Fitopatologia Brasileira最新文献

{"title":"Events of pre-penetration, penetration and colonization processes by Phakopsora pachyrhizi in soybean leaflets.","authors":"E. Magnani, E. Alves, D. V. Araújo","doi":"10.1590/S0100-41582007000200011","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200011","url":null,"abstract":"Light (LE) and scanning electron microscopy (SEM) were used to study the development of Phakopsora pachyrhizi from urediniospore germination to colonization on soybean. Drops of 50 µL of a spore suspension (3 x 104 urediniospores.mL-1) were inoculated on detached leaflets of seven cultivars, besides the genotypes PI 230970 and PI 459025. After inoculation, leaflets were stored in BOD at 23 ± 2 ± 2 oC for incubation. Samples were taken from four to 240 hours after the inoculation (h.a.i.), submitted to the process of fixation for scanning electron microscopy (SEM) and decolorized into a solution of absolute ethanol/acetic acid (1:1, v/v). In decolorized samples differences were observed among cultivars in percentage of germination, appressorium formation and consequently in the penetration. On PI 429025 the lowest percentage of germinated urediniospores (20%) and of appressoria formation (11 %) was observed, and the cultivar BRS 154 presented a higher percentage of both germination (85.5 %) and appressoria formation (66.5 %). Among other cultivars the percentage of germination was from 42% to 73.5 % and from 21.5 to 60.5 % for appressoria formation. Several events in the colonization process observed by SEM were different from those in the literature.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"157 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128142433","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flutuação populacional de Rhizoctonia spp. em jardim clonal de Eucalyptus spp","authors":"E. Sanfuentes, A. C. Alfenas, L. A. Maffia, R. G. Mafia","doi":"10.1590/S0100-41582007000200004","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200004","url":null,"abstract":"Leaf blight in shoots of clonal hedges and web blight of cuttings for rooting, caused by Rhizoctonia species, may be limiting to the production of eucalyptus seedlings by cuttings. Despite their importance, there have been few etiological and epidemiological studies of these diseases. To optimize disease management strategies, this research aimed to evaluate population dynamics of Rhizoctonia spp. in soil and eucalyptus cuttings to correlate with disease incidence, and to determine spatial distribution of Rhizoctonia spp. inoculum in a clonal nursery of eucalyptus cuttings. Population fluctuation of Rhizoctonia spp. was detected throughout the year. Pathogen distribution in soil was found to have an aggregated pattern. Temperature, but not rainfall, was correlated to population levels of Rhizoctonia spp in soil samples.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131104343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of Races of Selected Isolates of Uromyces appendiculatus from Minas Gerais (Brazil) Based on the new international classification system","authors":"Thiago de Oliveira Souza, V. A. Ragagnin, D. Sanglard, M. Moreira, E. G. Barros","doi":"10.1590/S0100-41582007000200002","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200002","url":null,"abstract":"ABSTRACT Twelve single-pustule isolates of Uromyces appendiculatus, the etiological agent of common bean rust, were collected in the state of Minas Gerais, Brazil, and classified according to the new international differential series and the binary nomenclature system proposed during the 3 rd Bean Rust Workshop. These isolates have been used to select rust-resistant genotypes in a bean breeding program conducted by our group. The twelve isolates were classified into seven different physiological races: 21-3, 29-3, 53-3, 53-19, 61-3, 63-3 and 63-19. Races 61-3 and 63-3 were the most frequent in the area. They were represented by five and two isolates, respectively. The other races were represented by just one isolate. This is the first time the new international classification procedure has been used for U. appendiculatus physiological races in Brazil. The general adoption of this system will facilitate information exchange, allowing the cooperative use of the results obtained by different research groups throughout the world. The differential cultivars Mexico 309, Mexico 235 and PI 181996 showed resistance to all of the isolates that were characterized. It is suggested that these cultivars should be preferentially used as sources for resistance to rust in breeding programs targeting development lines adapted to the state of Minas Gerais.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131803415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribuição Geográfica e Diversidade Morfológica de Culturas de Penicillium sclerotigenum em Inhames no Brasil","authors":"Idjane Santana de Oliveira, E. D. N. Luz, R. Moura, Leonor Costa Maia","doi":"10.1590/S0100-41582007000200006","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200006","url":null,"abstract":"A survey was carried out to determine the occurrence of soft-rot of yam in different states of Brazil. Fungus isolates were taken from diseased tubers of two edible yam species, Dioscorea cayennensis and D. alata. Observations were carried out to identify the 50 isolates of Penicillium obtained using specific techniques for the genus Penicillium taxonomy and routine laboratory techniques of plant pathology. It was concluded that the disease occurred in all surveyed states and Penicillium sclerotigenum was the only Penicillium species in constant association with the disease. The pathogen isolates presented high colony variation, independently of the yam species and collecting place.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"281 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134149516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atividade antifúngica de óleos essenciais de espécies de Piper sobre Crinipellis perniciosa, Phytophthora palmivora e Phytophthora capsici","authors":"da Silva, C. N. Bastos","doi":"10.1590/S0100-41582007000200008","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200008","url":null,"abstract":"Ten essential oils extracted from species of Piper collected in the Amazon region were evaluated in vitro according to their effectiveness in inhibiting mycelial growth and basidiospore germination of Crinipellis perniciosa and in inhibiting mycelial growth of Phytophthora palmivora and P. capsici. The essential oils of P. callosum, P. marginatum var. anisatum and P. enckea were most effective, causing 100% inhibition of the three fungi in concentrations of 0.75µL/mL and 1.0µl/mL. For basidiospore germination, the oil of P. dilatatum was the best at 0.4µL/mL concentration, followed by the oils of P. callosum and P. marginatum var. anisatum at 0.5µL/mL.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131386581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Papaya (Carica papaya) foot rot (Phytophthora palmivora) reduction due to phosphites","authors":"A. C. Dianese, Luiz E. B. Blum, Jaqueline Barbosa Dutra, Leonardo Ferreira Lopes, M. C. Sena, L. F. D. Freitas, O. K. Yamanishi","doi":"10.1590/S0100-41582007000200014","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200014","url":null,"abstract":"Papaya (Carica papaya) foot rot (Phytophthora palmivora) reduction due to phosphites This study showed that two weekly sprays of phosphite [A (40 % P2O5 + 20 % K2O, 150 mL commercial product. hL-1), B (40 % P2O5 + 20 % K2O, 250 mL), C (10 % P2O5 + 6 % Ca, 400 mL), D (20 % P2O5 + 20 % K2O, 200 mL), E (40 % P2O5 + 6 % Mg, 150 mL), F (30 % P2O5 + 20 % K2O, 175 mL), G (20 % P2O5 + 20 % K2O, 200 mL) ] for three consecutive weeks before pathogen inoculation reduced disease severity. A podridao do pe, causada por Phytophthora palmivora Butler, e uma das principais doencas mamoeiro (Carica papaya L.). Os fosfitos constituem uma alternativa para o controle de Phytophthora em plantas, pois inibem o patogeno ou induzem na hospedeira a producao de substâncias e compostos que agem no processo de defesa contra a infeccao. A determinacao de metodos eficientes de controle da doenca menos agressivos ao ambiente e necessaria. Neste estudo objetivou-se determinar o efeito de aplicacoes de fosfitos sobre a severidade da doenca. Os testes foram realizados em casa de vegetacao com plantas de ‘Tailândia Roxao’ (2 meses de idade). O patogeno (PP-24) foi multiplicado em meio seletivo (200 ml suco de tomate temperado ‘Superbom’, 18 g agar, 3 g CaCO3, 800 mL agua destilada, 10 mg pimaricina, 250 mg ampicilina, 10 mg rifampicina, 30 mg rosa de bengala). Os tratamentos aplicados estao apresentados na tabela 1. Os produtos foram aplicados nas folhas via pulverizacao (pulverizador manual – 500 mL) ate o ponto de escorrimento. A inoculacao do patogeno ocorreu 48 h apos a ultima pulverizacao, inserindo-se palitos colonizados pelo fungo na base do caule das plantas. Seguiu-se um delineamento em blocos ao acaso (9 tratamentos; 4 repeticoes de 5 plantas). A severidade da doenca foi avaliada diariamente utilizando-se a seguinte escala: (0) sem sintomas; (1) ate 50% de murcha; (2) de 51 a 100% de murcha; (3) – planta morta. Os dados foram submetidos a analise de variância com repeticao de medidas, e, as medias comparadas pelo teste de Tukey (P < 5 %). Com uma aplicacao semanal (Tabela 1), somente o tratamento com o fosfito C (10 % P2O5 + 6 % Ca – 400 mL.hL -1) diferiu significativamente da testemunha. Ja, com duas aplicacoes semanais, todos os tratamentos com fosfito diferiram da testemunha, sendo que, neste caso, o tratamento com fosfito B (40 % P2O5 + 20 % K2O 150 mL.hL-1), foi o que mais reduziu a doenca.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122463788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanso da pstula da ferrugem em trs cultivares do cafeeiro","authors":"Maria Eloisa Salustiano, E. A. Pozza, A. C. F. Filho, P. Souza","doi":"10.1590/S0100-41582007000200009","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200009","url":null,"abstract":"Lesion expansion is considered an important epidemiological component in various pathosystems. To evaluate rust pustule expansion (Hemileia vastatrix) in three coffee cultivars and the respective lesion expansion rates (LER) under controlled conditions, the following assay was carried out. The experiment was installed in plant growth chambers at a temperature of 20 ± 2 oC and relative humidity of 70 %. Twenty three-month-old plants of each cultivar were inoculated with 0.5 mg/mL of a uredospore suspension. Seven pustules from each cultivar were randomly marked on the 42nd day after inoculation in the abaxial leaf surface. They were photographed daily with a digital camera for 15 days, for later area estimation using the UTHSCA Image Tool program. Every digital image was standardized at 4.0 x 4.0 cm. The production of uredinospores/cm2 in the lesion was evaluated by placing the uredinospores in microtubes containing 1mL of water with 0.05% Tween 80 at the end of the experiment. Concentration was determined using a hemacytometer. The curves of pustule expansion progression in the three cultivars were adjusted to the exponential model. The rates of lesion expansion were 0.14, 0.16 and 0.16 mm2/day and the number of urediniospores produced was 918.6, 929.3 and 934.8/cm2 for the cultivars Acaia, Catuai and Rubi, respectively. There were no differences between the three susceptible cultivars, in relation to the rates of lesion expansion and the final production of urediniospores. These results may contribute to better knowledge of possible mechanisms that act to increase rust severity, without the occurrence of new infections.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123675256","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural variability in Arabidopsis thaliana germplasm response to Xanthomonas campestris pv. campestris","authors":"L. Carmo, E. Cândido, P. F. Campos, A. M. Quezado-Duval, E. Leonardecz, C. A. Lopes, B. Quirino","doi":"10.1590/S0100-41582007000200001","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200001","url":null,"abstract":"This work aimed to study the interaction between the model plant Arabidopsis thaliana and Xanthomonas campestris pv. campestris (Xcc), the pathogen responsible for black rot of crucifers. The response of 32 accessions of A. thaliana to the Brazilian isolate of Xcc CNPH 17 was evaluated. No immunity-like response was observed. \"CS1308\", \"CS1566\" and \"CS1643\" grown in continuous light were among the accessions that showed strongest resistance when inoculated with 5 x 106 CFU/mL. In contrast, \"CS1194\" and \"CS1492\" were among the most susceptible accessions. Similar results were obtained when plants were grown under short-day conditions. To quantify the differences in disease symptoms, total chlorophyll was extracted from contrasting accessions at different time points after inoculation. Chlorophyll levels from controls and Xcc inoculated plants showed a similar reduction in resistant accessions, whereas Xcc-inoculated susceptible accessions showed a greater reduction compared to controls. To test the specificity of resistance, accessions CS1308, CS1566, CS1643 and CS1438 (which showed partial resistance to CNPH 17), were inoculated with a more aggressive isolate of Xcc (CNPH 77) and Ralstonia solanacearum. Among the accessions tested, \"CS1566\" was the most resistant to Xcc CNPH 77 and also displayed resistance to R. solanacearum. Accessions CS1308, CS1566 and CS1643 were also inoculated with a high titer of Xcc CNPH 17 (5 x 108 CFU/mL). No collapse of tissue was observed up to 48 h after inoculation, indicating that a hypersensitive response is not involved in the resistance displayed by these accessions.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130487224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avaliação de produtos alternativos no controle da ferrugem do cafeeiro","authors":"Mauro J. N. Costa, L. Zambolim, F. Rodrigues","doi":"10.1590/S0100-41582007000200010","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200010","url":null,"abstract":"The main objective of this study was to evaluate the use of organic products for their protective effect against coffee leaf rust (Hemileia vastatrix Berk. & Br.) and also their ability to induce resistance , compared to systemic fungicides. This study was carried out under greenhouse conditions using the cv. 'Catuai Vermelho 144'. Leaf extracts, suspensions of fungal conidia and bacterial cells, foliar fertilizers, hypochlorites and acibenzolar-S-methyl (ASM) were evaluated as potential inducers of resistance. The experiment was installed in a complete randomized block design with three replications. Each experimental plot contained five coffee plants and each treatment had 15 plants. The experiments were repeated twice with similar results. With regard to the protective effect, most of the treatments decreased the number of pustules and the leaf area with rust in comparison to treatment 1 (leaves sprayed with water). Water extracts of coffee leaves and methanol extracts of seeds of Azadirachta indica (\"neem\") gave similar results, but never better than the protection obtained by using epoxiconazole + piraclostrobin. Regarding induction of resistance, extracts of coffee leaves, ASM, Bacillus subtilis and Pseudomonas putida reduced the infection caused by H. vastatrix by more than 77 %.","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130792013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Occurrence of rice blast in barley leaves in Rio Grande do Sul, Brazil","authors":"M. I. Lima, E. Minella, F. S. Vilasbôas","doi":"10.1590/S0100-41582007000200015","DOIUrl":"https://doi.org/10.1590/S0100-41582007000200015","url":null,"abstract":"Occurrence of Rice Blast in Barley leaves in Rio Grande do Sul, Brazil Magnaporthe grisea is reported for the first time affecting barley leaves in the state of Rio Grande do Sul, in experimental plots and in farmers fields in Victor Graeff county and surroundings. A brusone, causada pelo fungo Magnaporthe grisea (T.T. Hebert) M.E. Barr (anamorfo Pyricularia grisea Sacc.), foi constatada pela primeira vez na cultura de cevada (Hordeum vulgare L.) no Brasil em 1998 (Anjos & Charchar, Fitopatol. Bras. 25:205. 2000), no Distrito Federal afetando folhas da planta, cujos sintomas foram descritos como lesoes elipticas com centro de cor cinza e margem de cor marrom. Em 2001 e 2002, registrou-se sua ocorrencia afetando espigas nos estados de Goias, Minas Gerais e tambem no Rio Grande do Sul (Lima & Minella, Fitopatol. Bras. 28:207. 2003), cujos sintomas foram caracterizados por morte da porcao superior da espiga no ponto de infeccao no raquis e lesao preta brilhante nesse. Em 2005, a brusone em espigas de cevada foi observada, novamente, no Rio Grande do Sul em ensaios e lavouras no municipio Victor Graeff e arredores. Observou-se nas folhas sintomas similares aos de brusone descritos em cevada (Figura 1A). Na Embrapa Trigo, no Laboratorio de Fitopatologia, apos incubacao das folhas com sintomas em câmara umida, constatou-se nas lesoes a presenca de conidios em formato semelhante a pera, hialinos, com ate tres celulas, caracteristicas inerentes a conidios de Pyricularia. Realizou-se isolamento do fungo em meio de cultura BDA conforme Anjos & Charchar (2000). Plantas de cevada, cultivar BR 2, de aproximadamente 30 dias foram pulverizadas com uma suspensao de conidios na concentracao de 1,0 X 105 esporos mL-1 e mantidas em câmara umida no escuro por 24 horas a temperatura de 28 oC. Os primeiros sintomas da doenca foram registrados 48 horas apos a inoculacao. As dimensoes dos conidios produzidos em câmara umida foram de 10 μm de largura e 30-40 μm de comprimento. O re-isolamento do microorganismo a partir das lesoes produzidas nas folhas inoculadas (Figura 1B) comprovou a ocorrencia de P. grisea afetando folhas de cevada no estado do Rio Grande do Sul. Recebido 13 Dezembro 2006 Aceito 16 Marco 2007 FB 6134 FIG. 1 Folhas de cevada (Hordeum vulgare) com sintomas causados por Pyricularia grisea A. Sintomas em folha em condicoes naturais; B. Sintomas observados na cv. BR 2 apos inoculacao. A B","PeriodicalId":211183,"journal":{"name":"Fitopatologia Brasileira","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125375472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}