16,677 research outputs found

    Studies on the mycoflora associated with the leaves of some plants

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    About twenty four diseased plants were collected from around Aurangabad city of Maharashtra State. The mycoflora on the leaf surfaces was observed by various methods such as direct observation on stained leaf, leaf wash method, spore fall method, leaf print method. About fifteen genera of different pathogenic fungi have been recorded. Potato dextrose agar media was used for growing the fungi. The some fungi which recorded are Alternaria spp., Aspergillus niger, Aspergillus flavus, Cladosporium spp., Fusarium spp., Helminthosporium spp., Phytopthora spp., Pythium spp., Phyllactinia spp, Uncinulla spp., Urosystis spp., Uromyces spp., etc. The maximum infection is by Fussarium spp. and Alternaria spp. to 13 plant species. The pathogen Fussarium spp. and Alternaria spp. are found causing disease both on same host on up to 9 different plant species

    Mycoflora of fungal contamination in wheat storage (silos) in golestan province, north of Iran

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    Background: Cereal products are susceptible to mould damage during pre- and post-harvesting stages of the production. The regional specificity of Golestan province in the northern region of of Iran, with its high temperature and high relative humidity, acts as a leading factor for the growth of aflatoxin-producing fungi. It is well known that contamination of starch-based ingredients with mycotoxigenic fungi is a risk factor among the consumers due to its aflatoxins. Objectives: This survey was carried out to determine the extent of fungal contamination of wheat in three silos of Golestan province in Iran. Materials and Methods: 34 samples from three active silos were collected in order to clean the polyethylene bags. Wheat analyzed for fungal contamination and aflatoxins extracted by immunoaffinity column chromatography, and measured by HPLC method. Results: The most common moulds isolated were Alternaria spp. 26.7%, Aspergillus niger 21.4%, Fusarium spp. 17.8%, Aspergillus flavus 10.7%, Cladosporium spp. 10.7%, Penicillium spp. 8.9%, and Rhizopus spp. 3.5%. The screening of aflatoxin, B1, B2, G1 and G2 was carried out. 10(29.4%) samples of wheat had traces of aflatoxin, but in a level lower than the standard levels [Institute of Standards and Industrial Research of Iran (ISIR< 15 ng/g)]. Conclusions: Despite the lower detected aflatoxin levels (lower than the ISIR level), the fungal contamination rate could not be neglected. Since the isolated mycotoxigenic fungi such as Aspergillus spp. and Fusarium spp. are important in food industry, it would be possible that the increased retention time of samples might have raised the detected contamination rate. © 2013, Ahvaz Jundishapur University of Medical Sciences

    Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

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    The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems

    Antagonistic capacities of Trichoderma species and their mass multiplication with agricultural wastes

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    El objetivo de esta investigación fue aislar y caracterizar cepas de Trichoderma nativas de Misiones (Argentina)explorando sus capacidades antagónicas y su multiplicación masiva utilizando diferentes residuos agroindustriales.Quince cepas nativas de Trichoderma spp. fueron aisladas de muestras de suelo. Estos aislamientos secaracterizaron mediante observaciones morfológicas y moleculares basados en secuencias de ADN de la regiónespaciadora transcrita interna del ADNr. Las cepas de Trichoderma spp. fueron identificadas como T. koningiopsis,T. harzianum, T. pleuroticola y T. brevicompactum. Estas cepas mostraron actividades antagónicas in vitro contraAlternaria sp., Fusarium sp. y Botrytis sp.. T. koningiopsis LBM 090, LBM 091, LBM 092 y LBM 098, T. pleuroticolaLBM 097 y T. harzianum LBM 096 presentaron una inhibición del crecimiento micelial mayor del 50% y un índicede antagonismo entre 3 y 4 contra los fitopatógenos ensayados. La cáscara de arroz y el pulido del arroz fueronlas combinaciones más adecuadas para la multiplicación de T. harzianum LBM 096.The aim of this research was to isolate and characterize Trichoderma native strains from Misiones (Argentina) exploring their antagonistic capacities to phytopatogens fungi and their mass multiplication using different agricultural wastes. Fifteen native strains of Trichoderma spp. were isolated from soil samples. These isolates were characterized via morphological observations and molecular phylogenetic analysis based on DNA sequences of the rDNA internal transcribed spacer region. The Trichoderma native strains were identified as T. koningiopsis, T. harzianum, T. pleuroticola and T. brevicompactum. All strains showed antagonistic activities in vitro against Alternaria sp., Fusarium sp. and Botrytis sp. T. koningiopsis LBM 090, LBM 091, LBM 092, and LBM 098 strains, T. pleuroticola LBM 097 and T. harzianum LBM 096 presented radial mycelial growth inhibition higher than 50% and antagonism index between 3 and 4 against the phytopathogens assayed. Among the different substrate sources evaluated, rice husk and rice polishing were the most suitable combination for mass multiplication of T. harzianum LBM 096.Fil: Sadañoski, Marcela Alejandra. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Gutierrez Brower, Gimena. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Castrillo, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Lopez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Ojeda, Paola. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Zapata, Pedro Dario. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; ArgentinaFil: Villalba, Laura Lidia. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; ArgentinaFil: Otegui, Monica Beatriz. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Departamento de Bioquímica Clínica. Laboratorio de Biotecnología Molecular; Argentin

    RESEARCH ON MYCOFLORA PRESENT ON SOYBEAN SEEDS (GLYCINE MAX L.)

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    The aim of this research was to identify the associated mycoflora and to determine their incidence on soybean seeds. Untreated seeds of the varieties Onix, Sigalia and Procera 1020 have been examined. The detected mycoflora has been represented by fungi from the genera: Aspergillus spp., Rhizopus spp., Alternaria spp., Stemphylium spp., Fusarium spp. The pathogen Aspergillus spp. had the highest incidence, of 44%, in the Procera 1020 variety, followed by the Alternaria spp. and Stemphylium spp. complex, with a 33% incidence, in the Onix variety. An attack of Fusarium spp. has been detected in the Onix variety

    Genera of phytopathogenic fungi: GOPHY 3

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    This paper represents the third contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions, information about the pathology, distribution, hosts and disease symptoms for the treated genera, as well as primary and secondary DNA barcodes for the currently accepted species included in these. This third paper in the GOPHY series treats 21 genera of phytopathogenic fungi and their relatives including: Allophoma, Alternaria, Brunneosphaerella, Elsinoe, Exserohilum, Neosetophoma, Neostagonospora, Nothophoma, Parastagonospora, Phaeosphaeriopsis, Pleiocarpon, Pyrenophora, Ramichloridium, Seifertia, Seiridium, Septoriella, Setophoma, Stagonosporopsis, Stemphylium, Tubakia and Zasmidium. This study includes three new genera, 42 new species, 23 new combinations, four new names, and three typifications of older names

    Prisustvo Alternaria spp. na semenu biljaka iz familije Apiaceae i njihov uticaj na nicanje

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    Considerable damping-off of the seedlings of several commercial Apiaceae plant species was observed in Serbia. The infection of a total of 48 seed samples of nine vegetable and spice plants with phytopathogenic Alternaria spp. was established using the deep-freeze-blotter method. Identification of Alternaria species was performed using both conventional methods and PCR. Four different plant-pathogenic Alternaria species were detected in Serbia: A. dauci, A. radicina, A. petroselini, and A. alternata, all of which caused reduction of carrot, parsley, parsnip, and celery seed emergence. Alternaria dauci, A. radicina, and A. petroselini were relatively more aggressive compared to A. alternata. Substantial seed infection levels and strong influence of Alternaria spp. on seed emergence indicated that production of Apiaceae seed needs to be improved in order to obtain pathogen-free seed.U proizvodnji nekoliko useva biljaka izfamilije Apiaceae, uočeno je intenzivno propadanje sejanaca u Srbiji. Primenom metode zamrzavanja na filter papiru, ustanovljena je zaraza ukupno 48 uzoraka semena 9 gajenih biljaka povrća i začinskih biljaka fitopatogenim vrstama izroda Alternaria. Identifikacija Alternaria spp. obavljena je primenom konvencionalnih metoda i PCR. U Srbiji je detektovano prisustvo ukupno četiri fitopatogene vrste izroda Alternaria: A. dauci, A. radicina, A. petroselini i A. alternata koje su izazvale smanjeno nicanje mrkve, peršuna, paštrnaka i celera. A. dauci, A. radicina i A. petroselini bile su relativno agresivnije u poređenju sa A. alternata. Značajan nivo zaraze semena, kao i ispoljeni uticaj Alternaria spp. na nicanje, ukazali su da bi proizvodnju semena vrsta familije Apiaceae trebalo poboljšati u cilju dobijanja zdravog semena

    Endophytic Fungi of Bitter Melon \u3ci\u3e(Momordica Charantia)\u3c/i\u3e in Guangdong Province, China

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    Endophytic fungi can mutualistically interact with their host plants by deterring herbivores. Overall 1172 endophytic fungal isolates were recovered from roots, stems, leaves, flowers and fruits of bitter melon, Momordica charantia, at five sites in Guangdong Province. These isolates were identified to 25 genera using morphological and molecular characteristics. The endophyte communities at the five sites were similar. Alternaria alternata, Aspergillus spp., Cladosporium spp., Colletotrichum spp., Nigrospora spp., Penicillium spp., Arthrinium spp., Chaetimium spp., Curvularia spp., Fusarium spp., Phoma spp., and Phomopsis spp. were isolated from at least three of the five sites. The coefficient of similarity for endophytes ranged from 60.6% to 83.3% between any two sites. There were significant differences in the species composition of endophytes recovered from different tissues of bitter melon. Fusarium spp. was the most frequent in root and stem samples, Colletotrichum spp. in leaf samples, A. alternata in flower samples, and Cladosporium spp. in fruit samples. The coefficients of similarity for endophytes were between 42.9% and 80.0% from any two tissues. We found that the composition of endophytes of bitter melon was relatively stable across sites, but differed greatly among tissues. We also found that there were fewer insects such as aphids (Homoptera: Aphididae), leafminers (Lepidoptera, Gracillariidae), and cotton leafworms Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) collected from the leaves of bitter melon at the Huadu site compared to those collected at the Yunfu site. Whether this is related to the endophyte communities isolated from different sites requires further research
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