Response of cattleya hybrids for Fusarium oxysporum f. sp. cattleyae Foster

The Cattleya genus has a great importance in the flower agro-business market. Fusarium wilts, caused by Fusarium oxysporum f. sp. cattleyae, is considered one of the main factors of decline and death of plants of this genus. Using seven hybrids (intra and intergenerics) of Cattleya, tests of resistance and susceptibility to F. oxysporum were performed in conditions of greenhouse for 12 months, using, as evaluation criterion, a scale of the disease severity ranging from one (resistant) to eight (highly susceptible). High susceptibility to the fungus by Cattleya Nobile's Wax Toy, Cattleya Orquidacea's Mister Fast intrageneric hybrids and Potinara Orquidacea's Havana Brown intergeneric hybrid, related to Brassocattleya Orquidacea's Melody intergeneric hybrid, high resistance to the pathogens was observed.

Efeito de casca de camarão, hidrolisado de peixe e quitosana no controle da murcha de Fusarium oxysporum f.sp. chrysanthemi em crisântemo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potential of non-pathogenic Fusarium oxysporum isolates for control of Fusarium wilt of tomato

O trabalho avaliou a eficiência dos isolados (141/3, 233, 233/1, 245, 245/1, 251, 251/2, 251/5 e 257) de Fusarium oxysporum não patogênico ao tomateiro (Lycopersicon esculentum), no controle da murcha vascular causada por Fusarium oxysporum f. sp. lycopersici, raça 2 em plântulas de tomateiro cv. Viradoro. Para verificar o efeito dos isolados de F. oxysporum não patogênicos, o sistema radicular de plântulas de tomateiro, com 30 dias de idade, foi imerso na suspensão de conídios (10(6) ml-1) e as mudas transplantadas para substrato de cultivo. Após 35 dias do transplante foi verificado que esses isolados não foram patogênicos às plantas de tomateiro, nem afetaram o desenvolvimento das mudas. A eficiência dos isolados de Fusarium oxysporum não patogênicos no controle da murcha foi determinada imergindo-se as raízes de mudas de tomateiro em suspensão de conídios (10(6) conídios ml-1) e transplantando-as em substratos previamente infestados com os isolados de F. oxysporum f.sp. lycopersici, raça 2 (10(5) conídios ml-1 de substrato). Transcorridos 35 dias do transplante, foram realizadas as avaliações da severidade na escala de 1=planta sadia a 6=planta morta ou com vasos coloridos e folhas murchas até o ponteiro e altura das mudas. Os isolados de F. oxysporum não patogênicos foram eficientes em reduzir a severidade da doença e em manter normal o seu desenvolvimento. Esses resultados evidenciam a atividade antagônica dos isolados de F. oxysporum não patogênico no controle da murcha vascular do tomateiro, causada por Fusarium oxysporum f. sp. lycopersici raça 2.

Biomass production and secretion of hydrolytic enzymes are influenced by the structural complexity of the nitrogen source in Fusarium oxysporum and Aspergillus nidulans

The structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. Fusarium oxysporum and Aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids (casamino acids), peptides (peptone) and protein (gelatin). In glucose, when the initial pH was adjusted to 5.0, for both microorganisms, higher biomass production occurred upon supplementation with a nitrogen source in the peptide form (peptone and gelatin). With a close to neutrality pH, biomass accumulation was lower only in the presence of the ammonium salt. When grown in starch, biomass accumulation and secretion of hydrolytic enzymes (amylolytic and proteolytic) by Fusarium also depended on the nature of the nitrogen supplement and the pH. When the initial pH was adjusted to 5.0, higher growth and higher amylolytic activities were detected in the media supplemented with peptone, gelatin and casamino acids. However, at pH 7.0, higher biomass accumulation and higher amylolytic activities were observed upon supplementation with peptone or gelatin. Ammonium sulfate and casamino acids induced a lower production of biomass, and a different level of amylolytic enzyme secretion: high in ammonium sulfate and low in casamino acids. Secretion of proteolytic activity was always higher in the media supplemented with peptone and gelatin. Aspergillus, when grown in starch, was not as dependent as Fusarium on the nature of nitrogen source or the pH. The results described in this work indicate that the metabolism of fungi is regulated not only by pH, but also by the level of structural complexity of the nitrogen source in correlation to the carbon source.

Reação de genótipos de feijoeiro comum a Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina e Xanthomonas campestris pv. phaseoli

The behavior of dry bean (Phaseolus vulgaris L.) genotypes PI 150414, PI 163117, PI 175829 white, PI 175829 purple, PI 175858, PI 197687, A 417, A 420, A 429, Xan 160, Xan 161, WISHBR 40, and IAC Carioca inoculated with Fusarium oxysporum f. sp. phaseoli, Macrophomina phaseolina, and Xanthomonas campestris pv. phaseoli was evaluated under greenhouse condition. The bean genotypes Xan 160, PI 150414, A 417, PI 175829 purple, Xan 161, A 420, PI 163117, and PI 175829 white were resistant to F. oxysporum f. sp. phaseoli, and only PI 155829 white had a good level of resistance to M. phaseolina. All bean genotypes were susceptible to Feij-4 strain, and only Xan 161 had some level of leaf resistance to Feij-41 strain of X. campestris pv. phaseoli.

Produção de lipase por Fusarium oxysporum em fermentação em estado sólido e sua aplicação em reações de síntese de ésteres de biodiesel

Pós-graduação em Ciências Biológicas (Microbiologia Aplicada) - IBRC

Imobilização e caracterização parcial de lipase produzida por Fusarium oxysporum em fermentação submersa

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de isolados de Fusarium oxysporum não patogênicos na redução da severidade da Murcha-de-Fusário do tomateiro

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Influência de fungos micorrízicos arbusculares associa- dos ou não a Fusarium oxysporum Schecht. sobre plantas de alecrim (Rosmarinus officinalis L.) e manjericão (Ocimum basilicum L.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de substrato supressivo à murcha do crisântemo causada por Fusarium oxysporum

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização de isolados de Fusarium oxysporum f.sp . lactucae obtidos de campos de produção comercial no Estado de São P aulo e avaliação de genótipos de alface

Pós-graduação em Agronomia (Horticultura) - FCA

Supressividade a Fusarium oxysporum f. sp. cubense por produtos orgânicos

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Endophytic fungi from Vitis labrusca L. ('Niagara Rosada') and its potential for the biological control of Fusarium oxysporum

We investigated the diversity of endophytic fungi found on grape (Vitis labrusca cv. Niagara Rosada) leaves collected from Salesopolis, SP, Brazil. The fungi were isolated and characterized by amplified ribosomal DNA restriction analysis, followed by sequencing of the ITS1-5.8S-ITS2 rDNA. In addition, the ability of these endophytic fungi to inhibit the grapevine pathogen Fusarium oxysporum f. sp herbemontis was determined in vitro. We also observed that the climatic factors, such as temperature and rainfall, have no effect on the frequency of infection by endophytic fungi. The endophytic fungal community that was identified included Aporospora terricola, Aureobasidium pullulans, Bjerkandera adusta, Colletotrichum boninense, C. gloeosporioides, Diaporthe helianthi, D. phaseolorum, Epicoccum nigrum, Flavodon flavus, Fusarium subglutinans, F. sacchari, Guignardia mangiferae, Lenzites elegans, Paraphaeosphaeria pilleata, Phanerochaete sordida, Phyllosticta sp, Pleurotus nebrodensis, Preussia africana, Tinctoporellus epiniltinus, and Xylaria berteri. Among these isolates, two, C. gloeosporioides and F. flavus, showed potential antagonistic activity against F. oxysporum f. sp herbemontis. We suggest the involvement of the fungal endophyte community of V. labrusca in protecting the host plant against pathogenic Fusarium species. Possibly, some endophytic isolates could be selected for the development of biological control agents for grape fungal disease; alternatively, management strategies could be tailored to increase these beneficial fungi.

Bioactive extracts and chemical constituents of two endophytic strains of Fusarium oxysporum

Ethyl acetate extracts of cultures grown in liquid Czapek and on solid rice media of the fungal endophyte Fusarium oxysporum SS46 isolated from the medicinal plant Smallanthus sonchifolius (Poepp.) H. Rob., Asteraceae, exhibited considerable cytotoxic activity when tested in vitro against human cancer cells. Chromatographic separation yielded anhydrofusarubin (1) and beauvericin (2) that were identified based on their ¹H and 13C NMR data. Compounds 1 and 2 showed the strongest cytotoxic activity against different cancer cell lines. Compound 2 also showed promising activity against Leishmania braziliensis. Hexanic extract of F. oxysporum SS50 grown on solid rice media also afforded a mixture of compounds that displayed cytotoxic activity against different cancer cell lines. Chemical analysis of the mixture of compounds, investigated by gas chromatography-mass spectrometry (GC-MS), showed that there was a predominance of methyl esters of fatty acids and alkanes.

Comportamiento de patrones de tomate frente a la patogenicidad de Fusarium oxysporum f. sp. radicis-lycopersici

La fusariosis del cuello y de las raíces del tomate ("mancha chocolate"), causada por el hongo F. o. f. sp. radicis-lycopersici, es una micosis cada vez más extendida en los cultivos de tomate de las provincias de Almería y Granada. Su gravedad es alta, llegando a alcanzar al 78% de las plantas en algún invernadero con cultivo sobre fibra de coco. Ante esta situación, se estimó necesario evaluar la resistencia de patrones utilizados para injertar variedades de tomate. Así, 16 patrones fueron valorados frente a una cepa muy patógena del hongo. Los patrones fueron:CLXTPG01, AR9704, AR97015, AR97009, Morgan, Spirit, Herman, Armstrong, Arnold, Big Power, Emperador, 61-071, Montezuma, Beaufort, Multifort, Maxifort, Tovi Star y Alegro. Dos ensayos sobre plantas en estado de 6-8 hojas verdaderas bien formadas, mostraron que todos los patrones expresaron una resistencia completa, exceptuando los denominados CLXTPG01 y AR97015. Entendemos que esta información es necesaria debidio a la escasa disponibilidad.