Genetic variations among the isolates of Bipolaris Maydis based on phenotypic and molecular markers

Abstract Maydis leaf blight, caused by Bipolaris maydis, is an important disease of maize crop in Khyber Pakhtunkhwa (KP) Pakistan. Fifteen isolates of the pathogen, collected across KP, were studied for variability based on phenotypic and molecular markers. Significant variability among the isolates was observed when assessed using phenotypic traits such as radial growth, spore concentration, fungicide sensitivity and virulence. The isolates were classified into six culture groups based on colour, texture and margins of the colony. Conidial morphology was also variable. These were either straight or slightly curved and light to dark brown in colour. Fungicide test showed significant variation in the degree of sensitivity against Carbendazim. Isolate Bm8 exhibited maximum radial growth on carbendazim spiked plates. Conversely, isolate Bm15 showed the lowest radial growth. Variations in virulence pattern of the isolates were evident when a susceptible maize variety Azam was inoculated with spores of B. maydis. Genetic variability amongst the isolates was also estimated by RAPD as well as sequencing of ITS region. The RAPD dendrogram grouped all the isolates into two major clusters. Average genetic distance ranged from 0.6% to 100%, indicating a diverse genetic gap among the isolates. Maximum genetic distance was found between isolates Bm9 and Bm10 as well as Bm2 and Bm8. Conversely, isolates Bm13 and Bm15 were at minimum genetic distance. Phylogenetic dendrogram based on sequencing of ITS region grouped all the isolates into a single major cluster. The clusters in both the dendrogram neither correlate to the geographical distribution nor to the morphological characteristics.

Resumo A ferrugem das folhas de maydis, causada por Bipolaris maydis, é uma doença importante da cultura do milho em Khyber Pakhtunkhwa (KP), Paquistão. Quinze isolados do patógeno, coletados em KP, foram estudados quanto à variabilidade com base em marcadores fenotípicos e moleculares. Variabilidade significativa entre os isolados foi observada quando avaliada por meio de características fenotípicas, como crescimento radial, concentração de esporos, sensibilidade a fungicida e virulência. Os isolados foram classificados em seis grupos de cultura com base na cor, textura e margens da colônia. A morfologia dos conídios também foi variável. Estes eram retos ou ligeiramente curvos e de cor marrom-claro a escuro. O teste de fungicida mostrou variação significativa no grau de sensibilidade ao carbendazim. O isolado Bm8 exibiu crescimento radial máximo em placas com adição de carbendazim. Por outro lado, o isolado Bm15 apresentou o menor crescimento radial. As variações no padrão de virulência dos isolados foram evidentes quando uma variedade de milho suscetível Azam foi inoculada com esporos de B. maydis. A variabilidade genética entre os isolados também foi estimada por RAPD, bem como sequenciamento da região ITS. O dendrograma RAPD agrupou todos os isolados em dois grupos principais. A distância genética média variou de 0,6% a 100%, indicando uma lacuna genética diversa entre os isolados. A distância genética máxima foi encontrada entre os isolados Bm9 e Bm10 e também entre Bm2 e Bm8. Por outro lado, os isolados Bm13 e Bm15 estavam a uma distância genética mínima. O dendrograma filogenético baseado no sequenciamento da região ITS agrupou todos os isolados em um único aglomerado principal. Os agrupamentos em ambos os dendrogramas não se correlacionam com a distribuição geográfica nem com as características morfológicas.

A Survey of Symptoms of Fungal Disease in Sugarcane (Saccharum officinarum L.) in Buea, in the South West Region of Cameroon

Aim: Sugarcane (Saccharum officinarum L.) which is mostly cultivated in tropical and subtropical regions of the world is an important source of sucrose. This crop which was originally grown in South Eastern Asia and the Pacific for the sole purpose of chewing is mainly used nowadays for the production of sugar, bio-fuels, medicine etc. In spite of its numerous uses, the production of sugarcane in Buea, South West region of Cameroon is hampered by many factors including the incidence of disease. It is possible that some varieties are no longer cultivated because of their susceptibility to fungal diseases. It was for these reasons that we decided to survey the sugarcane farms in this area, to evaluate the presence of diseased symptoms due to activity of fungi. Study Design: Random sampling. Place and Duration of Study: Buea and its environs, Rubber Pathology Laboratory IRAD Ekona, and Life Sciences Laboratory, University of Buea, between June 2016 and July 2017. Methodology: During the survey, sugarcane farms in five villages in Buea and its environments were visited. The leaves and stems of the plants were observed for any symptoms of fungal activity. The incidence, severity and prevalence of the symptoms were noted. Leaf samples were collected from diseased sugarcane plants and transported to the laboratory for the isolation of fungi on Potato Dextrose Agar growth medium. The isolates were identified based on their cultural and micro-morphological characteristics. Results: Sugarcane plants with fungal disease symptoms were seen in all the farms visited during the survey, thus a prevalence of 100%. The disease incidence varied from 54- 100%, while the severity ranged from 20- 55%. Two genera of fungi were isolated from the diseased plants viz: Chaetomium sp. and Bipolaris sp. Conclusion: Chaetomium and Bipolaris are associated with fungal symptoms in diseased sugarcanes hence any management plans geared towards the improvement of sugarcane production in this area must include control measures for these fungi.

Defense responses of wheat plants (Triticum aestivum L) against brown spot as a result of possible elicitors application / Resposta de defesa das plantas de trigo (Triticum aestivum L) contra a mancha marrom diante da aplicação de possíveis elicitores

The objective of this research was to evaluate the response of wheat plants to the application of possible elicitor compounds against Bipolaris sorokiniana pathogen. This response was measured through the quantification of antioxidant enzymes, malondialdehyde and flavonoids, evaluation of the severity of brown spot disease and productivity in wheat, greenhouse and field crops. The treatments consisted of suspensions of endophytic fungi Aspergillus japonicus and Trichoderma tomentosum, salicylic acid, acibenzolar-S-methyl and fungicide. In the field trials, in 2015 and 2016, the development of the disease was lower and productivity was higher in all treatments, with emphasis on the fungicide. However, endophytic fungi suspensions demonstrated potential as growth promoters, disease severity reducers and protective antioxidant response activators, as they promoted significant increase in superoxide dismutase, catalase, glutathione and flavonoid enzymes.(AU)

O objetivo desta pesquisa foi avaliar a resposta de plantas de trigo diante da aplicação de possíveis compostos elicitores perante o patógeno Bipolaris sorokiniana. Tal resposta foi examinada por meio da quantificação de enzimas antioxidantes, malondialdeído e flavonoides, da análise da severidade da doença mancha marrom e da produtividade na cultura do trigo, em casa de vegetação e em campo. Os tratamentos consistiram em suspensões de fungos endofíticos Aspergillus japonicus e Trichoderma tomentosum, ácido salicílico, acibenzolar-S-metil e fungicida. Nos ensaios em campo, em 2015 e 2016, o desenvolvimento da doença foi menor e a produtividade foi superior em todos os tratamentos, com destaque para o fungicida. No entanto, as suspensões de fungos endofíticos demonstraram potencial como promotores de crescimento, redutores da severidade da doença e ativadores de resposta antioxidante protetora, pois promoveram o aumento significativo das enzimas superóxido dismutase e catalase, das glutationas e flavonoides.(AU)

Bipolarins A-H, eight new ophiobolin-type sesterterpenes with antimicrobial activity from fungus Bipolaris sp. TJ403-B1 / 中国天然药物

Bipolarins A-H (1-8), eight new tetracyclic ophiobolin-type sesterterpenes featuring a rare oxaspiro[4.4]nonane moiety, were isolated from cultures of fungus Bipolaris sp. TJ403-B1. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, electronic circular dichroism and C NMR calculations. Additionally, compound 5 exhibited significant selective antimicrobial activity against Enterococcus faecalis with an MIC value 8 μg·mL.

Claviceps purpurea e Bipolaris sp. como causa de ergotismo em bovinos no estado de Santa Catarina / Claviceps purpurea e Bipolaris sp. as a cause of ergotism in cattle in Santa Catarina State

Claviceps purpurea é o fungo associado ao ergotismo. Esta é uma enfermidade causada pela ingestão de escleródios chamados de ergot, que contém alcalóides que atuam em receptores adrenérgicos, dopaminérgicos e seratoninérgicos causando efeito direto em vasos sanguíneos, musculatura lisa e sistema nervoso central e autônomo. Descrevem-se dados epidemiológicos, sinais clínicos e lesões de uma enfermidade de bovinos caracterizada por hipertermia, taquicardia, taquipneia e ulcerações na coroa do casco de bovinos. Entre 2000 e 2014 foram diagnosticados 13 surtos, três da forma distérmica, sete da forma gangrenosa e três da forma convulsiva. Porém, em cinco destes sete surtos, nos locais onde esses animais pastoreavam havia alta incidência de inflorescências de Sporobolus indicus conhecido como "capim-mourão", infectadas por um fungo com coloração enegrecida, identificado como Bipolaris sp. A enfermidade foi reproduzida experimentalmente em cinco bovinos com a administração destas inflorescências. Os bovinos em experimentação receberam inflorescências de S. indicus respectivamente nas doses diárias de 0,1g/kg, 0,2g/kg, 0,2g/kg, 0,26g/kg e 0,34g/kg por um período de 4, 7, 9 e 30 dias. Após três a sete dias de ingestão das inflorescências infectadas, quatro dos cinco bovinos apresentaram diarreia e manifestaram taquicardia, taquipneia e hipertermia em algum período durante a ingestão. Estes sinais coincidiram com os dias mais quentes deste período. Um bovino manifestou hiperemia na coroa do casco e perda de pêlos da extremidade da cauda. Baseado na reprodução experimental é possível afirmar que o capim Sporobolus indicus infectado pelo fungo Bipolaris sp é capaz de causar diarreia, hipertermia, taquicardia, taquipneia, hiperemia na coroa do casco e perda de pêlos da extremidade da cauda.(AU)

Claviceps purpurea is the fungus associated with ergotism. Ergotism is a disease caused by the ingestion of esclerodios called ergot, which contains alkaloids that act on dopaminergic and adrenergic receptors, causing seratoninergic effect on blood vessels, smooth muscles and central nervous and autonomic system. The present study describes epidemiological data, clinical signs and lesions of a bovine cattle disease characterized by hyperthermia, tachycardia, tachypnea and injuries in the coronary band of the hooves. Initially the cause was attributed to the fungus Claviceps purpurea. Between 2000 and 2014, 13 outbreaks were described, being three of distermic form, seven of gangrenous and three of the convulsive form. However, in five out of the seven of the gangrenous form outbreaks, it has been observed a high incidence of smut grass (Sporobolus indicus) inflorescences infected by a blackened fungus, classified as Bipolaris sp., in the places where the bovine grazed. The disease was reproduced experimentally by administration of inflorescences of smut grass contaminated by Bipolaris sp. Five bovine received daily doses of 0.1g/kg, 0.2g/kg, 0.2g/kg, 0.26g/kg and 0.34g/kg during 4, 7, 9, 30 and 30 days respectively. After three to seven days of eating contaminated inflorescences four cattle had diarrhea, tachycardia, tachypnea and intermittent hyperthermia. These clinical signs happened on the warmest days and during the warmest temperatures of the day. A bovine showed hyperemia in the coronary band of the hoof and loss of tail tip hair. According to data obtained during the experimental reproduction, smut grass contaminated by Bipolaris sp. can cause hyperthermia, tachycardia, tachypnea, injuries in the coronary band of the hoof and loss of the tail tip hair in bovine cattle.(AU)

Feohifomicosis nasal por Curvularia spicifera en un paciente pediátrico con neutropenia y leucemia mieloide aguda / Nasal phaeohyphomycosis by Curvularia spicifera in pediatric patient with neutropenia and acute myeloid leukemia

There are very few reports of pediatric patients with infections by dematiaceous filamentous fungi. In this publication we report a case of invasive fungal infection of the nasal septum by Curvularia spicifera in a pediatric patient with acute myeloid leukemia. The patient presented with a painful scabby wound in the nasal vestibule. Culture and universal PCR were consistent with Curvularia spicifera. Early management with surgical debridement and bi-associated antifungal therapy achieved complete resolution of the lesions, with no evidence of dissemination and relapses. Clinical management of these fungal infections represents a challenge as the antifungal selection and duration of therapy is not yet well stablished.

Existen pocos reportes de infecciones por hongos dematiáceos en pediatría. Comunicamos el caso de una infección fúngica invasora del tabique nasal en un niño con una leucemia mieloide aguda, que se presentó como una lesión costrosa dolorosa en el vestíbulo nasal. Se realizó desbridamiento quirúrgico precoz y recibió tratamiento antifúngico biasociado, lográndose resolución completa de las lesiones, sin diseminación ni recaídas. El cultivo y la RPC universal fueron compatibles con Curvularia spicifera. El manejo de estas infecciones fúngicas representa un desafío, considerando que la elección del agente antifúngico y la duración de la terapia no están completamente establecidas.

Genotypic value in hybrid progenies of Panicum maximum Jacq / Valor genotípico de progênies híbridas de Panicum maximum Jacq

ABSTRACT: Genetic breeding of forage plants has increasingly contributed to the release of more productive plants. In this regard, evaluating the genotypic value is essential when aiming to rank genotypes based on the mean free of environmental factors. Therefore, this study aimed to predict the genotypic value of agronomic and nutritive value characters of three progenies of Panicum maximum. Hybrids were evaluated in a clonal test in an incomplete-randomized design with three treatments (progenies 1, 2, and 3) and two replications (clones). Six harvests were performed at 25cm from the ground level throughout one year. Progeny 2 provided better results for total and leaf dry mass yield, regrowth, and height, and lower incidence of leaf spot. Progenies 1 and 3 had a better response for qualitative characters such as higher crude protein and digestibility and lower lignin and fiber content. Hybrid progenies of P. maximum have forage characters of interest for breeding, and when using 'Mombaça' grass as parents, the progeny stands out for leaf production and resistance to leaf spot and for 'Tanzania' grass as parent has resulted in better forage quality.

RESUMO: O lançamento de forrageiras resultantes de programas de melhoramento genético tem sido importante fonte de liberação de novas forrageiras mais adaptadas e competitivas. Nessas situações, a avaliação do valor genético é essencial quando se objetiva ranquear os genótipos com base no valor genotípico, isento dos efeitos ambientais. O objetivo com este trabalho foi estimar e avaliar o valor genotípico de características agronômicas e de valor nutritivo de três progênies de P. maximum, resultantes do cruzamento entre duas progenitoras sexuais e as cultivares 'Mombaça' e 'Tanzânia'. O experimento foi implantado em teste clonal no delineamento em blocos incompletos com três tratamentos (progênies 1, 2 e 3) com duas repetições (clones). Os híbridos foram manejados por meio de cortes na altura de 25cm do nível do solo por um ano, realizando seis cortes. A progênie 2 proporcionou melhores resultados para produção de folhas, rebrota, altura de planta e baixa incidência de mancha foliar causada por Bipolaris maydis. As progênies 1 e 3 apresentaram, em média, melhores resultados para características qualitativas como proteína bruta e digestibilidade e menor teor de lignina. As progênies híbridas de P. maximum apresentam características forrageiras de interesse para o melhoramento, sendo que a utilização do capim-mombaça como parental proporciona maior produção de folhas e resistência à mancha foliar, ao passo que o capim-tanzânia como parental proporciona melhoria da qualidade da forragem.

Infectious Pseudomonas and Bipolaris scleritis following history of pterygium surgery.

We report an interesting case of infectious scleritis from coinfection of Pseudomonas aeruginosa and Bipolaris with no corneal infiltrate. A healthy 60‑year‑old man with a history of infectious scleritis following pterygium excision presented with purulent material growing P. aeruginosa and 1+ colonies of Bipolaris species of fungus. Broad spectrum treatment was initiated with hourly topical moxifloxacin, fortified tobramycin, and natamycin along with a subconjunctival injection of voriconazole and topical cyclosporine, with PO ketoconazole. After 10 weeks of aggressive empiric treatment, the patient’s symptoms had resolved, and his vision returned to baseline although a scleral patch graft was utilized to stabilize scleral thinning.

Critical-point models to relate yield and disease intensity of the multiple pathosystem in rice leaf spots disease / Modelos de pontos críticos para relacionar o rendimento de grãos com a intensidade em patossistema múltiplo de manchas foliares em arroz irrigado

ABSTRACT: The occurrence of leaf spots in irrigated rice can reduce the yield and compromise the quality of the grain. However it is unknown the economic damage threshold (EDT) that these spots cause the yield of crop. The objective of this study was to obtain damage functions for models of critical, to relate damage by simultaneous occurrence of blast, brown spot and scald spot with grain yield harvests in 2011/12 and 2012/2013, in Rio do Oeste, Santa Catarina State, Brazil. Gradient of diseases intensity was generated by number of applications and fungicides rates. Design was a randomized block with four replications and six treatments consisting of mixing fungicide applications of triazole (difenoconazole) and strobilurin (azoxystrobin). In 2011/12 and 2012/13 growing season were made two and three tests respectively with the same experiment. Before each application it was determined the incidence and severity of fungal diseases. The critical point models were obtained by linear regression between grain yield and incidence (I) and severity (S). In 2011/12 the functions were not significant at the beginning of tillering and 2012/2013 harvest resulted in R=13.404-92.98I and R=10.685-3.804S. Respectively in each harvest resulted in tillering (R=9.141-103.6I; R=7.605-1.538 and R=8.864-73.91I; R=7.202-77S), panicle initiation (R=9.432-188.5I; R=7.,038-1.466S and R=10.176-87.33I; R=8.258-533.55S), booting (R=7.044-71.78I; R=6.881-1.296S and R=9.993-71.74I; R=8.846-763.83S), flowering (R=7.447-82.29I; R=8.731-1.398S and R=8.347-54.36I; R=7.338-681.52S) and milky grain (R=10.143-80.5I; R=7.522-1.402S and R=8.661-60.063I; R=9.754-1.465S). The generated functions allow getting the damage coefficient for use in the calculation of EDT in multiple pathossystem leaf spots in irrigated rice.

RESUMO: A ocorrência de manchas foliares na cultura do arroz irrigado pode reduzir o rendimento e comprometer a qualidade do grão. No entanto, é desconhecido o limiar de dano econômico (LDE) que essas manchas causam no rendimento da cultura. O objetivo deste trabalho foi obter funções de dano, por modelos de ponto crítico, ao relacionar o dano pela ocorrência simultânea da brusone, mancha parda e escaldadura com o rendimento de grãos nas safras de 2011/12 e 2012/2013, em Rio do Oeste, Santa Catarina (SC). O gradiente da intensidade das doenças foi gerado por número de aplicações e doses de fungicidas. O delineamento foi de blocos casualizados, com quatro repetições e seis tratamentos, constituídos de aplicações de mistura de fungicidas triazol (difenoconazole) e estrobilurina (azoxistrobina). Na safra de 2011/12 e 2012/13, foram feitos dois e três ensaios, respectivamente, com o mesmo experimento. Antes de cada aplicação, foi determinada a incidência e a severidade das doenças foliares. Os modelos de ponto crítico foram obtidos por regressão linear entre rendimento de grãos e incidência (I) e severidade (S). Em 2011/12, as funções não foram significativas no início do perfilhamento e, na safra de 2012/2013, resultou em R=13.404-92,98I e R=10.685-3.804S. Respectivamente, em cada safra, resultaram no perfilhamento (R=9.141-103,6I; R=7.605-1.538 e R=8.864-73,91I; R=7.202-77S), iniciação da panícula (9.432-188,5I; R=7.038-1.466S e 10.176-87I; R=8.258-533,55S), emborrachamento (R=7.044-71,78I; 6.881-1.296S e R=9.993-71,74I; R=8.846-763,83S), floração (R=7.447-82,29I; R=8.731-1.398S e R=8.347-54,36I; R=7.338-681,52S) e grão leitoso (R=10.143-80,5I; R=7.522-1.402S e R=8.661-60.063I; R=9.754-1.465S). As funções geradas permitem obter o coeficiente de dano para uso no cálculo do LDE em patossistema múltiplo de manchas foliares, em arroz irrigado.

A new cochlioquinone from endophytic fungus Bipolaris sorokiniana derived from Pogostemon cablin and its bioactivity / 中草药

Objective: To study the chemical structure and activity of secondary metabolites of the endophytic fungus Bipolaris sorokiniana A606 isolated from Pogostemon cablin. Methods: The compounds were isolated and purified from the ethyle acetate extract of the fungal fermentation broth by silica gel, reverse phase silica gel, Sephadex-LH20, HPLC, and so on. Their structures were identified by extensive spectroscopic analysis. The compounds were evaluated for their cytotoxic activities against human tumor cell lines by the SRB assay and their antibacterial activities against bacteria were evaluated by the filter paper method. Results: Two compounds were isolated from the fermentation broth extract of the strain A606 and identified as (3S*,4aS*,6aS*,12bS*)-3-(2-hydroxypropan-2-yl)-6a,12b-dimethyl-9-[(2R*,4R*)-4-methyl-3-oxohexan-2-yl]-1,2,3,4a,5,6-hexahydropyrano [3,2-a]xanthene-8,11-dione (1) and precochlioquinol D (2). Conclusion: Compound 1 is a new compound, named 11-hydroxy-12,13-dehydrocochlioquinone B. Compound 2 is isolated from the species of genus Bipolaris for the first time. Compound 1 shows the cytotoxic and antibacterial activities.

Especies oportunistas de importancia clínica de los géneros bipolaris shoemaker y curvularia boedijn: su caracterización bajo los nuevos criterios taxonómicos / Opportunistic species of clinical relevance in the bipolaris shoemaker & curvularia boedijn genera: its characterization under newest taxonomic criteria

Los géneros fúngicos Bipolaris y Curvularia,incluyen numerosas especies fitopatógenas,saprotrofas y algunas oportunistas emergentes enel ser humano como en otros animales. La distribuciónecológica de ambos taxas es cosmopolita enla gran mayoría de sus integrantes, encontrándosefrecuentemente en hojas, tallos y raíces de diferentespastos, en especial Poaceae, pero tambiénen una gran variedad de dicotiledoneas, aire y sueloen todos los continentes. Cochliobolus, Bipolarisy Curvularia integran un complejo de especiestaxonómicamente confuso, debido a los constantescambios en la nomenclatura de algunos de sus integrantesasexuales (Bipolaris y Curvularia), loscuales se han diferenciado principalmente en basea la morfología de sus conidios, situación a vecesmuy dificultosa debido a que en ambos génerosalgunas especies presentan similares característicasconidiales. Una cuidadosa identificación y unanominación precisa de las especies es crucial parael acceso a la información referente en la literaturamoderna, que gracias a la biología molecularha resuelto muchas de las dudas de la taxonomíabasada solo en el fenotipo.Las especies de ambos géneros (principalmenteCurvularia) pueden afectar a pacientesinmunocomprometidos e inmunocompetentes,en especial B. cynodontis, C. australiensis C.hawaiensis y C. spicifera, causando cuadros clínicosdiversos ya sea superficiales o profundos enmuchas áreas geográficas...

The fungal genera Bipolaris and Curvularia,include numerous plant pathogenic species,saprophitic and some emerging opportunistic inman and other animals. The ecological distributionof both taxa is cosmopolitan in the vast majority ofits members, often being in leaves, stems and rootsof different grasses, especially Poaceae, but also ina variety of dicotyledonous, air and soil on all continents. Cochliobolus, Bipolaris and Curvulariaintegrate a complex of species taxonomically confusingdue to the constant changes in the nomenclatureof some of its asexual members (Bipolarisand Curvularia), which are differentiated mainlybased on the morphology of its conidia, a situationsometimes very difficult because in both generaconidial of some species have similar characteristics. Careful identification and a precise nominationof species is crucial for access to informationconcerning in modern literature, actually thanks tomolecular biology has solved many of the doubtsof taxonomy based only on the phenotype.The species of both genera (mainly Curvularia)can affect immunocompetent or debilitatepatients, especially B. cynodontis, C. australiensis,C. hawaiensis and C.spicifera, causing varioussuperficial or systemic clinical cases in manygeographic areas...

Critical yield-point model to estimate damage caused by brown spot and powdery mildew in barley / Modelo do ponto crítico para estimar danos causados pela mancha-marrom e oídio em cevada

Barley (Hordeum vulgaris L.) is the second most important winter crop in Southern Brazil. The excessive rainfall in this region during the crop-growing season increases the frequency and intensity of foliar fungal diseases. The research aimed to determine the damage function equations (DFE) for the multiple pathosystem of barley brown spot and powdery mildew based on the relationship between grain yield and diseases intensity at different 'BRS Cauê' cultivar growth stages (GS) during 2009 and 2010 growing seasons in Southern Brazil. The experiments were arranged in a randomized complete block design with nine treatments and four replicates. The disease gradients were generated by strobilurins and triazols fungicides rates and number of applications on barley cv. Cauê. The fungicide applications and disease incidence and severity assessments were performed at the 22, 31, 39, 45 and 56 plant GS. The DFE were obtained by variance analysis and linear regression between grain yield and diseases intensity. Significant and negative DFE were obtained and the damage coefficients (DC) varied from 29.48 to 100.08 (2009) and from 36.08 to 113.57kg ha-1 (2010) for incidence, and from 219.5 to 6,276.6 (2009) and 102.3 to 5,292.5kg ha-1 (2010) for severity. The largest damage coefficients were obtained when diseases assessments were made on GS 22 and 31 on both growing seasons evaluated. DFE were used to calculate the economic damage threshold (EDT) as a criterion to indicate the fungicide application moment to control the diseases in cultivars similar to 'BRS Cauê' in Southern Brazil.

A cevada (Hordeum vulgaris L.) é a segunda mais importante cultura de inverno no Sul do Brasil. Nessa região, o excesso de chuvas durante a estação de crescimento da cultura favorece o aumento na frequência e intensidade de doenças foliares. O trabalho objetivou determinar as equações de função de dano (EFD) para o patossistema múltiplo mancha-marrom e oídio da cevada pela relação entre rendimento de grãos e intensidade foliar das doenças em diferentes estádios fenológicos da cultivar de cevada 'BRS Cauê', nas safras 2009 e 2010 no sul do Brasil. O delineamento foi em blocos casualizados com nove tratamentos e quatro repetições. Os tratamentos foram constituídos de diferentes doses e número de aplicações dos fungicidas triazóis e estrobilurinas para gerar os gradientes de intensidade das doenças. As aplicações de fungicidas e as avaliações da incidência e severidade foliar foram realizadas nos estádios fenológicos (EF) 22, 31, 39, 45 e 56. As equações foram obtidas pela análise de variância e regressão linear entre rendimento de grãos e intensidade das doenças. As EFD foram significativas e negativas e os coeficientes de danos variaram de 29,48 a 100,08kg ha-1 (2009) e 36,08 a 113,57kg ha-1 ( 2010) para a incidência e de 219,5 a 6.276,6kg ha-1 ( 2009) e 102,3 a 5.292,5kg ha-1 (2010). Os maiores coeficientes de dano foram obtidos nos estádios EF 22 e 31em ambas as safras. As EFD foram usadas para calcular o limiar de dano econômico, que é um critério que indica o correto momento de aplicação de fungicidas para o controle das doenças em cultivares similares a 'BRS Cauê' no sul do Brasil.

Bipolaris: a rare etiology of ureteric mycosis with Double J stent in situ.

Fungi classified under the genera Bipolaris are dematiaceous hyphomycetes which are rare sources of human diseases. The dematiaceous fungi in other words “black fungi” are so named due to the presence of dark melanin like pigment in their cell wall. Majority of the species of Bipolaris, are either soil saprobes or plant pathogens, however few species of these saprobes like Bipolaris australiensis, Bipolaris hawaiiensis & Bipolaris spicifera are potential pathogens which are capable of causing infections in both immunocompetent & immunocompromised humans. The spectrum of human infections caused by Bipolaris include cutaneous and subcutaneous infections, allergic sinusitis, keratitis, allergic broncho pulmonary diseases, orbitopathy, CNS infections, Peritonitis associated with Ambulatory peritoneal dialysis, infections of implant devices & allografts. Here we report a case of ureteric infection due to Bipolaris species in a patient with Double J (DJ) stent in situ. Amphotericin B, itraconazole, voriconazole and imidazole are common antifungals found to be effective in treating Bipolaris infections.

Tratamento químico de sementes sobre o desenvolvimento de mancha marrom em plantas de trigo / Chemical treatment in seeds on the development of the spot blotch in wheat plants

O objetivo do trabalho foi avaliar o efeito dos fungicidas difenoconazole e carboxin + thiram aplicados em sementes de trigo cultivares 'CD 104' e 'OR Mirante', inoculadas com Cochliobolus sativus. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 2x3 (2 cultivares e 2 fungicidas + testemunha sem controle) em sete repetições. O fungo foi isolado e reproduzido em meio de cultura BDA (batata-dextrose-ágar) e, posteriormente, multiplicado em sementes de trigo pré-cozidas, constituindo a fonte de inóculo. As avaliações foram do número de lesões na folha basal de cinco plantas por vaso aos 22, 25, 29, 31, 35 e 38 dias após a semeadura (DAS) e aos 41 dias foram avaliados o comprimento (cm), massa fresca (g) e seca (g) da parte aérea e das raízes. A partir das avaliações do número de lesões, também foi calculada a área abaixo da curva de progresso da doença (AACPD), cujos dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey, a 5% de probabilidade. A cultivar 'CD 104' foi mais suscetível ao patógeno do que 'OR Mirante'; difenoconazole foi eficiente no controle da doença na parte aérea, enquanto carboxin + thiram se igualou à testemunha; os dois fungicidas interferiram negativamente no desenvolvimento das plantas, uma vez que as médias de comprimento, massa fresca e seca da parte aérea e das raízes obtidas das sementes tratadas é inferior à média das sementes não tratadas.

The objective of this research was to evaluate the effect of fungicides difenoconazole and carboxin + thiram applied in seed wheat cultivars 'CD 104' and 'OR Mirante', inoculated with Cochliobolus sativus. The experimental design was completely randomized in a 2x3 factorial design (2 cultivars and 2 fungicides + untreated control) in seven replications. The fungi was isolated and reproduced in PDA culture medium (potato-dextrose-agar) and subsequently multiplied in seeds of wheat pre-cooked and is the source of inoculum. The evaluations were the number of lesions in the basal leaf of five plants per pot at 22, 25, 29, 31, 35 and 38 days after sowing (DAS), and at 41DAS were evaluated the length (cm), fresh weight (g) and dry weight (g) of shoot and root. From the evaluations of the number of lesions was also calculated the area under the disease progress curve (AUDPC). The datas were subjected to analysis of variance and means were compared by Tukey test at 5% probability. The 'CD 104' cultivar was more susceptible to the pathogen than 'OR Mirante'; difenoconazole was efficient to control the disease as carboxin + thiram equaled the witness; both fungicides interfered negatively on plant development, since the average length, fresh weight and dry shoot and root obtained from treated seed is lower than the untreated seeds.

Escala diagramática para avaliação de severidade de mancha-parda em arroz / Diagrammatic scale for assessment of rice brown spot severity

Uma escala diagramática com seis níveis: 1,6; 3,2; 6,4; 12,6; 23,1 e 38,6 por cento foi desenvolvida e validada para quantificar a severidade da mancha-parda em arroz causada por Bipolaris oryzae. A escala considerou o limite de severidade máxima da doença observado no campo, e os níveis intermediários seguiram incrementos logarítmicos, obedecendo-se à "Lei do estímulo de Weber-Fechner". Inicialmente, a estimativa da severidade foi realizada sem auxílio da escala, em 30 folhas com diferentes níveis de severidade, por oito indivíduos, sem experiência na avaliação de doenças. Em seguida, os mesmos avaliadores utilizaram a escala diagramática proposta. As avaliações com a escala diagramática foram mais precisas e acuradas nas estimativas de todos os avaliadores, não ocorrendo erro sistemático na superestimativa ou subestimativa da doença entre estes. A escala diagramática proposta foi considerada adequada para estimar a severidade da mancha-parda em arroz.

A diagrammatic scale with six levels of disease severity: 1.6; 3.2; 6.4; 12.6; 23.1 and 38.6 percent was developed and validated to assess rice brown spot, caused by Bipolaris oryzae. The scale was developed considering the maximum limit of disease severity observed in the field and the intermediate values followed logarithmic increases according to the "Stimulus Law by Weber-Fechner". Initially, the estimatives of severity were performed without the use of the scale in 30 leaves with different levels of severity by eight people without previous experience in assessing diseases severity. Then, the same people estimated the severity of leaves using the proposed diagrammatic scale. Assessments with the diagrammatic scale were of great precision for all raters and did not presented systematic errors in over- or underestimating the disease severity. The proposed diagrammatic scale was considered adequate to estimate rice brown spot severity.

Control of brown spot pathogen of rice (Bipolaris oryzae) using some phenolic antioxidants / Controle da macha-parda do arroz (Bipolaris oryzae) pelo emprego de antioxidantes fenólicos

Bipolaris oryzae is the causal agent of rice brown spot disease and is responsible for significant economic losses. In order to control this disease, three phenolic antioxidants were tested (salicylic acid, benzoic acid and hydroquinone). The antifungal activity of the tested substances were investigated against B. oryzae at different concentrations in vitro, as well as the efficacy of their exogenous application in controlling rice brown spot disease under field conditions. In vitro, benzoic acid or salicylic acid at 9 mM completely inhibited the growth of B. oryzae. Under field conditions, spraying of benzoic acid at 20 mM led to a significant reduction in disease severity (DS) and disease incidence (DI) on the plant leaves, in addition to a significant increase in the grain yield and its components. Some biochemical responses were also detected, where the application of the previous treatment led to a significant increase in the total photosynthetic pigments (chlorophyll a and b and carotenoids) in rice leaves and in the total carbohydrate and protein contents of the yielded grains.

Bipolaris oryzae é o agente causador da doença mancha-parda do arroz e é responsável por significativas perdas econômicas. Três antioxidantes fenólicos (ácido salicílico, ácido benzóico e hidroquinona) foram avaliados para o controle dessa doença do arroz. A atividade antifúngica destes compostos foi avaliada in vitro contra B. oryzae em diferentes concentrações e a eficiência de sua aplicação exógena no controle da mancha-parda foi avaliada em condições de campo. Nos ensaios in vitro, os ácidos benzóico e salicílico a 9 mM inibiram completamente a multiplicação de B. oryzae. Em condições de campo, a aspersão de ácido benzóico a 20 mM causou uma redução significativa na gravidade e incidência da doença na folhas da planta, além de aumentar significativamente o rendimento dos grãos e seus componentes. Algumas respostas bioquímicas foram também observadas, verificando-se que a aplicação do tratamento prévio causou um aumento significativo nos pigmentos fotossintéticos totais (clorofila a e b e carotenóides) nas folhas e no conteúdo de carboidratos e proteínas nos grãos.

The use of RAPD to characterize Bipolaris sorokiniana isolates

Bipolaris sorokiniana is a phytopathogenic fungus causing diseases of cereal crops such as common root rot, the leaf spot disease, seedling blight, and black point of the grain. Random-amplified polymorphic DNA (RAPD) assay was used to investigate the genetic diversity of 20 isolates collected from different cultivars in wheat-producing regions in Brazil. Seventy primers, with random nucleotide sequences, were tested. Reproducibility to amplify the genomic DNA of isolates was found for 30 of the 70 primers tested, generating between 1 and 17 fragments ranging from 0.35 to 2.0 kb (average size). The degree of similarity between samples was calculated through simple association and the dendrogram was assessed using the unweighted pair group method with arithmetical average. After the RAPD analyses 19 isolates were closely grouped, having a similarity coefficient of >or= 78%. Isolate I017 showed very low similarity coefficients, ranging between 38 and 46%. The RAPD analyses provided important information as to the degree of genetic variability and the relationship between the isolates investigated, revealing polymorphism and establishing electrophoretic profiles useful to characterize the phytopathogen.

Cultural Characteristics of a Seedborne Fungus, Bipolaris spicifera Detected from Imported Grass Seeds into Korea

The study on the cultural characteristics of Bipolaris spicifera was conducted to provide with information for the identification, and inoculation studies, etc. B. spicifera grew well at 30~35degrees C and wide range of pH 5.0~9.0. However, the fungal growth was retarded at pH 4.0 and 10.0, respectively. Conidia were germinated with 70% at 30degrees C but maintained 50% germination even at 40degrees C, indicating that this pathogen could infect plants at relatively high temperature. The pathogen could not produce conidia under 24 hr fluorescent light condition for 7 days. In contrast, it produced many more conidia at 24 hr dark condition.

Molecular Analysis of Intraspecific Variations of the Indonesian Cochliobolus heterostrophus

The primary objective of the current research was to detect genetic variations within the Indonesian isolates of Cochliobolus heterostrophus collected from ecologically different places of the country at molecular level using PCR-RFLP analyses. The primer pair of NS3 and NS6 produced amplification fragment in all of the isolates tested. A single fragment of estimated 907 bp was observed in the PCR product pattern. RFLP analysis of the PCR product employing three restriction enzymes, HaeIII, HhaI, and RsaI, respectively, did not reveal intraspecific variations within the fungus. Similarly, nucleotide sequences of portion of small subunit of the ribosomal DNA gene of two of the isolates collected showed no appreciable differences, indicating the absence of genetic diversities among the isolates tested. A phylogenetic tree was constructed and the Indonesian C. heterostrophus, represented by SM-1 isolate, was found to be phylogenetically located near C. sativus, a closely related species.

Germination and mycelial growth of Bipolaris euphorbiae Muchovej & Carvalho as influenced by herbicides and surfactants

Bipolaris euphorbiae Muchovej & Carvalho can be combined with herbicide in order to control a large spectrum of weed species, being a strong candidate for the biocontrol of Euphorbia heterophylla L. (milk weed). The fungus release can be combined with herbicide in order to control a broader spectrum of weed species. Thus, laboratory experiments were set up to study the feasibility of using tank mixes of B. euphorbiae spores with herbicides or surfactants recommended for soybean. Mycelial growth and conidia germination were evaluated in PDA medium enriched with the herbicides oxasulfuron (80 g/ha), glyphosate (4 L/ha), bentazon (1.5 L/ha), fomesafen (1 L/ha), chlorimuron-ethyl (80 g/ha), lactofen (1 L/ha) and imazetaphyr (1 L/ha), and the surfactants Energic (2 ml/L), Aterbane (2.5 ml/L), Silwet L-77Ag (1 ml/L), Herbitensil (2 ml/L) and Natur L'óleo (10 ml/L). Dilution of the herbicides at 50% and 25% were evaluated based on solution consumption of 300 L/ha. The surfactants were evaluated only in the recommended concentrations. Mycelial growth was not affected by bentazon and fomesafen and slightly by oxasulfuron. However, glyphosate and the surfactants Energic, Herbitensil and Aterbane strongly reduced its growth. The reduction observed on imazetaphyr enriched medium was intermediate and the Natur L'óleo promoted mycelial growth. All of the surfactants allowed B. euphorbiae conidia germination equivalent to that reached in the presence of water. Energic and Herbitensil caused an expressive retardation on spore germination. The germinative process only began after 120 minutes in the presence of Herbitensil. In relation to the herbicides, it was observed that only in the presence of glyphosate and imazetaphyr the conidia germination did not follow the trend of the treatment with water.

Bipolaris euphorbiae Muchovej & Carvalho é um forte candidato para o controle de Euphorbia heterophylla L. (amendoim bravo). Este fungo pode ser aplicado em combinação com herbicidas para controlar um maior espectro de espécies daninhas. Para tanto, experimentos laboratoriais foram realizados para verificar a possibilidade da utilização de mistura de tanque de esporos de B. euphorbiae e herbicidas ou surfatantes recomendados para a cultura da soja. Crescimento micelial e germinação de conídios foram avaliados em meio BDA acrescido dos herbicidas, nas concentrações recomendadas dos produtos comerciais, oxasulfuron (80 g/ha), glifosato (4 L/ha), bentazon (1.5 L/ha), fomesafen (1 L/ha), chlorimuron-ethyl (80 g/ha), lactofen (1 L/ha) e imazetaphyr (1 L/ha) e dos surfatantes Energic (2 ml/L), Aterbane (2,5 ml/L), Silwet L-77Ag (1 ml/L), Herbitensil (2 ml/L) e Natur L'óleo (10 ml/L). Diluições dos herbicidas de 50% e 25% foram avaliadas com um consumo de calda equivalente a 300 L/ha. Os surfatantes foram somente utilizados nas concentrações recomendadas. O crescimento micelial não foi afetado por bentazon e fomesafen e apenas levemente por oxasulfuron. Porém, glifosato, chlorimuron-ethyl, lactofen, Energic, Herbitensil, Silwet, e Aterbane o reduziram drasticamente. A redução observada com imazetaphyr foi intermediária e Natur L' óleo promoveu o crescimento micelial. Na presença dos surfatantes, observou-se que todos permitiram uma porcentagem de germinação equivalente àquela alcançada na presença de água. Energic e Herbitensil causaram um retardamento expressivo. Com Herbitensil, o processo germinativo iniciou somente aos 120 minutos. Com herbicidas, foi observado que somente na presença de glifosato e imazetaphyr a germinação dos conídios não seguiu a tendência observada com água, como ocorreu com os outros produtos testados.