Fungal Planet description sheets: 320-370

Novel species of fungi described in the present study include the following from Malaysia: Castanediella eucalypti from Eucalyptus pellita, Codinaea acacia from Acacia mangium, Emarcea eucalyptigena from Eucalyptus brassiana, Myrtapenidiella eucalyptorum from Eucalyptus pellita, Pilidiella eucalyptigena from Eucalyptus brassiana and Strelitziana malaysiana from Acacia mangium. Furthermore, Stachybotrys sansevieriicola is described from Sansevieria ehrenbergii (Tanzania), Phacidium grevilleae from Grevillea robusta (Uganda), Graphium jumulu from Adansonia gregorii and Ophiostoma eucalyptigena from Eucalyptus marginata (Australia), Pleurophoma ossicola from bone and Plectosphaerella populi from Populus nigra (Germany), Colletotrichum neosansevieriae from Sansevieria trifasciata, Elsinoë othonnae from Othonna quinquedentata and Zeloasperisporium cliviae (Zeloasperisporiaceae fam. nov.) from Clivia sp. (South Africa), Neodevriesia pakbiae, Phaeophleospora hymenocallidis and Phaeophleospora hymenocallidicola on leaves of a fern (Thailand), Melanconium elaeidicola from Elaeis guineensis (Indonesia), Hormonema viticola from Vitis vinifera (Canary Islands), Chlorophyllum pseudoglobossum from a grassland (India), Triadelphia disseminata from an immunocompromised patient (Saudi Arabia), Colletotrichum abscissum from Citrus (Brazil), Polyschema sclerotigenum and Phialemonium limoniforme from human patients (USA), Cadophora vitícola from Vitis vinifera (Spain), Entoloma flavovelutinum and Bolbitius aurantiorugosus from soil (Vietnam), Rhizopogon granuloflavus from soil (Cape Verde Islands), Tulasnella eremophila from Euphorbia officinarum subsp. echinus (Morocco), Verrucostoma martinicensis from Danaea elliptica (French West Indies), Metschnikowia colchici from Colchicum autumnale (Bulgaria), Thelebolus microcarpus from soil (Argentina) and Ceratocystis adelpha from Theobroma cacao (Ecuador). Myrmecridium iridis (Myrmecridiales ord. nov., Myrmecridiaceae fam. nov.) is also described from Iris sp. (The Netherlands). Novel genera include (Ascomycetes): Budhanggurabania from Cynodon dactylon (Australia), Soloacrosporiella, Xenocamarosporium, Neostrelitziana and Castanediella from Acacia mangium and Sabahriopsis from Eucalyptus brassiana (Malaysia), Readerielliopsis from basidiomata of Fuscoporia wahlbergii (French Guyana), Neoplatysporoides from Aloe ferox (Tanzania), Wojnowiciella, Chrysofolia and Neoeriomycopsis from Eucalyptus (Colombia), Neophaeomoniella from Eucalyptus globulus (USA), Pseudophaeomoniella from Olea europaea (Italy), Paraphaeomoniella from Encephalartos altensteinii, Aequabiliella, Celerioriella and Minutiella from Prunus (South Africa). Tephrocybella (Basidiomycetes) represents a novel genus from wood (Italy). Morphological and culture characteristics along with ITS DNA barcodes are provided for all taxa.

Fungitoxic non-glycosidic iridoids from Alibertia macrophylla

The aqueous alcohol extract of the leaves of Alibertia macrophylla afforded two epimeric pairs of iridoid aglycones and one of them showed high inhibitory activity against Aspergillus niger, Cladosporium sphaerospermum, C. cladosporioides and Colletotrichum gloesporioides. Three of the compounds are reported for the first time from natural sources. Their structures were established on the basis of spectroscopic studies, mainly through 13C NMR analysis. © 1992.

Quitosana e óleos essenciais no controle de antracnose e na qualidade pós-colheita de abacates

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Diversidade e prospecção de fungos endofíticos de Begonia spp. encontradas na Mata Atlântica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Epicoccum nigrum P16, a Sugarcane Endophyte, Produces Antifungal Compounds and Induces Root Growth

Background: Sugarcane is one of the most important crops in Brazil, mainly because of its use in biofuel production. Recent studies have sought to determine the role of sugarcane endophytic microbial diversity in microorganism-plant interactions, and their biotechnological potential. Epicoccum nigrum is an important sugarcane endophytic fungus that has been associated with the biological control of phytopathogens, and the production of secondary metabolites. In spite of several studies carried out to define the better conditions to use E. nigrum in different crops, little is known about the establishment of an endophytic interaction, and its potential effects on plant physiology. Methodology/Principal Findings: We report an approach based on inoculation followed by re-isolation, molecular monitoring, microscopic analysis, plant growth responses to fungal colonization, and antimicrobial activity tests to study the basic aspects of the E. nigrum endophytic interaction with sugarcane, and the effects of colonization on plant physiology. The results indicate that E. nigrum was capable of increasing the root system biomass and producing compounds that inhibit the in vitro growth of sugarcane pathogens Fusarium verticillioides, Colletotrichum falcatum, Ceratocystis paradoxa, and Xanthomomas albilineans. In addition, E. nigrum preferentially colonizes the sugarcane surface and, occasionally, the endophytic environment. Conclusions/Significance: Our work demonstrates that E. nigrum has great potential for sugarcane crop application because it is capable of increasing the root system biomass and controlling pathogens. The study of the basic aspects of the interaction of E. nigrum with sugarcane demonstrated the facultative endophytism of E. nigrum and its preference for the phylloplane environment, which should be considered in future studies of biocontrol using this species. In addition, this work contributes to the knowledge of the interaction of this ubiquitous endophyte with the host plant, and also to a better use of microbial endophytes in agriculture.

Effect of fungicides and alternative products in control of anthracnose and black spot of guava

This work aimed to evaluate the efficiency of fungicides in controlling in vitro and in vivo the causal agents of anthracnose (Colletotrichum gloeosporioides and C. acutatum) and black spot (Guignardia psidii) and evaluate the effect of alternative products to control these diseases. Inhibition of mycelial growth of the pathogens was evaluated for ten fungicides at concentrations of 1, 10 and 100 mg L-1 of active ingredient in potato-dextrose-agar medium. The effectiveness of the fungicides azoxystrobin + difenoconazole, cyproconazole, pyraclostrobin, tebuconazole and tebuconazole + trifloxystrobin in controlling disease incidence and severity of anthracnose, through applications in the field, was measured in fruits collected at three stages of maturation, according to the skin color ( dark green, light green and yellowish green). In postharvest dipping of fruits, the products evaluated were citric acid, peracetic acid, salicylic acid, sodium bicarbonate, chlorine dioxide, Ecolife (R) and chitosan. The fungicides azoxystrobin + difenoconazole, pyraclostrobin, tebuconazole and trifloxystrobin + tebuconazole were highly effective in inhibiting the in vitro mycelial growth of G. psidii and moderately to highly effective in inhibiting C. acutatum and C. gloeosporioides. In field conditions, the fungicide azoxystrobin + difenoconazole was effective in controlling anthracnose and black spot in fruit at three maturity stage ( skin color yellowish green). The alternative products tested were ineffective in the curative control of anthracnose and early blight at postharvest of guava.

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.

Potencial do flavedo (epicarpo) de Citrus aurantifolia cv. Tahiti no controle do bolor verde e da antracnose em citros

O Brasil é considerado o maior produtor de citros e o maior exportador de suco de laranja. Doenças de pós-colheita representam uma grande perda para a citricultura, sendo que para a exportação de frutos são rígidas as exigências com relação a isenção de resíduos químicos nos mesmos. Patógenos de importância em pós-colheita de citros incluem o Penicillium digitatum, agente causal do bolor-verde e o Colletotrichum gloeosporioides, agente causal da antracnose. Dada a importância econômica que representam estas doenças dos frutos cítricos, tanto em termos de comprometimento da qualidade e dificuldade de controle, a busca de alternativas adicionais que possam viabilizar a capacidade produtiva e garantir a obtenção de frutos com excelentes padrões de qualidade torna-se imprescindível. Portanto, estudou-se os efeitos dos extratos aquosos do flavedo de Citrus aurantifolia var. Tahiti, Lentinula edodes, Agaricus subrufescens (syn. Agaricus brasiliensis), albedo de Citrus sinensis var. Valência e do ácido jasmônico no controle póscolheita do bolor verde e da antracnose e na indução de resistência em frutos de laranjeira Valência (Citrus sinensis). Foi possível observar que o extrato aquoso do flavedo (C. aurantifolia) apresentou efeito inibitório sobre os patógenos, quando tratados em pós-colheita, em função da redução dos sintomas e esporulação. Porém, os extratos de albedo (C. sinensis), L. edodes, A. subrufescens e o ácido jasmônico não apresentaram efeitos sobre P. digitatum e C. gloeosporioides.

Aureobasidium pullulans as biological control agent: modes of action

The postharvest phase has been considered an environment very suitable for successful application of biological control agents (BCAs). However, the tri-interaction between fungal pathogen, host (fruit) and antagonist is influenced by several parameters such as temperature, oxidative stresses, oxygen composition, water activity, etc. that could be determining for the success of biocontrol. Knowledge of the modes of action of BCAs is essential in order to enhance their viability and increase their potentialities in disease control. The thesis focused on the possibility to explain the modes of action of a biological control agent (BCA): Aureobasidium pullulans, in particular the strains L1 and L8, control effective against fruit postharvest fungal pathogen. In particular in this work were studied the different modes of action of BCA, such as: i) the ability to produce volatile organic compounds (VOCs), identified by SPME- gas chromatography-mass spectrometry (GC-MS) and tested by in vitro and in vivo assays against Penicillium spp., Botrytis cinerea, Colletotrichum acutatum; ii) the ability to produce lytic enzymes (exo and endo chitinase and β-1,3-glucanase) tested against Monilinia laxa, causal agent of brown rot of stone fruits. L1 and L8 lytic enzymes were also evaluated through their relative genes by molecular tools; iii) the competition for space and nutrients, such as sugars (sucrose, glucose and fructose) and iron; the latter induced the production of siderophores, molecules with high affinity for iron chelation. A molecular investigation was carried out to better understand the gene regulation strictly correlated to the production of these chelating molucules. The competition for space against M. laxa was verified by electron microscopy techniques; iv) a depth bibliographical analysis on BCAs mechanisms of action and their possible combination with physical and chemical treatments was conducted.

Testing a Warning System for Anthracnose Fruit Rot on Day-neutral Strawberry

Anthracnose fruit rot (AFR) of strawberry is caused by three Colletotrichum spp. In the Midwest, however, only Colletotrichum acutatum is found. This fungus can attach itself to apparently healthy plants and spread throughout without causing symptoms on the foliage. When fruit begin to ripen and weather conditions are rainy and warm, AFR can suddenly cause great damage to the fruit. To protect against AFR where it has appeared in the past, growers need to spray every 7 to 10 days beginning at the start of bloom until harvest.

Trips (Frankliniella brevicaulis Hood) de las erupciones del fruto de banano (Musa acuminata Colla) en la provincia de Formosa, Argentina

El banano en la provincia de Formosa (Argentina) es uno de los principales cultivos de renta y generador de mano de obra para el productor por lo que representa un importante lugar en lo social y económico. La sanidad de los cultivos es fundamental para lograr una mayor rentabilidad. Se han observado en los frutos daños atribuibles a trips. Los objetivos de este trabajo fueron identificar la/s especie/s de trips causal de las erupciones del fruto de banano en la provincia de Formosa, realizar una descripción detallada de su morfología y caracterizar y evaluar los daños producidos. La zona de trabajo correspondió al Área-Laguna Naineck en el Departamento Pilcomayo de la provincia de Formosa considerando un total de 1.103,74 ha pertenecientes a 233 productores. Para la determinación del estado sanitario de las plantaciones con respecto a la presencia del insecto se realizó un diseño de muestreo estadístico. Se recolectaron muestras del insecto y se identificaron con ayuda de claves. La única especie de trips encontrada fue Frankliniella brevicaulis. Los daños producidos por esta especie serían debidos a las heridas causadas por la oviposición, siendo éstas posibles fuentes de entrada para el hongo Colletotrichum musae. Se observaron daños en el 100% de los cachos de banana en todas las plantaciones evaluadas.

Surface signaling in pathogenesis.

Surface signaling plays a major role in fungal infection. Topographical features of the plant surface and chemicals on the surface can trigger germination of fungal spores and differentiation of the germ tubes into appressoria. Ethylene, the fruit-ripening hormone, triggers germination of conidia, branching of hyphae, and multiple appressoria formation in Colletotrichum, thus allowing fungi to time their infection to coincide with ripening of the host. Genes uniquely expressed during appressoria formation induced by topography and surface chemicals have been isolated. Disruption of some of them has been shown to decrease virulence on the hosts. Penetration of the cuticle by the fungus is assisted by fungal cutinase secreted at the penetration structure of the fungus. Disruption of cutinase gene in Fusarium solani pisi drastically decreased its virulence. Small amounts of cutinase carried by spores of virulent pathogens, upon contact with plant surface, release small amounts of cutin monomers that trigger cutinase gene expression. The promoter elements involved in this process in F. solani pisi were identified, and transcription factors that bind these elements were cloned. One of them, cutinase transcription factor 1, expressed in Escherichia coli, is phosphorylated. Several protein kinases from F. solani pisi were cloned. The kinase involved in phosphorylation of specific transcription factors and the precise role of phosphorylation in regulating cutinase gene transcription remain to be elucidated.

Uso de Metarhizium spp. na produção de mudas pré-brotadas de cana-de-açúcar e seus efeitos na planta, em pragas e doenças

Os fungos do gênero Metarhizium são entomopatogênicos e ainda apresentam relações endofíticas e podem viver saprofiticamente no solo. A associação desses microrganismos com insetos é bem conhecida, mas as interações diretas com as plantas ainda são incipientes. Objetivou-se com este estudo, determinar a capacidade de colonização endofítica em raízes de cana-de-açúcar (Saccharum spp.) de M. robertsii, M. anisopliae e três linhagens brasileiras recém-descobertas, bem como revelar o potencial destes fungos como antagonistas a dois fungos fitopatogênicos responsáveis pela podridão-vermelha (Fusarium moniliforme e Colletotrichum falcatum) e no controle de duas importantes pragas, a broca da cana-de-açúcar, Diatraea saccharalis e o nematóide-das-galhas, Meloidogyne javanica. Foram utilizados 24 isolados de Metarhizium spp. nos experimentos de promoção de crescimento de plantas após a inoculação em gemas de cana-de-açúcar em condições de casa-de-vegetação e campo. O efeito da inoculação do fungo em mudas de cana-de-açúcar foi investigado quanto a mortalidade e redução no desenvolvimento de D. saccharalis e redução nas populações de M. javanica. Experimentos de inibição in vitro em cultivo pareado foram conduzidos com os fungos F. moniliforme e C. falcatum e Trichoderma harzianum. Além disto, foram realizados testes qualitativos \"in vitro\" para avaliar a capacidade desses fungos em produzir β-1,3-Glucanase e Sideróforos. A inoculação de Metarhizium de todas as espécies testadas promoveu o crescimento de parte aérea, peso úmido e seco de raízes em relação ao controle (água). Enquanto o tratamento de gemas rotineiramente usado na usina onde se realizou a produção de mudas pré-brotadas com aplicação do fungicida Comet® + o fertilizante Biozyme TF resultou em pegamento de 32% e 59,6%, apenas com o uso de isolados de Metarhizium spp. estes valores foram de até 50% e 86,4%, nos dois experimentos em campo, respectivamente. As mortalidades observadas em lagartas de D. saccharalis que se alimentaram das plantas inoculadas com isolados de Metarhizium spp. atingiram valores de até 80%, sendo a mortalidade confirmada pela esporulação do fungo de até 55%. As lagartas sobreviventes apresentaram menor peso do que aquelas do controle não tratado. A inoculação de Metarhizium spp. em mudas de cana-de-açúcar conferiu proteção a M. javanica, resultando em uma densidade de massa de ovos por grama de raiz nas mudas inoculadas com o fungo até 59,8% menor no primeiro experimento e 64,1% menor no segundo em relação as mudas sem inoculação. Os ensaios de antagonismo mostraram que, todos os isolados de Metarhizium spp. apresentaram alguma forma de inibição tanto para F. moniliforme como para C. falcatum. Dos 24 isolados testados, 20,8% produziram a enzima hidrolítica, β-1,3-glucanase, o que pode estar associado a capacidade de inibição dos fungos fitopatogênicos. Constatou-se que 8 (33,3%) dos isolados produziram sideróforos e sugere que esses fungos apresentam mecanismos de disponibilização do ferro. O conhecimento gerado com este estudo poderá subsidiar novas estratégias de utilização de Metarhizium spp. em campo na produção de MPB de cana-de-açúcar.

Transcriptional response of sugarcane roots to methyl jasmonate

The effect of methyl jasmonate treatment on gene expression in sugarcane roots signalling between roots and shoots was studied. A collection of 829 ESTs were obtained from sugarcane roots treated with the defence-regulator methyl jasmonate (MJ) treatment. A subset of 747 of these were combined with 4793 sugarcane ESTs obtained from stem tissues in a cDNA microarray and experiments undertaken to identify genes that were induced in roots 24-120 h following treatment with MJ. Two data analysis systems (t-statistic and tRMA) were used to analyse the microarray results and these methods identified a common set of 21 ESTs corresponding to transcripts significantly induced by MJ in roots and 23 that were reduced in expression following MJ treatment. The induction of six transcripts identified in the microarray analysis was tested and confirmed using northern blotting. Homologues of genes encoding lipoxygenase and PR-10 proteins were induced 824 It after MJ treatment while the other four selected transcripts were induced at later time points. Following treatment of roots with MJ, the lipoxygenase homologue, but not the PR-10 homologue, was induced in untreated stem and leaf tissues. The PR-10 homologue and a PR-1 homologue, but not the lipoxygenase homologue, were induced in untreated tissues after the application of SA to roots. Repeated foliar application of MJ had no apparent effects on plant growth and was demonstrated to increase lipoxygenase transcripts in roots, but did not increase transcript levels-of other genes tested. These results lay a foundation for further studies of induced pest and disease resistance in sugarcane roots. (C) 2004 Elsevier Ireland Ltd. All rights reserved.