM Hg(2+). The laccase retained more than 50% of its activity in the presence of 5% acetone, acetonitrile, dimethyl sulphoxide (DMSO), ethanol and methanol. The kinetic constants (K(m) and k(cat)) showed that 2,6-dimethoxyphenol (DMOP) and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) diammonium salt (ABTS) were the more effective substrates rather than catechol and guaiacol. The novel properties of this laccase suggest its potential for biotechnological and environmental applications. PMID:20716485

Wu, Yi-Rui; Luo, Zhu-Hua; Kwok-Kei Chow, R; Vrijmoed, L L P

2010-12-01

302

Efeito de meios de cultura e fatores físicos no crescimento e esporulação de Alternaria dauci e A. solani / Effect of culture media and physical factors on growth and sporulation of Alternaria dauci and A. solani  

Scientific Electronic Library Online (English)

Full Text Available Alternaria dauci e Alternaria solani são espécies / 24 h). O método desenvolvido neste trabalho foi comparado ao reconhecidamente difíceis de esporular em meios de cultura. Este tradicionalmente utilizado (BDA, 25 ºC, 12 h luz branca / 12 h trabalho teve o objetivo de verificar a influência de algun [...] s meios escuro e raspagem da colônia). O meio V8-ágar, temperatura de 25 de cultura e fatores fisicos sobre o crescimento micelial e a ºC, luz NUV e raspagem das colônias exerceram influência mais esporulação dessas espécies. Testaram-se os meios de cultura BDA, marcante no crescimento e esporulação. O fotoperíodo 12 h luz NUV Aveia e V8; temperaturas (15ºC, 20ºC, 25ºC, 30ºC e 35ºC) / 12 h escuro foi o que mais estimulou a esporulação. Observou-se que, comprimentos de onda da luz durante a incubação (amarelo, azul, de modo geral, períodos de escuro maiores que os períodos de luz, branco, NUV, verde e vermelho); tipos de injúria aplicados à aplicados após injúria da colônia, favoreceram a esporulação. O colônia (raspagem, UV, irradiação de microondas, e temperatura método desenvolvido mostrou-se nitidamente superior ao de 100 ºC) e fotoperíodos (luz / escuro, respectivamente, de 24 h tradicionalmente utilizado, para crescimento e esporulação de ambas / 0 h, 22 h / 2 h, 17 h / 7 h, 12 h / 12 h, 7 h / 17 h, 2 h / 22 e 0 h as espécies. Abstract in english Alternaria dauci and A. solani are fungal species known for h and 0 h / 24 h) were tested. The method developed in this study was difficult sporulation in culture media. This study had the objective of compared to the traditional procedure (BDA, 25 ºC, 12 h white / 12 verifying the influence of some [...] physical factors on mycelia growth h dark light and scratching of the colony). V8-agar medium, and sporulation of these two species. Culture media (BDA, oat and temperature of 25 ºC, NUV light and scratching of the colonies had a V8), temperature (15ºC, 20ºC, 25ºC, 30ºC and 35ºC), light wavelengths marked effect on growth and sporulation. The 12 h light / 12 h dark during incubation (yellow, blue, white, NUV, green, and red), injury photoperiod stimulated sporulation most. In general, longer dark types applied to the colony (scratching, UV, microwave irradiation, than light periods after the injury of the colony favored sporulation. and temperature of 100 ºC) and photoperiods (light / dark, respectively, The developed procedure is clearly superior to the traditional method of 24 h / 0 h, 22 h / 2 h, 17 h / 7 h, 12 h / 12 h, 7 h / 17 h, 2 h / 22 for growth and sporulation of both species.

Pablo, Pulz; Nelson S., Massola Jr..

2009-06-01

303

EVALUACIÓN DE LA CAPACIDAD BIOCONTROLADORA DE TRICHODERMA HARZIANUM RIFAI CONTRA FUSARIUM SOLANI (MART.) SACC. ASOCIADO AL COMPLEJO “SECADERA” EN MARACUYÁ, BAJO CONDICIONES DE INVERNADERO / EVALUATION OF THE BIOCONTROL CAPACITY OF TRICHODERMA HARZIANUM RIFAI AGAINST FUSARIUM SOLANI (MART.) SACC. ASSOCIATED TO THE COMPLEX “DRYER” IN PASSION FRUIT UNDER GREENHOUSE CONDITIONS  

Scientific Electronic Library Online (English)

Full Text Available En la zona bananera del Magdalena en Colombia se ha reportado una disminución del 30% en la producción del cultivo de maracuyá (Passiflora edulis var. flavicarpa) como consecuencia de la muerte de unidades productivas causadas por la enfermedad secadera o marchitez vascular, a la cual está asociada [...] el hongo Fusarium solani. Con el objeto de contribuir al manejo del problema sanitario, se evaluó bajo condiciones de invernadero el efecto biocontrolador de la cepa nativa TCN-014 y la cepa comercial TCC-005 de Trichoderma harzianum contra F. solani. Para el estudio se utilizaron plantas de dos meses de edad, establecidas en invernadero. Se ensayaron dos tiempos de aplicación del antagonista: 1. inoculando las plantas con el patógeno y cinco días después el antagonista. 2. inoculando primero el antagonista y cinco días después el patógeno. El experimento se estableció bajo un diseño experimental de bloques completos al azar con arreglo factorial 2x3, y los resultados fueron sometidos al análisis de varianza (ANOVA) y comparación de promedios mediante la prueba de rangos múltiples de Duncan, obteniéndose que al inocular primero el antagonista se presenta un mejor efecto biocontrolador de F. solani utilizando concentraciones de 106 y 108 conidias/mL tanto de la cepa nativa como comercial. Los resultados sugieren una acción efectiva de T. harzianum como biocontrolador de F. solani, mostrando que se pueden realizar estudios en campo que permitan desarrollar un bioproducto para el manejo ecológico de la marchitez en el cultivo de maracuyá. Abstract in english In the banana zone of Magdalena in Colombia has been reported a 30% decrease in crop production of passion fruit (Passiflora edulis var. Flavicarpa) due to the death of plants caused by the Dryer or vascular wilt disease, which is associated with the fungus Fusarium solani. In order to help manage o [...] f the disease was evaluated under greenhouse conditions the effect of the biocontrol strain native TCN-014 and CCL-005 commercial strain of Trichoderma harzianum against F. solani. For the evaluation were used plants with two months of age, set in the greenhouse; were tested two times of application of the antagonist: (1) inoculating the antagonist five days after of pathogen agent, and (2) inoculating the antagonist five days before the pathogen. The experiment was established under an experimental design of randomized blocks with 2x3 factorial arrangement, and data were submitted to analysis of variance (ANOVA) and comparison of averages using the multiple range test of Duncan. Results indicated that to inoculate the antagonist before the pathogen is obtained a better biocontrol effect of F. solani using concentrations of 106 and 108 conidia/ mL of both native and commercial strains. The results suggest an effective action of T. harzianum as a biocontrol of F. solani, showing that it can perform field studies in order to develop a byproduct for ecological management of wilt in cultivation of passion fruit.

Juan Guillermo, Cubillos Hinojosa; Alberto, Páez Redondo; Lauris, Mejía Doria.

2011-06-01

304

Reação de cultivares de soja à podridão vermelha da raiz causada por Fusarium solani f. sp. glycines  

Directory of Open Access Journals (Sweden)

Full Text Available A podridão vermelha da raiz, causada por Fusarium solani f. sp. glycines, é considerada uma das doenças mais severas de soja (Glycine max no Sul do Brasil. Este trabalho avaliou a reação de 30 genótipos de soja em experimentos conduzidos em câmara de crescimento, na Embrapa Trigo, Passo Fundo, RS. Inoculou-se o fungo nos genótipos pelo método "palito-de-dente", através da introdução de uma ponta de palito colonizada pelo fungo no hipocótilo de cada plântula e pelo método "grão de sorgo", em que o inóculo, constituído de grãos de sorgo (Sorghum bicolor colonizados, foi colocado ao redor do colo da planta. Avaliaram-se os sintomas na parte aérea e no sistema radicular. Para ambos métodos de inoculação, houve diferenças entre genótipos e a amplitude de reação variou de resistência moderada à alta suscetibilidade. Os genótipos BRS 66, BRS 137 e BRS 138, pelo método "palito-de-dente", e IAS 5 e BRS 137, pelo método "grão de sorgo", foram considerados moderadamente resistentes. Os genótipos Embrapa 59, CEP 12-Cambará, Ipagro 21, FT-Guaíra, FT-Abyara, BR-4 e FT-2003 foram moderadamente suscetíveis (MS pelo método "palito-de-dente", enquanto Ivorá, RS 7-Jacuí, Fepagro RS-10, BR-16, CD 203, BR-4, CEP 20-Guajuvira, BRS 154, BRS 138 e Cobb foram MS pelo método "grão de sorgo". Por outro lado, Bragg, CD 205, RS 5-Esmeralda, RS 9- Itaúba, IAS 4, Ocepar 14, CD 201, FT 2011, FT-Saray, BRS 153 e FT-2004 foram suscetíveis em ambos os métodos usados.

Gásperi Audir C.

2003-01-01

305

Mechanism by which contact with plant cuticle triggers cutinase gene expression in the spores of Fusarium solani f. sp. pisi  

International Nuclear Information System (INIS)

Spores of the phytopathogenic fungus Fusarium solani f. sp. pisi were shown to produce the extracellular enzyme, cutinase, only when cutin or cutin hydrolysate was added to the spore suspension. Dihydroxy-C16 acid and trihydroxy-C18 acid, which are unique cutin monomers, showed the greatest cutinase-inducing activity. Experiments with several compounds structurally related to these fatty acids suggested that both a omega-hydroxyl and a midchain hydroxyl are required for cutinase-inducing activity. Cutinase appeared in the medium 30-45 min after the addition of the inducers to the spore suspension, and the activity level increased for 6 hr. Addition of cycloheximide (5 ?g/ml) completely inhibited cutinase production, suggesting that protein synthesis was involved in the increase of cutinase activity. Immunoblot analysis with rabbit antibodies prepared against cutinase showed that cutinase protein increased in parallel with the increase in enzyme activity. Measurement of cutinase-specific RNA levels by dot-blot hybridization with 32P-labeled cutinase cDNA showed that the cutinase gene transcripts could be detected within 15 min after addition of the inducers. Addition of exogenous cutinase greatly enhanced the level of cutinase gene transcripts induced by cutin. These results strongly suggest that the fungal spore senses that it is in contact with the plant by the production of small amounts of cutin monomers catalyzed by the low level utin monomers catalyzed by the low level of cutinase carried by the spore and that these monomers induce the synthesis of cutinase needed for penetration of the fungus into the plant

306

Tolerancia in vitro de Fusarium solani y Fusarium semitectum (anamorfos, Ascomycota) a la exposición a desinfectantes de superfi cie utilizados en acuicultura  

Scientific Electronic Library Online (English)

Full Text Available Se evaluó in vitro el efecto del: acido acético (AcH), ácido acético tamponado (AcH+AcNa), ioduro de potasio (IK) y Iodopovidona (IP) sobre la tasa de crecimiento (TC) de Fusarium solani (Mart.) Sacc. 1881 y Fusarium semitectum Berk. & Ravenel, 1875. Ambas especies fueron aisladas de ovas de Odontes [...] thes bonariensis (Cuvier & Valenciennes, 1835). Las sustancias estudiadas son comúnmente utilizadas en acuicultura como desinfectantes de superfcie. Las concentraciones ensayadas con actividad fungicida para ambas cepas fueron mucho más elevadas que las correspondientes concentraciones letales medias a 96 horas (CL50-96h) para ovas de pejerrey. Concentraciones inferiores a la CL50 - 96h exhibieron un efecto fungistático escaso o nulo. Abstract in english In vitro tolerance of Fusarium semitectum and Fusarium solani (anamorphic, Ascomycota) exposed to surface disinfectant commonly used in aquaculture. An in vitro evaluation of the antifungal effect of acetic acid (AcH), buffered acetic acid (AcH+AcNa), potassium iodide (KI) and Iodopovidone (IP); on [...] the growth rate (GR) of Fusarium solani (Mart.) Sacc. 1881 and Fusarium semitectum Berk. & Ravenel, 1875 was performed. Both fungal species were isolated from eggs of the Argentinian silverside Odontesthes bonariensis (Cuvier & Valenciennes, 1835). The studied substances are commonly used in fsh farming as surface disinfectants. The tested concentrations of this substances exhibited antifungal activity for both strains at concentrations higher than their 96h median lethal concentrations (LC50-96h) for the treated eggs; concentrations below the (LC50-96h) exhibited little or no effect.

Suani G, Pacheco Marino; Marta N, Cabello; Alfredo, Salibián.

2013-08-01

307

Reduction of the 20-carbonyl group of C-21 steroids by spores of Fusarium solani and other microorganisms. I. Side-chain degradation, epoxide cleavage, and substrate specificity.  

Science.gov (United States)

The spores of Fusarium solani reduced the C(2)-carbonyl group, 1-dehydrogenated ring "A" and cleaved the side chain of 16alpha, 17alpha-oxidopregn-4-ene-3, 20-dione (16alpha, 17alpha-oxidoprogesterone)(I) to give the following products: 20alpha-hydroxy-16alpha, 17alpha-oxidopregn-4-en-3-one(II); 20alpha-hydroxy-16alpha, 17alpha-oxidopregna-1, 4-dien-3-one(III); 16alpha-hydroxy-17a-oxa-androsta-1, 4-diene-3, 17-dione (16alpha-hydroxy-1-dehydrotestololactone)(IV); and 16alpha, 17beta-dihydroxy-androsta-1, 4-dien-3-one (16alpha-hydroxy-1-dehydrotestosterone)(V). When II was used as a substrate, it was metabolized into III, IV, and V at a slower rate than I. Furthermore, 16alpha-hydroxy-androst-4-ene-3, 17-dione (16alpha-hydroxyandrostenedione)(X) was transformed into IV and V. Pregn-4-ene-3, 20-dione (progesterone)(XII) was transformed into androsta-1, 4-diene-3, 17-dione (androstadienedione)(VIII) and 17a-oxa-androsta-1, 4-diene-3, 17-dione (1-dehydrotestololactone)(IX), while 17alpha-hydroxy-pregn-4-ene-3, 20-dione (17alpha-hydroxyprogesterone)(VI) was converted into its 1-dehydro analogue (VII) without accumulation of any 20-dihydro compounds. Substrate specificity in the 20-reductase system of F. solani, Cylindrocarpon radicicola, Septomyxa affinis, Bacillus lentus, and three strains of B. sphaericus are demonstrated. The 20-reductase is active only on steroids having the 16alpha, 17alpha-oxido, and Delta(4)-3-keto functions. Evidence of competition between side-chain degrading enzymes and the 20-reductase for the steroid molecule and evidence of side-chain degradation followed by epoxide cleavage (and not the reverse) are presented. A mechanism for the epoxide opening by nongerminating spores of F. solani is postulated. PMID:5021973

Plourde, R; el-Tayeb, O M; Hafez-Zedan, H

1972-03-01

308

Phylogenetic relationships among members of the Fusarium solani species complex in human infections and the descriptions of F. keratoplasticum sp. nov. and F. petroliphilum stat. nov.  

DEFF Research Database (Denmark)

Fusarium species are frequently associated with mycotic keratitis and, to a lesser extent, cases of localized and disseminated infections. The Fusarium solani species complex (FSSC) is the most common group of fusaria associated with human infectious diseases. Several studies to date have revealed dozens of strongly supported phylogenetic species within this important evolutionary clade, though little work has been done to improve the taxonomy and understanding of the reproductive mode and phenotypes of the predominant clinically relevant species. Here we described Fusarium keratoplasticum sp. nov., and Fusarium petroliphilum stat. nov., two phylogenetic species that are among the most frequently isolated fusaria in plumbing drain biofilms and outbreaks of contact lens-associated mycotic keratitis. F. keratoplasticum isolates were highly variable and showed a range of morphological characteristics typical for most classical concepts of ‘F. solani.’ Many isolates failed to produce sporodochia and macroconidia.Although most attempts to sexually cross F. keratoplasticum isolates failed, a heterothallic sexual stage typical for the FSSC was discovered by pairing isolates of opposite mating type on V-8 agar, the ascospores of which showed molecular evidence of recombination. Secondary metabolite profiles of FSSC species defined through molecular data were compared for the first time and revealed the production of bioactive compounds including cyclosporines and several novel compounds of unknown function. We speculate that the inferred phenotypic variability in these species is the result of the almost entirely anthropogenic sources from which they are derived, including biofilms on plumbing systems.

Short, Dylan P.G.; O’Donnell, Kerry

2013-01-01

309

Preliminary evidence of the role of hydrogen peroxide in the degradation of benzo[a]pyrene by a non-white rot fungus Fusarium solani  

Energy Technology Data Exchange (ETDEWEB)

In order to study the enzymatic mechanisms involved in the successive steps of BaP degradation by a Deuteromycete fungus Fusarium solani, we developed an indirect approach by using inhibitors of enzymes. We used either specific inhibitors of peroxidases (i.e. salicylhydroxamic acid) and of cytochrome P-450 (i.e. piperonyl butoxyde) or inhibitors of both enzymes (i.e. potassium cyanide). Surprisingly, no expected decrease of BaP degradation was observed with most inhibitors tested. On the contrary, more BaP was degraded. Only butylated hydroxytoluene, which acts as a free radical scavenger, inhibited BaP degradation. The inhibition of these enzymes, which use H{sub 2}O{sub 2} as a cosubstrat, might have resulted in an increase of hydrogen peroxide availability in the fungal cultures. This enhancement could induce formation of reactive oxygen species (ROS) which might be the agents that initiate benzo[a]pyrene oxidation. This study proposed a hypothetic alternative metabolic pathway involved in PAH metabolism by Fusarium solani. - An alternative metabolic pathway was demonstrated.

Veignie, Etienne; Rafin, Catherine; Woisel, Patrice; Cazier, Fabrice

2004-05-01

310

Fusarium oxysporum AND Fusarium solani INOCULATION AND SHADING LEVELS IN THE ERVA-MATE: SEVERITY INFLUENCE OF THE ROOT-ROT  

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Full Text Available Ilex paraguariensis A. St.-Hill is a broadly cultivated species in the South of Brazil. With the increasing planted area, mainly in the last decade, fitosanitary problems caused by pest and diseases have increased in this crop, and the root-rot is becoming one of the main problems. Among the pathogens, Fusarium oxysporum Schlecht. and Fusarium solani (Mart. Sacc are the main ones. These fungi provoke severe damages resulting in the destruction of the root system and, in the most serious cases, they cause the death of the plant. It is suspected that the incidence and severity of disease are influenced by cultivation of Ilex paraguariensis in different levels of shading or full sun. Therefore, experiments were conducted in the Forest Nursery area belonging to Forest Sciences Department/CCR/UFSM with the objective of confirming this assumption. The experiment was conducted in a factorial design (2 x 5, composed by Fusarium oxysporum and Fusarium solani inoculation and by shading levels. It was verified that the plants submitted to lower shading levels or full sun had their predisposed to the disease.

Igor Poletto

2009-10-01

311

Preliminary evidence of the role of hydrogen peroxide in the degradation of benzo[a]pyrene by a non-white rot fungus Fusarium solani  

International Nuclear Information System (INIS)

In order to study the enzymatic mechanisms involved in the successive steps of BaP degradation by a Deuteromycete fungus Fusarium solani, we developed an indirect approach by using inhibitors of enzymes. We used either specific inhibitors of peroxidases (i.e. salicylhydroxamic acid) and of cytochrome P-450 (i.e. piperonyl butoxyde) or inhibitors of both enzymes (i.e. potassium cyanide). Surprisingly, no expected decrease of BaP degradation was observed with most inhibitors tested. On the contrary, more BaP was degraded. Only butylated hydroxytoluene, which acts as a free radical scavenger, inhibited BaP degradation. The inhibition of these enzymes, which use H2O2 as a cosubstrat, might have resulted in an increase of hydrogen peroxide availability in the fungal cultures. This enhancement could induce formation of reactive oxygen species (ROS) which might be the agents that initiate benzo[a]pyrene oxidation. This study proposed a hypothetic alternative metabolic pathway involved in PAH metabolism by Fusarium solani. - An alternative metabolic pathway was demonstrated

312

Genetic Diversity in the Fungus Fusarium solani f.sp. cucurbitae Race 1, the Casual Agent of Root and Crown Rot of Cucurbits in Iran, using Molecular Markers  

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Full Text Available Fusarium solani f.sp. cucurbitae race 1 is a pathogen on cucurbit plants. In this study genetic diversity among 26 isolates of Fusarium solani f.sp. cucurbitae race 1 was studied using Restriction Fragment Length Polymorphism (RFLP of ITS (Interal Transcribed Spacer regions and Random Amplified Polymorphic DNAs (RAPD markers. Outcome of digestion with six restriction enzymes including EcoR I, Rsa I, Bme 18I, Msp I, Hae III and Hind III, together with the patterns of restriction fragment length polymorphism of ITS regions divided the isolates into two groups. Deoxy Ribonuckin Acid DNA pattern was obtained for the isolates using 12 random primers and genetic distance between them was calculated and relationships (by cluster analysis determined. Among the primers used, seven primers showed polymorphism. Genetic distance between isolate pairs ranged from 0.03 to 0.48. Genetic diversity was high (e.g., the isolates were distributed into 10 genetic groups at a similarity percentage of 75. The lowest distance was observed between isolates 50 and 73 and the highest distance observed between isolates 50 and 73 with isolate 102. Restriction fragment length polymorphism results show diversity in ITS regions, without any correlation to geographic origin and RAPD. However, this genomic regions usually have high constancy in species, but in this study diversity was shown in ITS regions even for race 1. The data suggest that taxonomical situation of Foc race 1 probably needs revision.

M.R. Alymanesh

2009-01-01

313

Fusarium keratitis in South India: causative agents, their antifungal susceptibilities and a rapid identification method for the Fusarium solani species complex.  

Science.gov (United States)

Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the ?-tubulin (?-TUB) and translation elongation factor 1? (EF-1?) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum-equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF-1? gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (?64 ?g ml(-1) ). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds. PMID:23437826

Homa, Mónika; Shobana, Coimbatore S; Singh, Yendrembam R B; Manikandan, Palanisamy; Selvam, Kanesan P; Kredics, László; Narendran, Venkatapathy; Vágvölgyi, Csaba; Galgóczy, László

2013-09-01

314

Genome Sequence of Dickeya solani, a New soft Rot Pathogen of Potato, Suggests its Emergence May Be Related to a Novel Combination of Non-Ribosomal Peptide/Polyketide Synthetase Clusters  

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Full Text Available Soft rot Enterobacteria in the genera Pectobacterium and Dickeya cause rotting of many crop plants. A new Dickeya isolate has been suggested to form a separate species, given the name Dickeya solani. This bacterium is spreading fast and replacing the closely related, but less virulent, potato pathogens. The genome of D. solani isolate D s0432-1 shows highest similarity at the nucleotide level and in synteny to D. dadantii strain 3937, but it also contains three large polyketide/fatty acid/non-ribosomal peptide synthetase clusters that are not present in D. dadantii 3937. These gene clusters may be involved in the production of toxic secondary metabolites, such as oocydin and zeamine. Furthermore, the D. solani genome harbors several specific genes that are not present in other Dickeya and Pectobacterium species and that may confer advantages for adaptation to new environments. In conclusion, the fast spreading of D. solani may be related to the acquisition of new properties that affect its interaction with plants and other microbes in the potato ecosystem.

Linda Garlant

2013-12-01

315

Dose response of soilborne plant pathogens and Meloidogyne incognita to citrus-based experimental compounds.  

Science.gov (United States)

Two novel citrus-based compounds have been tested in vitro against Colletotrichum gleosporioides, Fusarium oxysporum, Sclerotinia sclerotiorum, Sclerotium rolfsii, Rhizoctonia solani, Verticillium albo-atrum, Pythium aphanidermatum, P. myriotilum, Phytophthora nicotianae and P. capsici. One of the...

316

Suppression of phytopathogenic fungi by hexane extract of Nepenthes ventricosa x maxima leaf.  

Science.gov (United States)

The hexane extract of Nepenthes ventricosa x maxima leaf exhibited antifungal activity against Alternaria alternata, Aspergillus niger, Bipolaris oryzae, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani, Rhizopus stolonifer var. stolonifer and Sclerotinia sclerotiorum. PMID:17573203

Shin, Kwang-Soo; Lee, Samkeun; Cha, Byeong Jin

2007-12-01

317

Effect of topical 0.5% povidone-iodine compared to 5% natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study / Efeito tópico de iodo-povidona 0,5% comparado com natamicina 5% em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5% em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de [...] tratamento: Grupo I (iodo-povidona) - tratados com iodo-povidona 0,5%; Grupo II (natamicina) - tratados com natamicina 5%; Grupo III (controle) - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC). Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de coelhos nos quais não houve crescimento de colônias. Entretanto, não houve diferença estatística significante entre os 3 grupos quando se analizou o número de UFC (p>0,05). CONCLUSÃO: Este estudo demonstrou considerações metodológicas importantes na utilização de modelos animais para o teste de agentes antifúngicos. Usando a metodologia de contar UFC e com este tamanho amostral, administração tópica de iodo-povidona 0,5% não demonstrou benefício do tratamento de ceratite fúngica experimental causada por Fusarium solani quando comparado com a administração tópica de natamicina 5%. Abstract in english PURPOSE: To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different tre [...] atment groups: Group I (povidone-iodine) - treated with topical 0.5% povidone-iodine; Group II (natamycin) - treated with topical 5% natamycin; and Group III (control) - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU) was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05). CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5% povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5% natamycin.

Lauro Augusto de, Oliveira; Thales Takeo, Takata; Alvio Isao, Shiguematsu; Luiz Alberto Soares, Melo Júnior; Olga Fischman, Gompertz; Luciene Barbosa de, Sousa; Mark J., Mannis.

2008-12-01

318

Effect of topical 0.5% povidone-iodine compared to 5% natamycin in fungal keratitis caused by Fusarium solani in a rabbit model: a pilot study Efeito tópico de iodo-povidona 0,5% comparado com natamicina 5% em ceratites fúngicas causadas por Fusarium solani em um modelo animal de coelhos: estudo piloto  

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Full Text Available PURPOSE: To evaluate the efficacy of topical administration of 0.5% povidone-iodine in experimental Fusarium solani keratitis in rabbits. METHODS: Fungal keratitis caused by Fusarium solani was induced in the right eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Group I (povidone-iodine - treated with topical 0.5% povidone-iodine; Group II (natamycin - treated with topical 5% natamycin; and Group III (control - treated with topical saline solution. In all groups the rabbits were treated for three days and then sacrificed. The corneas were excised, macerated and immersed in 10 mL BHI. Culture samples were plated daily on Sabouraud's agar for 7 days, and the number of colony-forming units (CFU was counted. The rabbits were clinically evaluated during the treatment period. RESULTS: The povidone-iodine and natamycin groups demonstrated better efficacy than the control group based on the number of rabbits with no colonies growing. However, there were no statistically significant differences between the three groups when the number of CFU was analyzed (p>0.05. CONCLUSIONS: Our study demonstrates important methodological considerations in the use of in vivo animal models for the testing of antifungal agents. Using this sample size and methodology of counting CFU, topical 0.5% povidone-iodine demonstrated no benefit in the treatment of experimental Fusarium solani when compared with topical 5% natamycin.OBJETIVO: Avaliar a eficácia do uso tópico de iodo-povidona 0,5% em ceratite experimental por Fusarium solani em coelhos. MÉTODOS: Ceratite fúngica por Fusarium solani foi induzida no olho direito de 24 coelhos da raça New Zealand. Os coelhos foram divididos aleatoriamente em 3 diferentes grupos de tratamento: Grupo I (iodo-povidona - tratados com iodo-povidona 0,5%; Grupo II (natamicina - tratados com natamicina 5%; Grupo III (controle - tratados com solução salina. Os coelhos dos 3 grupos foram tratados por 3 dias e sacrificados em seguida. As córneas foram removidas cirurgicamente, maceradas e incubadas em meio BHI. Semeou-se culturas em placas de ágar Sabouraud, diariamente, durante 7 dias, e contou-se o número de unidades formadoras de colônias (UFC. Os coelhos foram avaliados clinicamente durante o período de tratamento. RESULTADOS: Os grupos iodo-povidona e natamicina demonstraram melhor eficácia do que o grupo controle considerando-se o número de coelhos nos quais não houve crescimento de colônias. Entretanto, não houve diferença estatística significante entre os 3 grupos quando se analizou o número de UFC (p>0,05. CONCLUSÃO: Este estudo demonstrou considerações metodológicas importantes na utilização de modelos animais para o teste de agentes antifúngicos. Usando a metodologia de contar UFC e com este tamanho amostral, administração tópica de iodo-povidona 0,5% não demonstrou benefício do tratamento de ceratite fúngica experimental causada por Fusarium solani quando comparado com a administração tópica de natamicina 5%.

Lauro Augusto de Oliveira

2008-12-01

319

Fusarium solani breast abscess  

OpenAIRE

An unusual manifestation of breast fusariosis was encountered in a 55-year-old female diabetic patient. Two fine needle aspirates (FNA) from the abscess were done at three days interval and they showed hyaline, septate, branched, fungal hypahe in 10% potassium hydroxide mount. Fungal infection was confirmed by demonstrating the fungal hyphae in the midst of lymphocytes, macrophages and neutrophils in Leishman stained smears. Culture of both FNAs yielded a heavy and pure growth of Fusa...

Anandi V; Vishwanathan P; Sasikala S; Rangarajan M; Subramaniyan C; Chidambaram N

2005-01-01

320

Biological Control of Tomato Seedling Damping off with Streptomyces sp.  

OpenAIRE

Twenty six antibiotic producing Streptomyces were isolated from soils of Cuddalore Tamil Nadu, India and were evaluated for their ability to inhibit plant pathogenic Rhizoctonia solani in vitro. It was found that the isolates having pathogenic inhibitory ability and also controls Rhizoctonia solani damping off in tomato in interested field soils. The Streptomyces isolates tested significantly reduced damping off severity in tomato. A variation in their effect on plant disease severity, percen...

Dhanasekaran, D.; Sivamani, P.; Panneerselvam, A.; Thajuddin, N.; Rajakumar, G.; Selvamani, S.

2005-01-01

321

Synthesis, characterization, and biological activity of a new class of dialkylphosphorylhydrazone derivatives of isatin  

Scientific Electronic Library Online (English)

Full Text Available Sixteen dialkylphosphorylhydrazones were synthesized by condensation of phosphorylhydrazines with substituted isatins. Products were characterized by FTIR, ¹H-NMR, 13C-NMR, and 31P-NMR. Fungicidal activities of these compounds against Rhizoctonia solani and Fusarium oxysporum were also evaluated. So [...] me compounds inhibited the growth of Rhizoctonia solani and Fusarium oxysporum by 43% and 51%, respectively. These compounds exhibited no effects on germination of lettuce seeds (Lactuca sativa L).

Letícia Silotti, Zampirolli; Marcela Jacques de, Lemos; Vinícius Tomaz, Gonçalves; Marco Andre Alves de, Souza; Sonia Regina de, Souza; Victor Marcos, Rumjanek; João Batista Neves, DaCosta.

2014-07-01

322

Morphological characterization of aerial hypahe and simulation growth of Fusarium solani under different carbon source for application in the hydrofobic VOCs biofiltration / Caracterización morfológica de hifas aéreas y simulación del crecimiento de Fusarium solani bajo diferentes fuentes de carbono para su aplicación en la biofiltración de COVs hidrofóbicos  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Este trabajo presenta el efecto de diferentes fuentes de carbono (glicerol, 1-hexanol y n-hexano) sobre la morfología de las hifas aéreas del hongo filamento Fusarium solani para su aplicación en la biofiltración de compuestos orgánicos volátiles (COVs). Un modelo matemático que combina parámetros m [...] icroscópicos y macroscópicos que describen el crecimiento del micelio del hongo fue desarrollado y verificado. Análisis de imágenes de los microcultivos y cultivos en placas de agar fue realizado para determinar los parámetros morfológicos. Los resultados muestran que las fuentes de carbono hidrofóbicas y volátiles modifican la morfología de Fusarium solani, esto está asociado con la mejor utilización de la fuente de carbono volátil. Los principales cambios morfológicos observados con glicerol y n-hexano, fueron la reducción en ambos diámetros de las hifas (desde 2.99+0.29 ?m a 2.01+0.35 ?m) y la longitud promedio de la hifa (desde 603.8+48.3 ?m a 280.1+36.6 ?m). Éstos resultados indican un aumento en el Área de transporte para la misma cantidad de biomasa como una respuesta de adaptación para aumentar la captación de los sustratos hidrofóbicos volátiles. Abstract in english This work presents the effect of different carbon sources (glycerol, 1-hexanol and n-hexane) over the morphology of the aerial hyphae of the filamentous fungus Fusarium solani for its application in the biofiltration of volatile organic compounds (VOCs). A mathematical model was developed and furthe [...] r verified that combines microscopic and macroscopic parameters describing the mycelial fungal growth. Image analysis of microcultures and culture in agar dishes was performed to determine the morphological parameters. Theresults show that the hydrophobic and volatile carbon rources modified the morphology of Fusarium solani, this is associated with thebettor utilization of the volatile carbon source. The main morphology changes observed with glycerol and n-hexane, were the reduction in both the hyphal diameter (from 2.99+0.29 ?m to 2.01+0.35 ?m) and the average hyphal length (from 603.8+48.3 ?m to 280. 1+36.6 ?m). These results indicate an increase in the transport area for the same amount of biomass as an adaptation response to increase the uptake of volatile hydrophobic substrates.

A., Vergara-Fernández; S., Hernández; J., San Martín-Davison; S., Revah.

2011-08-01

323

Unravelling Effects of Temperature and Soil Moisture Stress Response on Development of Dry Root Rot [Rhizoctonia bataticola (Taub.] Butler in Chickpea  

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Full Text Available Erratic rainfalls and rise in temperature have become more frequent under the changing scenario of climate particularly in semiarid tropics. As a consequence of it, a drastic shift of chickpea diseases have been recorded throughout the major chickpea growing regions in India and elsewhere. Dry root rot (DRR caused by Rhizoctonia bataticola (Taub. Butler [Pycnidial stage: Macrophomina phaseolina (Tassi Goid] was found as a potentially emerging constraint to chickpea production than wilt (Fusarium oxysporum f. sp. ciceris. Increasing incidence of DRR indicate strong influence of c