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Sample records for cercosporiose cercospora coffeicola

  1. Caracterização patogênica, morfológica, fisiológica, molecular e sensibilidade a fungicida de Cercospora coffeicola

    OpenAIRE

    Lombardi, Ana Paula Zimbardi [UNESP

    2002-01-01

    A cercosporiose do cafeeiro, causada por Cercospora coffeicola Berk e Cooke, é uma doença importante porque prejudica o desenvolvimento do cafeeiro, principalmente em condições de viveiro, pela intensa desfolha, raquitismo e atraso no crescimento. Em 1998, notou-se, em uma propriedade em Santa Juliana, Minas Gerais, intensa desfolha de plantas no campo e presença de manchas grandes e típicas daquelas causadas por Cercospora, e os exames das lesões mostraram conídios longos, mais finos na sua ...

  2. Proteção do cafeeiro contra cercosporiose por acibenzolar-S-metil e proteína harpina Protection of coffee plants against brown eye spot by acibenzolar-S-methyl and harpin protein

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    Diogo Manzano Galdeano

    2010-07-01

    Full Text Available O objetivo deste trabalho foi avaliar, em cafeeiro suscetível, a proteção contra a cercosporiose, pela aplicação da proteína harpina e acibenzolar-S-metil (ASM, e avaliar seu efeito na germinação de conídios e crescimento micelial in vitro. No primeiro experimento, cafeeiros tratados com ASM (25, 50, 100, 200 μg mL-1 receberam o inóculo de uma suspensão de conídios de Cercospora coffeicola, e a severidade da doença foi avaliada aos 30 e 60 dias após a inoculação. No segundo experimento, cafeeiros foram aspergidos com harpina (7,5, 15, 30, 60, 120 μg mL-1, tendo-se utilizado o mesmo procedimento. No terceiro experimento, plantas aspergidas previamente com ASM (200 μg mL-1 ou harpina (15 μg mL-1 foram tratadas novamente com esses produtos, aos 30 dias após terem recebido inóculo do patógeno. ASM e harpina protegeram os cafeeiros contra cercosporiose 30 dias após a inoculação com C. coffeicola. Entretanto, 60 dias após a inoculação, apenas o ASM (200 μg mL-1, com uma ou duas aplicações, protegeu as plantas contra C. coffeicola. Os cafeeiros foram protegidos contra cercosporiose, em reaplicação de harpina, 30 dias após o primeiro tratamento com essa proteína. Harpina e acibenzolar-S-metil não inibiram o desenvolvimento micelial nem a germinação in vitro dos conídios do patógeno.The objective of this work was to evaluate the protective effect of harpin protein and acibenzolar-S-methyl (ASM against brown eye spot, in coffee plants, and its effect on in vitro conidial germination and mycelial growth of Cercospora coffeicola. In the first assay, plants treated with ASM (25, 50, 100, 200 μg mL-1 received the inoculum of a C. coffeicola conidial suspension, and the disease severity was evaluated 30 and 60 days after inoculation. In the second assay, plants were sprayed with harpin (7.5, 15, 30, 60, 120 μg mL-1 following the same procedure. In a third trial, plants previously sprayed with ASM (200 μg mL-1 or

  3. Elaboração e validação de escala diagramática para a cercosporiose do pimentão Development and validation of a diagrammatic key for Cercospora leaf spot of sweet pepper

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    Sami Jorge Michereff

    2006-09-01

    Full Text Available A cercosporiose do pimentão, causada pelo fungo Cercospora capsici, é uma importante doença que ocorre em condições tropicais. Devido à inexistência de métodos padronizados para quantificação desta doença em campo, uma escala diagramática com os níveis de 1,5; 3,5; 8,0; 16,5; 31,0 e 50% de área foliar lesionada foi elaborada e testada para a acurácia, a precisão e a reprodutibilidade das estimativas de severidade da cercosporiose do pimentão, sem e com a sua utilização. Na validação da escala diagramática, 50 folhas com diferentes níveis de severidade da doença, mensurados previamente com o programa AutoCAD®, foram avaliadas por 13 avaliadores, sem e com a utilização da escala diagramática. Foram realizadas duas avaliações com utilização da escala, com intervalo de sete dias, onde seqüências diferentes das mesmas folhas foram estimadas visualmente pelos mesmos avaliadores. A acurácia e a precisão de cada avaliador foi determinada por regressão linear simples, entre a severidade real e a estimada. Sem a escala, oito avaliadores superestimaram significativamente a severidade da doença. Com a escala, os avaliadores obtiveram melhores níveis de acurácia e precisão, embora quatro tendessem a superestimar a severidade, com os erros absolutos concentrando-se abaixo de 10%. Os avaliadores apresentaram boa repetibilidade e elevada reprodutibilidade das estimativas com a utilização da escala, o mesmo não sendo verificado sem a utilização desta. A escala diagramática proposta mostrou-se adequada para avaliação da severidade da cercosporiose do pimentão.Cercospora leaf spot of sweet pepper caused by the fungus Cercospora capsici is an important disease occurring in tropical conditions. Due to the inexistence of standard methods to quantify this disease in field conditions, a diagrammatic key including the levels 1.5, 3.5, 8.0,16.5, 31.0 and 50.0% of diseased leaf area was elaborated and tested for accuracy

  4. Citronella essential oil in the control and activation of coffee plants defense response against rust and brown eye spot Óleo essencial de citronela no controle e na ativação de respostas de defesa do cafeeiro contra a ferrugem e cercosporiose

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    Ricardo Borges Pereira

    2012-08-01

    Full Text Available The rust and brown eye spot are the main coffee diseases. The losses are due to intense defoliation of plants, which has reduced its production and longevity. The brown eye spot also occurs in fruits, with negative effects on the beverage quality. Some essential oils have presented promising results in the control of plant diseases, as an alternative to the use of fungicides. The objective of this study was to evaluate citronella essential oil in the control of rust and brown eye spot and in the activation of coffee plants defense responses. Twelve-month-old plants were sprayed with citronella oil 1000 µL L-1, acibenzolar-S-methyl 200 mg L-1 and tebuconazole fungicide 200 mg L-1. Plants were inoculated with Hemileia vastatrix and Cercospora coffeicola seven days later. The application was repeated after 30 days. Plants with five months were sprayed with the same treatments to assess the induced defense responses. Citronella oil controlled rust and brown eye spot with efficiencies of 47.2% and 29.7%, respectively, while tebuconazole presented control of 96.5% and 90.5%, respectively. Acibenzolar-S-methyl reduced brown eye spot by 55.9% and showed no significant control of rust. Citronella oil increased peroxidase and chitinase activities in five months coffee plants 336, and 24 and 336 hours after spraying, respectively. Acibenzolar-S-methyl increased peroxidase, chitinase and ββ-1,3-glucanase activities 192, 288 and 336; 24 and; 240 hours after spraying, respectively. The treatments did not increase accumulation of phenols, but a significant increase in lignin was observed in plants sprayed with citronella oil.A ferrugem e a cercosporiose são as principais doenças de cafeeiro. Os prejuízos se devem a intensa desfolha das plantas que têm sua produção e longevidade reduzidas. A cercosporiose também ocorre nos frutos, com reflexos negativos na qualidade da bebida. Alguns óleos essenciais têm apresentado resultados promissores no

  5. Progresso da ferrugem e da cercosporiose em cafeeiro (coffea arabica l. Com diferentes épocas de início e parcelamentos da fertirrigação Progress of coffee rust and brown eye spot with differents periods at initial irrigation and fertirrigation time

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    Viviane Talamini

    2003-02-01

    Full Text Available Avaliações da incidência da ferrugem (Hemileia vastatrix Berk. & Br. e da cercosporiose (Cercospora coffeicola Berk. & Cooke foram realizadas em experimento com a cultura do café cultivar 'Catuai', com 12 anos de cultivo. Os objetivos foram avaliar o efeito da irrigação e da fertirrigação na incidência da ferrugem e da cercosporiose, analisar a curva de progresso dessas doenças e sua correlação com as variáveis climáticas. O delineamento experimental foi o de blocos ao acaso, com 4 tratamentos de diferentes parcelamentos de adubação (1: 12 aplicações manuais, 2: 12 aplicações via fertirrigação, 3: 24 aplicações fertirrigado, 4: 36 aplicações fertirrigado. As parcelas foram divididas em 3 subparcelas com diferentes épocas de início de irrigação (subparcelas A: 1º de junho, B: 15 de julho, C: 1º de setembro e 2 tratamentos adicionais (testemunhas: tratamento adicional 1- fertirrigação parcelada em 4 vezes e não irrigado; tratamento adicional 2- adubação convencional, não irrigado. Observou-se a incidência de ambas as doenças em 6 folhas por planta a cada 14 dias durante o período de 21 de março de 1998 a 6 de fevereiro de 1999. Calculou-se a área abaixo da curva de progresso da doença (AACPD, procedendo-se à análise de variância e teste de Tukey a 5%. Para a ferrugem do cafeeiro, nenhum tratamento foi significativo, e as incidências máximas foram nos meses de julho a setembro. Houve correlação significativa entre todos os tratamentos e as variáveis climáticas, com exceção da temperatura máxima. Para a cercosporiose, observou-se nas parcelas, maior AACPD para os tratamentos 2 e 4. O tratamento adicional 1 apresentou maior AACPD, seguida pelo tratamento adicional 2 . De acordo com as curvas de progresso da doença, a incidência máxima foi entre maio a setembro. Houve correlação significativa da incidência da cercosporiose com as variáveis climáticas na maioria dos tratamentos

  6. Epidémiologie de la cercosporiose de la laitue (Lactuca sativa L.) en République de Côte d'Ivoire : étude de quelques étapes du cycle épidémiologique

    OpenAIRE

    Savary, Serge

    1983-01-01

    La cercosporiose de la laitue, due à #Cercospora longissima$ Sacc., est responsable de pertes considérables en Côte d'Ivoire. Cette étude apporte des précisions sur quelques étapes du cycle du parasite. En l'absence de rotations culturales, l'inoculum primaire semble provenir au moins en partie du sol, sous une forme qui reste à déterminer. Il paraît être disséminé par effet de rejaillissement des gouttes d'eau de pluie ou d'arrosage contre le sol, sur les feuilles ("splashing"). Les conidies...

  7. FORMAS DE PENETRAÇÃO DO GÊNERO CERCOSPORA

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    PAULA, Paulo Victor Augusto Azevedo de

    2015-11-01

    Full Text Available The genus Cercospora has species that cause diseases in important crops causing yield losses worldwide. These pathogens are commonly associated with leaf spot symptoms, but can cause injury of flowers, fruits, bracts, pedicels and seeds in various plant families. This review aims to describe the different forms of penetration of the genus Cercospora, causing diseases in crops of commercial importance, such as C. beticola in sugar beet, cassava in C. heningsii, C. coffeicola in coffee, C. sojina in soybean, C. zeae-maydis in corn, C. ricinella in castor and C. kikuchii in soybean. The penetration may occur through the stomata of the leaf of the host can also occur through the epidermal tissue injury and which occur by physical force and/or the action of enzymes directly through the epidermis of the host body. And for the development of the germ tube, different species may develop one or more germ tubes. Then, Cercospora spp has different ways of penetration depending of your host. O gênero Cercospora destaca-se por ser o agente etiológico de doenças em importantes culturas acarretando perdas de produção em todo o mundo. Esses patógenos comumente estão associados a sintomas de manchas foliares, mas podem causar lesões em flores, frutos, brácteas, sementes e pedicelos em diversas famílias de plantas. Essa revisão tem como objetivo descrever as diferentes formas de penetração de espécies do gênero Cercospora, agentes etiológicos de doenças em culturas de grande importância comercial, como C. beticola em beterraba, C. heningsii em mandioca, C. coffeicola em cafeeiro, C. sojina em soja, C. zeae-maydis em milho, C. ricinella em mamona e C. kikuchi em soja. A penetração pode ocorrer através dos estômatos das folhas dos hospedeiros, também pode ocorrer através de ferimentos nos tecidos da epiderme e ainda por força física e/ou ação de enzimas diretamente através da epiderme do órgão do hospedeiro. E em relação ao tubo

  8. Distinct species exist within the Cercospora apii morphotype

    NARCIS (Netherlands)

    Groenewald, M.; Groenewald, J.Z.; Crous, P.W.

    2005-01-01

    The genus Cercospora is one of the largest genera of hyphomycetes. Cercospora apii sensu lato is the oldest name for a large complex of morphologically indistinguishable Cercospora spp. occurring on a wide host range. There are currently 659 recognized Cercospora spp., and names of another 281 morph

  9. Cercospora leaf spot: monitoring and managing fungicide resistance in populations of Cercospora beticola in Michigan

    Science.gov (United States)

    Cercospora leaf spot (CLS, Cercospora beticola) is the most serious foliar disease of sugarbeet in Michigan and Ontario.Management of CLS depends on timely fungicide applications, disease forecasting prediction models and the use of CLS resistant sugar beet varieties. Fungicides have a dominant role...

  10. Electrophoretic karyotype of Cercospora kikuchii.

    Science.gov (United States)

    Hightower, R C; Callahan, T M; Upchurch, R G

    1995-02-01

    Classical genetic analyses are not possible with the phytopathogenic fungus Cercospora kikuchii since no sexual stage has been identified. To facilitate gene mapping and to develop an understanding of the genome organization of C. kikuchii, an electrophoretic karyotype has been obtained using contour-clamped homogeneous electric field gel electrophoresis (CHEF). Eight chromosomes, two of which migrate as a doublet, have been separated into seven bands ranging from 2.0 to 5.5 Mb. Using this determination of chromosome number and size, the total genome size of C. kikuchii is estimated to be 28.4 Mb. In addition, genes encoding tubulin, ribosomal DNA, and four previously isolated light-enhanced cDNAs from C. kikuchii were assigned to chromosomes by Southern-hybridization analysis of CHEF blots.

  11. Effect of crop density of two genotypes of maize in the severity of gray leaf spot and yield in the second season cropInfluência da densidade de cultivo de dois genótipos de milho na severidade da mancha de cercospora e no rendimento de grãos na safrinha

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    Luis Gustavo Amorim Pessoa

    2012-08-01

    Full Text Available Among the diseases that affect the corn crop and can reduce the yield, there is cercospora gray leaf, caused by Cercospora spp. This disease is very important in the second season crop or ‘safrinha’. The objective of this study was to evaluate the severity of cercospora leaf spot in transgenic corn hybrids Agroceres Yieldgard AG 9010 YG and Advance NK Agrisure TL (Bt11, using two plant densities: 78,000 and 100,000 plants per hectare. The results showed that the higher density of plants increased the severity of the disease and provided a lower yield. There was no significant interaction between hybrids and severity of the disease. Entre as doenças que incidem na cultura do milho e podem reduzir seu rendimento, há a mancha de cercospora, causada por Cercospora spp., especialmente importante em milho de segunda época, ou ‘safrinha’. O objetivo deste trabalho foi avaliar a severidade da cercosporiose em nos híbridos transgênicos de milho Agroceres Yieldgard AG 9010 YG e Advance NK Agrisure TL (Bt11, em duas densidades de cultivo: 78.000 e 100.000 plantas por hectare. Os resultados permitiram constatar que a menor densidade de plantas favoreceu o incremento da severidade da doença e proporcionou menor rendimento de grãos. Não houve interação significativa entre os híbridos e a severidade da doença.

  12. Aerobiologia de Cercospora kikuchii Aerobiology of Cercospora kikuchii

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    Ângela Sathiko Kudo

    2011-10-01

    Full Text Available Neste estudo, foram quantificados os conídios de Cercospora kikuchii [crestamento foliar em soja (Glycine max] presentes no ar, sua relação com a intensidade da doença e com os fatores ambientais [temperatura, umidade relativa do ar (UR, precipitação e molhamento foliar] no período de novembro a março de 2006/07 e 2007/08 em Brasília, DF. Para tanto, foi instalada uma armadilha volumétrica capta-esporos 'Burkard' de sete dias em campo experimental com soja. Houve maior captura de conídios no período diurno, com mais de 60% dos esporos coletados entre 8h e 15h. Os dados climáticos variaram de acordo com a safra, mas, de modo geral, em ambos os experimentos, o período de maior captura de esporos ocorreu quando houve redução da precipitação e do molhamento foliar. A UR acima de 80% e temperatura entre 20 e 24°C foram mais favoráveis para a captura de conídios e a intensidade do crestamento foliar. Nos dois anos de avaliação, a maior quantidade de esporo capturado ocorreu quando a soja se apresentava no estádio R6-R7, assim como a intensidade da doença foi maior após o início do estágio reprodutivo da cultura. Apesar da quantidade de conídio capturado em 2006/07 ter sido maior que em 2007/08, o padrão da flutuação aérea de conídios foi semelhante.The objective of this study was to evaluate the relation of airborne released conidia of Cercospora kikuchii [cercospora leaf blight of soybean (Glycine max] with the disease intensity and some environmental factors [temperature, relative humidity (RH, precipitation and leaf wetness period under experimental field conditions in Brasília, DF, Brazil. The evaluation was from November to March of 2006/07 and 2007/08. Data for the amount of airborne conidia were collected using a Burkard's seven-day volumetric spore trap set in a field with soybean. Most of the conidia were collected during the day, with over 60% of the spores collected between 8h and 15h. Climatic data varied

  13. Controle químico da Cercosporiose, Mancha-Branca e dos Grãos Ardidos em milho

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    André Humberto Brito

    2013-10-01

    Full Text Available Este trabalho foi realizado com o objetivo de avaliar os efeitos da aplicação de fungicida, no controle da Cercosporiose e da Mancha-Branca do milho, e suas consequências na produtividade de grãos e na incidência de grãos ardidos, além de estabelecer a relação existente entre a produtividade de grãos e a severidade dessas doenças. Dois experimentos distintos (com Azoxystrobina + Cyproconazole e tratamento controle foram conduzidos em três locais, no ano agrícola de 2007/2008. Utilizaram-se 12 híbridos comerciais de milho, que foram avaliados em delineamento de blocos casualizados, com três repetições. Foram realizadas cinco avaliações da severidade das doenças Cercosporiose e Mancha-Branca, por meio de escala de notas, variando de 1 (altamente resistente a 9 (altamente susceptível. Estimou-se a área abaixo da curva de progresso da doença (AACPD. A aplicação de fungicida é eficiente no controle de doenças foliares e na redução da incidência de grãos ardidos, além de proporcionar 12% de aumento na produtividade de grãos, em relação à do tratamento controle. As doenças foliares Cercosporiose e Mancha-Branca reduzem a produtividade de grãos de milho e essa redução é maior quando as doenças ocorrem mais precocemente. A Cercosporiose provoca maior redução na produtividade de grãos, quando comparada com a Mancha-Branca.

  14. Distinct Species Exist Within the Cercospora apii Morphotype.

    Science.gov (United States)

    Groenewald, Marizeth; Groenewald, Johannes Z; Crous, Pedro W

    2005-08-01

    ABSTRACT The genus Cercospora is one of the largest genera of hyphomycetes. Cercospora apii sensu lato is the oldest name for a large complex of morphologically indistinguishable Cercospora spp. occurring on a wide host range. There are currently 659 recognized Cercospora spp., and names of another 281 morphologically identical species are included in the synonymy of C. apii sensu lato. Two of the species that belong to the C. apii complex, C. apii and C. beticola, cause Cercospora leaf spot on Apium graveolens (celery) and Beta vulgaris (sugar beet), respectively. In the present study, multilocus sequence data, amplified fragment length polymorphism analysis, and cultural characteristics were used as additional features to characterize morphologically similar Cercospora strains occurring on celery and sugar beet. From the data obtained, it is shown that C. apii and C. beticola, although morphologically similar and able to cross-infect each others' hosts, are distinct functional species that should be retained as separate entities. Furthermore, a third, as yet undescribed species of Cercospora was detected in celery fields in Korea and Venezuela, suggesting that additional undescribed species also may be found to cause Cercospora leaf spot on celery. A polymerase chain reactionbased diagnostic protocol distinguishes all three Cercospora spp.

  15. Controle genético da resistência da soja à raça 4 de Cercospora sojina

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    Martins Filho Sebastião

    2002-01-01

    Full Text Available O objetivo deste trabalho foi estudar o controle genético da resistência à Cercospora sojina, em populações segregantes derivadas do cruzamento entre as cultivares de soja Paraná e Bossier. Foram avaliadas nos genitores e nas gerações F1, F2, RC1 e RC2 seis características das plantas associadas com a doença: nota para infecção (NT; número de lesões por folíolo (NLF; diâmetro médio de lesão (DML; porcentagem de área foliar lesionada (PAFL; número de lesões por cm² (NLC e índice de doença (ID. A resistência da soja à cercosporiose comportou-se como um caráter quantitativo, e o efeito gênico aditivo o mais importante. As influências sobre NT foram as seguintes: efeito aditivo (62,05%, efeito da dominância (7,68% e as interações epistáticas aditiva x aditiva, aditiva x dominante e dominante x dominante (7,32%. O modelo aditivodominante foi suficiente para explicar as variações somente nos caracteres PAFL e NLC. A influência dos efeitos das interações epistáticas variaram de 2,22% no caráter PAFL e em até 30,78% no caráter DML. O modelo genético aditivo-dominante é satisfatório para explicar o comportamento da média das gerações em relação aos caracteres PAFL e NLC. Entretanto, quanto a NT, NLF, DML e ID, o modelo aditivo-dominante-epistático é o mais adequado.

  16. Is morphology in Cercospora a reliable reflection of generic affinity?

    NARCIS (Netherlands)

    Bakhshi, Mounes; Arzanlou, Mahdi; Babai-Ahari, Asadollah; Groenewald, Johannes Z.; Crous, Pedro W.

    2015-01-01

    Cercospora (Mycosphaerellaceae) is a large genus of fungi comprising many important plant pathogens. In recent years DNA-based studies have revealed multiple genera of cercosporoid fungi being poly- and paraphyletic. Among these genera, the genus Cercospora has always been perceived as monophyletic.

  17. Molecular basis of fungicide resistance in Cercospora beticola

    Science.gov (United States)

    Cercospora leaf spot (CLS), caused by the fungus Cercospora beticola, is the most important foliar disease of sugarbeet. Control measures include the application of sterol demethylation inhibitor (DMI) and quinone outside inhibitor (QoI) fungicides. Understanding the molecular mechanism of fungici...

  18. Species concepts in Cercospora: spotting the weeds among the roses

    NARCIS (Netherlands)

    Groenewald, J.Z.; Nakashima, C.; Nishikawa, J.; Shin, H.D.; Park, J.H.; Jama, A.N.; Groenewald, M.; Braun, U.; Crous, P.W.

    2013-01-01

    The genus Cercospora contains numerous important plant pathogenic fungi from a diverse range of hosts. Most species of Cercospora are known only from their morphological characters in vivo. Although the genus contains more than 5 000 names, very few cultures and associated DNA sequence data are avai

  19. THE PRODUCTIVITY OF SUGAR BEET MONOGERM LINES DEPENDING ON CERCOSPORA (Cercospora beticola Sacc. SUSCEPTIBILITY

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    Andrija Kristek

    2003-06-01

    Full Text Available The producing values of monogerm CMS lines of sugar beet and their tolerance on cercospora leaf spot are investigated in Osijek during two years (2001, 2002 under the following conditions: natural infection and full protection with fungicides. The parameters for evaluation were root quality and yield, just as visual review of leaf damages. Twenty eight genetically divergent CMS lines and two standards were confirmed by the examinations. The test results indicate achieved progress in breeding and monogerm CMS lines value which can be used for obtaining new hybrids and further improvements. Three investigated lines achieved high root yield on the level of standards and even ten lines had the same or higher digestion than better standard. It was found out that in the case of fungicide apply, root yield increased on the average by 7.09 t/ha (16%, sugar content by 0.81% (rel. 5% and sugar yield by 1.38 t/ha (22.8%. Protection measures with fungicides had higher influence on production results of line being susceptible to cercospora and compared to cercospora tolerant lines.

  20. More Cercospora Species Infect Soybeans across the Americas than Meets the Eye

    OpenAIRE

    Ana Paula Gomes Soares; Eduardo A Guillin; Leandro Luiz Borges; da Silva, Amanda C. T.; Almeida,Álvaro M.R.; Grijalba, Pablo E.; Gottlieb, Alexandra M.; Bluhm, Burton H.; Luiz Orlando de Oliveira

    2015-01-01

    Diseases of soybean caused by Cercospora spp. are endemic throughout the world's soybean production regions. Species diversity in the genus Cercospora has been underestimated due to overdependence on morphological characteristics, symptoms, and host associations. Currently, only two species (Cercospora kikuchii and C. sojina) are recognized to infect soybean; C. kikuchii causes Cercospora leaf blight (CLB) and purple seed stain (PSS), whereas C. sojina causes frogeye leaf spot. To assess cryp...

  1. Óleo de melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel no controle de cercosporiose em beterraba

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    A.D. SOUZA

    2015-01-01

    Full Text Available RESUMO O óleo volátil da melaleuca (Melaleuca alternifolia Maiden & Betche, Cheel possui atividade antimicrobiana podendo causar efeitos sobre as plantas. Avaliou-se a inibição do óleo em Cercospora beticolaSacc., e seu efeito no aumento da produção e qualidade de raízes de beterraba. As doses foram de 0,13; 0,67; 0,80 e 1,00% do óleo, além das testemunhas composta pelo meio de cultura Batata Dextrose Ágar (BDA no experimento in vitro, e água no experimento in vivo. As plantas foram pulverizadas duas vezes por semana. O delineamento foi inteiramente casualizado, com 4 repetições, e as médias foram comparadas pelo teste Tukey a 5% de probabilidade. O índice de infecção das folhas foi determinado por escala diagramática além do peso e diâmetro das raízes. Os resultados de inibição do crescimento micelial para as doses do óleo foram 0; 56; 87; 83 e 99%, e os índices de infecção: 77,08; 35,62; 21,04; 19,37 e 20,00%, respectivamente, para a testemunha e as doses 0,13; 0,67; 0,80 e 1,00% do óleo. Somente na concentração de 0,80% o óleo proporcionou relação positiva entre o ganho de peso e o diâmetro das raízes. O óleo de Melaleuca foi eficaz no controle de C. beticola e, como consequência, houve produção de raízes de beterraba com melhor desenvolvimento.

  2. Aggressiveness between genetic groups I and II of isolates of Cercospora zeae-maydis Agressividade entre isolados dos grupos genéticos I e II de Cercospora zeae-maydis

    Directory of Open Access Journals (Sweden)

    Sandra Marisa Mathioni

    2006-12-01

    Full Text Available For many years, the gray leaf spot disease (GLS caused by the fungus Cercospora zeae-maydis Tehon & Daniels, was not considered an important pathogen of maize (Zea mays, L. in Brazil. However, the recent adoption of agronomical practices such as no-tillage and cultivation under central pivot irrigation systems increased the incidence and severity to the extent that GLS is now one of the most important diseases of maize. Isolates of C. zeae-maydis can be distinguished by two genetic groups (I and II based on AFLP markers and on polymorphisms of the ITS and 5.8S rDNA regions. Until now, however, the biological implications of this distinction remain unclear. This study investigated whether isolates from the two genetic groups differ in aggressiveness towards maize. For this, symptoms of a susceptible hybrid were evaluated under greenhouse conditions with 9 and 11 isolates of C. zeae-maydis from groups I and II, respectively. Plants in the V3 growth stage were inoculated by placing sorghum seeds colonized with the pathogen in the leaf whorl and symptoms were evaluated with a visual rating scale 30 days later. On average, isolates of genetic group II were more aggressive than those of group I, with mean disease scores of 3.1 and 2.3, respectively. Differences were also observed between experiments, which suggested that group I and II might also differ in their fitness under different environments. This is the first report on differences in aggressiveness between the two genetic groups of C. zeae-maydis.Durante muitos anos, a cercosporiose, causada pelo fungo Cercospora zeae-maydis Tehon & Daniels, não foi considerada importante para a cultura do milho (Zea mays, L. no Brasil. Entretanto, a recente utilização de práticas culturais como o plantio direto e o cultivo sob pivôs centrais favoreceram o aumento de sua severidade e incidência, de forma que a doença é hoje considerada uma das mais importantes da cultura. Isolados de C. zeae

  3. Diversidad morfo-genética de Cercospora en soja. Detección precoz de la infección por Cercospora kikuchii

    OpenAIRE

    Latorre Rapela, María Gabriela de los Milagros

    2015-01-01

    Entre los agentes causales de enfermedades infecciosas en la soja, las especies del género Cercospora constituyen un problema importante. El tizón de la hoja y la mancha púrpura de la semilla causada por Cercospora kikuchii y la mancha ojo de rana producida por Cercospora sojina, reducen el valor nutricional de la planta y provocan severo deterioro de las cosechas. Los objetivos de este trabajo fueron el aislamiento de las especies de Cercospora que ocasionaron patología en las plantas de soj...

  4. PCR-based detection of fungicide resistance in Cercospora beticola

    Science.gov (United States)

    Leaf spot, caused by the fungus Cercospora beticola, is an endemic disease of sugarbeets in the North Dakota and Minnesota growing regions. Control measures against the fungus include resistant sugarbeet varieties and crop rotation, but the disease is managed effectively only when combined with tim...

  5. Progresso da ferrugem e da cercosporiose do cafeeiro consorciado com grevílea, com ingazeiro e a pleno sol em Lavras - MG Progress of rust and coffee plant cercosporiose mixed with grevílea, with ingazeiro and in the full sunshine in Lavras - MG

    Directory of Open Access Journals (Sweden)

    Bruno Grandi Salgado

    2007-08-01

    Full Text Available Com o presente trabalho, objetivou-se avaliar a incidência da ferrugem e da cercosporiose do cafeeiro em diferentes sistemas de cultivo, agroflorestais e a pleno sol, através da curva de progresso dessas doenças. Utilizou-se o delineamento inteiramente casualizado, com três tratamentos e sete repetições. Os tratamentos foram compostos por cafeeiros consorciados com ingazeiro, cafeeiros consorciados com grevílea e cafeeiros cultivados convencionalmente a pleno sol. As avaliações foram realizadas mensalmente no período de abril de 2001 a março de 2003. Realizou-se o cálculo da área abaixo da curva de progresso da doença (AACPD, a qual foi submetida à análise de variância. Para a incidência da ferrugem do cafeeiro o consórcio cafeeiro x ingazeiro mostrou-se com maiores índices da doença, sendo que os tratamentos consórcio cafeeiro x grevílea e cafeeiro a pleno sol não diferiram entre si e apresentaram menores incidências da doença. Diminuição na luz solar direta e maior umidade podem ter favorecido a ferrugem no sistema cafeeiro x ingazeiro. Para a incidência de cercosporiose, os cafeeiros a pleno sol obtiveram maiores valores de incidência da doença, seguidos por cafeeiros x grevílea, e menores taxas da doença foram observadas no consórcio cafeeiros x ingazeiro. A incidência de radiação solar direta pode ter favorecido a maior incidência de cercosporiose nos cafeeiros a pleno sol.The present work aimed to evaluate the incidence of rust and coffee plant cercosporiose in different systems of agroforest cultivation and in the full sunshine through the progress curve of those diseases. The completely randomized design with three treatments and seven replicates was utilized. The treatments were made up of coffee plants mixed with ingazeiro, coffee plants mixed with grevílea and coffee plants cultivated conventionally in the full sunshine. The evaluations were performed monthly during the period of April 2001 to

  6. Genetic Transformation System for the Fungal Soybean Pathogen Cercospora kikuchii.

    Science.gov (United States)

    Upchurch, R G; Ehrenshaft, M; Walker, D C; Sanders, L A

    1991-10-01

    An altered beta-tubulin gene that confers resistance to the fungicide benomyl was isolated from a genomic library of a UV-induced mutant of Cercospora kikuchii and used as a selectable marker for transformation. The level of benomyl resistance conferred to the transformants was at least 150-fold greater than the intrinsic resistance of the C. kikuchii recipient protoplasts. In the majority of cases, the tubulin fragment was integrated at the native beta-tubulin locus, apparently by gene replacement or gene conversion. The frequency of transformation ranged from 0.2 to 6 transformants per mug of DNA, depending on the recipient strain. Transformation with linearized plasmid resulted in a higher frequency, without changing the type of integration event. Transformants were phenotypically stable after eight consecutive transfers on medium without benomyl. This is the first report of a genetic transformation system for a Cercospora species.

  7. Field evaluation of soybean lines from a new source of resistance to Cercospora kikuchii, 2013

    Science.gov (United States)

    Purple seed stain, which is caused by the fungus Cercospora kikuchii, is an important seed disease which causes soybean seed quality losses when environmental conditions favor its growth, and harvest is delayed due to wet field conditions. Frogeye leaf spot caused by the fungus Cercospora sojina is...

  8. Root infection of sugar beet by Cercospora beticola in a climate chamber and in the field

    NARCIS (Netherlands)

    Vereijssen, J.; Schneider, J.H.M.; Termorshuizen, A.J.

    2005-01-01

    Sugar beet root infection by Cercospora beticola, the causal agent of Cercospora leaf spot (CLS), was studied in a climate chamber and in the field. In the climate chamber, root incubation of susceptible seedlings with a conidial suspension resulted in disease incidences that were significantly diff

  9. De novo genome assembly of Cercospora beticola for microsatellite marker development and validation

    Science.gov (United States)

    Cercospora leaf spot caused by Cercospora beticola is a significant threat to the production of sugar and table beet worldwide. A de novo genome assembly of C. beticola was used to develop eight polymorphic and reproducible microsatellite markers for population genetic analyses. These markers were u...

  10. First report of QoI insensitive Cercospora beticola on sugarbeet in Ontario, Canada

    Science.gov (United States)

    Cercospora beticola causes Cercospora leaf spot (CLS) of sugarbeet (Beta vulgaris) and is the most destructive foliar disease of sugarbeet worldwide. The QoI fungicide pyraclostrobin has been an important management tool for CLS in Canada since 2003. Beginning in 2010 some growers reported unsatisf...

  11. More Cercospora Species Infect Soybeans across the Americas than Meets the Eye.

    Directory of Open Access Journals (Sweden)

    Ana Paula Gomes Soares

    Full Text Available Diseases of soybean caused by Cercospora spp. are endemic throughout the world's soybean production regions. Species diversity in the genus Cercospora has been underestimated due to overdependence on morphological characteristics, symptoms, and host associations. Currently, only two species (Cercospora kikuchii and C. sojina are recognized to infect soybean; C. kikuchii causes Cercospora leaf blight (CLB and purple seed stain (PSS, whereas C. sojina causes frogeye leaf spot. To assess cryptic speciation among pathogens causing CLB and PSS, phylogenetic and phylogeographic analyses were performed with isolates from the top three soybean producing countries (USA, Brazil, and Argentina; collectively accounting for ~80% of global production. Eight nuclear genes and one mitochondrial gene were partially sequenced and analyzed. Additionally, amino acid substitutions conferring fungicide resistance were surveyed, and the production of cercosporin (a polyketide toxin produced by many Cercospora spp. was assessed. From these analyses, the long-held assumption of C. kikuchii as the single causal agent of CLB and PSS was rejected experimentally. Four cercosporin-producing lineages were uncovered with origins (about 1 Mya predicted to predate agriculture. Some of the Cercospora spp. newly associated with CLB and PSS appear to represent undescribed species; others were not previously reported to infect soybeans. Lineage 1, which contained the ex-type strain of C. kikuchii, was monophyletic and occurred in Argentina and Brazil. In contrast, lineages 2 and 3 were polyphyletic and contained wide-host range species complexes. Lineage 4 was monophyletic, thrived in Argentina and the USA, and included the generalist Cercospora cf. flagellaris. Interlineage recombination was detected, along with a high frequency of mutations linked to fungicide resistance in lineages 2 and 3. These findings point to cryptic Cercospora species as underappreciated global

  12. More Cercospora Species Infect Soybeans across the Americas than Meets the Eye.

    Science.gov (United States)

    Soares, Ana Paula Gomes; Guillin, Eduardo A; Borges, Leandro Luiz; Silva, Amanda C T da; Almeida, Álvaro M R de; Grijalba, Pablo E; Gottlieb, Alexandra M; Bluhm, Burton H; Oliveira, Luiz Orlando de

    2015-01-01

    Diseases of soybean caused by Cercospora spp. are endemic throughout the world's soybean production regions. Species diversity in the genus Cercospora has been underestimated due to overdependence on morphological characteristics, symptoms, and host associations. Currently, only two species (Cercospora kikuchii and C. sojina) are recognized to infect soybean; C. kikuchii causes Cercospora leaf blight (CLB) and purple seed stain (PSS), whereas C. sojina causes frogeye leaf spot. To assess cryptic speciation among pathogens causing CLB and PSS, phylogenetic and phylogeographic analyses were performed with isolates from the top three soybean producing countries (USA, Brazil, and Argentina; collectively accounting for ~80% of global production). Eight nuclear genes and one mitochondrial gene were partially sequenced and analyzed. Additionally, amino acid substitutions conferring fungicide resistance were surveyed, and the production of cercosporin (a polyketide toxin produced by many Cercospora spp.) was assessed. From these analyses, the long-held assumption of C. kikuchii as the single causal agent of CLB and PSS was rejected experimentally. Four cercosporin-producing lineages were uncovered with origins (about 1 Mya) predicted to predate agriculture. Some of the Cercospora spp. newly associated with CLB and PSS appear to represent undescribed species; others were not previously reported to infect soybeans. Lineage 1, which contained the ex-type strain of C. kikuchii, was monophyletic and occurred in Argentina and Brazil. In contrast, lineages 2 and 3 were polyphyletic and contained wide-host range species complexes. Lineage 4 was monophyletic, thrived in Argentina and the USA, and included the generalist Cercospora cf. flagellaris. Interlineage recombination was detected, along with a high frequency of mutations linked to fungicide resistance in lineages 2 and 3. These findings point to cryptic Cercospora species as underappreciated global considerations for soybean

  13. Vegetative Compatibility Groups in Cercospora kikuchii, the Causal Agent of Cercospora Leaf Blight and Purple Seed Stain in Soybean.

    Science.gov (United States)

    Cai, G; Schneider, R W

    2005-03-01

    ABSTRACT Nitrogen nonutilizing (Nit) mutants were used to assess vegetative compatibility of 58 isolates of Cercospora kikuchii, 55 of which were isolated from soybean plants in Louisiana. Two isolates were vegetatively self-incompatible. Of 56 self-compatible isolates, 16 were assigned to six multimember vegetative compatibility groups (VCGs), 01 to 06, with 2 or 3 isolates in each VCG. The other 40 isolates each belonged to a distinct VCG. All six multimember VCGs contained isolates from different soy bean cultivars, and three included isolates from different locations. Only one of six multimember VCGs included isolates both from soybean leaves and seed, while the other five included isolates from only leaves or seed. The likelihood of tissue specificity or preference was discussed. All isolates and tested Nit mutants produced cercosporin on potato dextrose agar under light. Significantly different amounts of cercosporin were produced among wild-type isolates, and two Nit mutants produced significantly more cercosporin than their wild-type counterparts. All isolates produced typical Cercospora leaf blight symptoms on soybean plants in greenhouse pathogenicity tests.

  14. Transformation of the Fungal Soybean Pathogen Cercospora kikuchii with the Selectable Marker bar

    OpenAIRE

    Upchurch, Robert G.; Meade, Maura J.; Hightower, Robin C.; Thomas, Robert S.; Callahan, Terrence M.

    1994-01-01

    An improved transformation protocol, utilizing selection for resistance to the herbicide bialaphos, has been developed for the plant pathogenic fungus Cercospora kikuchii. Stable, bialaphos-resistant transformants are recovered at frequencies eight times higher than those achieved with the previous system that was based on selection for benomyl resistance. In addition to C. kikuchii, this improved method can also be used to transform other species of Cercospora.

  15. Transformation of the Fungal Soybean Pathogen Cercospora kikuchii with the Selectable Marker bar.

    Science.gov (United States)

    Upchurch, R G; Meade, M J; Hightower, R C; Thomas, R S; Callahan, T M

    1994-12-01

    An improved transformation protocol, utilizing selection for resistance to the herbicide bialaphos, has been developed for the plant pathogenic fungus Cercospora kikuchii. Stable, bialaphos-resistant transformants are recovered at frequencies eight times higher than those achieved with the previous system that was based on selection for benomyl resistance. In addition to C. kikuchii, this improved method can also be used to transform other species of Cercospora.

  16. Mutants of Cercospora kikuchii altered in cercosporin synthesis and pathogenicity

    Energy Technology Data Exchange (ETDEWEB)

    Upchurch, R.G.; Walker, D.C.; Rollins, J.A.; Ehrenshaft, M.; Daub, M.E. (North Carolina State Univ., Raleigh (United States))

    1991-10-01

    The authors have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  17. Mutants of Cercospora kikuchii Altered in Cercosporin Synthesis and Pathogenicity.

    Science.gov (United States)

    Upchurch, R G; Walker, D C; Rollins, J A; Ehrenshaft, M; Daub, M E

    1991-10-01

    We have obtained spontaneous and UV-induced stable mutants, altered in the synthesis of cercosporin, of the fungal soybean pathogen Cercospora kikuchii. The mutants were isolated on the basis of colony color on minimal medium. The UV-induced mutants accumulated, at most, 2% of wild-type cercosporin levels on all media tested. In contrast, cercosporin accumulation by the spontaneous mutants was strongly medium regulated, occurring only on potato dextrose medium but at concentrations comparable to those produced by the wild-type strain. UV-induced mutants unable to synthesize cercosporin on any medium were unable to incite lesions when inoculated onto the soybean host. Cercosporin was reproducibly isolated from all inoculated leaves showing lesions. Although cercosporin involvement in disease has been indirectly suggested by many previous studies, this is the first report in which mutants blocked in cercosporin synthesis have been used to demonstrate that cercosporin is a crucial pathogenicity factor for this fungal genus.

  18. RNA-Sequencing of Cercospora beticola DMI-sensitive and -resistant isolates after treatment with tetraconazole identifies common and contrasting pathway induction

    Science.gov (United States)

    Cercospora beticola causes Cercospora leaf spot of sugarbeet. Cercospora leaf spot management measures often include application of the sterol demethylation inhibitor (DMI) class of fungicides. The reliance on DMIs and the consequent selection pressures imposed by their widespread use has led to th...

  19. [Detection of genetic variability in Cercospora kikuchii isolates from a single soybean field].

    Science.gov (United States)

    Lurá, M C; Di Conza, J A; González, A M; Latorre Rapela, M G; Turino, L; Ibáñez, M M; Iacona, V

    2007-01-01

    Detection of genetic variability in Cercospora kikuchii isolates from a single soybean field. Current knowledge about epidemiology and population structure of Cercospora kikuchii is little developed and no studies regarding this subject have been reported in Argentina. The aim of this work was to select primers to study genetic variability in C. kikuchii isolated from the same soybean field using RAPD (Random Amplified Polymorphism DNA). RAPD was applied to the DNA of 5 C. kikuchii, isolated from diseased tissue of the soybean in the same field, another isolate, from a strain collection. Out of seven primers, five of them proved to be useful to study the population of C. kikuchii isolates.

  20. Soybean Resistance to Cercospora sojina Infection Is Reduced by Silicon.

    Science.gov (United States)

    Nascimento, Kelly Juliane Telles; Debona, Daniel; França, Sueny Kelly Santos; Gonçalves, Mariana Gabriele Marcolino; DaMatta, Fábio Murilo; Rodrigues, Fabrício Ávila

    2014-11-01

    Frogeye leaf spot, caused by Cercospora sojina, is one of the most important leaf diseases of soybean worldwide. Silicon (Si) is known to increase the resistance of several plant species to pathogens. The cultivars Bossier and Conquista, which are susceptible and resistant, respectively, to frogeye leaf spot, supplied and nonsupplied with Si were examined for the activities of defense enzymes and the concentrations of total soluble phenolics (TSP) and lignin-thioglycolic acid (LTGA) derivatives at 8, 14, and 16 days after inoculation (dai) with C. sojina. The importance of cell wall degrading enzymes (CWDE) to the infection process of C. sojina and the effect of Si on their activities were also determined. Soybean plants were grown in hydroponic culture containing either 0 or 2 mM Si (-Si and +Si, respectively) and noninoculated or C. sojina inoculated. Severity of frogeye leaf spot was higher in cultivar Bossier plants than cultivar Conquista and also in the +Si plants compared with their -Si counterparts. Except for the concentrations of TSP and LTGA derivatives, activities of defense enzymes and the CWDE did not change for +Si noninoculated plants regardless of the cultivar. The activities of lipoxygenases, phenylalanine ammonia-lyases, chitinases, and polyphenoloxidases as well as the activities of CWDE decreased for the +Si inoculated plants. The results from this study demonstrated that defense enzyme activities decreased in soybean plants supplied with Si, which compromised resistance to C. sojina infection.

  1. A circadian rhythm regulating hyphal melanization in Cercospora kikuchii.

    Science.gov (United States)

    Bluhm, Burton H; Burnham, A Michele; Dunkle, Larry D

    2010-01-01

    Many metabolic and developmental processes in fungi are controlled by biological rhythms. Circadian rhythms approximate a daily (24 h) cycle and have been thoroughly studied in the model fungus, Neurospora crassa. However relatively few examples of true circadian rhythms have been documented among other filamentous fungi. In this study we describe a circadian rhythm underlying hyphal melanization in Cercospora kikuchii, an important pathogen of soybean. After growth in light or light : dark cycles, colonies transferred to darkness produced zonate bands of melanized hyphae interspersed with bands of hyaline hyphae. Rhythmic production of bands was remarkably persistent in the absence of external cues, lasting at least 7 d after transfer to darkness, and was compensated over a range of temperatures. As in N. crassa, blue light but not red light was sufficient to entrain the circadian rhythm in C. kikuchii, and a putative ortholog of white collar-1, one of the genes required for light responses in N. crassa, was identified in C. kikuchii. Circadian regulation of melanization is conserved in other members of the genus: Similar rhythms were identified in another field isolate of C. kikuchii as well as field isolates of C. beticola and C. sorghi, but not in wild-type strains of C. zeae-maydis or C. zeina. This report represents the first documented circadian rhythm among Dothideomycete fungi and provides a new opportunity to dissect the molecular basis of circadian rhythms among filamentous fungi.

  2. Population structure of Cercospora kikuchii, the causal agent of Cercospora leaf blight and purple seed stain in soybean.

    Science.gov (United States)

    Cai, G; Schneider, R W

    2008-07-01

    Random amplified polymorphic DNA (RAPD) and microsatellite-primed polymerase chain reaction (MP-PCR) were used to characterize 164 isolates of Cercospora kikuchii, most of which were collected from Louisiana. Plant tissue (seeds versus leaves), but not host cultivar, had a significant impact on pathogen population differentiation. Cluster analysis showed that the Louisiana population was dominated by a primary lineage (group I) with only a few Louisiana isolates belonging to the minor lineage that also included the non-Louisiana isolates (group II). A previous study showed that isolates could be differentiated according to vegetative compatibility groups (VCGs). However, RAPD and MP-PCR data demonstrated that isolates of C. kikuchii were not generally clustered according to these VCGs. Furthermore, genetic relationships within and between VCGs were examined using sequences of the intergenic spacer region of rDNA. These analyses showed that VCG is not an indicator of evolutionary lineage in this fungus. Our results suggest the likely existence of a cryptically functioning sexual stage in some portion of the C. kikuchii population.

  3. Application of the consolidated species concept to Cercospora spp. from Iran

    NARCIS (Netherlands)

    Bakhshi, M.; Arzanlou, M.; Babai-ahari, A.; Groenewald, J.Z.; Braun, U.; Crous, P.W.

    2015-01-01

    The genus Cercospora includes many important plant pathogenic fungi associated with leaf spot diseases on a wide range of hosts. The mainland of Iran covers various climatic regions with a great biodiversity of vascular plants, and a correspondingly high diversity of cercosporoid fungi. However, mos

  4. An examination of fungicide sensitivity of Cercospora beticola in Michigan and Ontario sugarbeet (Beta vulgaris) (2014)

    Science.gov (United States)

    Leaf spot caused by Cercospora beticola Sacc. is the major foliar disease of sugarbeet in Michigan. Fungicide applications are one of the most important tools in managing this disease. However, fungicide resistance has developed in C. beticola to several classes of fungicides. To look for the levels...

  5. Defense gene induction in soybean seeds after infection with Cercospora kikuchii and Diaporthe phaseolorum

    Science.gov (United States)

    We measured the expression levels of seven pathogen defense genes in detached soybean seeds after controlled inoculation with mycelial suspensions of Cercospora kikuchii (CK), causal agent of purple seed-stain and leaf blight and Diaporthe phaseolorum var. meridionales (DPM), causal agent of souther...

  6. Defense gene induction in the compatible interaction of soybean with Cercospora kikuchii and Diaporthe phaseolorum

    Science.gov (United States)

    We examined the compatible interaction of soybean [Glycine max (L.) Merr.] cultivar Dare with fungal pathogens Cercospora kikuchii (CK), a hemibiotroph, and Diaporthe phaseolorum (DP), a biotroph, in order to gain insight into basal host defense. Expression of defense genes in pathogen-, mock-, or ...

  7. Screening a diverse soybean germplasm collection for reaction to purple seed stain caused by Cercospora kikuchii

    Science.gov (United States)

    Purple seed stain (PSS), caused by Cercospora kikuchii, is a prevalent soybean disease that causes latent seed infection, seed decay, purple seed discoloration, and overall quality deterioration. The objective of this research was to screen soybean accessions from the USDA germplasm collection for r...

  8. Membrane transporters in self resistance of Cercospora nicotianae to the photoactivated toxin cercosporin.

    Science.gov (United States)

    Beseli, Aydin; Amnuaykanjanasin, Alongkorn; Herrero, Sonia; Thomas, Elizabeth; Daub, Margaret E

    2015-11-01

    The goal of this work is to characterize membrane transporter genes in Cercospora fungi required for autoresistance to the photoactivated, active-oxygen-generating toxin cercosporin they produce for infection of host plants. Previous studies implicated a role for diverse membrane transporters in cercosporin resistance. In this study, transporters identified in a subtractive cDNA library between a Cercospora nicotianae wild type and a cercosporin-sensitive mutant were characterized, including two ABC transporters (CnATR2, CnATR3), an MFS transporter (CnMFS2), a uracil transporter, and a zinc transport protein. Phylogenetic analysis showed that only CnATR3 clustered with transporters previously characterized to be involved in cercosporin resistance. Quantitative RT-PCR analysis of gene expression under conditions of cercosporin toxicity, however, showed that only CnATR2 was upregulated, thus this gene was selected for further characterization. Transformation and expression of CnATR2 in the cercosporin-sensitive fungus Neurospora crassa significantly increased cercosporin resistance. Targeted gene disruption of CnATR2 in the wild type C. nicotianae, however, did not decrease resistance. Expression analysis of other transporters in the cnatr2 mutant under conditions of cercosporin toxicity showed significant upregulation of the cercosporin facilitator protein gene (CFP), encoding an MFS transporter previously characterized as playing an important role in cercosporin autoresistance in Cercospora species. We conclude that cercosporin autoresistance in Cercospora is mediated by multiple genes, and that the fungus compensates for mutations by up-regulation of other resistance genes. CnATR2 may be a useful gene, alone or in addition to other known resistance genes, for engineering Cercospora resistance in crop plants.

  9. The disease prevalence and severity of Cercospora leaf spot in sugar beet cultivations in Kayseri

    Directory of Open Access Journals (Sweden)

    Hacer Handan ALTINOK

    2012-12-01

    Full Text Available Cercospora leaf spot disease (Cercospora beticola Sacc., is one of the most economically important fungal diseases in sugar beet growing. Under appropriate climatic conditions, the disease can reach epidemic levels. Although some fungicides exist for disease control, resistance development by pathogen against fungicides is creating difficulties. Besides, use of resistant varieties which is considered as the most efficient and environment-friendly method is adversely affected by pathogen’s ability to exhibit high genetic variations and varying resistance levels against different races of pathogen restricts the success of resistance breeding studies. In order to reveal status of this disease in Kayseri province, surveys were conducted in 2010 and 2011 in sugar beet growing areas and disease prevalence and severity were determined. Approximately, 1500 da area in 90 fields were examined and about 700 da of this area found as infected with Cercospora leaf spot disease in both years of the survey. Highest disease prevalence and severity were found as 80 % and 45 %, respectively, in Sarıoğlan district, which is followed by central district, Develi and Bünyan. Among surveyed districts, lowest prevalence and severity were detected as approx. 65 % and 35 %, respectively, in Yeşilhisar.

  10. Use of PCR-RFLP analysis to monitor fungicide resistance in Cercospora beticola populations from sugarbeet (Beta vulgaris) in Michigan, United States

    Science.gov (United States)

    Genetic resistance to Quinone outside inhibitor (QoI) and benzimidazole fungicides may be responsible for a recent decline in efficacy of chemical control management strategies for Cercospora leaf spot (CLS) caused by Cercospora beticola (Sacc.) in Michigan sugarbeet (Beta vulgaris L.) fields. The t...

  11. Adubação orgânica, nutrição e progresso de cercosporiose e ferrugem-do-cafeeiro Organic fertilization, nutrition and the progress of brown eye spot and rust in coffee trees

    Directory of Open Access Journals (Sweden)

    Florisvalda da Silva Santos

    2008-07-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de fontes nutricionais orgânicas, no progresso da cercosporiose e da ferrugem-do-cafeeiro, entre novembro/2003 e novembro/2005. Utilizou-se o delineamento de blocos ao acaso, com quatro repetições e seis tratamentos: palha de café + chorume suíno (PC+CS; torta de mamona + crotalária (TM+Cr; palha de café (PC; esterco bovino + crotalária (EB+Cr; palha de café + torta de mamona (PC+TM; e composto orgânico, torta de mamona, chorume suíno e crotalária (testemunha. A maior área abaixo da curva de progresso da incidência da cercosporiose e da ferrugem foi registrada no tratamento PC (respectivamente 62 e 38% superiores à testemunha. O maior progresso das doenças coincidiu com a elevação no teor de K e redução nos teores de Ca foliares no tratamento PC, comparado às demais fontes de adubação, e resultou em maior desfolha e menor produtividade. Os tratamentos PC+TM e PC+CS reduziram a incidência da cercosporiose em 38% e da ferrugem em 31 e 21%, respectivamente, e aumentou o teor de Ca foliar ao final da fase de granação do cafeeiro, em comparação ao tratamento PC. O equilíbrio nutricional desses cafeeiros conferiu-lhes maior resistência e reduziu o efeito da bienalidade nas safras 2003/2004 e 2004/2005.The objective of this work was to evaluate the effect of organic nutrional sources on the progress of brown eye spot and coffee rust in coffee plants, between November 2003 and November 2005. The experimental design adopted was the randomized blocks, with four replications and six treatment plots: coffee fruit peel + swine waste (CP+SW; castor bean presscake + crotalaria (CBP+Cr; coffee fruit peel (CP; bovine manure + crotalaria (BM+Cr; coffee fruit peel + castor bean presscake (CP+CBP; and standard fertilization used in the farm, which combines compost, castor bean presscake, swine waste and crotalaria (control. The higher area under the incidence progress curves of brown eye

  12. Pathological characteristics of Cercospora piaropi, potential fungal biocontrol agents for waterhyacinth%水葫芦生防菌Cercospora piaropi的病理学特性

    Institute of Scientific and Technical Information of China (English)

    谭飞; 褚建君

    2007-01-01

    尾孢菌属的Cercospora piaropi是一种有潜力开发成为防除水葫芦的生物除草剂的真菌.水葫芦原生叶片从被C.piaropi感染到完全死亡,需要约6周时间.C.piaropi接种水葫芦的适宜孢子浓度为105CFU/ml,适宜保湿时间为24 h.30℃时C.piaropi感染水葫芦的原生叶片病害严重度最高.除水葫芦和鸭舌草外,C.piaropi 对其他被测农作物和杂草均不产生病理作用,表现出较强的专一性.

  13. Isolation, characterization, and production of red pigment from Cercospora piaropi a biocontrol agent for waterhyacinth.

    Science.gov (United States)

    Jiménez, Maricela Martínez; Bahena, Selenia Miranda; Espinoza, César; Trigos, Angel

    2010-04-01

    A red pigment produced by a Mexican isolate of Cercospora piaropi (waterhyacinth pathogen) has been isolated and identified as cercosporin. The kinetic of cercosporin production in culture media during dark/light regimes was evaluated. When C. piaropi was cultivated in continuous light and potato dextrose broth culture, a maximum of cercosporin production was observed (72.59 mg/l). Despite other reports, C piaropi Mexican isolate produce cercosporin in dark conditions (25.70 mg/l). The results suggest that production of cercosporin in C. piaropi-waterhyacinth pathogenesis is an important factor to take into account in biocontrol strategies.

  14. Characterization and spray drying of lipase produced by the endophytic fungus Cercospora kikuchii

    OpenAIRE

    Costa-Silva,T. A.; Souza, C. R. F.; OLIVEIRA, W. P.; Said, S

    2014-01-01

    A lipase from the endophytic fungus Cercospora kikuchii was purified, biochemically characterized and the effects of spray drying on stabilization of the purified enzyme were studied. The lipase was purified 9.31-fold with recovery of 26.6% and specific activity of 223.6 U/mg. The optimum pH and temperature were 4.6 and 35 ºC, respectively, while the Vmax was 10.28 µmol/min.mg-1 protein and Km 0.0324 mM. All the metal ions tested enhanced the enzyme activity. The lipase retained almo...

  15. Defense-related gene expression in soybean leaves and seeds inoculated with Cercospora kikuchii and Diaporthe phaseolorum var. meriodinales

    Science.gov (United States)

    We characterized basal resistance in soybean inoculated with Cercospora kikuchii and Diaporthe phaseolorum var. meriodinales by comparing defense-related gene expression and pathogen growth in leaves and detached seeds. In leaves inoculated with C. kikuchii, 8/13 defense-related genes were upregula...

  16. Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

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    Geraldo de Amaral Gravina

    2004-01-01

    Full Text Available Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba, with different levels of resistance to Cercospora sojina, race 04, were crossed according to a diallel design, with no reciprocals, to determine the general and the specific combining abilities for the resistance. The evaluations of the reaction to the disease were performed 20 days after the inoculation of the fungus on the most infected leaflet of the plant, in the parents and in the F1 hybrids. To quantify the resistance, the following characteristics were evaluated: infection degree (ID; number of lesions per leaflet (NLL; lesion mean diameter (LMD; lesioned leaf area (LLA; percentage of lesioned leaf area (PLLA; number of lesions per square centimeter (NLC and disease index (DI. The relative importance of each characteristic was evaluated by the canonical variables analysis and the LLA and NLL characteristics were eliminated from the multivariate function. With the remaining five characteristics, a multivariate index was created using the first canonical vector, which was submitted to the diallel analysis, according to Griffings fixed model, method 2. The most important characters to discriminate resistant from susceptible soybean plants to C. sojina were: ID, LMD, NLC, DI and PLLA. Cristalina, Davis and Uberaba cultivars are the best ones among those tested that can be recommended as parents in soybean breeding programs seeking resistance to Cercospora sojina. The additive, dominant and epistatic genetic effects were important for the expression of the resistance, although the additive genetic effect was the most important component.

  17. Characterization and spray drying of lipase produced by the endophytic fungus Cercospora kikuchii

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    T. A. Costa-Silva

    2014-12-01

    Full Text Available A lipase from the endophytic fungus Cercospora kikuchii was purified, biochemically characterized and the effects of spray drying on stabilization of the purified enzyme were studied. The lipase was purified 9.31-fold with recovery of 26.6% and specific activity of 223.6 U/mg. The optimum pH and temperature were 4.6 and 35 ºC, respectively, while the Vmax was 10.28 µmol/min.mg-1 protein and Km 0.0324 mM. All the metal ions tested enhanced the enzyme activity. The lipase retained almost 100% activity in the presence of strong oxidants and was also resistant to Triton X, Tween 80 and 20 and SDS, as well as to proteases. The purified lipase was spray dried and kept until 85.2% of enzymatic activity. At least 70% of the enzymatic activity was maintained for spray dried purified lipase during the storage period. The lipase produced by Cercospora kikuchii has properties useful for industrial application and showed adequate stabilization and retention of its enzymatic activity after spray drying.

  18. Molecular identification of two strains of Cercospora rodmanii isolated from water hyacinth present in Yuriria lagoon, Guanajuato, Mexico and identification of new hosts for several other strains.

    Science.gov (United States)

    Montenegro-Calderón, José Guadalupe; Martínez-Álvarez, José Ascención; Vieyra-Hernández, Ma Teresa; Rangel-Macías, Luz Imelda; Razzo-Soria, Tannia; Chávez-Herrera, Roberto; Ponce-Noyola, Patricia; Leal-Morales, Carlos Alberto

    2011-11-01

    Water hyacinth is a beautiful monocotyledon plant that has been dispersed all over the world by humans. The plant has been present in Mexico since 1907, and many water bodies have become infested with it since then. In 2001, we initiated a survey in Yuriria lagoon in southern Guanajuato state to isolate fungi able to biocontrol the plant. We isolated 25 morphologically distinct fungal cultures, of which two were identified as members of the genus Cercospora. Cercospora species are among the most prevalent and destructive of plant pathogens and can be found on leaves, pedicels, stems, fruits, and bracts. Only two species of Cercospora, Cercospora piaropi, and Cercospora rodmanii, have been described on water hyacinth; however, the classification of these species has been controversial. Several molecular approaches have been used for Cercospora identification, and some candidate genes have been identified for use in Cercospora species determination. Although the nrRNA genes alone do not show sufficient resolution for species determination, histone H3, translation elongation factor1-α, β-tubulin, actin, and calmodulin have been shown in previous studies to have an adequate number of nucleotide changes to allow species identification. In the present study, we used partial sequences of the histone H3, actin, and calmodulin genes to identify our two isolates as C. rodmanii. Our two strains are not specific to water hyacinth, as they are also pathogenic to beet and sugar beet. Similar host ranges were found for C. rodmanii strains isolated from Tabasco in México, Zambia, and Brazil, however, the specificity for water hyacinth persists in Cercospora piaropi Tharp and C. rodmanii Conway, the latter being the most pathogenic.

  19. PENGENDALIAN PENYAKIT PATIK (Cercospora nicotianae PADA TEMBAKAU NA OOGST SECARA IN-VIVO DENGAN EKSTRAK DAUN GULMA KIPAHIT (Tithonia diversifolia

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    Aditya Reza Apriyadi

    2013-11-01

    Full Text Available [ENGLISH] Frog eyes diseases or leaf spot caused by Cercospora nicotinae that can reduce the quality of tobacco leaves, especially when used as a cigar deckblad. Affected leaves was easyly torn and the syhmptoms developed rapidly when processed in the storage. Therefore the alternative control of plant is by mexico sun flower leaf extracts. Mexico sunflower belonging to the broadleaf weeds. It suggested contains flavonoids, tannins, terpenoids, and saponins. The results showed mexico sunflower leaf extract concentration 50 g / L was effective to control this diseases, when compared mexico sunflower leaf extract concentration 25 g / L. However, there was no different between plant sprayed with mexico sun flower extract at concentration of 50 g/L and 75 g/L. Keywords: Mexico Sunflower leaf extract; Cercospora nicotianae; Tobacco. [INDONESIAN] Penyakit patik atau bercak daun Cercospora yang disebabkan oleh jamur Cercospora nicotinae dapat mengurangi mutu daun tembakau, terutama apabila digunakan sebagai daun pembalut cerutu. Biasanya penyakit ini dikendalikan dengan pestisida kimia tetapi karena ada batasan residu kimia maksimum sebesar 2,0 ppm, maka dicari alternatif pengendaliannya. Kipahit merupakan gulma berdaun lebar yang mempunyai potensi sebagai anti jamur patogen tanaman, karena mengandung senyawa flavonoid, tannin, terpenoid, dan saponin. Dengan penyemprotan empat kali dalam interval 15 hari, diketahui ekatrak daun kipahit dengan konsentrasi 50 g/l dan 75 g/L dapat menurunkan tingkat keparahan penyakit 1% sejak 60 hst sampai 70 hst. Akan tetapi, nilai insiden penyakit diketahui 100% pada semua perlakuan ekstrak daun kipahit. Ekstrak daun kipahit dengan konsentrasi 50 g/L sudah efektif mengendalikan penyakit patik jika dibandingkan dengan ekstrak daun kipahit dengan konsentrasi 25 g/L. Namun ekstrak daun kipahit dengan konsentrasi 75 g/L tidak berbeda efektifitasnya dengan ekstrak daun kipahit dengan konsentrasi 50 g/L. Kata Kunci: Ekstrak

  20. [Cercospora kikuchii isolated from Province of Santa Fe (Argentina): genetic variability and cercosporin production].

    Science.gov (United States)

    González, Ana María; Turino, Ludmila; Latorre Rapela, María Gabriela; Lurá, María Cristina

    2008-12-31

    The aims of the present study were to analyze the genetic variability of Cercospora kikuchii isolates and the in vitro cercosporin production, of these isolates obtained from soybean at the central-northern region of Santa Fe province (Argentina). Also the relationship between RAPD profiles and toxin production was also assessed. The strain C. kikuchii NBRC 6711 and 13 soybean isolates with symptoms of leaf blight were tested. Cercosporin production was analyzed by growing the fungus on Potato Dextrose Agar, extracting the toxin in alkaline medium and determining its concentration by spectrophotometry. The population of C. kikuchii studied showed variability, both genotypically, nine different groups were encountered, and have the ability to produce cercosporin. No relationship was found between toxin production and the RAPD profiles.

  1. Bioefficacy of plant extracts to control Cercospora leaf spot of mungbean (Vigna radiata

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    M.N. Uddin

    2013-06-01

    Full Text Available The experiment was conducted at Bangladesh Agricultural Research Institute farm, Joydebpur, Gazipur during March to July 2007 to evaluate the bioefficacy of some plant extracts in controlling Cercospora leaf spot of mungbean. Six indigenous plant species i.e. Neem leaves extract (1:4 w/v, Garlic cloves extract (1:5 w/v, Biskatali leaves extract (1:4 w/v, Alamanda leaves extract (1:6 w/v, Arjun leaves extract (1:4 w/v and Debdaru leaves extract (1:5 w/v were used in this experiment. The experiment was laid out in RCBD with seven treatments and four replications. Data on disease incidence, severity, yield contributing characters and yield of mungbean were recorded. Naturally, infection of the disease was considered in this experiment. The lowest disease incidence (7.33% at 60 DAS was found in T1. Lowest and similar disease severity (PDI= 4.55 was found in T2 and T3 at the same DAS. Neem extract treated plots gave better response in yield (1.26 t ha-1 and all the yield contributing parameters like inflorescences plant-1 (13.45, tallest plant (51.44 cm, the maximum number of pods plant-1 (26.81, length of pod (8.56 cm, number of seeds pod-1 (12.64 and 1000 seeds weight (27.33 g followed by T2 and T3. The highest disease incidence (26.50% and disease index (13.65% were recorded in treatment T7 at 60 DAS. Yield and all yield contributing factors were lowest in same treatment. The results of the experiment suggested that the use of neem leaves extracts are effective for minimizing Cercospora leaf spot incidence, severity and increasing yield of mungbean.

  2. Herencia de la resistencia al complejo Cercospora spp. en líneas de maíz tropical

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    Narro L. Luis

    2005-09-01

    Full Text Available Se evaluó un diseño dialélico (Griffing Modelo 1 entre 10 líneas endogámicas de maíz tropical contrastantes en su reacción a Cercospora spp. (5 tolerantes y 5 susceptibles, en tres localidades en lotes bajo siembra directa, con presencia natural del patógeno e inoculación artificial, para la variable índice de enfermedad (escala 1 a 5. En el análisis de varianza, por localidad y combinado, los efectos de habilidad combinatoria general (hcg, habilidad combinatoria específica (hce, y recíprocos resultaron altamente significativos; siendo >10 veces mayor los efectos de la hcg que los de hce, indicando predominio de la acción genética aditiva. Resultados también sugieren que la resistencia está controlada por efectos maternos o de citoplasma. La acumulación de genes de resistencia y la conformación de variedades sintéticas tolerantes es una alternativa a implementar en programas del mejoramiento de resistencia a Cercospora de maíces tropicales. ABSTRACT Inheritance of resistance to Cercospora Complex in tropical maize (zea mays inbred lines. Inheritance of resistance to the maize disease complex caused by Cercospora spp on tropical maize was studied by generating and evaluating a diallel mating model (Griffing model I using ten corn inbred lines with contrasting levels of disease reaction (5 tolerant and 5 susceptible. Parental lines and their crosses, both direct and reciprocal, were evaluated in three locations using conservation tillage and inoculated artificially with inoculum prepared using a mixture of foliar maize diseases collected from several farmer’s fields. Analysis of variance for the variable index of disease (scale 1 to 5, both locality and combined, the general combining ability (hcg, specific combining ability (hce, and reciprocal effects were highly significant, with the hcg portion being >10 times greater than the hce component, indicating that the genetic action is predominantly additive. Data

  3. Rhizobium radiobacter conjugation and callus-independent shoot regeneration used to introduce the cercosporin export gene cfp from Cercospora into sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Kuykendall, L David; Stockett, Tammy M; Saunders, Joseph W

    2003-05-01

    Leaf spot disease caused by Cercospora is responsible for crop and profitability losses in sugar beet crops in the US and worldwide. The cfp gene that encodes a protein that exports phytotoxic cercosporins from Cercospora was conjugally transferred to sugar beet using Rhizobium radiobacter (Agrobacterium tumefaciens), to improve Cercospora-induced leafspot resistance. Conditions for shoot regeneration were optimized to increase regeneration/transformation efficiencies. Low-light and room-temperature conditions were favorable to sugar beet regeneration without callus when cytokinin had been added to the tissue culture medium. Using this procedure adventitious shoots from leaf pieces were obtained in a simple, one-step regeneration procedure. T7, a cfp-transgenic clone verified by PCR with gene-specific primers, is being propagated for leaf spot disease resistance evaluation.

  4. Cercospora and Allied Genera in China (Ⅴ)%中国尾孢菌属及其近似属的研究(Ⅴ)

    Institute of Scientific and Technical Information of China (English)

    郭英兰

    2000-01-01

    报道3个中国新记录种:寄生在豆科Leguminosae植物上的葛尾孢Cercospora austrinae Chupp&Viegas和决明尾孢Cercospora cassiocarpa Chupp及寄生在牻牛儿苗科Geraniaceae植物上的老鹳草色链隔孢Phaeoramularia keranii(W.B.Cooke&C.G.Shaw)U.Braun.文中为3个种提供了形态描述.研究的标本保藏在中国科学院微生物研究所菌物标本馆(HMAS).

  5. Compatibility and infectivity of a Cercospora rodmanii formulation with enhancing agents. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pennington, J.C.; Theriot, E.A.

    1983-06-01

    A formulation of the fungus Cercospora rodmanii Conway has been produced, as a biocontrol of waterhyacinth (Eichhornia crassipes (Mart.) Solms.). To ensure the most efficient germination of the formulation, 12 potential enhancing agents were tested for addition during the spray application. The agents were aspartic acid, glucose, glutamic acid, gum xanthan, nutrient agar, Ortho X-77 Spreader, Tween 20, Tween 60, Tween 80, sodium alginate, Super Slupper, and yeast extract. Compatibility of test agents and combinations of test agents with two lots of the formulation was determined in the laboratory. All combinations of test agents were compatible with both lots of the C. rodmanii formulation. The C. rodmanii formulation was sprayed with test agents on waterhyacinth pseudolaminae. Damage was monitored each week for 8 weeks by assigning a disease index to each original and new pseudolaminae. No spots having characteristics suggestive of C. rodmanii infection were observed at any time during the study. Lack of infectivity could be remedied by isolating a virulent strain of C. rodmanii from the field. Agents determined to be compatible in this study could then be reexamined for enhancing infectivity on a virulent C. rodmanii formulation. 14 references, 2 figures, 5 tables.

  6. Immobilization of Lipases Produced by the Endophytic Fungus Cercospora kikuchii on Chitosan Microparticles

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    Lara Aparecida Buffoni Campos Carneiro

    2014-08-01

    Full Text Available This work studied the immobilization of Cercospora kikuchii lipases on chitosan microparticles by chemical attachment on chitosan acetate microparticles activated by glutaraldehyde (CAM added before or after the enzyme and physical adsorption on highly deacetylated chitosan hydrochloride microparticles (CHM. Lipases covalently immobilized on pre-activated CAM showed better performance retaining 88.4% of the enzymatic activity, with 68.2% of immobilization efficiency (IE. The immobilized enzyme retained an activity of about 53.5 % after five reuses, using p-NPP as substrate. Physical adsorption of lipase onto highly deacetylated CHM showed 46.2 % of enzymatic activity and 28.6% of IE. This immobilized derivative did not lose activity up to 80 days of storage at 4°C, while lipases immobilized on pre-activated CAM maintained its activity up to 180 days at same conditions. Taken together the results indicate that chitosan microparticles provide an optimal microenvironment for the immobilized enzyme to maintain good activity and stability.

  7. Genetic Relationships Between Cercospora kikuchii Populations from South America and Japan.

    Science.gov (United States)

    Imazaki, I; Homma, Y; Kato, M; Vallone, S; Yorinori, J T; Henning, A A; Iizumi, H; Koizumi, S

    2006-09-01

    ABSTRACT A collection 160 isolates of Cercospora kikuchii was made from South America and 245 from Japan. DNA fingerprint patterns were analyzed based on amplified fragment length polymorphism among the sample isolates, dividing the isolates into seven lineages (I to VII). Partial nucleotide sequence analyses of the beta-tubulin gene supported this division into seven lineages. Lineages I and III commonly existed in South America and Japan. In all, 136 of the 160 isolates from South America and 223 of the 245 isolates from Japan belonged to lineage I, indicating that lineage I was the major lineage in each area; 5 isolates from South America and 8 isolates from Japan belonged to lineage III. Lineages II (12 isolates) and IV (2 isolates) were specific to Japan and lineages V (3 isolates), VI (1 isolate), and VII (15 isolates) specifically existed in South America. These results suggest that the population genetic structure of C. kikuchii was different between South America and Japan, but the dominance of lineage I was common between the two areas.

  8. Efeito de Colletotrichum dematium var. truncata e Cercospora kikuchii na germinação de sementes de soja

    OpenAIRE

    Galli, Juliana Altafin; Panizzi, Rita de Cássia [UNESP; Fessel, Simone Aparecida; Simoni, Fabiana De [UNESP; Ito,Margarida Fumiko

    2005-01-01

    A antracnose, causada por Colletotrichum dematium var. truncata, é a principal doença da soja que afeta a fase inicial de formação das vagens, podendo causar a morte das plântulas. Cercospora kikuchii é o fungo causador da doença mancha púrpura nas sementes de soja, responsável por severas reduções no rendimento e na qualidade das sementes. O objetivo deste trabalho foi determinar o tempo mais apropriado para infecção das sementes de soja por C. dematium var. truncata e C. kikuchii, para post...

  9. Agressividade de três raças de Cercospora sojina em folhas de soja

    Directory of Open Access Journals (Sweden)

    Juliane Nicolodi Camera

    2014-06-01

    Full Text Available Este trabalho teve como objetivo avaliar a patogenicidade e a agressividade de três raças de Cercospora sojina, em dois cultivares de soja, BMX Magna e Bragg. Para isso, preparou-se suspensão, na concentração de 40 x 10³ conídio mL-1, para inoculação das plantas. Quinze dias após a inoculação com o fungo, verificou-se que a severidade e o número de lesões por folíolo, para a raça 23, não apresentaram diferenças estatísticas entre os cultivares. Para as raças 24 e 25, o cultivar BMX Magna apresentou maior valor do grau de infecção, diferindo estatisticamente daquele do cultivar Bragg. Com relação ao diâmetro das lesões, para a raça 23, o cultivar Bragg apresentou maior valor, para a raça 24, o maior valor ocorreu em BMX Magna e para a raça 25, não houve diferença estatística entre os cultivares. Portanto, as raças de C. sojina são patogênicas para os dois cultivares de soja e há diferença de agressividade entre elas, sendo as raças 24 e 25 mais agressivas do que a raça 23.

  10. Isolation of Light-Enhanced cDNAs of Cercospora kikuchii.

    Science.gov (United States)

    Ehrenshaft, M; Upchurch, R G

    1991-09-01

    Cercospora kikuchii is a fungal pathogen of soybeans which produces a photosensitizing phytotoxic polyketide metabolite, cercosporin. Cercosporin synthesis in culture is modulated by several environmental factors. In addition to the light requirement for toxin action, cercosporin biosynthesis is also highly light regulated. As a first step towards identifying genes involved in cercosporin regulation and biosynthesis, we have used subtractive hybridization to isolate light-enhanced cDNA clones. Six distinct cDNA clones representing genes from a wild-type C. kikuchii strain for which transcript accumulation is positively regulated by light were isolated. To assess the relationship of these light-enhanced cDNAs to cercosporin biosynthesis, we compared corresponding steady-state RNA levels in the wild type and in three mutant strains altered in toxin biosynthesis. Two of the mutant C. kikuchii strains which fail to accumulate cercosporin in response to light also fail to exhibit light-enhanced accumulation of transcripts corresponding to all six light-enhanced cDNAs. Cercosporin accumulation in the third mutant strain, S2, is regulated by medium composition as well as light. S2 fails to accumulate cercosporin in complete medium, a medium which allows significant cercosporin accumulation by the wild-type strain. When cultured in complete medium, this mutant strain also fails to show the wild-type, light-enhanced accumulation of transcripts corresponding to five of the six light-enhanced cDNAs. Kinetic analysis demonstrated that transcript accumulation for two of the six light-enhanced cDNAs strongly paralleled cercosporin accumulation in light-grown wild-type culture.

  11. Non-invasive Presymptomatic Detection of Cercospora beticola Infection and Identification of Early Metabolic Responses in Sugar Beet

    Science.gov (United States)

    Arens, Nadja; Backhaus, Andreas; Döll, Stefanie; Fischer, Sandra; Seiffert, Udo; Mock, Hans-Peter

    2016-01-01

    Cercospora beticola is an economically significant fungal pathogen of sugar beet, and is the causative pathogen of Cercospora leaf spot. Selected host genotypes with contrasting degree of susceptibility to the disease have been exploited to characterize the patterns of metabolite responses to fungal infection, and to devise a pre-symptomatic, non-invasive method of detecting the presence of the pathogen. Sugar beet genotypes were analyzed for metabolite profiles and hyperspectral signatures. Correlation of data matrices from both approaches facilitated identification of candidates for metabolic markers. Hyperspectral imaging was highly predictive with a classification accuracy of 98.5–99.9% in detecting C. beticola. Metabolite analysis revealed metabolites altered by the host as part of a successful defense response: these were L-DOPA, 12-hydroxyjasmonic acid 12-O-β-D-glucoside, pantothenic acid, and 5-O-feruloylquinic acid. The accumulation of glucosylvitexin in the resistant cultivar suggests it acts as a constitutively produced protectant. The study establishes a proof-of-concept for an unbiased, presymptomatic and non-invasive detection system for the presence of C. beticola. The test needs to be validated with a larger set of genotypes, to be scalable to the level of a crop improvement program, aiming to speed up the selection for resistant cultivars of sugar beet. Untargeted metabolic profiling is a valuable tool to identify metabolites which correlate with hyperspectral data. PMID:27713750

  12. The ABC transporter ATR1 is necessary for efflux of the toxin cercosporin in the fungus Cercospora nicotianae.

    Science.gov (United States)

    Amnuaykanjanasin, Alongkorn; Daub, Margaret E

    2009-02-01

    The Cercospora nicotianae mutant deficient for the CRG1 transcription factor has marked reductions in both resistance and biosynthesis of the toxin cercosporin. We cloned and sequenced full-length copies of two genes, ATR1 and CnCFP, previously identified from a subtractive library between the wild type (WT) and a crg1 mutant. ATR1 is an ABC transporter gene and has an open reading frame (ORF) of 4368bp with one intron. CnCFP encodes a MFS transporter with homology to Cercospora kikuchii CFP, previously implicated in cercosporin export, and has an ORF of 1975bp with three introns. Disruption of ATR1 indicated atr1-null mutants had dramatic reductions in cercosporin production (25% and 20% of WT levels) in solid and liquid cultures, respectively. The ATR1 disruptants also showed moderately higher sensitivity to cercosporin. Constitutive expression of ATR1 in the crg1 mutant restored cercosporin biosynthesis and moderately increased resistance. In contrast, CnCFP overexpression in the mutant did not restore toxin production, however, it moderately enhanced toxin resistance. The results together indicate ATR1 acts as a cercosporin efflux pump in this fungus and plays a partial role in resistance.

  13. Tolérance de quelques cultivars de manioc (Manihot esculenta Crantz et de l'espèce sauvage (Manihot glaziovii à la mosaïque virale africaine et à la cercosporiose du manioc

    Directory of Open Access Journals (Sweden)

    Ongono, YSB.

    2007-01-01

    Full Text Available Tolerance of some Cassava Cultivars (Manihot esculenta Crantz and the Wild Species (M. Glaziovii to Cassava Mosaic Virus Disease and Brown Leaf Spot. A study of the tolerance of three cultivars of Manihot esculenta Crantz (one local cultivar, Alot-Bikon, and two improved: IITA 8034, IITA 8061 and wild cassava (M. glaziovii collected from the Mbam and Kim forest (Cameroon towards the cassava mosaic virus disease (CMVD and brown leaf spot (BLS, was carried out in Yaoundé. CMVD was studied under natural conditions, whereas BLS was inoculated through a solution of Cercospora henningsii in concentration around 20 × 10² conidia/ml. Sixteen weeks after planting the cuttings, M. glaziovii plants were tallest (156 cm, whereas highest number of leaves (113 was obtained on the IITA 8061 cultivar. The lowest infection degrees by CMVD (17.2% and BLS (2.7% were registered on the wild species. Consequently, wild species seem to be more tolerant of the diseases studied. IITA 8061 cultivar is moderately resistant to CMVD (28.9% and rather resistant to BLS (7.8%. Cultivars IITA 8034 and the local variety are more sensitive respectively to CMVD (53.1 and 54.5% and BLS (18.8 and 32.8%. The highest yield in tubers was obtained from cultivar IITA 8061 (34.5 t/ha followed by IITA 8034 (32.1 t/ha and local cultivar, Alot-Bbikon (15.6 t/ha. These results show that the tolerance of cassava cultivars to disease has a large influence on tuber yield.

  14. Agrobacterium tumefaciens-mediated transformation as an efficient tool for insertional mutagenesis of Cercospora zeae-maydis.

    Science.gov (United States)

    Lu, Yuanyuan; Xiao, Shuqin; Wang, Fen; Sun, Jiaying; Zhao, Likun; Yan, Libin; Xue, Chunsheng

    2017-02-01

    An efficient Agrobacterium tumefaciens-mediated transformation (ATMT) approach was developed for the plant pathogenic fungus, Cercospora zeae-maydis, which is the causative agent of gray leaf spot in maize. The transformation was evaluated with five parameters to test the efficiencies of transformation. Results showed that spore germination time, co-cultivation temperature and time were the significant influencing factors in all parameters. Randomly selected transformants were confirmed and the transformants were found to be mitotically stable, with single-copy T-DNA integration in the genome. T-DNA flanking sequences were cloned by thermal asymmetric interlaced PCR. Thus, the ATMT approach is an efficient tool for insertional mutagenesis of C. zeae-maydis.

  15. CFP, the putative cercosporin transporter of Cercospora kikuchii, is required for wild type cercosporin production, resistance, and virulence on soybean.

    Science.gov (United States)

    Callahan, T M; Rose, M S; Meade, M J; Ehrenshaft, M; Upchurch, R G

    1999-10-01

    Many species of the fungal genus Cercospora, including the soybean pathogen C. kikuchii, produce the phytotoxic polyketide cercosporin. Cercosporin production is induced by light. Previously, we identified several cDNA clones of mRNA transcripts that exhibited light-enhanced accumulation in C. kikuchii. Targeted disruption of the genomic copy of one of these, now designated CFP (cercosporin facilitator protein), results in a drastic reduction in cercosporin production, greatly reduced virulence of the fungus to soybean, and increased sensitivity to exogenous cercosporin. Sequence analysis of CFP reveals an 1,821-bp open reading frame encoding a 65.4-kDa protein similar to several members of the major facilitator superfamily (MFS) of integral membrane transporter proteins known to confer resistance to various antibiotics and toxins in fungi and bacteria. We propose that CFP encodes a cercosporin transporter that contributes resistance to cercosporin by actively exporting cercosporin, thus maintaining low cellular concentrations of the toxin.

  16. 引起泡花树属叶斑的尾孢菌属一新种%A NEW SPECIES OF CERCOSPORA CAUSING LEAF SPOT OF MELIOSMA SP.

    Institute of Scientific and Technical Information of China (English)

    郭英兰; 徐莉

    2004-01-01

    A new species, Cercospora meliosmae, on Meliosma sp. is reported. Latin diagnosis,illustration and English description of the new species are provided. The type specimen is deposited in HMAS.%报道寄生在清风藤科 Sabiaceae 泡花树属 Meliosma sp. 植物上尾孢菌属的一个新种:泡花树尾孢 Cercospora meliosmae.尾孢菌属真菌在清风藤科尚属首次报道.文中为新种提供了拉丁文简介、图及英文描述,模式标本保存在中国科学院微生物研究所菌物标本馆(HMAS).

  17. Inibição do crescimento micelial de Cercospora calendulae Sacc. por extratos de plantas medicinais

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    J.M. Nascimento

    2013-01-01

    Full Text Available O uso de extratos e óleos essenciais de plantas medicinais tem sido amplamente estudado no controle de doenças de plantas. O objetivo da realização do presente trabalho foi avaliar o efeito de extratos de Ruta graveolens L., Mentha x villosa, Calendula officinalis L., Momordica charantia L., Symphytum officinale L., Ageratum conyzoides L. e Ricinus comunis L., nas concentrações de 0, 250, 500, 1000, 2000, 5000 e 10000 mg L-1, sobre a inibição do crescimento micelial de Cercospora calendulae Sacc. in vitro. Os extratos foram obtidos por infusão. O experimento foi desenvolvido no Laboratório de Fitopatologia da FCA/UFGD, estado de Mato Grosso do Sul, em delineamento inteiramente casualizado, esquema fatorial 7 extratos x 7 concentrações, com seis repetições. Foi detectado efeito dos extratos e suas concentrações sobre o crescimento do fungo, sendo a interação significativa. Os extratos de calêndula, arruda, hortelã e melão de São Caetano, nas maiores concentrações resultaram em maiores porcentagens de inibição, próximas de 100%, 30%, 35% e 40%, respectivamente, a 10000 mg L-1.

  18. An acidic class III chitinase in sugar beet: induction by Cercospora beticola, characterization, and expression in transgenic tobacco plants.

    Science.gov (United States)

    Nielsen, K K; Mikkelsen, J D; Kragh, K M; Bojsen, K

    1993-01-01

    An acidic chitinase (SE) was found to accumulate in leaves of sugar beet (Beta vulgaris) during infection with Cercospora beticola. Two isoforms, SE1 and SE2, with MW of 29 kDa and pI of approximately 3.0 were purified to homogeneity. SE2 is an endochitinase that also exhibits exochitinase activity, i.e., it is capable of hydrolyzing chito-oligosaccharides, including chitobiose, into N-acetyl-glucosamine. Partial amino acid sequence data for SE2 were used to obtain a cDNA clone by polymerase chain reaction. The clone was used to isolate a cDNA clone encoding SE2. The deduced amino acid sequence for SE2 is 58-67% identical to the class III chitinases from cucumber, Arabidopsis, and tobacco. A transient induction of SE2 mRNA during the early stages of infection with C. beticola is much stronger in tolerant plants than in susceptible plants. Transgenic tobacco (Nicotiana benthamiana) plants constitutively accumulate SE2 protein in the intercellular space of their leaves. In a preliminary infection experiment, the transgenic plants did not show increase in resistance against C. nicotianae.

  19. Over-expression of the cercosporin facilitator protein, CFP, in Cercospora kikuchii up-regulates production and secretion of cercosporin.

    Science.gov (United States)

    Upchurch, R G; Rose, M S; Eweida, M

    2001-10-16

    CFP (cercosporin facilitator protein), a light-regulated gene from the soybean fungal pathogen Cercospora kikuchii, encodes the putative major facilitator transporter of the fungal polyketide cercosporin. Gene disruption of CFP in C. kikuchii strain Gus-3 resulted in dramatically reduced cercosporin production and virulence, and increased sensitivity to the toxin. Two C. kikuchii transformant strains (10-1 and 10-11) that over-produce cercosporin were recovered from the complementation of CFP gene-disrupted strain Gus-3. Southern analysis revealed that these strains contained multiple genomic copies of CFP and over-expressed CFP transcript and protein. Although 10-1 and 10-11 produce and secrete significantly elevated levels of cercosporin, they exhibit wild-type resistance to cercosporin, and maintain a wild-type pattern of light-regulated toxin accumulation. Restoration of wild-type cercosporin resistance in 10-1 and 10-11 suggests that CFP does contribute substantially to cercosporin resistance via toxin secretion. The three-fold increase in toxin accumulation, predominantly associated with the mycelium fraction of these CFP multi-copy strains, suggests that CFP may also have a significant, but unknown, role in regulating toxin production.

  20. Genetic diversity of Cercospora kikuchii isolates from soybean cultured in Argentina as revealed by molecular markers and cercosporin production.

    Science.gov (United States)

    Lurá, María Cristina; Latorre Rapela, María Gabriela; Vaccari, María Celia; Maumary, Roxana; Soldano, Anabel; Mattio, Mónica; González, Ana María

    2011-05-01

    Leaf blight and purple seed, caused by the fungal pathogen Cercospora kikuchii (Matsumoto & Tomoyasu) M. W. Gardner are very important diseases of soybean (Glycine max L. Merr.) in Argentina. The aims of this work were: (a) to confirm and to assess the genetic variability among C. kikuchii isolates collected from different soybean growing areas in Santa Fe province using inter simple sequence repeats (ISSR) markers and sequence information from the internal transcribed spacer (ITS) region of rDNA and (b) to analyze the cercosporin production of the regional C. kikuchi isolates in order to assess whether there was any relationship between the molecular profiles and the toxin production. Isolates from different regions in Santa Fe province were studied. The sequence of the ITS regions showed high similarity (99-100%) to the GenBank sequences of C. kikuchii BRCK179 (accession number AY633838). The ISSR markers clustered all the isolates into many groups and cercosporin content was highly variable among isolates. No relationship was observed between ITS region, ISSR groups and origin or cercosporin content. The high degree of genetic variability and cercosporin production among isolates compared in this study characterizes a diverse population of C. kikuchii in the region.

  1. Expression in sugar beet of the introduced cercosporin toxin export (CFP) gene from Cercospora kikuchii, the causative organism of purple seed stain in soybean.

    Science.gov (United States)

    Kuykendall, L David; Upchurch, Robert G

    2004-05-01

    The Cercospora kikuchii cercosporin export gene, CFP, introduced into Beta vulgaris L. by conjugation with Rhizobium radiobacter, was stably maintained during vegetative propagation as verified by PCR using primers specific for the CFP gene. Transcriptional expression of the CFP gene in leaves was determined by RT-PCR using CFP-specific primers. CFP protein was detected using Western analysis with an affinity-purified polypeptide-specifc antibody. Analysis of the relative susceptibility of CFP-transgenic and non-transgenic sugar beet plants is planned but will probably take several years to complete.

  2. Reação de genótipos de soja ao crestamento foliar de cercospora

    Directory of Open Access Journals (Sweden)

    Angela Sathiko Kudo

    2011-01-01

    Full Text Available Foram realizados dois experimentos em um delineamento em blocos ao acaso com três repetições, em Cristalina (GO, na safra de 2005/2006, para avaliar a reação de genótipos de soja convencional e transgênica (RR ao crestamento foliar causado por Cercospora kikuchii. No experimento 1, foram avaliados 86 genótipos de soja convencional e no experimento 2, 30 genótipos de soja convencional e transgênica quanto à reação ao crestamento foliar. Como padrões de genótipos convencionais foram usados Emgopa 313 e Msoy 8001 e como genótipos transgênicos Msoy 8585 RR e Msoy 8787 RR. Os genótipos com menor incidência (<1% da doença no experimento 1 foram: GT04-7229, GT04-8987, GT04-8902, GT04-7991, GT04-8218, GT04-9501, GT04-7020, GT04-7505 e GT04-7439. No experimento 2, os menos afetados foram: GT04-7437 RR, GT04-9192 RR, GT04-8091 RR, GT04-8203, GT04-9265 RR e GT04-9085 RR. Não houve diferença na intensidade de doença entre genótipos transgênicos e convencionais. A intensidade do crestamento nos experimentos foi baixa (área foliar lesionada de 0 a 1,5% e incidência de 0 a 20%.

  3. Development of a Quantitative Polymerase Chain Reaction Detection Protocol for Cercospora kikuchii in Soybean Leaves and Its Use for Documenting Latent Infection as Affected by Fungicide Applications.

    Science.gov (United States)

    Chanda, A K; Ward, N A; Robertson, C L; Chen, Z-Y; Schneider, R W

    2014-10-01

    Cercospora leaf blight (CLB) of soybean, caused by Cercospora kikuchii, is a serious disease in the southern United States. A sensitive TaqMan probe-based real-time quantitative polymerase chain reaction (qPCR) assay was developed to specifically detect and quantify C. kikuchii in naturally infected soybean plants. The sensitivity was 1 pg of genomic DNA, which was equivalent to about 34 copies of genome of C. kikuchii. Using this qPCR assay, we documented a very long latent infection period for C. kikuchii in soybean leaves beginning at the V3 growth stage (as early as 22 days after planting). The levels of biomass of C. kikuchii remained low until R1, and a rapid increase was detected from the R2/R3 to R4/R5 growth stages shortly before the appearance of symptoms at R6. The efficacy of various fungicide regimens under field conditions also was evaluated over a 3-year period using this qPCR method. Our results showed that multiple fungicide applications beginning at R1 until late reproductive stages suppressed the development of C. kikuchii in leaves and delayed symptom expression. Different fungicide chemistries also had differential effects on the amount of latent infection and symptom expression during late reproductive growth stages.

  4. EFICIÊNCIA DE PRODUTOS FITOSSANITÁRIOS PULVERIZADOS NA CULTURA DA SOJA (Glycine max L., NO CONTROLE DA MANCHA PARDA (Septoria glycines E CRESTAMENTO FOLIAR-MANCHA PÚRPURA DOS GRÃOS (Cercospora kikuchii EFFICIENCY OF FUNGICIDES IN THE CONTROL OF Septoria glycines AND Cercospora kikuchii ON SOYBEAN (Glycine max L.

    Directory of Open Access Journals (Sweden)

    Alessandro Ramos Nonato

    2007-09-01

    Full Text Available

    Cultura de soja (Glycine max, variedade Crixás, cultivada a campo, naturalmente infectada por Cercospora kikuchii e Septoria glycines, foi pulverizada uma ou duas vezes com diferentes dosagens de produtos fitossanitários. Foram avaliados o nível de infecção nas folhas e sementes, nível de desfolha e rendimento de grãos. Entre os produtos testados, o mais eficiente foi o azoxystrobin, que foi superior ao difeconazole e benomyl, comparando-se à testemunha. Entre os tratamentos com fungicida não houve diferença estatística significante ao nível de 5% de probabilidade, fato este também constatado quando se comparam os tratamentos com fungicida e a testemunha, em relação à produção de grãos.

    PALAVRAS-CHAVE: Soja; Cercospora kikuchii; Septoria glycines.

    Soybean Crixás crop (Glycine max, naturally infected by Cercospora kikuchii and Septoria glycines was sprayed once or twice with different dosages of fungicides. Infection level on leaves and seeds, leaf fall level and seed production were evaluated. Among tested fungicides, the most efficient was azoxystrobin, which was superior to difeconazole and benomyl. All were superior to the control. Among the treatments, there was no significant difference at 5% level. This fact was also noticed when seed yield was compared between treatments and the control.

    KEY-WORDS: Cercospora kikuchii; Septoria glycines; soybean.

  5. Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth

    Directory of Open Access Journals (Sweden)

    Kema Gert HJ

    2008-11-01

    Full Text Available Abstract Background The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs from C. zeae-maydis and evaluate their expression during vegetative, infectious, and reproductive growth. Results A total of 27,551 ESTs was obtained from five cDNA libraries constructed from vegetative and sporulating cultures of C. zeae-maydis. The ESTs, grouped into 4088 clusters and 531 singlets, represented 4619 putative unique genes. Of these, 36% encoded proteins similar (E value ≤ 10-05 to characterized or annotated proteins from the NCBI non-redundant database representing diverse molecular functions and biological processes based on Gene Ontology (GO classification. We identified numerous, previously undescribed genes with potential roles in photoreception, pathogenesis, and the regulation of development as well as Zephyr, a novel, actively transcribed transposable element. Differential expression of selected genes was demonstrated by real-time PCR, supporting their proposed roles in vegetative, infectious, and reproductive growth. Conclusion Novel genes that are potentially involved in regulating growth, development, and pathogenesis were identified in C. zeae-maydis, providing specific targets for characterization by molecular genetics and functional genomics. The EST data establish a foundation for future studies in evolutionary and comparative genomics among species of Cercospora and other groups of plant pathogenic fungi.

  6. Efeito do tipo de substrato e da presença de adubação suplementar sobre o crescimento vegetativo, nutrição mineral, custo de produção e intensidade de cercosporiose em mudas de cafeeiro formadas em tubetes Effects of substrate type and supplementary fertilization on vegetative growth, mineral nutrition, production costs, and brown eye spot of coffee seedlings in stiff plastic containers

    Directory of Open Access Journals (Sweden)

    Adélia Aziz Alexandre Pozza

    2007-06-01

    Full Text Available A utilização de tubetes para produzir mudas de cafeeiro (Coffea arabica L. tornou-se uma realidade. Objetivando avaliar o uso de substratos adubados ou não com fertilizante de liberação gradual e seus efeitos na nutrição, na formação, na cercosporiose e nos custos de produção de mudas de cafeeiro em tubetes, conduziu-se um experimento em viveiro, em esquema fatorial (4x2 com quatro substratos combinados com duas adubações, tendo quatro repetições. As parcelas foram constituídas por 16 tubetes de 120 mL, considerando-se como plantas úteis as seis centrais. Os tratamentos consistiram dos substratos S1= Substrato comercial I, S2 = Substrato comercial II, S3 = Substrato de eucalipto e S4 = 80% esterco de curral + 20% terra de subsolo, todos com e sem adubação com fertilizante de liberação gradual. No geral, os melhores substratos para formação de mudas de cafeeiro em tubetes foram os substratos não comerciais ou orgânicos, independentemente de receberem ou não adubação suplementar. Observou-se redução da cercosporiose com a nutrição mineral, principalmente com o cálcio. Com a utilização de todos os substratos houve ganho econômico em relação ao custo por milheiro de mudas. A maior economia foi obtida com o substrato S4, seguida do substrato S3, com melhor relação custo/benefício.The utilization of stiff plastic containers for producing coffee seedlings (Coffea arabica L. is a reality. Aiming to evaluate the effects of substrate type enriched or not with slow-release fertilizer on vegetative growth, mineral nutrition, production cost and, brown eye spot of coffee seedlings, an experiment was conducted in the plant nursery. The experimental design was a factorial scheme with four substrates in the presence and absence of supplementary fertilization, with four replicates. The plots were made of 16 containers of 120 ml, using six central plants for evaluation. The treatments consisted of S1 = Commercial Substrate

  7. Changes occurring in compositions and antioxidant properties of healthy soybean seeds [Glycine max (L.) Merr.] and soybean seeds diseased by Phomopsis longicolla and Cercospora kikuchii fungal pathogens.

    Science.gov (United States)

    Lee, Jin Hwan; Hwang, Seung-Ryul; Lee, Yeon-Hee; Kim, Kyun; Cho, Kye Man; Lee, Yong Bok

    2015-10-15

    Changes in the compositions (isoflavone, protein, oil, and fatty acid) and antioxidant properties were evaluated in healthy soybeans and soybeans diseased by Phomopsis longicolla and Cercospora kikuchii. The total isoflavone content (1491.3 μg/g) of healthy seeds was observed to be considerably different than that of diseased seeds (P. longicolla: 292.6, C. kikuchii: 727.2 μg/g), with malonlygenistin exhibiting the greatest decrease (726.1 → 57.1, 351.9 μg/g). Significantly, three isoflavones exhibited a slight increase, and their structures were confirmed as daidzein, glycitein, and genistein, based on their molecular ions at m/z 253.1, 283.0, and 269.1 using the negative mode of HPLC-DAD-ESI/MS. The remaining compositions showed slight variations. The effects against 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radicals in healthy seeds were stronger than the diseased soybeans, depending upon the isoflavone level. Our results may be useful in evaluating the relationship between composition and antioxidant activity as a result of changes caused by soybean fungal pathogens.

  8. Efectividad biológica delazoxystrobin para el control de pyricularia oryzae cav. y cercospora oryzae miyake. en arroz de temporal en Veracruz, México

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    Enrique Becerra

    2001-01-01

    Full Text Available El estado de Veracruz, México, siembra anualmente 22000 ha de arroz de temporal con un rendimiento medio de 3,5 t/ha, debido principalmente a problemas de sequía lo cual favorece la presencia de hongos como Pyricularia oryzae Cav. (quema del arroz y Cercospora oryzae Miyake. (Mancha angosta. Con el objeto de conocer el comportamiento de nuevos fungicidas se evaluó la eficacia del Azoxystrobin en el control de estos hongos. El experimento se estableció en el municipio de Tres Valles, Veracruz, durante el temporal de 1999, con semilla de Milagro Filipino Depurado. El diseño estadístico utilizado fue bloques al azar con cuatro repeticiones. Los tratamientos evaluados fueron: Azoxystrobin a 0,2, 0,4 y 0,6 l/ha vs Tecto60 a 0,5 kg/ha y un testigo sin aplicación. Estos fueron aplicados al presentarse los primeros síntomas de las enfermedades. Se evaluó la incidencia, número de lesiones en 20 plantas, índice de intensidad, el rendimiento de grano y fitotoxicidad. Se encontró que el Azoxystrobin obtuvo mejores resultados que el Tecto 60 y éste a su vez que el testigo no tratado. El mejor control para P. oryzae y C. oryzae y el mayor rendimiento de grano (4432 kg/ha se logró cuando se aplicó Azoxystrobin en dosis de 0,6 l/ha, aunque con 0,2 y 0,4 l/ha de este fungicida tuvo un buen control de estas enfermedades. Ninguno de los fungicidas causó toxicidad al arroz

  9. NMR-Based Metabolic Profiling of Field-Grown Leaves from Sugar Beet Plants Harbouring Different Levels of Resistance to Cercospora Leaf Spot Disease

    Directory of Open Access Journals (Sweden)

    Yasuyo Sekiyama

    2017-01-01

    Full Text Available Cercospora leaf spot (CLS is one of the most serious leaf diseases for sugar beet (Beta vulgaris L. worldwide. The breeding of sugar beet cultivars with both high CLS resistance and high yield is a major challenge for breeders. In this study, we report the nuclear magnetic resonance (NMR-based metabolic profiling of field-grown leaves for a subset of sugar beet genotypes harbouring different levels of CLS resistance. Leaves were collected from 12 sugar beet genotypes at four time points: seedling, early growth, root enlargement, and disease development stages. 1H-NMR spectra of foliar metabolites soluble in a deuterium-oxide (D2O-based buffer were acquired and subjected to multivariate analyses. A principal component analysis (PCA of the NMR data from the sugar beet leaves shows clear differences among the growth stages. At the later time points, the sugar and glycine betaine contents were increased, whereas the choline content was decreased. The relationship between the foliar metabolite profiles and resistance level to CLS was examined by combining partial least squares projection to latent structure (PLS or orthogonal PLS (OPLS analysis and univariate analyses. It was difficult to build a robust model for predicting precisely the disease severity indices (DSIs of each genotype; however, GABA and Gln differentiated susceptible genotypes (genotypes with weak resistance from resistant genotypes (genotypes with resistance greater than a moderate level before inoculation tests. The results suggested that breeders might exclude susceptible genotypes from breeding programs based on foliar metabolites profiled without inoculation tests, which require an enormous amount of time and effort.

  10. Mapping and validation of quantitative trait loci for resistance to Cercospora zeae-maydis infection in tropical maize (Zea mays L.).

    Science.gov (United States)

    Pozar, Gilberto; Butruille, David; Silva, Heyder Diniz; McCuddin, Zoe Patterson; Penna, Julio Cesar Viglioni

    2009-02-01

    Breeding for resistance to gray leaf spot, caused by Cercospora zeae-maydis (Cz) is paramount for many maize environments, in particular under warm and humid growing conditions. In this study, we mapped and characterized quantitative trait loci (QTL) involved in the resistance of maize against Cz. We confirmed the impact of the QTL on disease severity using near-isogenic lines (NILs), and estimated their effects on three major agronomic traits using their respective near isogenic hybrids (NIHs), which we obtained by crossing the NILs with an inbred from a complementary heterotic pool. We further validated three of the four QTL that were mapped using the Multiple Interval Mapping approach and showed LOD values>2.5. NILs genotype included all combinations between favorable alleles of the two QTL located in chromosome 1 (Q1 in bin 1.05 and Q2 in bin 1.07), and the allele in chromosome 3 (Q3 in bin 3.07). Each of the three QTL separately significantly reduced the severity of Cz. However, we found an unfavorable epistatic interaction between Q1 and Q2: presence of the favorable allele at one of the QTL allele effectively nullified the effect of the favorable allele at the other. In contrast, the interaction between Q2 and Q3 was additive, promoting the reduction of the severity to a greater extent than the sum of their individual effects. When evaluating the NIH we found significant individual effects for Q1 and Q3 on gray leaf spot severity, for Q2 on stalk lodging and grain yield, and for Q3 on grain moisture and stalk lodging. We detected significant epitasis between Q1 and Q2 for grain moisture and between Q1 and Q3 for stalk lodging. These results suggest that the combination of QTL impacts the effectiveness of marker-assisted selection procedures in commercial product development programs.

  11. Effects of 12 beticolins, Cercospora beticola toxins, on proliferation of ras-transformed adrenocortical cell%真菌Cercospora beticola的12种毒素贝第高林对癌基因ras转导的肾上腺细胞生长的作用

    Institute of Scientific and Technical Information of China (English)

    丁国庆; Gabrielle MAUME; Hanan OSMAN; Martine PADIEU; Marie-Louise MILAT; Claude HUMBERT; Jean-Pierre BLEIN; Bernard F MAUME

    2001-01-01

    AIM: To explore different effects of 12 beticolins, Cercospora beticola toxins, on ras-transformed adrenocortical cell growth inhibition and their functional mechanism.METHODS: Beticolin-induced inhibition was measured with survival cell number determined by an automated photocolorimetric method. The penetration of beticolin was examined by confocal microscopy. Ras protein determined by Lowry method were separated by 14 % SDS-PAGE and electroblotted to Immobilon-P transfer membrane and detected with pan-Ras (Ab-3) monoclonal antibody. The Ca2+ chelation by beticolin was investigated using a calcium ionophore. RESULTS: Cell growth inhibition was found dose- and time-dependently at submicromolar level for beticolin-1, -2, and -13 (IC50 ≤250 nmol/L) and for beticolin-0, 6, and-11 (400 nmol/L < IC50 ≤ 500 nmol/L ). The inhibition by beticolin-1 was immediate, independent of cell culture step and not reversible for 3-day treatment. Beticolin-3 and -4 were slightly active (1 μmol/L < IC50 ≤ 2μmol/L) and beticolin-7, -9, -12, and -5 were inactive at micromolar level. The beticolin-induced cell growth inhibition was correlated with the hydrophobicity of these compounds. Beticolin-1 fluorescence in RTAC cells was detected by confocal microscopy whereas beticolin-3 and -12 were not even after a 24 h incubation period.Beticolin-1-induced cell growth inhibition was partially reverted by calcium ionophore suggesting a role of intracellular Ca2 + chelation by beticolin-1 on cell growth inhibition. Furthermore, beticolin-1 blocked up Ras p21 translocation to membrane and induced accumulation of Ras in the cytosol as an inactive form by different ways.

  12. Study on Biological Characteristics of Cercospora zeae-maydis in Southwest China%西南地区玉米灰斑病菌生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    崔丽娜; 张小飞; 邹成佳; 李晓; 杨晓蓉; 罗怀海

    2012-01-01

    为了进一步防治玉米灰斑病奠定基础,对西南地区玉蜀黍尾孢菌的生物学特性进行了初步研究.结果表明,该病菌生长温度为10 ~35℃,最适生长温度为20~25℃;病原菌对酸碱度的适应范围较广,在pH 4 -11都能生长,以pH 5 ~7为最适pH值;分生孢子萌发温度为5 ~35℃,最适温度为20 ~25℃;光照对菌丝和孢子萌发无显著影响;病原菌最适碳源为葡萄糖,最适氮源为酵母青,致死温度为55℃(10 min).%Some biological characters of Cercospora zeae-maydis were studied in this experiment. The results showed that the pathogen could grow and develop between 10 and 35 ℃ , and the optimum temperature was between 20 and 25 ℃, For growth of the pathogen, there had no strict pH requirement: the favorable pH was 4 -11 and the optimum pH was 5-7. For germination of conidia, the favorable temperature for conidial germination was between 5 and 35 ℃and the optimum temperature was 20 -25 ℃. Effect of light was not obvious on mycelial growth and conidial germination. The optimum carbon source was glucose, and the optimum nitrogen source was yeast extract. The lethal temperature for pathogen was at 55 ℃ for 10 minutes.

  13. Accumulation of the hormone abscisic acid (ABA) at the infection site of the fungus Cercospora beticola supports the role of ABA as a repressor of plant defence in sugar beet.

    Science.gov (United States)

    Schmidt, Klaus; Pflugmacher, Maike; Klages, Simone; Mäser, Anja; Mock, Andrea; Stahl, Dietmar J

    2008-09-01

    Inducible plant defence responses in sugar beet (Beta vulgaris L.) leaves are repressed during the early phase of infection by the fungus Cercospora beticola. In this report, we show that the concentration of the plant hormone abscisic acid (ABA) increases in sugar beet leaves during C. beticola infection. After an initial burst of ABA induced by inoculation of the fungus, elevated ABA concentrations were detected during the fungal penetration and colonization phases 3-9 days after inoculation. Fifteen days after inoculation, with visible onset of the necrotic phase of infection, the strongly elevated ABA concentrations in infected leaves were at levels similar to drought-stressed plants. A synthetic promoter composed of four copies of the ABA-responsive element (ABRE) A2 and the coupling element CE3 of the ABA-inducible barley gene HVA1 was strongly induced by ABA and C. beticola infection in transgenic sugar beet leaves. Analysis of the spatial pattern of promoter activity revealed that the ABA-inducible promoter was locally activated at the fungal infection sites. Furthermore, expression of the basic leucine zipper transcription factor AREB1 was induced by drought stress and fungal infection in the sugar beet. Application of ABA reduced the promoter activity of the phenylalanine ammonia lyase (BvPAL) gene, and this effect was observed with the -34 to +248 BvPAL promoter region. This region is equivalent to the core promoter, which is necessary for the suppression of BvPAL expression by C. beticola, as recently shown. These data indicate that ABA accumulation and activation of the ABA-dependent signalling cascade are the primary cause of suppression of BvPAL expression during infection of sugar beet leaves.

  14. Research methodology for maize gray leaf spot:Ⅰ.sporulation of Cercospora zeae-maydis%玉米灰斑病研究方法:Ⅰ.玉米灰斑病菌孢子的培养

    Institute of Scientific and Technical Information of China (English)

    赵正龙; 吴兴兴; 毛自朝; 何月秋

    2011-01-01

    为了明确玉米灰斑病菌的产孢条件,将玉米灰斑病菌接种到马铃薯蔗糖(PSA),燕麦番茄碳酸钙(OTCA)、玉米叶粉碳酸钙(MLPCA)、燕麦粉(OA)、粗面粉(CWPA)等5种培养基上,于25℃下培养,测定该菌生长速度、产孢时间和产孢量.结果表明,菌丝在上述培养基上生长速度均较慢,每天平均生长0.33 nun左右,其中以在OA和PSA上生长速度相对较快.基于上述结果,构建了玉米灰斑病菌孢子培养的二级分段培养法,即将菌丝块接种于加有10~15粒直径为5 mm玻璃珠的马铃薯蔗糖(PS)液体培养基三角瓶里,在25℃,180 r/min条件下振荡培养15 d,形成菌丝悬液,再取菌丝悬浮液涂布在MLPCA培养基上,避光培养13 d左右,可获得大童供接种的分生孢子.长期光照促进菌丝生长,不利于孢子的形成,而长期黑暗不利于菌丝生长,但有利于孢子的形成.%The pathogen of maize gray leaf spot, Cercospora zeae-maydis, was inoculated on potato sucrose agar (PSA), oat tomato plus CaCO3 agar(OTCA), maize leaf powder plus CaCO3 agar(MLPCA), oatmeal agar(OA) and crude wheat powder agar (CWPA), and incubated at 25 ℃ for measuring the mycelial growth, sporulation time and number. The results showed that the mycelia grew very slow on the media, with an average of 0.33 mm per day. They grew fastest on OA and PSA, slower on CWPA and most slowly on MLPCA. Based on the results,a sporulation method was set up, namely two-step culturing method. The mycelia were inoculated into flask with PS and 10-15 glass balls of 5mm diameter, and shaken at 25 ℃ and 180 r/min for 15 days, to culture the mycelial fragment suspension. Then the suspension was smeared on MLPCA medium and incubated for about 13 days at 25 ℃ without light. By this way, a large number of spores could be produced for inoculation. Long illumination promoted the mycelial growth, but on the contrary, long darkness was conducive to sporulation.

  15. 云南咖啡主要病虫害及防治调查研究①%Main Diseases and Pests of Coffee and Their Prevention and Control in Yunnan

    Institute of Scientific and Technical Information of China (English)

    刘树芳; 金桂梅; 杨艳鲜; 许叁卫

    2014-01-01

    As increasing in cultivated area of coffee and its occurrence of diseases and insects in Yunnan, the study on diseases and insects of coffee and their prevention and control has important significance on sustainable production of coffee. The diseases and insects of coffee were investigated in Baoshan, Dehong, Puer cities in Yunnan of China from 2012-2013. The results showed that Hemileia vastatrix Berk et Br., Colletotrichum coffeanum Noack, Cercospora coffeicola Berk. et Cooke, Rhizoctonia solani Kuhn., Acalolepta cervina Hope, Xylotrechus quadripes Chevr, Planococus lilacinus Cockrell were the main insects and diseases and resulted into higher damage for coffee in Yunnan. According to occurrence and damage of coffee diseases and insects, some corresponding prevention and control methods have been proposed. All these will provide scientific basis for Yunnan coffee production.%对云南保山、德宏、普洱等地咖啡病虫害开展调查研究,结果表明院咖啡锈病(Hemileia vastatrix Berk et Br.)、炭疽病(Colletotrichum coffeanum Noack)、褐斑病(Cercospora coffeicola Berk. et Cooke)、幼苗立枯病(Rhizoctonia solani Kuhn.)、旋皮天牛(Acalolepta cervina Hope)、灭字虎天牛(Xylotrechus quadripes Chevr)和根粉蚧(Planococus lilacinus Cockrell)是云南咖啡主要病虫害,其危害较重。根据调查研究结果,提出相应防治方法,为云南咖啡主要病虫害的防治提供依据。

  16. Incidência de pragas e doenças em agroecossistemas de café orgânico de agricultores familiares em Poço Fundo-MG Incidence of plagues and diseases in agroecossystems of organic coffee of familiar farmers in Poço Fundo-MG

    Directory of Open Access Journals (Sweden)

    Márcia Martins

    2004-12-01

    Full Text Available Objetivando-se determinar a incidência de pragas Leucoptera coffeella (GUÉRIN-MENÉVILLE, 1842 e Hypothenemus hampei (FERRARI, 1867 e doenças Hemileia vastatrix (BERK e BROOME, 1869 e Cercospora coffeicola (BERK e CURTIS, 1880, durante o período de janeiro de 2001 a dezembro de 2002, foram selecionados três agroecossistemas com produção de café orgânico conduzidos por agricultores familiares do município de Poço Fundo-MG. O agroecossistema I possui 2.200 pés da cultivar 'Catuaí Vermelho' em espaçamento 2,5 x 1,3 m (0,72 ha. O agroecossistema II possui 2.000 pés ('Catuaí Vermelho' em espaçamento 2,8 x 1,0 m (0,56 ha. O agroecossistema III possui 1.100 pés ('Icatu Amarelo' em espaçamento 3,0 x 0,9 m (0,36 ha. A determinação da incidência de L. coffeella, C. coffeicola e H. vastatrix foi realizada mediante levantamentos mensais. A determinação da infecção por C. coffeicola em frutos foi realizada nos meses de abril, maio e junho de 2001 e 2002. O levantamento da infestação por H. hampei foi realizado nos meses de janeiro a junho/julho de cada ano. Determinou-se que a infestação por L. coffeella ultrapassou 20% no terço superior (principalmente no período seco. A infestação por H. hampei atingiu o nível de dano somente no agroecossistema I, em 2001, e no agroecossistema III, em 2002. A infecção por H. vastatrix no agroecossistema III não atingiu nível de dano em conseqüência da tolerância da cultivar ('Icatu' à infecção por esse fungo; porém, nos agroecossistemas I e II ('Catuaí Vermelho', a infecção na lavoura ultrapassou o nível de 10% (principalmente no período seco. A infecção por C. coffeicola em folhas e frutos atingiu níveis elevados (período seco. A produtividade do agroecossistema I, em 2001, foi de 510 Kg ha-1 e, em 2002, de 2.340 Kg ha-1; no agroecossistema II, em 2001, foi de 420 Kg ha-1 e, em 2002, de 1.290 Kg ha-1; e, no agroecossistema III, foi praticamente zero, em 2001, e em

  17. Antifungal activity using medicinal plant extracts against pathogens of coffee tree

    Directory of Open Access Journals (Sweden)

    J.L. Silva

    2014-09-01

    Full Text Available Generally, the medicinal plants have antifungal substances that can be used for the plant protection against phytopathogens. The objective of this study was to know the efficiency of aqueous extracts from medicinal plants against the major etiological agents of coffee tree. The aqueous extracts used were extracted from bulbs of Allium sativum, leaves of Vernonia polysphaera, Cymbopogon citratus, Cymbopogon nardus, Cordia verbenacea, Eucalyptus citriodora, Ricinus communis, Azadirachta indica, Piper hispidinervum and flower buds of Syzygium aromaticum. The etiological agents considered for this study were Cercospora coffeicola, Colletotrichum gloeosporioides, Fusarium oxysporum, Phoma tarda, Rhizoctonia solani and Hemileia vastatrix. The screening for harmful extracts was done based on mycelial growth and conidial germination inhibition. All experiments performed were in vitro conditions. The inhibition of mycelial growth was performed mixing the extracts with the PDA. This mixture was poured in Petri dishes. On the center of the dishes was added one PDA disc with mycelium. It was incubated in a chamber set to 25ºC. The evaluation was done daily by measuring the mycelial growth. The germination assessment was also performed with Petri dishes containing agar-water medium at 2%. These were incubated at 25ºC for 24 hours. After this period the interruption of germination was performed using lactoglycerol. The experiments were conducted in a completely randomized design. The most effective plant extracts against the micelial growth and conidial germination were V. polysphaera, S. aromaticum and A. sativum.

  18. Editorial: First Report of Cercospora beticola as a Pathogen of German Statice (Goniolimon tataricum) in Bulgaria

    NARCIS (Netherlands)

    Bobev, S.G.; Groenewald, J.Z.; Crous, P.W.

    2009-01-01

    German statice (Goniolimon tataricum) is a protected, herbaceous, perennial plant species that occurs sporadically throughout Bulgaria. Some varieties, however, are cultivated outdoors because of their dry flowers, which are widely utilized by florists. For the past 3 years, a severe leaf disease ha

  19. Relationships between oleic and linoleic acid content and seed colonization by Cercospora kikuchii and Diaporthe phaseolorum

    Science.gov (United States)

    Seeds of soybean lines with the mid-oleic phenotype have sometimes shown increased colonization by fungi during later stages of development in the field. To approach this phenomenon experimentally, we manipulated the oleic and linoleic acid content in seeds of two near-isogenic soybean lines by all...

  20. Screening for resistance to purple seed stain Cercospora kikuchii by seed inoculation technique

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, S.H.; Oh, J.H.

    1978-01-01

    An attempt was made to establish a mass-screening technique for resistance to purple seed stain disease in soybean. Seeds sterilized in 1 : 10,000 mercuric chloride for 1 minute and transferred to Petridishes containing 20ml water agar plus 50 ppM of the sodium salt of 2,4-D were inoculated by placing a small agar cube containing fungal mycelium on the seed coat of each seed. A positive correlation betweeen natural infection of purple seed stain and purple discoloration by seed inoculation technique was highly significant and by this technique, some native soybean collections and introduced varieties were tested for resistance to the disease. Most of the soybean varieties tested were susceptible except for the varieties Hill, Harosoy and Sac, resistant comparatively.

  1. 大豆紫斑病菌(Cercospora kikuchii)生物学特性研究

    Institute of Scientific and Technical Information of China (English)

    王伟; 衣春生

    1998-01-01

    大豆紫斑病菌在PDA培养基上生长速率最快,在大豆叶葡萄糖琼脂培养基和番茄培养基瞳孢量经在PDA上高2倍,比病菌生长发育最适温度为25-28℃,低于15℃或高于37℃均不适宜,在连续黑暗条件下有利于生长,PH4-9之间,均能生长和产孢以PH-=7生长最适,PH=7-8产孢最多,分生孢子在葡萄糖液中萌发最好,在15-40℃之间均能萌发,最适温度为30-33℃,PH=3-9之间均能萌发,PH=7-8萌发

  2. Controle químico da "ERGOT" (Claviceps africana Frederickson, Mantle & de Milliano ou doença-açucarada e das principais doenças foliares do sorgo (Sorghum bicolor (L. Moench Chemical control of "ERGOT"(Claviceps africana Frederickson, Mantle & de Milliano or sugary disease and the main foliar diseases of sorghum (Sorghum bicolor (L. Moench

    Directory of Open Access Journals (Sweden)

    Nicésio Filadelfo Janssen de Almeida Pinto

    2003-08-01

    Full Text Available O controle químico da "ergot" (Claviceps africana foi realizado em campo de produção de sementes do híbrido de sorgo granífero BR 304 (Sorghum bicolor (L. Moench., utilizando-se os fungicidas (g i.a./ha: captan (1250,0, fenarimol (80,0, trifenil hidróxido de estanho (166,7, prochloraz (450,0, chlorothalonil (1500,0, iprodione (750,0, azoxystrobin (150,0, thiabendazole (360,0, procimidone (750,0, ziram (1500,0 e tebuconazole (200,0. Parcelas sem aplicação de fungicida constituíram a testemunha. As pulverizações foram realizadas com pulverizador costal manual, com o jato dirigido para as panículas. O intervalo das aplicações dos fungicidas foi de 4 dias, a partir da antese. Aos 7 dias após o término das pulverizações, a porcentagem de panículas doentes variou 5,4 para o fungicida tebuconazole e 100,0% para a maioria dos demais tratamentos. Para a porcentagem de flores doentes por panícula, os valores variaram de 0,3% a 65,0% para o fungicida tebuconazole e testemunha, respectivamente. Não ocorreu diferença significativa entre as porcentagens de flores doentes por panículas nos tratamentos tebuconazole (0,3%, chlorothalonil (2,5% e prochloraz (3,0%, sendo esses os mais eficientes no controle da ergot. Adicionalmente, o fungicida mais eficiente no controle da antracnose foliar (Colletotrichum graminicola foi o prochloraz, ao passo que para a ferrugem (Puccinia purpurea e a cercosporiose (Cercospora fusimaculans, o maior controle foi obtido com o fungicida tebuconazole. Não houve aumento da germinação das sementes em nenhum dos tratamentos; entretanto, o aumento do peso de mil sementes foi significativo para os tratamentos com os fungicidas prochloraz, chlorotalonil e tebuconazole.The efficiency of fungicides in the control of sugar disease of sorghum (Sorghum bicolor (L. Moench. was evaluated in a seed production field of the sorghum hybrid BR 304. The following fungicides and doses (g a.i./ha were evaluated : captan (1250

  3. Dicty_cDB: Contig-U05491-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ADI_5th_i... 46 1.9 1 ( FG250469 ) CBYC608.b1 CBYC Cercospora zeae-maydis cercosp...ori... 46 1.9 1 ( FG246443 ) CBYB4322.b1 CBYB Cercospora zeae-maydis cercospor... 46 1.9 1 ( FG244122 ) CBYB2657.g1 CBYB Cercospora

  4. Dicty_cDB: Contig-U11279-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ( FG251718 ) CBYF1589.g1 CBYF Cercospora zeae-maydis conidiati... 52 0.067 1 ( FG250521 ) CBYC640.g1 CBYC Cercospora... zeae-maydis cercospori... 52 0.067 1 ( FG243214 ) CBYB2040.g1 CBYB Cercospora zeae-maydis cercospor

  5. Influência da nutrição mineral na intensidade da mancha-de-olho-pardo em mudas de cafeeiro Influence of the mineral nutrition on intensity of brown-eye spot in young coffee plants

    Directory of Open Access Journals (Sweden)

    Adélia Aziz Alexandre Pozza

    2001-01-01

    Full Text Available Objetivando avaliar a intensidade da mancha-de-olho-pardo do cafeeiro, variedade Catuaí Vermelho, com relação ao estado nutricional das plantas quanto a N e K, realizou-se um experimento no viveiro da Universidade Federal de Viçosa, em Viçosa, MG, utilizando solução nutritiva circulante. Empregaram-se 16 tratamentos, em delineamento inteiramente casualizado, com três repetições e duas plantas por parcela, em esquema fatorial com quatro doses de K (3, 5, 7 e 9mmol/L e quatro doses de N (3, 7, 11 e 15mmol/L. Após sete inoculações de conídios, e avaliações, colheram-se as plantas. A produção de matéria seca total, a área foliar total, e a área abaixo da curva de progresso (AACP do número total de folhas não foram influenciadas pelas doses de K, mas aumentaram com o incremento das doses de N. Observou-se elevação, na AACP, do número de lesões por folha, e na desfolha com o aumento das doses de K e a redução das doses de N. A elevação nas doses de K promoveu redução nos teores foliares de Ca e Cu. Osteores foliares de P, Mg, Mn e Fe não foram influenciados pelas doses de K e tiveram pequena redução com o aumento de N na solução, elevando-se a seguir.The experiment was carried out at the coffee nursery of the Universide Federal de Viçosa, in Viçosa, MG, Brazil, using nutrient circulating solution to evaluate the intensity of brown-eye spot (Cercospora coffeicola, variety Catuaí Vermelho, as a function of N and K. Acompletely randomized design with 16 treatments, three replicates, and two plants per plot was used in a factorial with four levels of K (3, 5, 7 and 9mmol/L combined with four levels of N (3, 7, 11 and 15mmol/L. After seven inoculations and evaluations, the plants were picked. Total dry matter production, total leaf area, and the area below the curve of progress (AACP for the total number of leaves were not influenced by the levels of K, but increased with increasing levels of N. There was increase

  6. Influência de safras agrícolas e tratamentos fungicidas no café cereja descascado e bóia Influence of harvests and fungicide treatments on the parchment and floaters coffee

    Directory of Open Access Journals (Sweden)

    Adriano Andrade Abrahão

    2009-01-01

    Full Text Available O manejo adequado de doenças foliares, como a ferrugem e a cercosporiose do cafeeiro, é fator primordial para a produção de bebidas de qualidade. Nesse sentido, torna-se de extrema importância o conhecimento dos procedimentos técnicos e de produtos fitossanitários, bem como o efeito exercido pelos mesmos na qualidade do café. Objetivou-se, com este trabalho, estudar a qualidade dos grãos de café cereja descascado e bóia procedentes de tratamentos fungicidas, em duas safras agrícolas. Foram conduzidos ensaios nos anos agrícolas 2002/03 e 2003/04. O delineamento utilizado foi o inteiramente casualizado com parcelas subdivididas, utilizando-se quatro repetições, em esquema fatorial 2 x 3 x 2, compreendendo duas safras, três tratamentos fungicidas (fungicida sistêmico, nome comercial Ópera®, fungicida de contato, nome comercial Cobox®, e testemunha não tratada com fungicidas e dois tipos de processamento, cereja descascado e bóia. As avaliações da qualidade dos grãos foram realizadas por meio das análises químicas: acidez titulável, pH, lixiviação de potássio e condutividade elétrica. Os resultados indicaram que os tratamentos fungicidas afetaram apenas a lixiviação de potássio para o café bóia, no qual o Cobox® apresentou menor lixiviação comparado aos demais. Em ambos os processamentos estudados, o segundo ano de ensaio apresentou maior condutividade elétrica, e quando considerado o café bóia, maior lixiviação de potássio. O resultados apontam ainda que, no primeiro ano de ensaio o café cereja descascado apresentou efeito superior para a acidez titulável.The appropriate management of leaf diseases, such as rust and cercospora of the coffee plant, has become extremely important to the production of good quality coffee. In this context, the knowledge of technical procedures and phytosanitary products become extremely important, as well as the effect caused by them in the coffee quality. The objective

  7. Dicty_cDB: Contig-U06911-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 63 ) 7LEAF--06-J20.b1 Rice leaf plasmid cDNA library I... 46 1.2 1 ( FG253080 ) CBYG1302.g1 CBYG Cercospora ...zeae-maydis conidiati... 46 1.2 1 ( FG253079 ) CBYG1302.b1 CBYG Cercospora zeae-m...aydis conidiati... 46 1.2 1 ( FG243788 ) CBYB2420.g1 CBYB Cercospora zeae-maydis cercospor... 46 1.2 1 ( FD7

  8. Dicty_cDB: Contig-U13942-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 24 |pid:none) Cercospora beticola strain CBS 116... 43 7e-04 FB334766_1( FB334766...228_1( AY752228 |pid:none) Cercospora beticola strain CBS 122... 43 0.002 AY752237_1( AY752237 |pid:none) My

  9. Dicty_cDB: Contig-U14269-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available .. 81 3e-14 CP000667_2771( CP000667 |pid:none) Salinispora tropica CNB-440, co... 81 3e-14 DQ355149_1( DQ355149 |pid:none) Cercospora...2 2e-08 DQ991505_1( DQ991505 |pid:none) Cercospora nicotianae O-methyltran... 62 2e-08 BT036832_1( BT036832

  10. Dicty_cDB: Contig-U10097-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available tyostelium discoideum slug cDNA, clone SSL239. 307 e-108 2 ( FG252229 ) CBYF541.g1 CBYF Cercospora... zeae-maydis conidiatio... 58 3e-18 4 ( FG252228 ) CBYF541.b1 CBYF Cercospora zeae-maydis c

  11. AcEST: BP921793 [AcEST

    Lifescience Database Archive (English)

    Full Text Available e-07 sp|P48537|CRTI_CERNC Phytoene dehydrogenase OS=Cercospora nicoti... 52 1e-06 sp|Q64FG0|RETST_MACFA All-...EQGFEFDVG 114 >sp|P48537|CRTI_CERNC Phytoene dehydrogenase OS=Cercospora nicotian

  12. Dicty_cDB: Contig-U15661-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 8 ) SCCCLR1024F06.g LR1 Saccharum officinarum cDNA cl... 76 5e-09 1 ( FG245328 ) CBYB3528.b1 CBYB Cercospora... zeae-maydis cercospor... 76 5e-09 1 ( FG242556 ) CBYB1587.b1 CBYB Cercospora zea

  13. Dicty_cDB: Contig-U06609-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available accharopolyspora erythraea NRR... 77 6e-13 DQ355149_1( DQ355149 |pid:none) Cercospora nicotianae cercosporin...artiensis genome... 52 2e-05 DQ991505_1( DQ991505 |pid:none) Cercospora nicotianae O-methyltran... 51 3e-05

  14. Dicty_cDB: Contig-U15127-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available uncatula IOMT 7 mRNA, c... 64 5e-09 DQ355149_1( DQ355149 |pid:none) Cercospora nicotianae cercosporin ... 64...-methyl transfera... 52 2e-05 DQ991505_1( DQ991505 |pid:none) Cercospora nicotian

  15. Dicty_cDB: Contig-U15023-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available e) Podospora anserina genomic DNA c... 118 2e-24 EU530632_1( EU530632 |pid:none) Cercospora nicotianae MFS t...actis strain NRRL... 89 4e-24 AF091042_1( AF091042 |pid:none) Cercospora kikuchii putative cerco... 116 5e-2

  16. Occurrence Reason and Control Measure of Cercospora kikuchii Matsumoto and Tomoyasu%大豆紫斑病发生的原因及综合防治措施

    Institute of Scientific and Technical Information of China (English)

    赵凤玲; 高凤菊

    2008-01-01

    针对德州市2007年大豆收获前阴雨寡照、致使大豆紫斑病严重发生的生产实际,对大豆紫斑病发生的原因、病症、规律、传播途径及综合防治措施进行了研究探讨,为指导今后的大豆生产奠定了理论基础.

  17. Fungal Planet description sheets: 69–91

    NARCIS (Netherlands)

    Crous, P.W.; Groenewald, J.Z.; Shivas, R.G.; Edwards, J.; Seifert, K.A.; Alfenas, A.C.; Alfenas, R.F.; Burgess, T.I.; Carnegie, A.J.; Hardy, G.E.St.J.; Hiscock, N.; Hüberli, D.; Jung, T.; Louis-Seize, G.; Okada, G.; Pereira, O.L.; Stukely, M.J.C.; Wang, W.; White, G.P.; Young, A.J.; McTaggart, A.R.; Pascoe, I.G.; Porter, I.J.; Quaedvlieg, W.

    2011-01-01

    Novel species of microfungi described in the present study include the following from Australia: Bagadiella victoriae and Bagadiella koalae on Eucalyptus spp., Catenulostroma eucalyptorum on Eucalyptus laevopinea, Cercospora eremochloae on Eremochloa bimaculata, Devriesia queenslandica on Scaevola t

  18. THE USE OF COADJUTANTS IN TANK MIX WITH FUNGICIDES IN ORDER TO IMPROVE THEIR EFFECTIVENESS EVEN AT LOW DOSAGES

    OpenAIRE

    Giovanni Campagna; Pierlorenzo Brignoli

    2006-01-01

    One of the most important items of modern agriculture is the reduction of environmental impact thanks to the integration of new cultivation and protection techniques. Therefore it is important to optimise the use of chemicals and pesticides. We found that some coadjutants applied in tank mix with fungicides on sugar beet protection improve the effectiveness of active principles in cercospora leafspot (Cercospora bieticola sacc.) control.

  19. Influência do zinco na incidência de doenças do cafeeiro Zinc influence on coffee diseases

    Directory of Open Access Journals (Sweden)

    Vicente Luiz de Carvalho

    2008-06-01

    Full Text Available Em cafeeiros, poucos estudos foram feitos relacionando aumento ou diminuição da resistência das plantas às doenças, com alteração dos níveis de nutrientes utilizados. Com este trabalho, objetivou-se estudar os efeitos do sulfato de zinco aplicado isoladamente, e associado com fungicidas e cloreto de potássio sobre a ferrugem, cercosporiose e manchas foliares do cafeeiro. O trabalho foi desenvolvido em uma lavoura de café em produção, onde foram testados oxicloreto de cobre, tebuconazole, sulfato de zinco + cloreto de potássio e sulfato de zinco e nas subparcelas foram realizadas diferentes concentrações de sulfato de zinco: ausência, 0,3 %, 0,6 % e 1,2 %. Verificou-se que os tratamentos com oxicloreto de cobre e tebuconazole reduziram a incidência e severidade de ferrugem, a incidência de cercosporiose, de manchas foliares (phoma e ascochyta e a desfolha, independente das concentrações de sulfato de zinco utilizadas. Concentrações de sulfato de zinco na faixa de 0,6 % - 0,75 % apresentaram menor severidade da ferrugem e o aumento nas concentrações de sulfato de zinco aumentou a incidência de cercosporiose, manchas foliares e a desfolha dos cafeeiros.The are few studies have been done related to the increase or decrease of disease resistance in coffee plants, with alteration from plant nutrient levels. The ain of this work was to verify the effect of zinc sulfate, applied either alone or in association with fungicides, and the effect of potassium chloride on coffee leaf rust, brown-eyes and leaf stains in coffee plants. Copper oxichloride, tebuconazole, sulfate of zinc + potassium chloride and sulfate of zinc were applied on plots and concentrations of zinc sulfate (0,0 %, 0,3 %, 0,6 % and 1,2 % were applied on sub plot. Treatments with copper and tebuconazole reduced the incidence and severity of rust, the incidence of brown-eyes and stains leaf (phoma and ascochyta and the defoliate independent of the zinc sulfate

  20. Systems genetics reveals a transcriptional network associated with susceptibility in the maize-grey leaf spot pathosystem

    Science.gov (United States)

    We have applied a systems genetics approach to elucidate molecular mechanisms of maize responses to gray leaf spot (GLS) disease, caused by Cercospora zeina, a major threat to maize production globally. We conducted expression QTL (eQTL) analysis of gene expression variation measured in earleaf samp...

  1. Permanent Genetic Resources added to Molecular Ecology Resources database 1 January 2009-30 April 2009.

    Science.gov (United States)

    Abercrombie, L G; Anderson, C M; Baldwin, B G; Bang, I C; Beldade, R; Bernardi, G; Boubou, A; Branca, A; Bretagnolle, F; Bruford, M W; Buonamici, A; Burnett, R K; Canal, D; Cárdenas, H; Caullet, C; Chen, S Y; Chun, Y J; Cossu, C; Crane, C F; Cros-Arteil, S; Cudney-Bueno, R; Danti, R; Dávila, J A; Della Rocca, G; Dobata, S; Dunkle, L D; Dupas, S; Faure, N; Ferrero, M E; Fumanal, B; Gigot, G; González, I; Goodwin, S B; Groth, D; Hardesty, B D; Hasegawa, E; Hoffman, E A; Hou, M L; Jamsari, A F J; Ji, H J; Johnson, D H; Joseph, L; Justy, F; Kang, E J; Kaufmann, B; Kim, K S; Kim, W J; Koehler, A V; Laitung, B; Latch, P; Liu, Y D; Manjerovic, M B; Martel, E; Metcalfe, S S; Miller, J N; Midgley, J J; Migeon, A; Moore, A J; Moore, W L; Morris, V R F; Navajas, M; Navia, D; Neel, M C; De Nova, P J G; Olivieri, I; Omura, T; Othman, A S; Oudot-Canaff, J; Panthee, D R; Parkinson, C L; Patimah, I; Pérez-Galindo, C A; Pettengill, J B; Pfautsch, S; Piola, F; Potti, J; Poulin, R; Raimondi, P T; Rinehart, T A; Ruzainah, A; Sarver, S K; Scheffler, B E; Schneider, A R R; Silvain, J F; Siti Azizah, M N; Springer, Y P; Stewart, C N; Sun, W; Tiedemann, R; Tsuji, K; Trigiano, R N; Vendramin, G G; Wadl, P A; Wang, L; Wang, X; Watanabe, K; Waterman, J M; Weisser, W W; Westcott, D A; Wiesner, K R; Xu, X F; Yaegashi, S; Yuan, J S

    2009-09-01

    This article documents the addition of 283 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Agalinis acuta; Ambrosia artemisiifolia; Berula erecta; Casuarius casuarius; Cercospora zeae-maydis; Chorthippus parallelus; Conyza canadensis; Cotesia sesamiae; Epinephelus acanthistius; Ficedula hypoleuca; Grindelia hirsutula; Guadua angustifolia; Leucadendron rubrum; Maritrema novaezealandensis; Meretrix meretrix; Nilaparvata lugens; Oxyeleotris marmoratus; Phoxinus neogaeus; Pristomyrmex punctatus; Pseudobagrus brevicorpus; Seiridium cardinale; Stenopsyche marmorata; Tetranychus evansi and Xerus inauris. These loci were cross-tested on the following species: Agalinis decemloba; Agalinis tenella; Agalinis obtusifolia; Agalinis setacea; Agalinis skinneriana; Cercospora zeina; Cercospora kikuchii; Cercospora sorghi; Mycosphaerella graminicola; Setosphaeria turcica; Magnaporthe oryzae; Cotesia flavipes; Cotesia marginiventris; Grindelia Xpaludosa; Grindelia chiloensis; Grindelia fastigiata; Grindelia lanceolata; Grindelia squarrosa; Leucadendron coniferum; Leucadendron salicifolium; Leucadendron tinctum; Leucadendron meridianum; Laodelphax striatellus; Sogatella furcifera; Phoxinus eos; Phoxinus rigidus; Phoxinus brevispinosus; Phoxinus bicolor; Tetranychus urticae; Tetranychus turkestani; Tetranychus ludeni; Tetranychus neocaledonicus; Tetranychus amicus; Amphitetranychus viennensis; Eotetranychus rubiphilus; Eotetranychus tiliarium; Oligonychus perseae; Panonychus citri; Bryobia rubrioculus; Schizonobia bundi; Petrobia harti; Xerus princeps; Spermophilus tridecemlineatus and Sciurus carolinensis.

  2. Genomics of peanut leaf-spot pathogens; and RNA-interference-mediated control of aflatoxins

    Science.gov (United States)

    An overview update of the research done at USDA-ARS National Peanut Research Laboratory will be presented: including: the release of the Cercospora arachidicola genome, sequencing of Cercosporidium personatum, a workflow to study genetic diversity of aflatoxigenic Aspergillus, and progress on the us...

  3. Processing, disulfide pattern, and biological activity of a sugar beet defensin, AX2, expressed in Pichia pastoris

    DEFF Research Database (Denmark)

    Kristensen, A K; Brunstedt, J; Nielsen, J E

    1999-01-01

    AX2 is a 46-amino-acid cysteine-rich peptide isolated from sugar beet leaves infected with the fungus Cercospora beticola (Sacc.). AX2 strongly inhibits the growth of C. beticola and other filamentous fungi, but has little or no effect against bacteria. AX2 is produced in very low amounts in sugar...

  4. Soybean Toxin (SBTX) Impairs Fungal Growth by Interfering with Molecular Transport, Carbohydrate/Amino Acid Metabolism and Drug/Stress Responses

    NARCIS (Netherlands)

    Morais, Janne K. S.; Bader, Oliver; Weig, Michael; Oliveira, Jose Tadeu A.; Arantes, Mariana R.; Gomes, Valdirene M.; Da Cunha, Maura; Oliveira, Hermogenes D.; Sousa, Daniele O. B.; Lourencao, Andre L.; Vasconcelos, Ilka M.

    2013-01-01

    Soybean toxin (SBTX) is an antifungal protein from soybeans with broad inhibitory activity against the growth and filamentation of many fungi, including human and plant pathogenic species such as Candida albicans, Candida parapsilosis, Aspergillus niger, Penicillium herquei, Cercospora sojina and Ce

  5. Organic rice disease management using genetic resistance, cover crop and organic fertilizer

    Science.gov (United States)

    The strong market demand for organic rice has driven the continued increase of organic rice production in the US. However, growers still lack effective tools to manage narrow brown leaf spot (NBLS) caused by Cercospora janseana and brown spot caused by Cochliobolus miyabeanus, two common diseases af...

  6. Evaluation of Organic Pest Management Treatments for Bean Leaf Beetle in Soybean in Iowa

    Science.gov (United States)

    Many organic soybean producers face the challenge of bean leaf beetle (Ceratoma trifurcata), which harbors bean mottle pod virus and opens infection sites for Fusarium spp., Cercospora kikuchii, and Phomopsis spp., which cause discoloration in soybeans. Stained soybean seed is less acceptable for fo...

  7. Evaluation of maturity group III soybean lines for resistance to purple seed stain in Mississippi, 2010

    Science.gov (United States)

    Purple seed stain (PSS) of soybean is an important disease caused by Cercospora kikuchii. PSS reduces seed quality and market grade, affects seed germination and vigor, and has been reported wherever soybeans are grown worldwide. In 2009, PSS caused 6.4 million bushels of yield losses in 16 southern...

  8. Evaluation of maturity group IV soybean lines for resistance to purple seed stains in Mississippi 2010

    Science.gov (United States)

    Purple seed stain (PSS) of soybean is an important disease caused by Cercospora kikuchii. PSS reduces seed quality and market grade, affects seed germination and vigor, and has been reported wherever soybeans are grown worldwide. In 2009, PSS caused 6.4 million bushels of yield losses in 16 southern...

  9. Research on purple seed stain of soybean: germplasm screening and genetic resistance

    Science.gov (United States)

    Soybean purple seed stain (PSS) causes seed decay and purple seed discoloration, resulting in overall poor seed quality and reduced market grade and value. It is a prevalent disease that also affects seed vigor and stand establishment. PSS is caused by the fungus Cercospora kikuchii and other Cercos...

  10. Reaction of maturity group V soybean lines to purple seed stains in Mississippi 2010

    Science.gov (United States)

    In 2009, soybean purple seed stain (PSS) caused 6.4 million bushels of yield losses in 16 southern states. This disease severely reduces seed market grade and affects seed germination and vigor. PSS is caused by Cercospora kikuchii and is an economy important disease. To identify new sources of resi...

  11. Dicty_cDB: Contig-U12034-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 2365 ) Mus musculus mammary gland RCB-0526 Jyg-MC(A) cDN... 48 0.80 1 ( FG244122 ) CBYB2657.g1 CBYB Cercos...pora zeae-maydis cercospor... 48 0.80 1 ( EK182641 ) 1095458129632 Global-Ocean-Sam

  12. Inheritance of and molecular markers for purple seed stain resistance in soybean

    Science.gov (United States)

    Purple seed stain (PSS) caused by Cercospora kikuchii, is an important disease of soybean, causing seed quality deterioration. Use of genetic resistance is the most practical and economical way to control the disease. The objectives of this research were to investigate the inheritance of resistance...

  13. Synthesis, Structure and Biological Activities of 2-(1H-1,2,3-Benzotriazol-1-yl)-1-(4-methylphenyl)-2-(1H-1,2,4-triazol-1-yl)-1-ethanone

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The title compound was synthesized and characterized by IR, 1H NMR, elemental analysis and single crystal X-ray diffraction analysis. Its biological activities were also tested. The results show that the title compound reveals inhibiting activities towards wheat gibberellin, apple ringspot, tomato early blight, peanut cercospora arachidicola and stem wilt of asparagus.

  14. Sugar beet activities of the USDA-ARS East Lansing conducted in cooperation with Saginaw Valley Bean and Beet Farm during 2010

    Science.gov (United States)

    Cercospora leaf spot resistance evaluation plots were planted at the Saginaw Valley Research & Extension Center in Frankenmuth, MI in 2010. All trials were planted, following normal fall and spring tillage operations, with a USDA-ARS modified John Deere/Almaco research plot planter utilizing global ...

  15. Sugar Beet Activities of the USDA-ARS East Lansing Conducted in Cooperation with Saginaw Valley Bean and Beet Farm During 2009

    Science.gov (United States)

    Two evaluation plots were planted at the Saginaw Valley Research & Extension Center in Frankenmuth, MI in 2009; one agronomic trial and one combined Cercospora evaluation trial. All trials were planted, following normal fall and spring tillage operations, with a USDA-ARS modified John Deere/Almaco ...

  16. Cercosporoid fungi (Mycosphaerellaceae) 3. Species on monocots (Poaceae, true grasses).

    Science.gov (United States)

    Braun, Uwe; Crous, Pedro W; Nakashima, Chiharu

    2015-06-01

    The third part of a series of monographic treatments of cercosporoid fungi (formerly Cercospora s. lat., Mycosphaerellaceae, Ascomycota) continues with a treatment of taxa on monocots (Liliopsida; Equisetopsida, Magnoliidae, Lilianae), covering asexual and holomorph species with mycosphaerella-like sexual morphs on true grasses (Poaceae), which were excluded from the second part. The species concerned are keyed out, alphabetically listed, described, illustrated and supplemented by references to previously published descriptions, illustrations, and exsiccatae. A key to the recognised genera and a discussion of taxonomically relevant characters was published in the first part of this series. Several species are lecto- or neotypified. The following taxonomic novelties are introduced: Cercospora barretoana comb. nov., C. cymbopogonicola nom. nov., Cladosporium elymi comb. nov., Passalora agrostidicola sp. nov., P. brachyelytri comb. nov., and P. dichanthii-annulati comb. nov.

  17. Effect of genotype on sugar beet yield and quality

    Directory of Open Access Journals (Sweden)

    Nenadić N.

    2003-01-01

    Full Text Available The effect of a considerable number of both domestic and foreign sugar beet genotypes on root yield and quality was investigated. The data demonstrated the most favorable results of some genotypes for root yield and sugar content. Trials were conducted on rhizomania infested soil, thus tolerant genotypes were used. Susceptible cultivars represented the control. In the trial root yield was high and sugar content low. On average, in the genotypes tested, root yield varied from 73.98 to 93.30 t/ha and sugar content from 11.90 to 13.36%, depending on weather conditions. Root yield of the genotypes investigated varied from 30.61 to 112.64 t/ha and sugar content from 10.60 to 14.20%. The Swedish cultivar Dorotea (tolerant to both rhizomania and cercospora was the most yielding. The least yielding (susceptible to both rhizomania and cercospora was the domestic cultivar Dana.

  18. Transgenic assessment of CFP-mediated cercosporin export and resistance in a cercosporin-sensitive fungus.

    Science.gov (United States)

    Upchurch, Robert G; Rose, Mark S; Eweida, Mohamed; Callahan, Terrence M

    2002-04-01

    Cercosporin is a toxic polyketide produced by many phytopathogenic members of the fungal genus Cercospora. Cercospora species, themselves, exhibit the highest level of self-resistance to this almost universally toxic photosensitizer. Although the mechanism of cercosporin self-resistance is multi-faceted, partial resistance does appear to be provided by the encoded product of CFP ( cercosporin facilitator protein), a gene recently isolated from the pathogen of soybean, C. kikuchii. CFP has significant similarity to the major facilitator superfamily of integral membrane transport proteins. We expressed CFP in the cercosporin non-producing, cercosporin-sensitive fungus, Cochliobolus heterostrophus, in order to assess the transport activity of CFP and the contribution of CFP to cercosporin resistance in a fungal species free of endogenous toxin production. Expression of the CFP transgene in this fungus results in increased resistance to cercosporin due, apparently, to its export out of the fungus.

  19. Proceedings of the Annual Meeting, Aquatic Plant Control Research Program (18th) Held at Raleigh, North Carolina on 14-17 November 1983.

    Science.gov (United States)

    1984-06-01

    weevil . Sameodes albiguttalis - the Argentine waterhyacinth moth * Cercospora rod man ii - the w aterhyacinth leaf-spot fungus Findings Waterhyacinth...Hustache), and the Argentine waterhyacinth moth (Sameodes albiguttalis Warren). Biological control agents have not been extensively employed in Texas...appeared to increase and spider mites began to occur more frequently between 1979 and 1980. These factors coupled with stress from drought in spring and

  20. Characterization and toxicity of Amanita cokeri extract.

    Science.gov (United States)

    Drehmel, Dennis C; Chilton, William Scott

    2002-02-01

    The nonprotein amino acids 2-amino-3-cyclopropylbutanoic acid and 2-amino-5-chloro-4-pentenoic acid were isolated from the mushroom Amanita cokeri. The cyclopropyl amino acid is toxic to the fungus Cercospora kikuchii, the arthropod Oncopeltus fasciatus (milk weed bug), and the bacteria Agrobacterium tumefaciens, Erwinia amylovora, and Xanthomonas campestris. Toxicity to bacteria was reversible by addition of isoleucine to the medium. No toxicity was observed for 2-amino-5-chloro-4-pentenoic acid.

  1. PARASITE MYCOPOPULATION OF SOYBEAN GRAIN

    OpenAIRE

    Jasenka Ćosić; Karolina Vrandečić; Draženka Jurković; Ivan Ereš; Jelena Poštić

    2008-01-01

    Disease appearance on soybean can influence quality and quantity of yield. Different spieces of saprophyte and parasite fungi can be isolated from stems, pods and grain of soybean. The aim of the research was to evaluate the incidence of important disease on natural soybean grain over the period of 4 years (2004-2007) of experiment held on the location Sopot-Vinkovci and included 9 cultivars of soybean. The following plant pathogenic fungi were identified: Peronospora, Sclerotinia, Cercospora...

  2. Integrative taxonomy of root-knot nematodes reveals multiple independent origins of mitotic parthenogenesis

    Science.gov (United States)

    Janssen, Toon; Karssen, Gerrit; Topalović, Olivera; Coyne, Danny; Bert, Wim

    2017-01-01

    During sampling of several Coffea arabica plantations in Tanzania severe root galling, caused by a root-knot nematode was observed. From pure cultures, morphology and morphometrics of juveniles and females matched perfectly with Meloidogyne africana, whereas morphology of the males matched identically with those of Meloidogyne decalineata. Based on their Cox1 sequence, however, the recovered juveniles, females and males were confirmed to belong to the same species, creating a taxonomic conundrum. Adding further to this puzzle, re-examination of M. oteifae type material showed insufficient morphological evidence to maintain its status as a separate species. Consequently, M. decalineata and M. oteifae are synonymized with M. africana, which is herewith redescribed based on results of light and scanning electron microscopy, ribosomal and mitochondrial DNA sequences, isozyme electrophoresis, along with bionomic and cytogenetic features. Multi-gene phylogenetic analysis placed M. africana outside of the three major clades, together with M. coffeicola, M. ichinohei and M. camelliae. This phylogenetic position was confirmed by several morphological features, including cellular structure of the spermatheca, egg mass position, perineal pattern and head shape. Moreover, M. africana was found to be a polyphagous species, demonstrating that “early-branching” Meloidogyne spp. are not as oligophagous as had previously been assumed. Cytogenetic information indicates M. africana (2n = 21) and M. ardenensis (2n = 51–54) to be a triploid mitotic parthenogenetic species, revealing at least four independent origins of mitotic parthenogenesis within the genus Meloidogyne. Furthermore, M. mali (n = 12) was found to reproduce by amphimixis, indicating that amphimictic species with a limited number of chromosomes are widespread in the genus, potentially reflecting the ancestral state of the genus. The wide variation in chromosome numbers and associated changes in reproduction modes

  3. Ouro Verde MG 2: nova cultivar de mungo-verde para Minas Gerais Ouro Verde MG 2: new mungbean cultivar for Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Rogério F. Vieira

    2002-03-01

    Full Text Available Dentre várias linhagens introduzidas do "Asian Vegetable Research and Development Center" (AVRDC, sobressaiu a linhagem VC 3984-B-2-B-4-1-B, que recebeu o nome de Ouro Verde MG 2. Suas sementes são verde-brilhantes e o peso de 1000 unidades varia de 43 a 51 g. O início da floração ocorre em torno de 33 dias após a emergência e a primeira vagem madura surge entre 23 e 33 dias. Por se tratar de espécie de maturação desuniforme, podem ser necessárias duas a quatro colheitas. As plantas podem atingir 95 cm de altura. As vagens são marrom-escuras e concentram-se na parte superior da planta. É suscetível a duas doenças que geralmente aparecem no final do ciclo de vida do mungo-verde: míldio-pulverulento (Erysiphe polygoni e mancha-foliar-de-cercospora (Cercospora canescens. A 'Ouro Verde MG 2' é resistente ao acamamento, e o seu rendimento, em três ensaios instalados em dezembro, janeiro e fevereiro, variou de 1,5 a 2,0 t/ha. Esses rendimentos foram, em média, 12% superior ao da cultivar Ouro Verde.Among many accessions introduced from Asian Vegetable Research and Development Center (AVRDC, the VC 3984-B-2-B-4-1-B stood out and was named 'Ouro Verde MG 2'. The seeds are bright green and 1000-seed weight ranges from 43 to 51 g. Flowering starts approximately 33 days after emergence and the first pod ripens between 23 and 33 days later. As mungbean is a non-uniform maturation species, two to four harvests could be necessary. The plant can reach 95 cm high. The pods are dark brown and concentrated in the upper canopy. This cv. is susceptible to two diseases which generally appear late in the crop: powdery mildew (Erysiphe polygoni and cercospora leaf spot (Cercospora canescens. 'Ouro Verde MG 2' is resistant to lodging. The yield measured in three experiments carried out in December, January, and February, ranged from 1.5 to 2.0 t/ha. In average, these yields were 12% superior than the achieved by the cultivar 'Ouro Verde'.

  4. Synthesis and Biological Activities of Novel Anthranilic Diamides Analogues Containing Benzo[b]thiophene

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-feng; LIU Chen; LIU Peng-fei; YAN Tao; WANG Bao-lei; XIONG Li-xia; LI Zheng-ming

    2013-01-01

    A series of novel anthranilic diamides analogues containing benzo[b]thiophenyl ring was designed and synthesized.Their structures were characterized by melting points,1H nuclear magnetic resonance(1H NMR) and high-resolution mass spectrometry(HRMS).The bioassay tests indicate that their insecticidal activities were weak to moderate.Antibacterial tests indicate that some of the compounds showed favourable activity in vitro against Physalospora piricola,Alternaria solani,Cercospora arachidicola,Gibberella sanbinetti and Phytophthora infestans at a dosage of 50 mg/L.

  5. 我国西部三省区丝孢菌新记录种%New records of Hphomycetes from western provinces in China

    Institute of Scientific and Technical Information of China (English)

    翟凤艳; 杨蕊; 刘英杰; 李玉

    2011-01-01

    报道了宁夏、云南和四川三个省区的8个丝孢菌新记录种,分别是宁夏回族自治区新记录种荞麦尾孢Cercospora fagopyri、轮纹尾孢C.zonata、仁果枝孢Cladosporium malorum、藜钉孢Passalora dubia、插天泡假尾孢Pseudocercospora rubi、稍厚柱隔孢Ramularia crassiuscula;云南省新记录种紫草柱隔孢R.cerinthes;四川省新记录种莴苣柱隔孢 R.lactucosa.

  6. 我国西部三省区丝孢菌新记录种

    Institute of Scientific and Technical Information of China (English)

    翟凤艳; 杨蕊; 刘英杰; 李玉

    2011-01-01

    报道了宁夏、云南和四川三个省区的8个丝孢菌新记录种,分别是宁夏回族自治区新记录种荞麦尾孢Cercospora fagopyri、轮纹尾孢C.zonata、仁果枝孢Cladosporium malorum、藜钉孢Passalora dubia、插天泡假尾孢Pseudocercospora rubi、稍厚柱隔孢Ramularia crassiuscula;云南省新记录种紫草柱隔孢R.cerinthes;四川省新记录种莴苣柱隔孢R.lactucosa.

  7. PARAZITNA MIKOPOPULACIJA ZRNA SOJE

    OpenAIRE

    Ćosić, Jasenka; Vrandečić, Karolina; Jurković, Draženka; Ereš, Ivan; Poštić, Jelena

    2008-01-01

    Pojava bolesti na soji može utjecati na kvalitetu i količinu uroda. Različite vrste saprofitnih i parazitnih gljiva mogu se izolirati sa stabljika, mahuna i sjemena soje. Cilj ovih istraživanja bio je ocijeniti pojavu značajnijih bolesti na naturalnom zrnu soje tijekom 4 godine (2004.-2007.), a provedeno je na lokalitetu Sopot-Vinkovci i obuhvaćalo je 9 sorata soje. Identificirani su uzročnici bolesti iz rodova: Peronospora, Sclerotinia, Cercospora, Fusarium i Diaporthe/Phomopsis. Najčešće iz...

  8. Impact of Poultry Manure on Growth Behaviour, Black Sigatoka Disease Response and Yield Attributes of Two Plantain (Musa spp. AAB Genotypes

    Directory of Open Access Journals (Sweden)

    Aba, SC.

    2011-01-01

    Full Text Available La baisse de rendement en culture de plantain est un phénomène fréquent après quelques cycles de production; elle est due à de faibles niveaux de matière organique du sol et à une sensibilité accrue à des stress biotiques. L'utilisation de variétés améliorées est une option bon marché et respectueuse de l'environnement pour lutter contre les maladies des plantes, mais le maintien du rendement d'un nouveau cultivar en bananeraie nécessite une bonne gestion de la fertilité des sols qui pourrait être obtenue par une utilisation judicieuse de fumier de volaille. Les effets des trois doses [(0, 10 et 20 t.ha-1] de fumier de volaille décomposé sur la croissance, la réponse à la cercosporiose noire et le rendement de PITA 24' (un hybride de plantain et de son grand-parent maternel 'Mbi-Egome' (une banane plantain locale ont été évalués à Onne (Nigeria dans une station à fortes précipitations de l'IITA. L'expérience a été menée selon un dispositif split plot en blocs aléatoires complets. Les résultats ont montré que les deux clones étudiés avaient des variables de croissance similaires, sauf pour la surface foliaire et la teneur en chlorophylle. Malgré la sensibilité du génotype hybride à la cercosporiose foliaire d'origine atmosphérique, les données sur les composantes du rendement ont montré que 'PITA 24' produisait significativement plus de mains et de doigts par régime, un meilleur rendement du régime et un meilleur rendement végétatif global, toutefois, les deux génotypes ont présenté un schéma similaire pour la répartition de la biomasse. Les plants fumés ont eu un rendement significativement amélioré par rapport aux plants témoins, mais il y a eu un rendement moindre pour la dose de 20 t.ha-1. L'augmentation des doses d'engrais a réduit de plus de 30 jours le temps de récolte; de même, la taille des plants, le drageonnage, la teneur en chlorophylle des feuilles, l'indice des feuilles non

  9. Soybean toxin (SBTX impairs fungal growth by interfering with molecular transport, carbohydrate/amino acid metabolism and drug/stress responses.

    Directory of Open Access Journals (Sweden)

    Janne K S Morais

    Full Text Available Soybean toxin (SBTX is an antifungal protein from soybeans with broad inhibitory activity against the growth and filamentation of many fungi, including human and plant pathogenic species such as Candida albicans, Candida parapsilosis, Aspergillus niger, Penicillium herquei, Cercospora sojina and Cercospora kikuchii. Understanding the mechanism by which SBTX acts on fungi and yeasts may contribute to the design of novel antifungal drugs and/or the development of transgenic plants resistant to pathogens. To this end, the polymorphic yeast C. albicans was chosen as a model organism and changes in the gene expression profile of strain SC5314 upon exposure to SBTX were examined. Genes that were differentially regulated in the presence of SBTX were involved in glucose transport and starvation-associated stress responses as well as in the control of both the induction and repression of C. albicans hyphal formation. Transmission electron microscopy showed that C. albicans cells exposed to SBTX displayed severe signs of starvation and were heavily granulated. Our data were indicative of C. albicans cell starvation despite sufficient nutrient availability in the medium; therefore, it can be speculated that SBTX blocks nutrient uptake systems. Because neither the starvation signal nor the alkaline response pathway lead to the induction of hyphae, we hypothesise that conflicting signals are transmitted to the complex regulatory network controlling morphogenesis, eventually preventing the filamentation signal from reaching a significant threshold.

  10. Soybean toxin (SBTX) impairs fungal growth by interfering with molecular transport, carbohydrate/amino acid metabolism and drug/stress responses.

    Science.gov (United States)

    Morais, Janne K S; Bader, Oliver; Weig, Michael; Oliveira, Jose Tadeu A; Arantes, Mariana R; Gomes, Valdirene M; Da Cunha, Maura; Oliveira, Hermogenes D; Sousa, Daniele O B; Lourencao, Andre L; Vasconcelos, Ilka M

    2013-01-01

    Soybean toxin (SBTX) is an antifungal protein from soybeans with broad inhibitory activity against the growth and filamentation of many fungi, including human and plant pathogenic species such as Candida albicans, Candida parapsilosis, Aspergillus niger, Penicillium herquei, Cercospora sojina and Cercospora kikuchii. Understanding the mechanism by which SBTX acts on fungi and yeasts may contribute to the design of novel antifungal drugs and/or the development of transgenic plants resistant to pathogens. To this end, the polymorphic yeast C. albicans was chosen as a model organism and changes in the gene expression profile of strain SC5314 upon exposure to SBTX were examined. Genes that were differentially regulated in the presence of SBTX were involved in glucose transport and starvation-associated stress responses as well as in the control of both the induction and repression of C. albicans hyphal formation. Transmission electron microscopy showed that C. albicans cells exposed to SBTX displayed severe signs of starvation and were heavily granulated. Our data were indicative of C. albicans cell starvation despite sufficient nutrient availability in the medium; therefore, it can be speculated that SBTX blocks nutrient uptake systems. Because neither the starvation signal nor the alkaline response pathway lead to the induction of hyphae, we hypothesise that conflicting signals are transmitted to the complex regulatory network controlling morphogenesis, eventually preventing the filamentation signal from reaching a significant threshold.

  11. A review on threat of gray leaf spot disease of maize in Asia

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    Narayan Bahadur Dhami

    2015-12-01

    Full Text Available Biotic and biotic constraints are yield limiting factors in maize producing regions. Among these gray leaf spot is a yield limiting foliar disease of maize in high land regions of Asia. This review is done from related different national and international journals, thesis, books, research papers etc. The objectives of this review are to become familiar with genetics and inheritance, epidemiology, symptoms and disease management strategies etc. High relative humidity, temperature, minimum tillage and maize monoculture are important factors responsible for disease development. The sibling species of Cercospora zeae-maydis (Tehon and Daniels, 1925 Group I and Group II and Cercospora sorghai var. maydis (Chupp, 1954 are associated with this disease. Pathogens colonize in maize debris. Conidia are the source of inoculums for disease spread. Severe blighting of leaves reduces sugars, stalk lodging and causes premature death of plants resulting in yield losses of up to 100%. Disease management through cultural practices is provisional. The use of fungicides for emergencies is effective however; their prohibitive cost and detrimental effects on the environment are negative consequences. The inheritance of tolerance is quantitative with small additive effects. The introgression of resistant genes among the crosses of resistant germplasm enhances the resistance. The crosses of resistant and susceptible germplasm possess greater stability than the crosses of susceptible and resistant germplasm. The development of gray leaf spot tolerant populations through tolerance breeding principle is an economical and sustainable approach to manage the disease.

  12. Combined effects of elevated CO{sub 2} and natural climatic variation on leaf spot diseases of redbud and sweetgum trees

    Energy Technology Data Exchange (ETDEWEB)

    McElrone, Andrew J., E-mail: ajmcelrone@ucdavis.ed [USDA-ARS, Crops Pathology and Genetics Research Unit, 2154 RMI North, Davis, CA 95616 (United States); Department of Viticulture and Enology, University of California, Davis, CA 95616 (United States); Hamilton, Jason G. [Department of Biology, Ithaca College, Ithaca, NY 14850 (United States); Krafnick, Anthony J. [Department of Biology, Saint Joseph' s University, Philadelphia, PA 19131 (United States); Aldea, Mihai; Knepp, Rachel G.; DeLucia, Evan H. [Department of Plant Biology, University of Illinois, Urbana-Champaign, Urbana-Champaign, IL 61801 (United States)

    2010-01-15

    Atmospheric CO{sub 2} concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO{sub 2} and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO{sub 2}. Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO{sub 2} was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions. - Climatic variation had a greater impact than elevated CO{sub 2} on Cercospora diseases, especially since leaf photosynthetic efficiency increased under elevated CO{sub 2}.

  13. Early detection and quantification of Ramularia beticola in sugar beets using spore traps and real-time PCR

    DEFF Research Database (Denmark)

    Wieczorek, Thies Marten; Justesen, Annemarie Fejer; Jørgensen, Lise Nistrup;

    2012-01-01

    . If not controlled, yield losses can amount to 15 – 20 %. Over the last decades an increase of severe attacks of Ramularia leaf spot has been reported in Denmark, Sweden, and Finland. The disease is typically controlled preventatively using fungicides like epoxiconazole or epoxiconaozle + pyraclostrobin. According...... used fungicide dose is recommended for each treatment. Preliminary field trials have indicated a more efficient control of fungal diseases and higher sugar yield if sugar beets are treated with fungicides before visual symptoms occur. For a better determination of the optimized timing of disease...... method to detect and to quantify R. beticola DNA in air samples obtained from Burkard® spore traps. Primers were designed based on the ITS region sequences and tested on R. beticola isolates from 2010 and 2011. The specificity of the primers was tested on related fungi, including Cercospora beticola...

  14. Pathogenic microorganisms of medicinal herbal drugs

    Directory of Open Access Journals (Sweden)

    Stević Tatjana

    2012-01-01

    Full Text Available All the parts of plants (root, leaf, flower naturally have a high level of microorganisms, bacteria and fungi, especially molds. Microbial contamination could be a result of inappropriate harvesting, cleaning of the raw plant material, unhygienic processing of the plants, unsuitable transport and storage. After examination of over 40 dried medicinal plant species, the lowest microbial quality was determined for Maydis stigma, Mentha leaf and herb, Equisetum herb, Calendula flower, Urtica leaf, Melissa leaf, Serpylli herb, Chamomilla flower etc. Although mixed infections are recorded with different types of fungus, Fusarium was observed as the most dominant genus in most of the tested drugs, followed by Aspergillus and Alternaria. In addition to these fungi species from the following genera were identified: Phoma, Cephalosporium, Nigrospora, Cladosporium, Epicoccum, Gliocladium, Myrothecium, Cercospora, Phomopsis, Verticillium, Dreschlera (=Bipolaris, Rhizoctonia, Septoria, Trichoderma, Curvularia, Stachybotrys, Trichothecium, Puccinia, Botrytis, Mucor and Rhizopus sp., depending on plant species.

  15. Вплив добрив на ураження цукрових буряків плямистостями листків

    OpenAIRE

    Власюк, О. С.; Vlasjuk, O.

    2012-01-01

    The results of fertilizers influence on sugar beets affection with leaf spots have been presented in the paper. Straw as well as green manure used as a fertiliser are instrumental in diminishing the affection with Cercospora leaf spots in comparison with plants without fertilizers VS plants with organic and mineral fertilizers. Zonate leaf spots as well as alternaria leaf spots are more spread in crops with shortage of nutrition elements. Викладено результати вивчення впливу добрив на ураж...

  16. Fungicide resistance assays for fungal plant pathogens.

    Science.gov (United States)

    Secor, Gary A; Rivera, Viviana V

    2012-01-01

    Fungicide resistance assays are useful to determine if a fungal pathogen has developed resistance to a fungicide used to manage the disease it causes. Laboratory assays are used to determine loss of sensitivity, or resistance, to a fungicide and can explain fungicide failures and for developing successful fungicide recommendations in the field. Laboratory assays for fungicide resistance are conducted by measuring reductions in growth or spore germination of fungi in the presence of fungicide, or by molecular procedures. This chapter describes two techniques for measuring fungicide resistance, using the sugarbeet leaf spot fungus Cercospora beticola as a model for the protocol. Two procedures are described for fungicides from two different classes; growth reduction for triazole (sterol demethylation inhibitor; DMI) fungicides, and inhibition of spore germination for quinone outside inhibitor (QoI) fungicides.

  17. Permanent genetic resources added to Molecular Ecology Resources Database 1 February 2012 - 31 March 2012.

    Science.gov (United States)

    Andris, Malvina; Arias, M C; Barthel, Brandon L; Bluhm, Burton H; Bried, Joël; Canal, D; Chen, X M; Cheng, P; Chiappero, Marina B; Coelho, Manuela M; Collins, Angela B; Dash, M; Davis, Michelle C; Duarte, Margarida; Dubois, Marie-Pierre; Françoso, E; Galmes, M A; Gopal, Keshni; Jarne, Philippe; Kalbe, Martin; Karczmarski, Leszek; Kim, Hun; Martella, Mónica B; McBride, Richard S; Negri, Valeria; Negro, J J; Newell, Annakay D; Piedade, Ana F; Puchulutegui, Cecilia; Raggi, Lorenzo; Samonte, Irene E; Sarasola, J H; See, D R; Seyoum, Seifu; Silva, Mónica C; Solaro, C; Tolley, Krystal A; Tringali, Michael D; Vasemägi, A; Xu, L S; Zanón-Martínez, J I

    2012-07-01

    This article documents the addition of 171 microsatellite marker loci and 27 pairs of single nucleotide polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Bombus pauloensis, Cephalorhynchus heavisidii, Cercospora sojina, Harpyhaliaetus coronatus, Hordeum vulgare, Lachnolaimus maximus, Oceanodroma monteiroi, Puccinia striiformis f. sp. tritici, Rhea americana, Salmo salar, Salmo trutta, Schistocephalus solidus, Sousa plumbea and Tursiops aduncus. These loci were cross-tested on the following species: Aquila heliaca, Bulweria bulwerii, Buteo buteo, Buteo swainsoni, Falco rusticolus, Haliaeetus albicilla, Halobaena caerulea, Hieraaetus fasciatus, Oceanodroma castro, Puccinia graminis f. sp. Tritici, Puccinia triticina, Rhea pennata and Schistocephalus pungitii. This article also documents the addition of 27 sequencing primer pairs for Puffinus baroli and Bulweria bulwerii and cross-testing of these loci in Oceanodroma castro, Pelagodroma marina, Pelecanoides georgicus, Pelecanoides urinatrix, Thalassarche chrysostoma and Thalassarche melanophrys.

  18. Occurrence of broad bean (Vicia faba L. diseases in Olsztyn-Elbąg and Bydgoszcz Provinces

    Directory of Open Access Journals (Sweden)

    Stanisław Sadowski

    2013-12-01

    Full Text Available During the years 1981-1985, there were conducted studies of the healthiness of broad bean,'Nadwiślański' variety, cultivated in different soil and climate conditions of the two regions: i.e. Bydgoszcz - comparatively warmer and drier, and Olsztyn-Elbląg - colder and moister. It was found that the main reason for a premature broad bean leaves dry in up in the Olsztyn-Elbląg Region was caused by the fungi Cercospora and Botrytis, and in the Bydgoszcz Region - the root rot which occurs here to a greater extent. Root gangrene was greater intensity in drier and lighter soils. Rotting broad bean roots were most frequently occupied by the fungi of the Fusarium family (ca. 70%. The prevailing species were Fusarium oxysporum, next F. solani and more rarely F. culmorum and F. avenaceum. Climate conditions and soil species affected considerably the species composition of the root fungi.

  19. Enzyme encapsulation in magnetic chitosan-Fe3O4 microparticles.

    Science.gov (United States)

    Costa-Silva, Tales Alexandre; Marques, Polyana Samorano; Souza, Cláudia Regina Fernandes; Said, Suraia; Oliveira, Wanderley Pereira

    2015-01-01

    Two simple procedures for the preparation of magnetic chitosan enzyme microparticles have been investigated and used for the immobilisation of endophytic fungus Cercospora kikuchii lipase as model enzyme. In the first case, lipase was entrapped in Fe3O4-chitosan microparticles by cross-linking method, while in the second case magnetic immobilised derivatives were produced using spray drying. Immobilised enzymes showed high enzyme activity retention and stability during storage without significant loss of activity. Glutaraldehyde Fe3O4-chitosan powders presented a higher lipase activity retention and storage stability than the others preparations. However, the immobilised derivatives produced by cross-linking showed higher enzyme activity after reuse cycles. The results proved that the magnetic Fe3O4-chitosan microparticles are an effective support for the enzyme immobilisation since the immobilised lipase showed best properties than the free form.

  20. BRS 153: cultivar de soja com boa adaptação ao sistema plantio direto no Rio Grande do Sul

    Directory of Open Access Journals (Sweden)

    Bonato Emídio Rizzo

    2002-01-01

    Full Text Available A cultivar de soja BRS 153, oriunda do cruzamento EMBRAPA 1 x Braxton, é de ciclo médio, possui plantas de crescimento determinado, flor branca, pubescência cinza e grãos de hilo marromclaro. É resistente ao cancro-da-haste (Diaporthe phaseolorum f. sp. meridionalis, à podridão-parda-da-haste (Phialophora gregata, à mancha-olho-de-rã (Cercospora sojina e ao oídio (Microsphaera diffusa. O rendimento médio de grãos, em 19 ambientes do Rio Grande do Sul, foi 12% e 14% superior aos das cultivares RS 7-Jacuí e BR-16, respectivamente. É indicada para semeaduras em novembro, em todo o Rio Grande do Sul.

  1. Cultivar de soja BRS 205

    Directory of Open Access Journals (Sweden)

    Bonato Emídio Rizzo

    2002-01-01

    Full Text Available A BRS 205, cultivar de soja de ciclo semiprecoce, obtida do cruzamento [BR-16(2 x Ocepar 8] x Tracy-M, é indicada para o Rio Grande do Sul, em semeaduras de novembro. Possui crescimento determinado, plantas de flor branca, pubescência marrom, porte baixo e grãos de hilo preto. Tem resistência ao cancro-da-haste (Diaporthe phaseolorum f. sp. meridionalis, à podridão-parda-da-haste (Phialophora gregata, à mancha-olho-de-rã (Cercospora sojina e à pústula bacteriana (Xanthomonas axonopodis pv. glycines. É moderadamente resistente ao oídio (Microsphaera diffusa. O rendimento médio de grãos foi 6% e 11% superior ao das cultivares RS 7-Jacuí e BR-16, respectivamente.

  2. PARASITE MYCOPOPULATION OF SOYBEAN GRAIN

    Directory of Open Access Journals (Sweden)

    Jasenka Ćosić

    2008-07-01

    Full Text Available Disease appearance on soybean can influence quality and quantity of yield. Different spieces of saprophyte and parasite fungi can be isolated from stems, pods and grain of soybean. The aim of the research was to evaluate the incidence of important disease on natural soybean grain over the period of 4 years (2004-2007 of experiment held on the location Sopot-Vinkovci and included 9 cultivars of soybean. The following plant pathogenic fungi were identified: Peronospora, Sclerotinia, Cercospora, Fusarium and Diaporthe/Phomopsis. The most frequent fungi on soybean grains were: Cladosporium, Alternaria, Penicillium, Aspergillus and Epicoccum. The health condition of the natural soybean grains over the four years period on all cultivars was good.

  3. An endophytic/pathogenic Phoma sp. from creosote bush producing biologically active volatile compounds having fuel potential.

    Science.gov (United States)

    Strobel, Gary; Singh, Sanjay K; Riyaz-Ul-Hassan, Syed; Mitchell, Angela M; Geary, Brad; Sears, Joe

    2011-07-01

    A Phoma sp. was isolated and characterized as endophytic and as a pathogen of Larrea tridentata (creosote bush) growing in the desert region of southern Utah, USA. This fungus produces a unique mixture of volatile organic compounds (VOCs), including a series of sesquiterpenoids, some alcohols and several reduced naphthalene derivatives. Trans-caryophyllene, a product in the fungal VOCs, was also noted in the VOCs of this pungent plant. The gases of Phoma sp. possess antifungal properties and is markedly similar to that of a methanolic extract of the host plant. Some of the test organisms with the greatest sensitivity to the Phoma sp. VOCs were Verticillium, Ceratocystis, Cercospora and Sclerotinia while those being the least sensitive were Trichoderma, Colletotrichum and Aspergillus. We discuss the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship with implications for utilization as an energy source.

  4. Synthesis and antifungal activity of the derivatives of novel pyrazole carboxamide and isoxazolol pyrazole carboxylate.

    Science.gov (United States)

    Sun, Jialong; Zhou, Yuanming

    2015-03-09

    A series of pyrazole carboxamide and isoxazolol pyrazole carboxylate derivatives were designed and synthesized in this study. The structures of the compounds were elucidated based on spectral data (infrared, proton nuclear magnetic resonance and mass spectroscopy). Then, all of the compounds were bioassayed in vitro against four types of phytopathogenic fungi (Alternaria porri, Marssonina coronaria, Cercospora petroselini and Rhizoctonia solani) using the mycelium growth inhibition method. The results showed that some of the synthesized pyrazole carboxamides displayed notable antifungal activity. The isoxazole pyrazole carboxylate 7ai exhibited significant antifungal activity against R. solani, with an EC50 value of 0.37 μg/mL. Nonetheless, this value was lower than that of the commercial fungicide, carbendazol.

  5. Environmental Factors in the Growth of Jatropha at Potorono Village, Yogyakarta

    Directory of Open Access Journals (Sweden)

    Mohammad Nurcholis

    2015-01-01

    Full Text Available Jatropha curcas is a perennial crop that has been known by Indonesian people for more than seven decades as a plant that produces renewable biofuel. In the present decade, plants producing biofuel are expected to be developed to overcome the lowering nonrenewable fuel reserves. There is a myth that jatropha can grow well on marginal lands and draught condition, perform well on non-fertile soils, no need for agronomic management and is resistant to plant pests and diseases. This study was conducted to identify the environmental factors that influenced the growth of jatropha on the marginal land at Potorono village, Yogyakarta Province, Indonesia. Jatropha has been planted by local people at the village road sides and on the marginal land field at the local governmental land in this village. They grew jatropha on these areas with the purpose of preventing competition of area utilization with food crops. The results showed that the growth of jatropha was restricted by low content of organic matter, plant nutrition and poor soil drainage. Applications of manure and macro nutrients (N, P and K to this crop were able to increase crop performance. The number of shoots, flowers and fruit bunches increased by manure and nutrients treatments. Field observation showed that there were several plant pests, such as Aspidiotus sp., Paracoccus marginatus, Poliphagotarsonemus latus, Selenothrips rubrocinctus, Chrysochoris javanus, Valanga nigricornis, Chloracris prasina, and Helicoverpa armigera that attacked plant leaves and fruits. There were plant leaf necrotic symptoms that caused by plant pathogens were also observed. The diseases are bacterial leaf spot (Xanthomonas ricinicola, cercospora leaf spot (Cercospora ricinella and rust (Phakopsora jatrophicola. Thus, jatropha is like any other plants that need a good agro-ecological condition to grow well and produce high yield.

  6. BRS 137: cultivar de soja para cultivo no Sul do Brasil BRS 137: soybean cultivar for southern Brazil

    Directory of Open Access Journals (Sweden)

    Emídio Rizzo Bonato

    2001-05-01

    Full Text Available A liberação de cultivares de elevado potencial produtivo e com resistência a doenças é fundamental para continuar agregando rendimento na produção brasileira de soja. A cultivar BRS 137 é resultado do programa de melhoramento de soja desenvolvido pela Embrapa. A cultivar apresentou rendimento médio de grãos 2% superior ao da cultivar IAS 5, em 24 ambientes, no Rio Grande do Sul. É resistente à pústula-bacteriana (Xanthomonas axonopodis pv. glycines, ao cancro-da-haste (Diaporthe phaseolorum f. sp. meridionalis, à podridão-parda-da-haste (Phialophora gregata, à mancha-olho-de-rã (Cercospora sojina e ao oídio (Microsphaera diffusa. É indicada para cultivo no Rio Grande do Sul, em semeaduras realizadas a partir de meados de outubro até fim de novembro, com população máxima de 300.000 plantas/ha.The goals of the soybean breeding program for the release of a new cultivar include high yield potential and resistance to diseases in order to improve Brazilian production. The cultivar BRS 137 is a result of the soybean breeding program of Embrapa (Brazil. Prior to its release, the cultivar had shown a mean grain yield potential 2% higher than the cultivar IAS 5 in 24 environments in the State of Rio Grande do Sul, Brazil. Moreover, it is resistant to bacterial pustule (Xanthomonas axonopodis pv. glycines, soybean stem canker (Diaporthe phaseolorum f. sp. meridionalis, brown stem rot (Phialophora gregata, frogeye leaf spot (Cercospora sojina, and powdery mildew (Microsphaera diffusa. The cultivar is being indicated to be cropped in the Rio Grande do Sul state for sowing from mid October to the end of November with a maximum population of 300,000 plants/ha.

  7. Severidade da mela da soja causada por Rhizoctonia solani AG-1 IA em função de doses de potássio Severity of hte foliar blight of the soylean caused by Rhizoctonia solani AG-1 IA infunction of doses of potassium

    Directory of Open Access Journals (Sweden)

    Marco Antonio Basseto

    2007-03-01

    Full Text Available O fungo Rhizoctonia solani pertencente ao grupo de anastomose 1 IA (AG-1 IA é um dos patógenos mais importantes afetando a cultura da soja no Brasil. Este fungo causa queima da folha e/ou mela em soja, para a qual medidas de manejo cultural são consideradas alternativas importantes para controle antes do estabelecimento da doença. Há evidências de que a adubação potássica diminui substancialmente a severidade dos sintomas de várias doenças da soja como a queima foliar (Cercospora kikuchii, a seca da haste e da vagem (Phomopsis phaseoli var. sojae e o cancro da haste (Diaporthe phaseolorum f. sp. meridionalis. Apesar das evidências do efeito do potássio no controle de várias doenças da soja, não há informação na literatura sobre o efeito desse nutriente no controle da mela. A hipótese testada foi que a mela da soja pode ser controlada através de incrementos na adubação potássica. De maneira geral, concluiu-se que, sob condições de casa de vegetação, o incremento de K no solo não resultou no controle da mela da soja. É necessário, entretanto, confirmar esta observação conduzindo-se experimentos sob condições de campo, podendo-se incluir a avaliação do efeito da doença sob aspectos da produção.The fungus Rhizoctonia solani, belonging to anastomosis group 1IA (AG-1 IA is one of the most important pathogens affecting soybean in Brazil. This fungus causes aerial or foliar blight of soybean, and cultural measures are thought as important choices for the control before the establishment of the disease. Based on evidences that potassium amendments can substantially reduce the severity of several soybean diseases such as Cercospora leaf blight (Cercospora kikuchii, pod and stem blight (Phomopsis phaseoli var. sojae and stem canker (Diaporthe phaseolorum f. sp. meridionalis. Despite all evidence, there is no information in the literature about the effect of potassium controlling the soybean foliar blight. The

  8. Identification of Alfalfa Leaf Diseases Using Image Recognition Technology

    Science.gov (United States)

    Qin, Feng; Liu, Dongxia; Sun, Bingda; Ruan, Liu; Ma, Zhanhong; Wang, Haiguang

    2016-01-01

    Common leaf spot (caused by Pseudopeziza medicaginis), rust (caused by Uromyces striatus), Leptosphaerulina leaf spot (caused by Leptosphaerulina briosiana) and Cercospora leaf spot (caused by Cercospora medicaginis) are the four common types of alfalfa leaf diseases. Timely and accurate diagnoses of these diseases are critical for disease management, alfalfa quality control and the healthy development of the alfalfa industry. In this study, the identification and diagnosis of the four types of alfalfa leaf diseases were investigated using pattern recognition algorithms based on image-processing technology. A sub-image with one or multiple typical lesions was obtained by artificial cutting from each acquired digital disease image. Then the sub-images were segmented using twelve lesion segmentation methods integrated with clustering algorithms (including K_means clustering, fuzzy C-means clustering and K_median clustering) and supervised classification algorithms (including logistic regression analysis, Naive Bayes algorithm, classification and regression tree, and linear discriminant analysis). After a comprehensive comparison, the segmentation method integrating the K_median clustering algorithm and linear discriminant analysis was chosen to obtain lesion images. After the lesion segmentation using this method, a total of 129 texture, color and shape features were extracted from the lesion images. Based on the features selected using three methods (ReliefF, 1R and correlation-based feature selection), disease recognition models were built using three supervised learning methods, including the random forest, support vector machine (SVM) and K-nearest neighbor methods. A comparison of the recognition results of the models was conducted. The results showed that when the ReliefF method was used for feature selection, the SVM model built with the most important 45 features (selected from a total of 129 features) was the optimal model. For this SVM model, the

  9. Resistance to gray leaf spot of maize: genetic architecture and mechanisms elucidated through nested association mapping and near-isogenic line analysis.

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    Jacqueline M Benson

    2015-03-01

    Full Text Available Gray leaf spot (GLS, caused by Cercospora zeae-maydis and Cercospora zeina, is one of the most important diseases of maize worldwide. The pathogen has a necrotrophic lifestyle and no major genes are known for GLS. Quantitative resistance, although poorly understood, is important for GLS management. We used genetic mapping to refine understanding of the genetic architecture of GLS resistance and to develop hypotheses regarding the mechanisms underlying quantitative disease resistance (QDR loci. Nested association mapping (NAM was used to identify 16 quantitative trait loci (QTL for QDR to GLS, including seven novel QTL, each of which demonstrated allelic series with significant effects above and below the magnitude of the B73 reference allele. Alleles at three QTL, qGLS1.04, qGLS2.09, and qGLS4.05, conferred disease reductions of greater than 10%. Interactions between loci were detected for three pairs of loci, including an interaction between iqGLS4.05 and qGLS7.03. Near-isogenic lines (NILs were developed to confirm and fine-map three of the 16 QTL, and to develop hypotheses regarding mechanisms of resistance. qGLS1.04 was fine-mapped from an interval of 27.0 Mb to two intervals of 6.5 Mb and 5.2 Mb, consistent with the hypothesis that multiple genes underlie highly significant QTL identified by NAM. qGLS2.09, which was also associated with maturity (days to anthesis and with resistance to southern leaf blight, was narrowed to a 4-Mb interval. The distance between major leaf veins was strongly associated with resistance to GLS at qGLS4.05. NILs for qGLS1.04 were treated with the C. zeae-maydis toxin cercosporin to test the role of host-specific toxin in QDR. Cercosporin exposure increased expression of a putative flavin-monooxygenase (FMO gene, a candidate detoxification-related gene underlying qGLS1.04. This integrated approach to confirming QTL and characterizing the potential underlying mechanisms advances the understanding of QDR and will

  10. Survival of pathogens on soybean debris under no-tillage and conventional tillage systems Sobrevivência de patógenos em restos de cultura de soja mantidos em sistema de semeadura direta e convencional

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    Álvaro Manuel Rodrigues Almeida

    2001-10-01

    Full Text Available A study was conducted in the subtropical area of Southern Brazil to determine the survival of pathogens in soybean residues under conventional and no-tillage cultivation systems from March to September of 1998 and 1999. The pathogens most frequently isolated were Colletotrichum truncatum, Phomopsis spp., Cercospora kikuchii, Fusarium spp., Macrophomina phaseolina, and Rhizoctonia solani. Other fungi isolated were Myrothecium roridum, Penicillium sp., Chaetomium sp., Epicoccum sp., Corynespora cassiicola and Trichoderma sp. The percent of survival of each pathogen varied according to the month and the year. Survival of C. truncatum, Phomopsis spp. and C. kikuchii were significantly reduced (pAvaliou-se a sobrevivência de patógenos em restos de soja, em sistema de semeadura direta e convencional, entre março e setembro de 1998 e 1999, em Londrina, PR. Os patógenos mais freqüentemente isolados foram Colletotrichum truncatum, Phomopsis spp., Cercospora kikuchii, Fusarium spp., Macrophomina phaseolina e Rhizoctonia solani. Outros fungos isolados foram Myrothecium roridum, Penicillium sp., Chaetomium sp., Epicoccum sp., Corynespora cassiicola e Trichoderma sp. A porcentagem de sobrevivência variou com o mês e o ano. A sobrevivência de C. truncatum, Phomopsis spp. e C. kikuchii foi significativamente reduzida (P<0,05 entre a primeira e última avaliação nos resíduos mantidos sobre ou sob o solo. M. phaseolina e Fusarium spp. não foram afetados, ou foram favorecidos pelo enterro dos resíduos. A freqüência de isolamento de Fusarium spp. aumentou em resíduos enterrados no solo. A perda de biomassa mostrou redução de 44,4% no sistema convencional e 34,9% no sistema de semeadura direta, em 1998, quando a distribuição de chuvas foi mais regular. Em 1999, a redução foi de 48,2% e 39,0% para os sistemas convencional e de semeadura direta, respectivamente.

  11. Ocorrência de fungos em sementes de soja produzidas sob calagem e adubação potássica residuais The residual effect of liming and potassium fertilization on the occurrence of fungi in soybean seeds

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    H.A.A. Mascarenhas

    1995-12-01

    Full Text Available Estudou-se o efeito residual da adubação potássica e da calagem sobre a ocorrência de fungos em sementes de soja. O experimento foi instalado com a cultivar IAC-17, no ano agrícola de 1991/92, aplicando doses a lanço de O, 3,5 e 7 t/ha de calcário dolomítico e de 0, 150, 300, 450 e 600 kg/ha de K2O. As sementes colhidas no terceiro ano de cultivo, (1993/94 foram submetidas ao teste de sanidade, pelo método do papel de filtro. Observou-se que a calagem reduziu significativamente a incidência de Phomopsis sp., favorecendo, no entanto, a presença de Aspergillus sp. e de Fusarium sp.. Embora não tenham sido detectadas diferenças significativas, nos tratamentos com calagem, verificou-se redução da incidência de Cercospora kikuchii, Colltotrichum dematium var. truncata e Peronospora manshurica. Apenas a incidência de Phomopsis sp. diminuiu significativamente devido à adubação potássica, sendo menor quando se utilizou a dose de 450 kg/ha de K2O.To study the residual effect of liming and potassium fertilizer on the occurrence of fungi in soybean seeds, an experiment was installed during the 1991/92 growing season, using 0, 3.5 and 7.0 t/ha of dolomitic lime and 0, 150, 300, 450 and 600 kg/ha of K2O in the form of potassium cloride. In 1993/94 (the third year, the harvested seeds were submitted to a seed health test (blotter method. The results showed that liming reduced significantly the incidence of Phomopsis sp. and increased the presence of Aspergillus sp. and Fusarium sp.. Although no significant differences were observed with liming, there was a reduction in the incidence of Cercospora kikuchii, Colletotrichum dematium var. truncala and Peronospora manshurica. Among the fungi found in the seeds, only Phomopsis sp. was significantly reduced by potassium fertilization, the least incidence being observed at the rate of 450 kg/ha.

  12. TRATAMENTO DE SEMENTES DE ARROZ, TRIGO, FEIJÃO E SOJA COM UM PRODUTO FORMULADO À BASE DE CÉLULAS E DE METABÓLITOS DE Bacillus subtilis

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    E LAZZARETTI

    1997-01-01

    Full Text Available Um produto constituido de pó-molhável (PBBS formulado à base de células (60g e de metabólitos (60g de Bacillus subtilis, argila (480g, espalhante (7,92g e água (2400ml, moído e seco, mostrou-se semelhante aos tratamentos com fungicidas recomendados para o controle de Rhizoctonia solani, Aspergillus sp. e Sclerotinia sclerotiorum em sementes de feijão; Pyricularia oryzae e Rhinchosporium sativum em sementes de arroz; e Cercospora kikuchii, Phomopsis phaseoli e Fusarium spp. em sementes de soja. Para Dreschlera oryzae em arroz e Bipolaris sorokiniana, P. oryzae e Alternaria tenuis em sementes de trigo, o tratamento com o PBBS, embora não tenha se igualado ao tratamento com o fungicida padrão, diferiu estatisticamente do tratamento testemunha. A nodulação das raízes de feijão e soja por bactérias simbióticas, fixadoras de nitrogênio, não foi influenciada quando o PBBS foi aplicado simultaneamente ao inoculante contendo Rhyzobium sp. e Bradyrhizobium japonicum, respectivamente. O PBBS também não afetou a emergência das plântulas das culturas testadas.A biological fungicide product containing B. subtilis cells (60 g and metabolites (60g was transformed into a wettable powder formulated with, clay (480 g, surfactant (7,92 g and water (2400 ml.The product showed to be similar to the conventional fungicides used in the control of Rhizoctonia solani, Aspergillus sp. and Sclerotinia sclerotiorum in bean seeds. The control of Pyricularia oryzae and Rhinchosporium sativum in rice seeds and Cercospora kikuchii, Phomopsis phaseoli and Fusarium spp. in soybean seeds was also as efficient as the comercial fungicides. For Dreschlera oryzae in rice seeds and Bipolaris sorokiniana, P. oryzae and Alternaria tenuis in wheat seeds, the treatment with the product, althought not as efficient as the chemical treatment, was statistically distinct from the control. The root nodulation of bean and soybean by nitrogen fixing bacteria, was not affected

  13. Influência do espaçamento e população de plantas sobre doenças de final de ciclo e oídio e caracteres agronômicos em soja = Influence of row spacing and plant population on late season disease severity, powdery mildew and agronomic characters in soybean

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    Jorge Luiz Knebel

    2006-07-01

    Full Text Available Este trabalho foi conduzido em Cascavel, Estado do Paraná, na safra de2004/2005, utilizando a cultivar de soja CD 202, para avaliar a influência do espaçamento e da população de plantas sobre a severidade de (DFC doenças de final de ciclo (Septoria glycines e Cercospora kikuchii e oídio da soja (Microsphaera diffusa e caracteres agronômicos da cultura. Os tratamentos foram 3 espaçamentos (22,5; 45,0 e 67,5 cm e 3 populações (200; 400; e 600 mil plantas ha-1. As DFC tiveram menor severidade no espaçamento reduzido e na população mais baixa, enquanto a ocorrência de oídio não se alterou. Em todos os espa��amentos, quanto maior a população de plantas, maior a altura final e, conseqüentemente, maior o acamamento de plantas. O número de legumes/planta foi superior no maior espaçamento e reduziu com o aumento da população; o número de grãos/planta diminuiu com o aumento da população; e a produtividade foi superior no menor espaçamento.This study was carried out in Cascavel, Paraná State, during the growing season 2004/2005, using soybean cultivar CD 202. The aim was to evaluate the influence of row-spacing and plant population on lateseason disease severity (Septoria glycines and Cercospora kikuchii, soybean powdery mildew (Microsphaera diffusa and agronomic characters of the culture. The treatments were three row spacing (22.5; 45.0 and 67.5 cm and three plant populations (200; 400; and 600 thousand plants ha-1. Late season disease had smaller severity in the reduced spacing and in the lowest population, while the powdery mildew occurrence did not modify with these factors. In all spacing, as larger the plants density, larger the plants height and consequently larger the plants fallen. The number pods per plant was higher with the largest spacing and it decreased with the population increase; the number of grains per plant decreased with the population increase; and the productivity was higher in the smallest spacing.

  14. Study on Relativity Between Population of Nematode Crowd in Rhizosphere of Cryptomeria fortunei and Pestalotiopsis apiculatus%柳杉根际线虫群体数量与柳杉赤枯病的相关性研究

    Institute of Scientific and Technical Information of China (English)

    王邵军; 刘勇; 蔡秋锦; 彭九生

    2004-01-01

    于2002~2003年间,发现福建农林大学南平校区柳杉绿化林带有严重病害发生,经过病原鉴定为柳杉赤枯病(Cercospora secoiae).同时,从柳杉病区林木根系及根际土壤分离到大量双宫螺旋线虫(Helicotylenchus Dihystera)、马丁矮化线虫(Tylencnchorhynchus martini)、肾形肾脏线虫(Rotylenchulus reniformis)、微小针线虫(Paratylenchus minuts)、垫刃线虫(Tylenchus platycephalus)及一定量的盘旋线虫(Rotylenchus caudnphasmidius)、美洲剑线虫(Xiphinema americanum)、长针线虫未定种(Longidorus sp.)、尾滑刃线虫(Aphelenchoides composticola)、环线虫未定种(Macroposthonia sp.)、昏暗毛刺线虫(Trichdorus obscurus)、燕麦真滑线虫(Aphelenchus avenoe).根据相关性分析和有关报道,认为柳杉根际线虫某些类群的群体数量与柳杉赤枯病的发生有明显的相关性.

  15. Synthesis and Fungicidal Activity of 5-Aryl-1-(aryloxyacetyl)-3-(tert-butyl or phenyl)-4-(1H-1,2,4-triazol-1-yl)-4,5-Dihydropyrazole

    Institute of Scientific and Technical Information of China (English)

    毛会玉; Hong; SONG; SHI; Deqing

    2014-01-01

    A series of novel 5-aryl-1-(aryloxyacetyl)-3-(tert-butyl or phenyl)-4-(1H-1,2,4-triazol-1-yl)-4,5-dihydropyrazole 3a-3n were synthesized by the annulation of 2-aryloxyacetohydrazides with 3-aryl-1-t-butyl(or phenyl)-2-(1H-1,2,4-triazol-1-yl)prop-2-en-1-ones(1)in the presence of a catalytic amount of acetic acid.Compounds 2 were obtained by the Knoevenagel reactions of 1-t-butyl(or phenyl)-2-(1H-1,2,4-triazol-1-yl)ethanone(2)with aromatic aldehydes in the presence of piperidine.Their structures were confirmed by IR,1H-NMR,ESIMS,and elemental analyses.The preliminary bioassay indicated that some compounds displayed moderate to excellent fungicidal activity.For example,compounds 31,3m,and 3n possessed100%inhibition against Cercospora arachidicola Hori at the concentration of 50 mg/L.

  16. Diallel analyze of yield and progress of the severity of leaf diseases in maize hybrids in two population density

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    Marcos Ventura Faria

    2015-02-01

    Full Text Available Seven commercial maize hybrids (AS1575, 2B688, Penta, GNZ2004, AG8021, Sprint e P30F53 were intercrossed in a complete diallel, excluded reciprocal, obtaining 21 crosses. The 28 treatments were evaluated in two environments characterized by different densities (62,500 and 90,000 plants ha-1, with the aim of selecting the most promising parents for generating base population to obtain lines. Two experiments were carried out in Guarapuava-PR, at randomized block design with three replications. We estimated the general (GCA and specific (SCA combining abilities for yield and disease severity assessed by the area under the common rust (Puccinia sorghi progress curve (AURPC and the area under the leaf spot (Cercospora zeae-maydis progress curve (AULPC. The effects of GCA and SCA were significant for grain yield and diseases severity in both densities, revealing the importance of both additive and non-additive effects. There GCA x densities interaction was significant only for grain yield. Crossings P30F53 x AG8021 and P30F53 x Penta had negative estimates of SCA for AURPC and AULPC on the environments average. Hybrids GNZ 2004 and P30F53 stood out showing positive GCA for grain yield and negative for AURPC and AULPC in both densities and therefore are recommended for generating base populations for obtaining lines adapted for both densities, conventional and denser plantings, given the current trends in management of maize.

  17. Cercosporoid diseases of Citrus.

    Science.gov (United States)

    Huang, Feng; Groenewald, J Z; Zhu, Li; Crous, P W; Li, Hongye

    2015-01-01

    Citrus leaves and fruits exhibiting disease symptoms ranging from greasy spot, yellow spot, small or large brown spot, black dot, and brown dot were sampled from Fujian, Guangdong, Guizhou, Hunan, Jiangxi, Yunnan, Zhejiang provinces and the Guangxi Zhuang Autonomous Region in China. In total 82 isolates representing various cercosporoid genera were isolated from these disease symptoms, which were supplemented with eight Citrus cercosporoid isolates collected from other countries. Based on a morphological and phylogenetic study using sequence data from the nuclear ribosomal DNA's ITS1-5.8S-ITS2 regions (ITS), and partial actin (act), β-tubulin (tub2), 28S nuclear ribosomal RNA (28S rDNA) and translation elongation factor 1-α (tef1) genes, these strains were placed in the following genera: Cercospora, Pallidocercospora, Passalora, Pseudocercospora, Verrucisporota and Zasmidium. All isolates tended to be sterile, except the Zasmidium isolates associated with citrus greasy spot-like symptoms, which subsequently were compared with phylogenetically similar isolates occurring on Citrus and other hosts elsewhere. From these results four Zasmidium species were recognized on Citrus, namely Z. indonesianum on Citrus in Indonesia, Z. fructicola and Z. fructigenum on Citrus in China and Z. citri-griseum, which appears to have a wide host range including Acacia, Citrus, Eucalyptus and Musa, as well as a global distribution.

  18. Genetic characterization and linkage disequilibrium mapping of resistance to gray leaf spot in maize(Zea mays L.)

    Institute of Scientific and Technical Information of China (English)

    Liyu; Shi; Xiangling; Lv; Jianfeng; Weng; Hanyong; Zhu; Changlin; Liu; Zhuanfang; Hao; Yu; Zhou; Degui; Zhang; Mingshun; Li; Xiaoke; Ci; Xinhai; Li; Shihuang; Zhang

    2014-01-01

    Gray leaf spot(GLS),caused by Cercospora zeae-maydis,is an important foliar disease of maize(Zea mays L.)worldwide,resistance to which is controlled by multiple quantitative trait loci(QTL).To gain insights into the genetic architecture underlying the resistance to this disease,an association mapping population consisting of 161 inbred lines was evaluated for resistance to GLS in a plant pathology nursery at Shenyang in 2010 and 2011.Subsequently,a genome-wide association study,using 41,101 single-nucleotide polymorphisms(SNPs),identified 51 SNPs significantly(P<0.001)associated with GLS resistance,which could be converted into 31 QTL.In addition,three candidate genes related to plant defense were identified,including nucleotidebinding-site/leucine-rich repeat,receptor-like kinase genes similar to those involved in basal defense.Two genic SNPs,PZE-103142893 and PZE-109119001,associated with GLS resistance in chromosome bins 3.07 and 9.07,can be used for marker-assisted selection(MAS)of GLS resistance.These results provide an important resource for developing molecular markers closely linked with the target trait,enhancing breeding efficiency.

  19. Effect of Maize Hybrid and Foliar Fungicides on Yield Under Low Foliar Disease Severity Conditions.

    Science.gov (United States)

    Mallowa, Sally O; Esker, Paul D; Paul, Pierce A; Bradley, Carl A; Chapara, Venkata R; Conley, Shawn P; Robertson, Alison E

    2015-08-01

    Foliar fungicide use in the U.S. Corn Belt increased in the last decade; however, questions persist pertaining to its value and sustainability. Multistate field trials were established from 2010 to 2012 in Illinois, Iowa, Ohio, and Wisconsin to examine how hybrid and foliar fungicide influenced disease intensity and yield. The experimental design was in a split-split plot with main plots consisting of hybrids varying in resistance to gray leaf spot (caused by Cercospora zeae-maydis) and northern corn leaf blight (caused by Setosphaera turcica), subplots corresponding to four application timings of the fungicide pyraclostrobin, and sub-subplots represented by inoculations with either C. zeae-maydis, S. turcica, or both at two vegetative growth stages. Fungicide application (VT/R1) significantly reduced total disease severity relative to the control in five of eight site-years (Pfungicide-treated in three site-years. Fungicide application increased the yield by approximately 6% at Ohio in 2010, 5% at Wisconsin in 2010 and 6% in 2011. Yield differences ranged from 8,403 to 8,890 kg/ha in Wisconsin 2011 to 11,362 to 11,919 kg/ha in Wisconsin 2010. Results suggest susceptibility to disease and prevailing environment are important drivers of observed differences. Yield increases as a result of the physiological benefits of plant health benefits under low disease were not consistent.

  20. Decomposition of corn and soybean residues under field conditions and their role as inoculum source

    Directory of Open Access Journals (Sweden)

    E.M. Reis

    2011-03-01

    Full Text Available Necrotrophic parasites of above-ground plant parts survive saprophytically, between growing seasons in host crop residues. In an experiment conducted under field conditions, the time required in months for corn and soybean residues to be completely decomposed was quantified. Residues were laid on the soil surface to simulate no-till farming. Crop debris of the two plant species collected on the harvesting day cut into pieces of 5.0cm-long and a 200g mass was added to nylon mesh bags. At monthly intervals, bags were taken to the laboratory for weighing. Corn residues were decomposed within 37.0 months and those of soybean, within 34.5 months. Hw main necrotrophic fungi diagnosed in the corn residues were Colletotrichum gramicola, Diplodia spp. and Gibberella zeae, and those in soybeans residues were Cercospora kikuchii, Colletotrichum spp, Glomerella sp. and Phomopsis spp. Thus, those periods shoulb be observed in crop rotation aimed at to eliminating contaminated residues and, consequently, the inoculum from the cultivated area.

  1. Effects of 4 Fungicides on Control of Banana Leaf Spot Diseases%4种药剂防治香蕉叶斑病效果比较

    Institute of Scientific and Technical Information of China (English)

    谢圣华; 王泰吉

    2004-01-01

    用25%敌力脱乳油、25%顷止乳油、25%富力库水乳剂和43%大生富悬浮剂4种药剂进行香蕉叶斑病[Cercospora musae Zimm、Cordana musae(Zimm)Hohn、Helminthosporiumtorulosum(Syd.)Ashby]防治试验.结果表明:25%敌力脱乳油、25%顷止乳油和25%富力库水乳剂3种新型药剂对香蕉叶斑病的防效均较传统药剂43%大生富悬浮剂的防效高,持效期也较长;3种新型药剂中,25%敌力脱乳油的防效和持效性均表现最好,最高防效达84.80%,药后21 d防效仍达77.57%;4种药剂防治香蕉叶斑病的施药间隔期,25%敌力脱乳油为20~25 d,25%顷止乳油为12~15 d,25%富力库水乳剂为15~20 d,43%大生富悬浮剂为7~10 d.

  2. Influence of Cultural and Pest Management Practices on Performance of Runner, Spanish, and Virginia Market Types in North Carolina

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    Bridget R. Lassiter

    2016-01-01

    Full Text Available Virginia market type peanut (Arachis hypogaea L. cultivars are grown primarily in North Carolina, South Carolina, and Virginia in the US, although growers in these states often plant other market types if marketing opportunities are available. Information on yield potential and management strategies comparing these market types is limited in North Carolina. In separate experiments, research was conducted to determine response of runner, Spanish, and Virginia market types to calcium sulfate and inoculation with Bradyrhizobium at planting, planting and digging dates, planting patterns, and seeding rates. In other experiments, control of thrips (Frankliniella spp. using aldicarb, southern corn rootworm (Diabrotica undecimpunctata Howardi using chlorpyrifos, eclipta (Eclipta prostrata L. using threshold-based postemergence herbicides, and leaf spot disease (caused by the fungi Cercospora arachidicola and Cercosporidium personatum fungicide programs was compared in these market types. Results showed that management practice and market types interacted for peanut pod yield in only the planting date experiment. Yield of runner and Virginia market types was similar and exceeded yield of the Spanish market type in most experiments.

  3. Present status of the development of mycoherbicides against water hyacinth: successes and challenges. A review

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    Jijakli, MH.

    2012-01-01

    Full Text Available Recent trends in the implementation of bioherbicide use in the control of water hyacinth (Eichhornia crassipes [Martius] Solms Laubach have depended primarily on several strategies. The use of bioherbicides has been stimulated as part of the search for alternatives to chemical control, as the use of these more environmentally-friendly formulations minimizes hazards resulting from herbicide residue to both human and animal health, and to the ecology. In addition, one of the major strategies in the concept of biological control is the attempt to incorporate biological weed control methods as a component of integrated weed management, in order to achieve satisfactory results while reducing herbicide application to a minimum. Several fungal pathogens with mycoherbicide potential (Sclerotinia sclerotiorum in Hyakillä and Cercospora rodmanii, named ABG-5003 have been discovered on diseased water hyacinth plants, but none has become commercially available in the market. Biological, technological, and commercial constraints have hindered progress in this area. Many of these constraints are being addressed, but there is a critical need to better understand the biochemical and physiological data regarding the pathogenesis of these new bioherbicides. Oil emulsions are recognized as a way to increase both efficiency of application and efficacy of biocontrol agents.

  4. Inventory of Green Spaces and Woody Plants in the Urban Landscape in Ariogala

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    Lina Straigytė

    2012-12-01

    Full Text Available Background and Purpose: Regulation of urban greenery design, management and protection was approved in 2008 in Lithuania after the Green Space Law was passed, allowing protection of public green spaces and woody plants. Protection of these resources first requires an inventory, and we have created a digital database that will help in management of urban green spaces. Material and Methods: An inventory of green spaces and woody plants was conducted in the public urban territory of Ariogala, using GIS technology. A digital cartographic database was created using ArcGis 9.1 software. Results and Conclusion: Most of the woody plants in the survey area are deciduous trees, and the survey results highlighted the major green space management problems. Often, planted trees grow under power lines, and their crowns touch the power cables. Near blocks of flats, trees are often in the wrong place-planted too close to buildings, trees shade windows and their roots heave pavers and penetrate building foundations. According to the inventory, street trees sustain the most damage, most commonly showing injuries on their trunks and roots. Leaves of Aesculus hipocastanum L. show massive damage from Cameraria ohridella Deschka & Dimić, and Tilia cordata Mill. are damaged by Cercospora microsora Sacc. T. cordata is a favourite city tree, but is susceptible to infestation and when damaged appears unsightly, ending its vegetation period very early. The inventory of green spaces also showed that there are sufficient public parks.

  5. Research Progress and Prospect on Biological technology research Sugar beet for disease resistance and pest resistance%甜菜抗病虫生物技术研究现状与展望

    Institute of Scientific and Technical Information of China (English)

    马靖靖; 孙亚卿; 邵科; 张少英

    2012-01-01

    病虫害是制约甜菜生长的重要因素,通过生物技术改良作物抗病虫性是一条有效的新途径.本文分别从甜菜抗丛根病、根腐病、褐斑病,抗线虫、夜蛾方面综述了国内外对甜菜抗病虫生物技术所开展的研究工作,取得的进展,并展望了基因工程改良甜菜抗病虫的前景,为同类研究提供参考.%Pests and diseases are the important factors to restrict the growth of sugar beet, take biotechnology to improve crop resistance to disease and insect is a new effective way. This article respectively summarize the research work and consequence of resistance to Rhizomania,black root.cercospora leaf spot and nematodes,leaf-feeding insects on sugar beet in domestic and overseas on sugar beet, the Progress it has got, and the prospect the future of genetic engineering in the improvement of Sugarbeet on the resistance to the disease and insect, provide a reference for the similar research.

  6. Discrimination of Five Citrus Diseased Leaves by FTIR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Xingxiang; ZHAO; Gang; LIU; Weixing; LI; Xiaohua; Wang; Jianming; HAO; Xiangping; ZHOU

    2014-01-01

    In this paper,citrus brown spot,huanglongbing,canker,fuliginous,Cercospora sp. and healthy leaves were studied using Fourier transform infrared spectroscopy( FTIR) combined with statistical analysis. The results showed that the spectra of the samples were similar,whereas there were obvious differences in the second derivatives of infrared spectra in the range of 1 500- 700 cm- 1. The correlative analysis were evaluated,results showed that the correlation coefficients were larger than 0. 918 between healthy leaves,and between the same diseased leaves. However,the values were all decreased between healthy and diseased leaves,and among different diseased leaves. The preprocessed original,first derivative and second derivative spectra in the range of 1 200- 700 cm- 1were chosen to evaluated principal component analysis( PCA) and hierarchical cluster analysis( HCA),respectively. The performance of the overall accuracy of PCA was 92.5%,which were better than original dataset and first derivative dataset. HCA by selecting second derivative dataset yield about 90% accuracy. This study proved that FTIR spectroscopy could be detected citrus diseases quickly and accurately.

  7. Fungicides and Application Timing for Control of Early Leafspot, Southern Blight, and Sclerotinia Blight of Peanut

    Directory of Open Access Journals (Sweden)

    W. James Grichar

    2016-01-01

    Full Text Available Field studies were conducted in 2013 and 2014 in south Texas near Yoakum and from 2008 to 2011 in central Texas near Stephenville to evaluate various fungicides for foliar and soilborne disease control as well as peanut yield response under irrigation. Control of Sclerotinia blight caused by Sclerotinia minor Jagger with penthiopyrad at 1.78 L/ha was comparable to fluazinam or boscalid; however, the 1.2 L/ha dose of penthiopyrad did not provide consistent control. Peanut yield was reduced with the lower penthiopyrad dose when compared with boscalid, fluazinam, or the high dose of penthiopyrad. Control of early leaf spot, caused by Cercospora arachidicola S. Hori or southern blight, caused by Sclerotium rolfsii Sacc., with penthiopyrad in a systems approach was comparable with propiconazole, prothioconazole, or pyraclostrobin systems and resulted in disease control that was higher than the nontreated control. Peanut yield was also comparable with the penthiopyrad, propiconazole, prothioconazole, or pyraclostrobin systems and reflects the ability of the newer fungicides to control multiple diseases found in Texas peanut production.

  8. Fenton reagent and titanium dioxide nanoparticles as antifungal agents to control leaf spot of sugar beet under field conditions

    Directory of Open Access Journals (Sweden)

    Hamza Amany

    2016-07-01

    Full Text Available In this study, foliar sprays of Fenton solutions (Fenton reaction, Fenton-like reaction and Fenton complex, titanium dioxide (TiO2 and the recommended fungicide (chlorothalonil were estimated in the control of sugar beet leaf spot caused by Cercospora beticola under field conditions in two growing seasons. In addition, the impacts of these treatments on some crop characters (leaf dry weight, root fresh weight, soluble solid content, sucrose content and purity of sugar were examined. Biochemical and histological changes in the livers and kidneys of treated rats compared to an untreated control were utilized to assess the toxicity of the examined curative agents. Overall, chlorothalonil and Fenton complex were the most effective treatments for disease suppression in both tested seasons followed by Fenton-like reagent, Fenton’s reagent and TiO2, respectively. Growth and yield characters of treated sugar beet significantly increased in comparison to an untreated control. There were mild or no (biochemical and histological changes in the livers and kidneys of treated rats compared to the control. Fenton solutions and TiO2 may offer a new alternative for leaf spot control in sugar beet.

  9. Bcmfs1, a novel major facilitator superfamily transporter from Botrytis cinerea, provides tolerance towards the natural toxic compounds camptothecin and cercosporin and towards fungicides.

    Science.gov (United States)

    Hayashi, Keisuke; Schoonbeek, Henk-Jan; De Waard, Maarten A

    2002-10-01

    Bcmfs1, a novel major facilitator superfamily gene from Botrytis cinerea, was cloned, and replacement and overexpression mutants were constructed to study its function. Replacement mutants showed increased sensitivity to the natural toxic compounds camptothecin and cercosporin, produced by the plant Camptotheca acuminata and the plant pathogenic fungus Cercospora kikuchii, respectively. Overexpression mutants displayed decreased sensitivity to these compounds and to structurally unrelated fungicides, such as sterol demethylation inhibitors (DMIs). A double-replacement mutant of Bcmfs1 and the ATP-binding cassette (ABC) transporter gene BcatrD was more sensitive to DMI fungicides than a single-replacement mutant of BcatrD, known to encode an important ABC transporter of DMIs. The sensitivity of the wild-type strain and mutants to DMI fungicides correlated with Bcmfs1 expression levels and with the initial accumulation of oxpoconazole by germlings of these isolates. The results indicate that Bcmfs1 is a major facilitator superfamily multidrug transporter involved in protection against natural toxins and fungicides and has a substrate specificity that overlaps with the ABC transporter BcatrD. Bcmfs1 may be involved in protection of B. cinerea against plant defense compounds during the pathogenic phase of growth on host plants and against fungitoxic antimicrobial metabolites during its saprophytic phase of growth.

  10. Genetic mapping of resistance to purple seed stain in PI 80837 soybean.

    Science.gov (United States)

    Jackson, Eric Wayne; Feng, Chunda; Fenn, Patrick; Chen, Pengiun

    2008-01-01

    Purple seed stain (PSS) of soybean caused by Cercospora kikuchii is an important disease that reduces market grade and can affect seed germination and vigor. A single dominant gene was shown to confer PSS resistance in PI 80837. The objective of this research was to map the PSS resistance gene in PI 80837 using simple sequence repeat (SSR) markers. A cross was made between the PSS-susceptible cultivar Agripro 350 (AP 350) and PI 80837. The F2 population and parents were grown in the field, and the resistance or susceptibility of individual plants was determined by assaying the seed for infection by C. kikuchii. DNA of parent and F2 plants was extracted for SSR analysis and mapping. Segregation ratios for seed infection and for SSR markers showed that a single dominant gene conditions resistance to PSS in PI 80837. The candidate resistance gene was mapped between Sat_308 (6.6 cM) and Satt594 (11.6 cM) on molecular linkage group G. These markers may be useful in marker-assisted selection for utilizing PSS resistance from PI 80837 in a breeding program.

  11. Effects of temperature during soybean seed development on defense-related gene expression and fungal pathogen accumulation.

    Science.gov (United States)

    Upchurch, Robert G; Ramirez, Martha E

    2011-12-01

    Soybean [Glycine max (L.) Merr] plants were exposed to three temperature regimens during seed development to investigate the effect of temperature on the expression of eight defense-related genes and the accumulation of two fungal pathogens in inoculated seeds. In seeds prior to inoculation, either a day/night warm (34/26 °C) or a cool temperature (22/18 °C) relative to normal (26/22 °C) resulted in altered patterns of gene expression including substantially lower expression of PR1, PR3 and PR10. After seed inoculation with Cercospora kikuchii, pathogen accumulation was lowest in seeds produced at 22/18 °C in which of all defense genes, MMP2 was uniquely most highly induced. For seeds inoculated with Diaporthe phaseolorum, pathogen accumulation was lowest in seeds produced at 34/26 °C in which of all defense genes, PR10 was uniquely most highly induced. Our detached seed assays clearly demonstrated that the temperature regimens we applied during seed development produced significant changes in seed defense-related gene expression both pre- and post inoculation and our findings support the hypothesis that global climate change may alter plant-pathogen interactions and thereby potentially crop productivity.

  12. Uso de mezclas de azoxistrobina y triazoles para controlar enfermedades de fin de ciclo de la soja

    Directory of Open Access Journals (Sweden)

    Marcelo Carmona

    2011-06-01

    Full Text Available Las enfermedades de fin de ciclo de la soja (EFC, ampliamente difundidas en Argentina, afectan el rendimiento del cultivo y la calidad de la semilla cosechada. La aplicación foliar de fungicidas representa una alternativa eficiente en las actuales condiciones de cultivo (monocultivo y siembra directa. Los objetivos del presente trabajo fueron 1 determinar los agentes causales de la EFC presentes en los ensayos, 2 evaluar la disminución de rendimiento causada por las EFC y 3 valorar la eficiencia de control de mezclas de triazoles y azoxistrobina aplicados en las etapas reproductivas R3 o R5, para el control de las mismas. Se realizaron cuatro ensayos, dos en la campaña 2004/2005, y dos en la campaña 2005/2006, en Armstrong, Santa Fe, núcleo del área sojera de la Región Pampeana. Se utilizaron dos mezclas de azoxistrobina, una con cyproconazole y otra con difenoconazole, y una mezcla de los dos últimos. Los patógenos detectados fueron: Cercospora kikuchii, Colletotrichum truncatum, Septoria glycines, Glomerella glycines y Phomopsis sojae. Todos los tratamientos tuvieron mayores rendimientos que el control no tratado en todos los ensayos, con un nivel de significancia del 5%. Se concluye que, bajo las condiciones de los ensayos, con altas precipitaciones entre R1 y R5.5, los productos utilizados, controlaron eficientemente las EFC presentes.

  13. JLT-408 A New High Yielding Sesame Variety for Maharashtra State

    Directory of Open Access Journals (Sweden)

    M. G. Jadhav, G.B.Chaudhari,T. R. Patil, and S. C. Patil

    2015-03-01

    Full Text Available Sesame variety JLT-408 is developed through hybridization followed by advance generation selection from the cross Padma x Yuzhi-8 by pedigree method at Oilseeds Research Station, Jalgaon. This variety gave 29.9 % and 20.8% higher yield than checks JLT-7 and JLT-26, respectively. It has medium maturity period (81-85 days, white bold seed and found superior in quality viz. high oil content (53.2%, low in free fatty acid (1.46% and its Iodine value is 107.0. This new variety is moderately resistant to major diseases like Phyllody, Cercospora leaf spot, Alternaria leaf spot, Powdery mildew and Macrophomina stem/ root rot and it is moderately tolerant to leaf roller /capsule borer and tolerant to gall fly under field conditions. Considering merits in respect of yield, oil content and quality parameters JLT-408 has been released for cultivation in kharif season in North Maharashtra and adjoining areas of Vidarbha and Marathwada regions in Maharashtra.

  14. Atividade antimicrobiana e indutora de fitoalexinas do hidrolato de carqueja [Baccharis trimera (Less. DC.

    Directory of Open Access Journals (Sweden)

    G.S. Moura

    2014-01-01

    Full Text Available Hidrolato é o líquido resultante da extração de óleo essencial de plantas aromáticas por arraste a vapor apresentando em sua composição importantes metabólitos do vegetal de origem. O objetivo deste trabalho foi avaliar a atividade indutora de fitoalexinas, bem como as propriedades antifúngica e antibacteriana do hidrolato de carqueja (Baccharis trimera. Foram testadas as concentrações de 1, 10, 25, 50, 75 e 100%. A atividade indutora de fitoalexinas foi avaliada em mesocótilos estiolados de sorgo e em cotilédones de soja. A atividade antifúngica foi avaliada sobre a germinação de esporos de Pseudocercospora vitis, Cercospora kaki e Hemileia vastatrix. A atividade antibacteriana foi avaliada sobre a multiplicação de Xanthomonas campestris pv. passiflorae, Erwinia carotovora e Bacilllus subtilis. O hidrolato não induziu a produção de fitoalexinas em soja, mas promoveu esta atividade em sorgo a partir da concentração de 50%. Atividade antibacteriana ocorreu para os três isolados a partir da concentração de 75%, com inibição de até 87,9% sobre B. subtilis. O hidrolato não mostrou atividade antifúngica.

  15. Detection of Disease Symptoms on Hyperspectral 3d Plant Models

    Science.gov (United States)

    Roscher, Ribana; Behmann, Jan; Mahlein, Anne-Katrin; Dupuis, Jan; Kuhlmann, Heiner; Plümer, Lutz

    2016-06-01

    We analyze the benefit of combining hyperspectral images information with 3D geometry information for the detection of Cercospora leaf spot disease symptoms on sugar beet plants. Besides commonly used one-class Support Vector Machines, we utilize an unsupervised sparse representation-based approach with group sparsity prior. Geometry information is incorporated by representing each sample of interest with an inclination-sorted dictionary, which can be seen as an 1D topographic dictionary. We compare this approach with a sparse representation based approach without geometry information and One-Class Support Vector Machines. One-Class Support Vector Machines are applied to hyperspectral data without geometry information as well as to hyperspectral images with additional pixelwise inclination information. Our results show a gain in accuracy when using geometry information beside spectral information regardless of the used approach. However, both methods have different demands on the data when applied to new test data sets. One-Class Support Vector Machines require full inclination information on test and training data whereas the topographic dictionary approach only need spectral information for reconstruction of test data once the dictionary is build by spectra with inclination.

  16. Greenhouse evaluation of Bacillus subtilis AP-01 and Trichoderma harzianum AP-001 in controlling tobacco diseases Avaliação em estufa de dois agentes biológicos de controle de doenças do tabaco

    Directory of Open Access Journals (Sweden)

    Monchan Maketon

    2008-06-01

    Full Text Available Two biological control agents, Bacillus subtilis AP-01 (LarminarTM and Trichoderma harzianum AP-001 (TrisanTM alone or/in combination were investigated in controlling three tobacco diseases, including bacterial wilt (Ralstonia solanacearum, damping-off (Pythium aphanidermatum, and frogeye leaf spot (Cercospora nicotiana. Tests were performed in greenhouse by soil sterilization prior to inoculation of the pathogens. Bacterial-wilt and damping off pathogens were drenched first and followed with the biological control agents and for comparison purposes, two chemical fungicides. But for frogeye leaf spot, which is an airborne fungus, a spraying procedure for every treatment including a chemical fungicide was applied instead of drenching. Results showed that neither B. subtilis AP-01 nor T. harzianum AP-001 alone could control the bacterial wilt, but when combined, their controlling capabilities were as effective as a chemical treatment. These results were also similar for damping-off disease when used in combination. In addition, the combined B. subtilis AP-01 and T. harzianum AP-001 resulted in a good frogeye leaf spot control, which was not significantly different from the chemical treatment.Dois agentes de controle biológico, Bacillus subtilis AP-01 (Larminar® e Trichoderma harzianum AP-001 (Trisan® foram avaliados separadamente ou em combinação quanto à capacidade de controlar três doenças do tabaco: murcha bacteriana (bacterial wilt, Ralstonia solanacearum, tombamento de mudas (damping-off, Pythium aphanidermatum, e mancha olho-de-rã (frogeye leaf spot, Cercospora nicotiana. Os testes foram realizados em estufa, esterilizando-se o solo antes da inoculação dos patógenos. Os patógenos causadores da murcha bacteriana e tombamento de mudas foram inicialmente encharcados e acompanhados com os agentes de controle biológico e, para comparação, com um fungicida químico. Para a mancha olho-de-rã, causada por um fungo anem

  17. Characterization of rust, early and late leaf spot resistance in wild and cultivated peanut germplasm Caracterização da resistência à ferrugem, mancha preta e mancha castanha em germoplasma silvestre e cultivado de amendoim

    Directory of Open Access Journals (Sweden)

    Alessandra Pereira Fávero

    2009-02-01

    Full Text Available Groundnut (Arachis hypogaea has an AB genome and is one of the most important oil crops in the world. The main constraints of crop management in Brazil are fungal diseases. Several species of the genus Arachis are resistant to pests and diseases. The objective of our experiments was to identify wild species belonging to the taxonomic section Arachis with either A or B (or " non-A" genomes that are resistant to early leaf spot (Cercospora arachidicola, late leaf spot (Cercosporidium personatum and rust (Puccinia arachidis. For the identification of genotypes resistant to fungal diseases, bioassays with detached leaves were done in laboratory conditions, with artificial inoculation, a controlled temperature of 25ºC and a photoperiod of 10 h light/14 h dark, for 20-42 days, depending on the fungi species. Most of the accessions of wild species were more resistant than accessions of A. hypogaea for one, two or all three fungi species studied. Arachis monticola, considered to be a possible tetraploid ancestor or a derivative of A. hypogaea, was also more susceptible to Cercosporidium personatum and Puccinia arachidis, as compared to most of the wild species. Therefore, wild germplasm accessions of both genome types are available to be used for the introgression of resistance genes against three fungal diseases of peanut.O amendoim (Arachis hypogaea possui genoma AB e é uma das mais importantes culturas oleaginosas em todo o mundo. Os principais problemas da cultura no Brasil são as doenças fúngicas. Várias espécies do gênero Arachis são resistentes a pragas e doenças. Este trabalho visou a identificar espécies silvestres pertencentes à seção Arachis associadas aos genomas A ou B (ou " não-A" do amendoim que são resistentes à mancha castanha (Cercospora arachidicola, mancha preta (Cercosporidium personatum e ferrugem (Puccinia arachidis. Para a identificação de genótipos resistentes a doenças fúngicas, bioensaios utilizando

  18. Nuevo cultivar de soja de la EEAOC: Yanasu RR New soybean cultivar released by the EEAOC: Yanasu RR

    Directory of Open Access Journals (Sweden)

    José R. Sánchez

    2012-06-01

    Full Text Available Durante las últimas décadas, el cultivo de la soja a nivel mundial tuvo un crecimiento tanto en superficie, como en productividad. En la Argentina sucedió de igual manera, particularmente a comienzos de este siglo, como resultante del uso de alta tecnología, convirtiendo a este cultivo y a sus subproductos en el pilar del sistema granario y exportador. El desarrollo del Noroeste Argentino (NOA coincidió con el proceso a nivel nacional. La Estación Experimental Agroindustrial Obispo Colombres (EEAOC de Tucumán buscó permanentemente producir cultivares adaptados a esta zona, siendo este el principal objetivo del subprograma Mejoramiento Genético del Proyecto Soja. Yanasu es una nueva variedad de soja liberada por la EEAOC, que completa su madurez fisiológica a los 123 días de su siembra (pertenece al grupo de madurez VIII corto y que logra excelentes potenciales de rendimiento. Fue obtenida a través de cruzamiento y posterior avance generacional en la subestación de Monte Redondo (San Agustín, Tucumán. Yanasu RR fue sometida a ensayos comparativos de rendimiento (ECR en cuatro diferentes sitios del área sojera tucumana durante la campañas 2005/2006 y 2006/2007, alcanzando rendimientos superiores a los testigos en la mayoría de los ensayos. Exhibe, entre otras características, baja o nula dehiscencia de vainas y un peso de 1000 semillas de 162,6 gramos. En cuanto a su sanidad, se destaca su tolerancia a las enfermedades cancro del tallo y mancha ojo de rana, así como ante patógenos de semillas como Cercospora kikuchii, Alternaria spp. y Macrophomina spp. Desde 2009/2010 se la incluyó en la Red de Evaluación de Variedades Comerciales del NOA, destacándose por encima del testigo en 12 localidades de la región, con un excelente potencial de rendimiento.In recent decades, soybean planted area, production, and productivity have increased worldwide. This has also occurred in Argentina, especially during the last century, based on

  19. Potencial produtivo de linhagens de amendoim do grupo ereto precoce com e sem controle de doenças foliares Yield potential of upright early maturing peanut lines with and without control of foliar diseases

    Directory of Open Access Journals (Sweden)

    IGNÁCIO JOSÉ DE GODOY

    2001-01-01

    Full Text Available Avaliaram-se o potencial produtivo, o rendimento de grãos após descascamento e a massa de grãos de onze linhagens de amendoim (Arachis hypogaea L. do programa de melhoramento do Instituto Agronômico e da cultivar IAC-Tatu-ST, com e sem controle de doenças foliares. O material genético classifica-se no grupo ereto precoce (A. hypogaea subsp. fastigiata, Waldron. Seis experimentos foram desenvolvidos na época das águas, no Núcleo de Agronomia da Alta Mogiana e na Estação Experimental de Agronomia de Pindorama, em 1994/95, 1995/96 e 1996/97, em esquema com duas parcelas subdivididas, em blocos ao acaso com quatro repetições, em que as parcelas principais consistiram em tratamentos com e sem o controle químico das doenças. As parcelas tratadas foram pulverizadas periodicamente com 3,0 L.ha-1 do fungicida chlorothalonil para controle da mancha-castanha e da mancha-preta (Cercospora arachidicola e Cercosporidium personatum e da verrugose (Sphaceloma arachidis. A ausência de controle químico resultou em significativas reduções, até de 60%, na produção de todos os genótipos. Com as doenças controladas, as linhagens IAC 5, IAC 21, IAC 22 e IAC 81-12 apresentaram maior potencial produtivo, atingindo 5.000 kg.ha-1 em dois dos experimentos. As linhagens IAC 81-7 e IAC 88-1 apresentaram os melhores desempenhos relativos entre as médias de ambientes com e sem controle químico. As doenças causaram reduções até de 14% no peso médio dos grãos, sobretudo nas linhagens IAC 5, IAC 21 e IAC 22, cujos grãos são de maior tamanho médio. Não foram observadas diferenças significativas em rendimento de grãos entre os tratamentos, na maioria dos ambientes; essa característica mostrou, também, ser pouco influenciada pela presença das doenças.Eleven peanut lines and the cultivar IAC-Tatu-ST, of the upright early maturing group (Arachis hypogae subsp. fastigiata, Waldron, were evaluated for pod yield, shelling percentage and average

  20. 国内木薯病害普查及细菌性萎蔫病安全性评估%General Survey on Cassava Diseases and Safety Assessment of Cassava Bacterial Blight

    Institute of Scientific and Technical Information of China (English)

    李超萍; 时涛; 刘先宝; 蔡吉苗; 裴月令; 黄贵修

    2011-01-01

    2007~2010年,对广西、海南、云南等木薯主产区进行病害普查.结果发现,至今危害国内木薯的主要病害有7种,包括真菌病害6种[褐斑病(Cercosporidium henningsii)、炭疽病(colletotrichum gloeosPorioides)、离孺孢叶斑病(Bipolaris setariae)、棒孢霉叶斑病(Corynespora cassiicola)、白点病(phaeoramularia manihotis)和萎蔫叶斑病(Cercospora vicosae)],细菌病害1种[细菌性萎蔫病(Xanthomonas axonopodis pv manihotis)],其中离孺孢叶斑病和棒孢霉叶斑病为新发病害;7种病害中褐斑病和细菌性萎蔫病发生面积最大,危害最为严重.风险评估结果表明,细菌性萎蔫病菌为高度危险性有害生物.%During 2007 to 2010, cassava(Manihot esculenta Crantz)diseases survey was conducted in Guangxi, Hainan and Yunnan, the main cassava planting areas of China. The results showed that only seven diseases, six fungal diseases and one bacterial disease, were found. The cassava brown leaf spot caused by Cercosporidium henningsii and the bacterial blight caused by Xanthomonas axonopodis pv Manihotis prevailed in most cassava planting areas and caused serious damage. The safety assessment indicated that the cassava bacterial blight was a high risk disease. At present, cassava diseases are becoming one of the most important limiting factors for the development of cassava industry and would have a very serious,potential economic risk on correlative industry and the ecology of the tropic area.

  1. Predicting favorable conditions for early leaf spot of peanut using output from the Weather Research and Forecasting (WRF) model.

    Science.gov (United States)

    Olatinwo, Rabiu O; Prabha, Thara V; Paz, Joel O; Hoogenboom, Gerrit

    2012-03-01

    Early leaf spot of peanut (Arachis hypogaea L.), a disease caused by Cercospora arachidicola S. Hori, is responsible for an annual crop loss of several million dollars in the southeastern United States alone. The development of early leaf spot on peanut and subsequent spread of the spores of C. arachidicola relies on favorable weather conditions. Accurate spatio-temporal weather information is crucial for monitoring the progression of favorable conditions and determining the potential threat of the disease. Therefore, the development of a prediction model for mitigating the risk of early leaf spot in peanut production is important. The specific objective of this study was to demonstrate the application of the high-resolution Weather Research and Forecasting (WRF) model for management of early leaf spot in peanut. We coupled high-resolution weather output of the WRF, i.e. relative humidity and temperature, with the Oklahoma peanut leaf spot advisory model in predicting favorable conditions for early leaf spot infection over Georgia in 2007. Results showed a more favorable infection condition in the southeastern coastline of Georgia where the infection threshold were met sooner compared to the southwestern and central part of Georgia where the disease risk was lower. A newly introduced infection threat index indicates that the leaf spot threat threshold was met sooner at Alma, GA, compared to Tifton and Cordele, GA. The short-term prediction of weather parameters and their use in the management of peanut diseases is a viable and promising technique, which could help growers make accurate management decisions, and lower disease impact through optimum timing of fungicide applications.

  2. Systems genetics reveals a transcriptional network associated with susceptibility in the maize-grey leaf spot pathosystem.

    Science.gov (United States)

    Christie, Nanette; Myburg, Alexander A; Joubert, Fourie; Murray, Shane L; Carstens, Maryke; Lin, Yao-Cheng; Meyer, Jacqueline; Crampton, Bridget G; Christensen, Shawn A; Ntuli, Jean F; Wighard, Sara S; Van de Peer, Yves; Berger, Dave K

    2017-02-01

    We used a systems genetics approach to elucidate the molecular mechanisms of the responses of maize to grey leaf spot (GLS) disease caused by Cercospora zeina, a threat to maize production globally. Expression analysis of earleaf samples in a subtropical maize recombinant inbred line population (CML444 × SC Malawi) subjected in the field to C. zeina infection allowed detection of 20 206 expression quantitative trait loci (eQTLs). Four trans-eQTL hotspots coincided with GLS disease QTLs mapped in the same field experiment. Co-expression network analysis identified three expression modules correlated with GLS disease scores. The module (GY-s) most highly correlated with susceptibility (r = 0.71; 179 genes) was enriched for the glyoxylate pathway, lipid metabolism, diterpenoid biosynthesis and responses to pathogen molecules such as chitin. The GY-s module was enriched for genes with trans-eQTLs in hotspots on chromosomes 9 and 10, which also coincided with phenotypic QTLs for susceptibility to GLS. This transcriptional network has significant overlap with the GLS susceptibility response of maize line B73, and may reflect pathogen manipulation for nutrient acquisition and/or unsuccessful defence responses, such as kauralexin production by the diterpenoid biosynthesis pathway. The co-expression module that correlated best with resistance (TQ-r; 1498 genes) was enriched for genes with trans-eQTLs in hotspots coinciding with GLS resistance QTLs on chromosome 9. Jasmonate responses were implicated in resistance to GLS through co-expression of COI1 and enrichment of genes with the Gene Ontology term 'cullin-RING ubiquitin ligase complex' in the TQ-r module. Consistent with this, JAZ repressor expression was highly correlated with the severity of GLS disease in the GY-s susceptibility network.

  3. Mn foliar sobre a qualidade sanitária e lignina de sementes de soja convencional e resistente ao glifosato1

    Directory of Open Access Journals (Sweden)

    Everson Reis Carvalho

    Full Text Available O Mn pode estar associado à resistência das plantas aos fungos, por meio da lignificação ou inibição direta. Objetivou-se neste trabalho avaliar a aplicação foliar de Mn sobre a incidência de fungos, teores de Mn e de lignina nas sementes de soja oriundas de cultivares convencionais e de suas derivadas transgênicas resistentes ao glifosato (RR. O ensaio foi conduzido na Universidade Federal de Lavras, em blocos casualizados, com três repetições e esquema fatorial 4 x 4 x 2, sendo quatro cultivares de soja, duas convencionais e suas derivadas RR (BRS Celeste e BRS Baliza RR; BRSGO Jataí e BRS Silvânia RR, quatro doses de Mn via foliar (0; 200; 400 e 600 g Mn ha-1 e dois estádios de aplicação (R1 ou R3. Antes e após seis meses de armazenamento, as sementes foram submetidas ao teste de sanidade (Blotter test. Foram determinados os teores de Mn nas sementes e de lignina no tegumento. Verificou-se que a aplicação foliar de Mn proporciona menores incidências de Cercospora kikuchii, Fusarium spp. e Aspergillus spp. nas sementes de soja produzidas. O Mn aplicado via foliar na soja, tanto no estádio R1 como em R3, transloca até as sementes, mas não afeta a produção de lignina no tegumento das mesmas. Os teores de lignina no tegumento das sementes de soja são inferiores nas cultivares convencionais, Celeste e Jataí, em relação às suas derivadas transgênicas resistentes ao glifosato, Baliza RR e Silvânia RR.

  4. Characteristics and determinants of ambient fungal spores in Hualien, Taiwan

    Science.gov (United States)

    Ho, Hsiao-Man; Rao, Carol Y.; Hsu, Hsiao-Hsien; Chiu, Yueh-Hsiu; Liu, Chi-Ming; Chao, H. Jasmine

    Characteristics and determinants of ambient aeroallergens are of much concern in recent years because of the apparent health impacts of allergens. Yet relatively little is known about the complex behaviors of ambient aeroallergens. To address this issue, we monitored ambient fungal spores in Hualien, Taiwan from 1993-1996 to examine the compositions and temporal variations of fungi, and to evaluate possible determinants. We used a Burkard seven-day volumetric spore trap to collect daily fungal spores. Air pollutants, meteorological factors, and Asian dust events were included in the statistical analyses to predict fungal levels. We found that the most dominant fungal categories were ascospores, followed by Cladosporium and Aspergillus/Penicillium. The majority of the fungal categories had significant diurnal and seasonal variations. Total fungi, Cladosporium, Ganoderma, Arthrinium/Papularia, Cercospora, Periconia, Alternaria, Botrytis, and PM 10 had significantly higher concentrations ( p<0.05) during the period affected by Asian dust events. In multiple regression models, we found that temperature was consistently and positively associated with fungal concentrations. Other factors correlated with fungal concentrations included ozone, particulate matters with an aerodynamic diameter less than 10 μm (PM 10), relative humidity, rainfall, atmospheric pressure, total hydrocarbons, carbon monoxide, nitrogen dioxide, and sulfur dioxide. Most of the fungal categories had higher levels in 1994 than in 1995-96, probably due to urbanization of the study area. In this study, we demonstrated complicated interrelationships between fungi and air pollution/meteorological factors. In addition, long-range transport of air pollutants contributed significantly to local aeroallergen levels. Future studies should examine the health impacts of aeroallergens, as well as the synergistic/antagonistic effects of weather, and local and global-scale air pollutions.

  5. Arabidopsis thaliana plant defensin AtPDF1.1 is involved in the plant response to biotic stress.

    Science.gov (United States)

    De Coninck, Barbara M A; Sels, Jan; Venmans, Esther; Thys, Wannes; Goderis, Inge J W M; Carron, Delphine; Delauré, Stijn L; Cammue, Bruno P A; De Bolle, Miguel F C; Mathys, Janick

    2010-09-01

    *Previously, it was shown that the Arabidopsis thaliana plant defensins AtPDF1.1 (At1g75830) and AtPDF1.2a (At5g44420) exert in vitro antimicrobial properties and that their corresponding genes are expressed in seeds and induced in leaves upon pathogen attack, respectively. *In this study, the expression profile of both AtPDF1.1 and AtPDF1.2a is analysed in wild-type plants upon different stress-related treatments and the effect of modulation of their expression in transgenic plants is examined in both host and nonhost resistance. *AtPDF1.1, which was originally considered to be seed-specific, is demonstrated to be locally induced in leaves upon fungal attack and exhibits an expression profile distinct from that of AtPDF1.2a, a gene frequently used as marker for the ethylene/jasmonate-mediated signaling pathway. Transgenic plants with modulated AtPDF1.1 or AtPDF1.2a gene expression show no altered phenotype upon Botrytis cinerea inoculation. However, constitutive overexpression of AtPDF1.1 in A. thaliana leads to a reduction in symptoms caused by the nonhost Cercospora beticola causing non-spreading spots on A. thaliana leaves. *These results indicate that AtPDF1.1 and AtPDF1.2a clearly differ regarding their expression profile and functionality in planta. It emphasizes the additional level of complexity and fine-tuning within the highly redundant plant defensin genes in A. thaliana.

  6. Influence of He-Ne laser irradiation of soybean seeds on seed mycoflora, growth, nodulation, and resistance to Fusarium solani.

    Science.gov (United States)

    Ouf, S A; abdel-Hady, N F

    1999-01-01

    Laser irradiation of soybean seeds for 3 min caused a clear reduction in the number of seed-borne fungi which became more pronounced as the irradiation time was extended. Pretreatment of the seeds with methylene blue, methyl red and carmine enhanced the effect of laser. Rhizoctonia solani, Alternaria tenuissima, Cercospora kikuchii and Colletotrichum truncatum were completely eliminated when the seeds were pretreated with a dye and irradiated for 10 min. Seed germination was stimulated on exposure of the seed to 1-min irradiation. At such dose, most of the dyes were accelerators while the higher doses were inhibitory to seed germination. Chlorophyll a, chlorophyll b and carotenoid content of developed plants differed, depending on the irradiation dose and dye treatment of the seeds. In seeds irradiated for 1 or 3 min, chlorophyll a formation was less affected than chlorophyll b formation. In seeds irradiated for 10 min, both the chlorophyll contents were decreased especially in the presence of some applied dyes. On the other hand, there was an increase in carotenoid content of soybean leaves when the laser dose increased. The number and dry mass of nodules were mostly greater (as compared to the corresponding control), when the seeds irradiated for 1 or 3 min were pretreated with methyl red, chlorophenol red, crystal violet and methylene blue. Irradiation of pre-sowing seeds greatly protected soybean stands against F. solani. The disease incidence differed somewhat when the irradiated seeds were pretreated with dyes. The reduction in disease incidence was accompanied by accumulation of high proline and phenol levels in the infected root tissues of soybean, suggesting that these compounds have a certain role in the prevention of disease development.

  7. Pod and seed mycoflora on transgenic and conventional soybean [Glycine max (L.) Merrill] cultivars in Mississippi.

    Science.gov (United States)

    Villarroel, D A; Baird, R E; Trevathan, L E; Watson, C E; Scruggs, M L

    2004-02-01

    A 2-year (1999-2000) study was conducted at Starkville and Stoneville, MS to determine if the occurrence of the mycoflora varied on Roundup Ready (transgenic) compared to conventional soybean (Glycine max) cultivars. A total of 7,658 fungal isolates were identified from the pod and seed tissues of four cultivars compared at growth stages R6 and R8. Ninety-nine percent of all fungi isolated were mitosporic fungi and ascomycetes. In both years, total fungal isolates from the two locations were greater from the pod (65%) than from seed (33%) tissues. Isolation frequency from conventional cultivars was 54% compared to 46% for the transgenic cultivars. The most common fungi identified that are reported pathogens of soybean included Alternaria, Cercospora, Cladosporium, Diaporthe, Fusarium and Verticillium spp. When main effects and interactions were compared among the frequency data for the fungal genera, significant differences occurred, but consistent trends were not noted. Isolation frequencies of Diaporthe spp. during the R6 growth stage, were significantly greater on the conventional than on the transgenic cultivars in both years of the study, but only at Starkville. Isolation frequencies from samples taken during the R8 growth stage were similar at both locations in 1999 and 2000. Fusarium spp. isolated at R6 and R8 growth stages from pod and seed tissues were significantly greater on conventional than on transgenic cultivars in 2000. Even though frequencies were often significantly different between the transgenic and conventional cultivars, the data was not consistent between locations, pod and seed tissues, or growth stages. The pod and seed mycoflora of transgenic and conventional soybean cultivars was, therefore, similar in Mississippi.

  8. 我国不同地区大豆主栽品种种子携带真菌研究%Seed-Borne Fungi Detection in Different Soybean Cultivars

    Institute of Scientific and Technical Information of China (English)

    魏思楠; 朱晓峰; 陈立杰; 王媛媛; 段玉玺

    2014-01-01

    采用组织分离法与形态鉴定相结合,对全国不同大豆产区的304个大豆主栽品种种子携带真菌情况进行了研究.结果表明:大豆种子携带的真菌主要有10个属,其中从大豆表面分离到的真菌中青霉属(Penicillium spp.)所占比例最大,其次是曲霉属(Aspergillus spp.)、镰刀属(Fusarium spp.)和根足霉属(Rhizopus spp.),此外还有链格孢属(Alternaria spp.)、木霉属(Trichoderma spp.)、枝孢属(Cladosporium spp.)、尾孢属(Cercospora spp.)、赤霉属(Gibber-ella spp.)、疫霉属(Phytophthora spp.);大豆种皮内携带的真菌优势种群为青霉属,其次为镰刀属,此外还有根足霉属、木霉属等;大豆种子内寄藏的真菌中青霉属占绝对优势,其次为镰刀属和曲霉属,此外还有链格孢属、根足霉属等.种外、种内携带的优势种群相互影响很大,呈正相关.

  9. Características agronómicas y sanidad de germoplasma promisorio de maní (Arachis hypogaea L. en Quevedo, Ecuador

    Directory of Open Access Journals (Sweden)

    Felipe Rafael Garcés-Fiallos

    2014-12-01

    Full Text Available Durante las épocas secas de 2010 y 2011, en la finca experimental La María de la Universidad Técnica Estatal de Quevedo, Ecuador, localizada en el km. 7.5 vía Quevedo-El Empalme, a 79° 30' 08" O y 01° 00' 35" S, se evaluaron las características agronómicas y las condiciones sanitarias de líneas y variedades de maní (Arachis hypogaea L.. Se utilizaron las líneas promisorias de maní CB-02, CB-05, CB-12, CB-13, CB-15, CB-16 y CB-23 de la Universidad y como testigos las variedades comerciales Diamante, Polachi, INIAP-380 e INIAP-381. Se midieron la emergencia de plántulas, días a floración, altura de planta, algunos componentes productivos (número de granos, frutos llenos y estériles, peso de frutos y granos y la presencia de cercosporiosis (Cercospora arachidicola y Cercosporidium personatum y roya (Puccinia arachidis. Se utilizó un diseño de bloques completos al azar (DBCA con 11 tratamientos y tres repeticiones en 2010 y cuatro repeticiones en 2011. Para las comparaciones entre las medias de los tratamientos se empleó la prueba de rangos múltiples de Duncan (P < 0.05. La línea CB-23 se destacó entre el germoplasma promisorio por su mayor productividad; esta misma línea junto con la variedad comercial INIAP-380, presentaron los menores ataques de cercosporiosis. La línea CB-15 y la variedad Polachi no presentaron lesiones de la roya.

  10. Predicting favorable conditions for early leaf spot of peanut using output from the Weather Research and Forecasting (WRF) model

    Science.gov (United States)

    Olatinwo, Rabiu O.; Prabha, Thara V.; Paz, Joel O.; Hoogenboom, Gerrit

    2012-03-01

    Early leaf spot of peanut ( Arachis hypogaea L.), a disease caused by Cercospora arachidicola S. Hori, is responsible for an annual crop loss of several million dollars in the southeastern United States alone. The development of early leaf spot on peanut and subsequent spread of the spores of C. arachidicola relies on favorable weather conditions. Accurate spatio-temporal weather information is crucial for monitoring the progression of favorable conditions and determining the potential threat of the disease. Therefore, the development of a prediction model for mitigating the risk of early leaf spot in peanut production is important. The specific objective of this study was to demonstrate the application of the high-resolution Weather Research and Forecasting (WRF) model for management of early leaf spot in peanut. We coupled high-resolution weather output of the WRF, i.e. relative humidity and temperature, with the Oklahoma peanut leaf spot advisory model in predicting favorable conditions for early leaf spot infection over Georgia in 2007. Results showed a more favorable infection condition in the southeastern coastline of Georgia where the infection threshold were met sooner compared to the southwestern and central part of Georgia where the disease risk was lower. A newly introduced infection threat index indicates that the leaf spot threat threshold was met sooner at Alma, GA, compared to Tifton and Cordele, GA. The short-term prediction of weather parameters and their use in the management of peanut diseases is a viable and promising technique, which could help growers make accurate management decisions, and lower disease impact through optimum timing of fungicide applications.

  11. Inhibitory activity of Cymbopogon citratus essential oil against nine phytopathogens%柠檬草精油对9种植物病原菌的抑菌活性

    Institute of Scientific and Technical Information of China (English)

    赵杰; 周超英; 顾振芳; 姚雷

    2011-01-01

    By the mycelium growth rate methods, the inhibitory activities of Cymbopogon citratus essential oil was tested against Valsa ambiens (Pers. ) Fr, Diaporthe citri (Fazvcett) Wolf, Alternaria citri, Colletotrichum orbicalare, Fusarium oxysporum f. Sp. Melonis, Alternaria alternate, Didymella bryoniae, and Cercospora fabae . The results showed that C. Citratus essential oil had good inhibition effects on 8 fungi and EC50 were 308. 052 2,433. 319 6,399. 733 8,319. 010 3,366. 895 7,279. 126 1,270. 738 8 and 333. 495 6 fiL/L respectively. In additions, inhibition zone experiment showed that C. Citratus essential oil had good inhibition effect on Xanthomonas pruni (Smith) Down with 500 μL/L of minimum inhibitory concentration MIC).%采用生长速率法测定了柠檬草精油对梨树腐烂病菌、柑橘树脂病菌、柑橘黑腐病菌、西瓜炭疽病菌、甜瓜枯萎病菌、甜瓜叶斑病菌、甜瓜蔓枯病菌、蚕豆轮纹病菌的抑菌活性.结果表明,柠檬草精油对8种病原真菌都具有很好的抑菌活性,其EC50分别为308.052 2、433.319 6、399.733 8、319.010 3、366.895 7、279.126 1、270.738 8和333.495 6μL/L;用抑菌圈法测定了柠檬草精油对桃细菌性穿孔病菌的抑菌活性,结果表明,柠檬草精油对桃细菌性穿孔病菌也具有一定的抑菌活性,其最低抑菌浓度为500 μL/L.

  12. Breeding of new monogerm sugarbeet variety HlT—TianDan 2%甜菜新品种工大甜单 2 号选育

    Institute of Scientific and Technical Information of China (English)

    罗成飞; 程大友; 鲁兆新; 史淑芝; 崔杰

    2015-01-01

    The rlew sugalbeet variety HlT—TianDan 2 is a diploid monogermmale steritle hybrid ,It was bred by crossing at first a monogerm MS line with a special shaped 0一type,then by crossing the obtainable MS line with a diploid pollinator .The result of regional test from 2012 to 2013 in Heilonjiang province showed:sugalbeet varie-ty HlT—TianDan 2 has an outstanding performance in sugar content .the rate of sugar contentin beetroot tubers has reached 17.0~17.2°S,and were higher than CK 1.2°S,the average root yield were higherthan CK 6.0%. The result of demonstrative trial showed:the rate of sugar content has reached 17.2°S,and were higher than CK 1.2°S,the average root yield were higherthan CK 14.2%.HlT—TianDan 2 has high sugar content and is very good in the suitability of variety .It has resistance to Cercospora leaf spot and root rot .It is good in root yield also .%甜菜新品种工大甜单2号是利用单胚型不育系与异型保持系单交,获得的不育系再与二倍体授粉系杂交育成的单胚品种. 该品种2012~2013 年参加黑龙江省甜菜品种区域试验,根产量较对照品种提高6.0%. 含糖率结果表现突出,块根含糖率17 .0~17 .2度,比对照提高1 .2度. 工大甜单2号在生产试验中,根产量比对照提高14 .2%,含糖率达到17 .2度,比对照提高1 .2度. 工大甜单2号含糖率高,适应性广、抗病性强、且丰产性好.

  13. 新型含吡啶环取代的吡唑肟醚类化合物的合成及生物活性研究%Synthesis and Biological Activities of Novel Pyrazole Oxime Ether Derivatives Containing Pyridyl Ring

    Institute of Scientific and Technical Information of China (English)

    戴红; 刘建兵; 苗文科; 吴珊珊; 秦雪; 张欣; 王婷婷; 方建新

    2011-01-01

    为了寻找新型高效低毒的农药先导化合物,通过N-吡啶基吡唑肟与2-氯-5-氯甲基吡啶的缩合反应,合成了一系列含吡啶环取代的吡唑肟醚类化合物.目标化合物的结构均经1H NMR,13C NMR和元素分析确证.初步生物活性试验结果表明,部分化合物具有一定的杀菌、杀虫和植物生长调节活性.如化合物5e在浓度为50 μtg/mL时对番茄早疫的抑制率为61.4%;化合物5j在浓度为50 μg/mL时对花生褐斑的抑制率为60.2%;化合物5i在浓度为500 μg/mL时对蚜虫表现出50.3%的杀死率;化合物5f在浓度为10 μg/mL时对黄瓜子叶生根表现出71.0%的促进生长作用.%In search of new low toxicity and potent pesticide lead compounds, a series of novel pyrazole oxime ether derivatives containing a pyridyl ring were synthesized by the condensation of iV-pyridyl pyrazole oximes with 2-chloro-5-chloromethyl pyridine. Their structures were determined by 1H NMR, 13C NMR spectra and elemental analysis. Preliminary bioassay showed that some of the target compounds displayed fungicidal, insecticidal, and plant growth regulatory activities to some extent. For example, compound 5c exhibited 61.4% inhibition rate against Alternaria solani at the concentration of 50 ug/mL, compound 5j showed 60.2% inhibition rate against Cercospora arachidicola at the concentration of 50 ug/mL, the mortality rate of compound 5i was 50.3% against Aphis craccivora at the concentration of 500 ug/mL, and compound 5f displayed 71.0% promotion effect on the radicle growth of cucumber cotyledons at the concentration of 10 ug/mL.

  14. Effects of ultraviolet radiation on Hibiscus rosa-sinensis, Beta vulgaris and Helianthus annuus

    Energy Technology Data Exchange (ETDEWEB)

    Panagopoulos, I.

    1992-01-01

    It is believed that increased levels of ultraviolet B-radiation (UV-B;280-320 nm) will result in serious threat to plant. In the present study the effects of UV (particularly UV-B) were studied on chlorophyll fluorescence, ultraweak luminescence (UL) and plant growth. Parameters related to light emission were determined, and the effects of UV-B on hypocotyl elongation and levels of free IAA were examined. The plants were grown in greenhouse or in growth chambers and exposed to short or long term UV-B simulating different levels of ozone depletion. Short exposure of Hibiscus leaves to UV resulted in a gradual increase in both UL and peroxidase activity followed by a decline after 72 h and a decrease in variable chlorophyll fluorescence. The action of UV-B on sugar beet plants depended on light quality and irradiance and infection by Cercospora beticola Sacc. The interaction between UV-B and the disease resulted in a large reduction of dry weight and enhanced UL. The lowest Chl a and growth was found in plants grown under low irradiance and exposed to UV-B supplemented with UV-A (320-400 nm). UVB also inhibited photosystem II, increased UL and peroxidase activity. Under relatively high PAR, UV-B increased dry weight of laminae and UL but no effect on Chl content. Sugar beet plants grown with light depleted in the 320-400 nm region of the spectrum and exposed to UV-B died. Low levels of UV-B did neither affected hypocotyl elongation nor amounts of free IAA in sunflower plants grown under low (LL; 143 [mu]mol m[sup -2]s[sup -1]) or high PAR (HL; 800 [mu]mol m[sup -2]s[sup -1]). Three times more daily UV-B increased the amount of free IAA, but inhibited hypocotyl elongation. Higher F[sub v]/F[sub max] and F690/F735, Chl a and carotenoids were found in plants exposed to low UV-B. Indeed, UV-B can be harmful but may also have enhancing effects on plants. (au) (114 refs.).

  15. The phytosanitary form and fighting measures diseases and pests of sugar beet from Republic of Moldova

    Directory of Open Access Journals (Sweden)

    Timus Asea M.

    2006-01-01

    Full Text Available Sugar beet is one of the most important agricultural crops in the Republic of Moldova. The North and Central regions have good enough pedoclimatic conditions. The genetic potential of sorts and hybrids can be created through the application of modern technologies in order to grow at least 32-35 tons/ha of sugar beet roots. In the Republic of Moldova, sugar beet vegetates between 160 and 180 days in the first year and needs approximately an amount of 2400-2900°C, average of 15.3-15.4°C. Each phenological phase needs different temperatures: at least 4C° is necessary for planting and springing an amount of 650°C is necessary for foliar apparatus; an amount of 1150- 1800°C is necessary to grow the volume of roots and for sugar depositing the average of 2400 to 2600°C is necessary. The mentioned temperatures ensure a normal development of sugar beet plants. If these temperatures fluctuate, the pathogens and pests are stimulated to develop. The most frequent diseases of sugar beet are: Pythium de baryanum Hesse., Aphanomyces cochlioides Dresch. Peronospora schachtii Fuck., Phoma betae Fr. Cercospora beticola Sacc. Erysiphe communis Grev. f. betae Jacz., virosis - Beta virus 2, 3 si 4 etc. The main pests belong to the following categories: Homoptera: Aphis fabae Scop. (fam. Aphididae, Pemphigus fuscicornis Koch. (fam. Pemphigidae Coleoptera: Agriotes sp. (fam. Elateridae, Chaetocnema concinna M. Ch. breviuscula Fld., Cassida nebulosa L. (fam. Chrysomelidae, Atomaria linearis Step. (fam. Cryptophagidae; Bothynoderes punctiventris Germ., Tanymechus dilaticollis Gyll., T. palliatus F., Psalidium maxillosum F. (Curculionidae; Lepidoptera: Agrotis segetum Den. et Schiff., Authographa gamma L. Mamestra (Barathra brassicae L. (Noctuidae, Loxostege sticticalis L. (Pyralidae, Gnorimoschema ocellatella Boyd.; Diptera Pegomyia betae Curtis. (fam. Anthomyidae. Heterodera schachtii Schmidt (Heteroderidae. The most recommended insecticides for fighting the

  16. Antifungal Activity of The Extraction of Hopea chinensis Stem and Leaves Against Plant Pathogenic Fungi%狭叶坡垒枝叶粗提物抑菌活性研究

    Institute of Scientific and Technical Information of China (English)

    熊婷; 许亚楠; 周明晓晗; 苏坚; 王忠文; 唐文伟

    2016-01-01

    With the growth rate method,15 kinds of plant materies were selected for their antifungal activity against Fusarium oxysporum Schl. f. sp. cucumerirum Owen,Alternaria longipes( Ell. et Eu) Tisdale et Wadk,Curvularia lunata (Wakker) Boedijin,Botrytis cinerea Pers,and Rhizoctonia solani Kuhn.The results were as follows.Hopea chinensis Hand.Mass,Solanum touvum swartz together and other five materials showed inhibitory activity,H. chinensis showed the strongest inhibition.Further experiment on the antifungal activity of the petro⁃leum,ethyl acetate and water extracts of H. chinensisi stem and leaves with against 21 plant pathogenic fungi such as Helminthosporium turcicum Pass,Helminthosporium oryzae Breda de Haan,Fusarium oxysporum Schl. f. sp and other 21 plant was determined.The results showed that the ethyl acetate extract of H. chinensis had high antifungal activity against 18 plant pathogenic fungi such as Gibberella fujikuroi ( Saw) Wollenw, Mycosphaere⁃lla fijiensis Mareletto,Cercospora musae Zimm. Their antifungal activity against Phytophthora nicotianae Breda was the strongest whose inhibiting rate was 100%,flowed by that against Alternaria musae Bour. et Bat,Curv⁃alaria lunata(Wakker) Boedijin,Ceratocystis paradoxa(Dade)Moreau,Alternaria brassicola(Schw.)Wiltshire, Rhizoctonia solani Kuhn,whose inhibiting rates were 89.00%,94.12%,90.35%,89.93% and 95.13%,respective⁃ly,and whose EC50 were 0.475 8mg/mL,2.642 9 mg/mL,0.614 7 mg/mL,0.467 4 mg/mL,0.977 7 mg/mL and 3.463 7 mg/mL,respectively.The spore germination experiment was conducted on C. paradoxa and A.brassicola using ethyl acetate extract of H. chinensis and the EC50 of each were 0. 716 6 mg/mL and 1. 784 4 mg/mL, respectively.The results lay the foundation for further investigation on the active antifungal components in Hopea chinensis.%采用菌丝生长速率法,以西瓜枯萎菌( Fusarium oxysporum Schl. f. sp. cucumerirum Owen)、烟草赤星菌[ Al⁃ternaria longipes(Ell. et

  17. Doenças da mandioquinha-salsa e sua situação atual no Brasil Present situation of arracacha (Arracacia xanthorrhiza diseases in Brazil

    Directory of Open Access Journals (Sweden)

    Gilmar P. Henz

    2002-06-01

    Full Text Available Este artigo tem como objetivo principal relatar as doenças registradas para a mandioquinha-salsa até a data presente e descrever sua situação atual no País. Na literatura, foram registrados para a cultura 27 gêneros de fungos, três de bactérias, doze de nematóides e cinco espécies de vírus. Destes, já foram relatados no Brasil treze fungos, e todos nematóides e bactérias, enquanto nenhum vírus foi oficialmente registrado, embora já tenham sido observadas plantas com sintomas típicos de viroses a campo. A maior parte dos registros estão na forma de resumos, capítulos de livros ou publicações genéricas, desprovidos de uma série de dados relevantes, como provas de patogenicidade, importância da doença, perdas, identificação mais acurada, entre outras. A cultura da mandioquinha-salsa ainda é tida como rústica, sendo poucas as doenças consideradas limitantes. O nematóide das galhas (Meloidogyne spp. e a podridão-mole pós-colheita causada por Erwinia spp. são os principais problemas atualmente, e causam perdas significativas. Também ocorrem com muita frequência manchas foliares causadas por Septoria, Cercospora e Xanthomonas campestris pv. arracaciae, e em algumas regiões podridão de plantas a campo causadas por Sclerotinia sclerotiorum e Sclerotium rolfsii. Como não existe nenhum produto químico oficialmente registrado para a mandioquinha-salsa no Ministério da Agricultura, Pecuária e Abastecimento, as medidas de controle passíveis de recomendação incluem ações preventivas, como o uso de material propagativo sadio (preferencialmente mudas pré-enraizadas de origem conhecida, a adoção de rotação de culturas, a eliminação de plantas ou partes doentes, e a adubação e a irrigação adequadas. O estudo sistematizado das doenças e o registro cuidadoso de surtos ou novas enfermidades para a cultura são importantes para subsidiar futuras medidas de controle.The diseases of arracacha that have already

  18. Efeito da aplicação de fungicida sobre caracteres agronômicos e severidade das doenças de final de ciclo na cultura da soja. = Effect of fungicide application on Agronomic characteristics and final cycle diseases severity in soybean.

    Directory of Open Access Journals (Sweden)

    Everton Luis Finoto

    2011-04-01

    Full Text Available Nas últimas safras, um complexo de doenças, chamadas de doenças de final de ciclo da soja (DFC, vem provocando reduções consideráveis no rendimento da cultura. Atualmente, não há variedades resistentes a todos os patógenos causadores das DFC. Objetivou-se no presente trabalho avaliar o efeito da aplicação de fungicida em diferentes estádios reprodutivos, nos caracteres agronômicos e severidade das DFC em três cultivares de soja de diferentes grupos de maturação. O trabalho foi conduzido em área experimental da Universidade Federal de Viçosa. Foram realizados quatro tratamentos com fungicida sendotrês aplicações em estádios reprodutivos diferentes (R5, R5,5 e R6 e a testemunha sem aplicação. As cultivares utilizadas foram: BRSMG Liderança, UFVS 2001 e UFVS 2003. Foi avaliado: altura da planta, altura da inserção da primeira vagem, número de nós por planta, número de vagens por planta, peso total da planta e peso de sementes. A severidade das DFC foi avaliada no estado R6 através de escala de notas. Os dados das avaliações foram submetidos aos testes de normalidade e homogeneidade constatando-se a desnecessidade de transformações. Realizou-se as análises de variância e as médias foram comparadas pelo teste de Tukey, a 5% de probabilidade de erro. Na avaliação da severidade das doenças, foi constatada a presença dos seguintes patógenos: Septoria glycines, Cercospora kikuchii e Peronospora manshurica. Para a avaliação das características agronômicas foi observado que a cultivar UFVS 2001 apresentou maiores alturas de planta. A cultivar UFVS 2003 apresentou maior númerode nós e também maior produtividade de grãos, seguida pela cultivar Liderança. A aplicação de fungicida proporcionou o controle satisfatório de Septoria glycines no folíolo, quando realizada no estádio R5. A aplicação do fungicida proporcionou também aumento na produtividade de grãos, sendo os melhores resultados obtidos

  19. 广西甘蔗主要真菌病害调查初报%Preliminary report on investigating major sugarcane fungal diseases in Guangxi

    Institute of Scientific and Technical Information of China (English)

    韦金菊; 邓展云; 黄诚华; 黄伟华; 颜梅新; 刘海斌; 唐红琴

    2012-01-01

    [Objective]The purpose of the present study was to determine the species and the occurrence status of major sugarcane fugal diseases in sugarcane plantation areas of Guangxi in order to provide scientific references for controlling sugarcane diseases. [Method]In 2009-2011, species and occurrence degrees of major sugarcane fugal diseases in sugarcane plantation areas of Guangxi were investigated through randomized surveys, fanner interviews, literature references, and location investigations; diseased sugarcane samples were collected and their species were identified through pathogen isolated culture and other relevant methods. [Result]Thirteen species of fungal diseases were identified, which were Thielaviopsis paradoxa (de Seynes) V. Hohnel, Ustilago scitaminea Sydow, Fusarium moniliforme Sheldon, Puccinia melanocephala H.&P. Syd., Stagonospora sacchari Lo et Ling, Colletotrichum falcatum Went, Phyllosticta saccharicola P. Henn., Pellicularia sasakii (Shirai) Ito, Elsinoe sacchari L., Helminthosporium sacchari (Breda de Haan) Butler, My-covellosiella koepkei (kruger) Deighton, Bipolaris stenospilum (Drechs.) Shoem., and Cercospora longipes Butler. Out of all of the fungal disease characteristics, smut, rust, tip rot, and pineapple disease were the most rampantly detrimental to sugarcane quality and yield. [ Conclusion ] Ustilago scitaminea Sydow turned out to be the most serious sugarcane disease; it is urgent to begin breeding highly-disease-resistant sugarcane varieties with elite field and environment adaptations to replace the current susceptible-to-diseases sugarcane varieties in order to increase production.%[目的]明确广西蔗区主要真菌病害的发生情况和种类,为甘蔗病害综合防治提供科学依据.[方法]2009~2011年采用随机踏查、种植户随访、资料查询和定点调查等方法对广西蔗区甘蔗真菌病害种类及发生程度进行调查,并采集病害样本,通过病原分离培养鉴定等方法确定真菌病

  20. Synthesis,Structure and Fungicidal Activity of Organotin 1-Aryl-3,5-dimethylpyrazole-4-carboxylates%1-芳基-3,5-二甲基吡唑-4-羧酸有机锡酯的合成、结构及杀菌活性研究

    Institute of Scientific and Technical Information of China (English)

    王志宏; 王贺; 郭彦召; 韦张文; 马琳; 范志金

    2012-01-01

    由1-芳基-3,5-二甲基吡唑-4-羧酸与适当的有机锡反应,合成表征了一系列的1-芳基-3,5-二甲基吡唑-4-羧酸有机锡酯(1~14),并通过单晶衍射确定了1-苯基-3,5-二甲基吡唑-4-羧酸三乙基锡酯(7)的结构.该化合物与一分子水共同结晶,通过分子间O-H…O及O-H…N氢键形成二维网状结构.杀菌活性筛选表明新合成的化合物对于番茄早疫菌、花生褐斑菌、小麦赤霉菌、苹果轮纹菌及灰霉菌全部具有良好的生长抑制作用.1-苯基-3,5-二甲基吡唑-4-羧酸三乙基锡酯及1-(2-吡啶基)-3,5-二甲基吡唑-4-羧酸三乙基锡酯在50 μg·mL-1浓度下的体外实验中表现出很高的生长抑制率.对于高活性的三取代锡羧酸酯进行了EC50值的测定,结果表明1-(2-吡啶基)-3,5-二甲基吡唑-4-羧酸三乙基锡酯对苹果轮纹菌的EC50值为0.06 μg·mL-1,对小麦赤霉菌的EC50值为0.14 μg· mL-1.%A series of organotin 1-phenyl-3,5-dimethylpyrazole-4-carboxylates and 1-(2-pyridyl)-3,5-dimethyl-pyrazole-4-carboxylates(1~14)have been obtained and characterized by IR,NMR(1H,13C and 119Sn)and elemental analysis.The structure of triethyltin 1-phenyl-3,5-dimethylpyrazole-4-carboxylate 7 has been further confirmed by X-ray diffraction crystallography.This complex crystallizes with a molecule of water and forms an infinite 2D network through intermolecular O-H…O and O-H… N hydrogen bonds.Fungicide screening indicates that all complexes display good growth inhibition against Alternaria solani,Cercospora arachidicola,Gibberella zeae,Physalospora piricola and Botrytis cinerea.Moreover,high growth inhibition percentage at 50 μg· mL-1 was observed in vitro in case of triorganotin 1-phenyl-3,5-dimethylpyrazole-4-carboxylates and 1-(2-pyridyl)-3,5-dimethylpyrazole-4-carboxylates.The corresponding EC50 of these highly active triorganotin carboxylates have been detected.The value of EC50 of triethyltin 1-(2-pyridyl)-3,5-dimethylpyrazole-4

  1. Preliminary Identification of Six Antagonistic Actinomycetes in Soil Determination of Its Fungicidal Activities%6株土壤拮抗放线菌的初步鉴定及其抗菌活性测定

    Institute of Scientific and Technical Information of China (English)

    龙建友; 夏建荣

    2011-01-01

    cinerea Pets. , Alternaria alternate and Fusarium oxysporum were also greater than 80%. The inhibition rates of the fermentation products of GZ-204 and GZ-331 strains against the spore germination of Bipolaris sorokiniana and Cercospora sorghi were 97.8%, 98.2%, 99. 5% and 94. 6%, respectively. Potting test showed that the protection effects of the fermentation products of GZ-204 and GZ-331 strains on wheat powdery mildew were 78.8% and 87. 1%, and their cure effects were 62.4% and 68.5%, respectively. Field test showed that the control effects of 200 times fermentation liquids of GZ-204 and GZ-331 strains on wheat powdery mildew were 50.5% and 69.2%, respectively. [ Conclusion ] The research provided the reference for the development-of new pesticides with actinomycetes as the resource.

  2. Study on Effect of Several Herbicides on Weeds and Diseases of Mung Bean (Vigna radiata)in Field%几种除草剂对绿豆田杂草的防治效果及绿豆病害影响的研究

    Institute of Scientific and Technical Information of China (English)

    葛维德; 付思齐; 薛仁风; 赵阳; 栾好民

    2014-01-01

    Mung bean (Vigna radiata)is an important grain,vegetables and medicinal crops,nutritional and medicinal value are both high.It plays an important role in the adjustment of planting structure and optimiza-tion of planting pattern.In this study,10 herbicide combinations were applied for controlling weeds in the mung bean field,the effect was compared among 10 different combinations in order to discover the suitable weed-controlling method for Liaoning province.The results showed that No.4 combination (fomesafen and high -flurbiprofen diclofop),No.5 combination (sethoxydim and fomesafen)and No.10 combination (quiza-lofop and fomesafen)had the best controlling effect,percentage of controlling effects were 92.3%,95.5%and 93.5%,respectively.Among these,No.10 combination showed highest hectare yield of 1326.9 kg.In addition,No.1 combination (metolachlor and fomesafen),No.5 combination (sethoxydim and fomesafen) and No.1 1 combination (quizalofop and fluoroglycofen)also played a role in controlling diseases in mung bean field.No.1 1 combination showed best effect,and the disease scores of Cercospora leaf spot and bacterial blight of mung bean were only 3.2 and 4.2,respectively.In this study,we analyzed the effects of 10 different herbicide combinations on the weed-controlling,yield per hectare and disease controlling in the field of mung bean in order to provide technical guidline for weed-controlling in Liaoning province.%绿豆(Vigna radiata)是重要的粮食、蔬菜和药用作物,营养价值和药用价值均很高,在农业种植结构调整和种植模式的优化中具有重要的作用。研究通过10种除草剂组合防除绿豆田杂草,比较不同组合间杂草防除效果的差异,筛选出适用于辽宁地区的杂草防除方法。结果表明,除草效果最好的是4号组合(氟磺胺草醚高效氟吡甲禾草灵苗后喷雾),5号组合(拿捕净氟磺胺草醚苗后喷雾)和10号组合(精喹禾灵、氟磺胺草醚苗