Interactions between xylotrophic mushrooms and mycoparasitic fungi in dual culture experiments

Seventeen wood-decaying mushroom species were paired with three Trichoderma species and Clonostachys rosea in dual-culture experiments on agar based medium. Xylotrophic mushrooms and mycoparasitc fungi in general showed similar competitive ability. Deadlock or mutual inhibition after mycelial contact was observed in 45% of pairings, stable inhibition at a distance occurred in 4.4% of pairings, replacement of xylotrophic fungus by mycoparasitic fungus was observed in 29.4% and the opposite in 20.6% of pairings. Xylotrophi

Secondary Metabolites of Mycoparasitic Fungi

Mycoparasitic fungi, fungi preying on other fungal species, are prolific producers of volatile and non-volatile secondary metabolites. Several secondary metabolites are produced during mycoparasitism to weaken the host and support attack and parasitism. Further, evidence accumulated that some secondary metabolites also act as communication molecules. Besides their antagonistic activity, several fungal mycoparasites exhibit beneficial effects on plants and some of their secondary metabolites have plant growth-promoting and defense stimulating activities. As many secondary metabolism-associated gene clusters remain silent under standard laboratory conditions, the full variety as well as the underlying biosynthetic pathways employed by fungal mycoparasites for secondary metabolite production still await clarification. Nonetheless, the variety of currently known secondary metabolites and their range of activities is impressive already and they exhibit a great potential for agriculture, pharmacology and other industrial applications

Identification Of Potential Entomopathogenic Fungi Of Tetranychus Kanzawai Kishida (Tetranychidae: Acarina) Using Its-5.8s Rdna Region AS Molecular Marker

Fungi has been tested as one of the potential control agents for insect pests, which raises hopes for developing fungi as good biopesticides. The high variation within fungi species made taxonomic identification procedures more complex, thus molecular identification techniques are needed in addition to traditional morphological characteristics currently used as primary methods to classify fungi species. The objective of this research was to identify the species of the most pathogenic fungi to Tetranychus kanzawai Kishida using RAPD-PCR. The internal transcribed spacer of 5.8s rDNA (ITS-5.8s rDNA) sequence of these fungal isolates were amplified using two sets of universal primers for ITS and then analyzed. Molecular identification showed that these isolates had a higher of similarity to Metarhizium anisopliae than Metarhizium flavoviride

Evaluation of biological control agents for managing cucurbit powdery mildew on greenhouse-grown melon

An evaluation was made of the ability of two mycoparasite-based products AQ10® (Ampelomyces quisqualis) and Mycotal® (Lecanicillium lecanii), as well as three strains of Bacillus subtilis, to manage powdery mildew disease, caused by Podosphaera fusca on melon seedlings maintained under different regimes of relative humidity and on plants grown under greenhouse conditions in Spain. In every case fungal and bacterial biocontrol agents (BCAs) performed better under conditions of high relative humidity (90–95% RH). In greenhouse experiments, the effectiveness of the mycoparasites to manage powdery mildew was absolutely dependent on mineral oil. The strains of B. subtilis provided disease control similar to that achieved with the mycoparasites or the fungicide azoxystrobin. Microscopic analysis showed the ability of these bacterial strains to efficiently colonize leaf surfaces and revealed the occurrence of antagonistic interactions between biological agents and P. fusca structures. These results confirmed the usefulness of these BCAs for managing powdery mildew on greenhouse-grown cucurbits either as single products or as a component of integrated control programmes.Estación Experimental ‘La Mayora’ (CSIC), Algarrobo-Costa, 29750 Málaga, Spain Grupo de Microbiología y Patología Vegetal-Unidad Asociada a CSIC, Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 MálagaPeer reviewe

Molecular and microscopic studies of a Fusarium-associated biotrophic mycoparasite

Environmental hazards and health problems due to the application of chemical pesticides in agricultural sectors incite huge public concerns. Therefore, one of the better solutions is through introduction of biological control means to manage the outbreaks of plant diseases. To date, only small numbers of beneficial microorganisms - belonging to the category of hyperparasitic or mycoparasitic fungi have proven to keep plants or protect crops from plant pathogen infection. The objective of this study was to characterize a group of Fusarium-associated melanosporaceous biotrophic mycoparasitic fungal isolates, which were identified and pre-selected by Dr. Vladimir Vujanovic and deposited in the Saskatchewan Microbial Collection and Database (SMCD). Particular objectives were to examine spore germination of a biotrophic mycoparasite, to test effects of this fungus on seed germinations, to study interactions between the mycoparasite and Fusarium hosts, and to investigate relationships between the mycoparasite-the Fusarium host-wheat root under controlled conditions in the university Phytotron facilities. Information related to this group of fungi is relatively limited. In order to characterize potential biotrophic mycoparasitic fungal isolate(s), molecular and microscopy methods were performed to accomplish taxonomical, phylogenetical and morphological studies. Since, spore germination is a very crucial stage in fungal life cycle and growth, ascospores (sexual spores) of the biotrophic mycoparasite were isolated from a fungal colony. These spores were inoculated on media supplemented with different Fusarium-filtrates or suspended in different Fusarium-filtrates to examine spore germination rates and growth patterns. Together with other mycoparasitic fungi, this biotrophic mycoparasite was inoculated on spring wheat seeds, to test effects of these fungal inoculants on seedlings growth using in vitro assays. Dual-culture, slide culture, and microscopy approaches were carried out to elucidate intimate and special relationship between the biotrophic mycoparasite and Fusarium-hosts. In order to study tritrophic interactions (biotrophic mycoparasite-Fusarium host-wheat root), spring wheat was grown in the phytotron with different treatments of fungal inoculations. Wheat roots were then subjected to genus-specific quantitative real-time PCR analyses. One melanosporaceous biotrophic mycoparasitic strain was identified as a new species in the genus Sphaerodes. This biotrophic mycoparasite was isolated from Fusarium-infected fields in Saskatchewan and Quebec, and named Sphaerodes mycoparasitica. Germination of S. mycoparasitica sexual spores was improved when treated with filtrates or extracellular extracts from the Fusarium-host as compared to Fusarium-non-host filtrates. No pathogenic effects on wheat seeds were observed when inoculated with S. mycoparasitica. Furthermore, seedlings growth was enhanced with this biotrophic mycoparasite compared to other mycoparasitic fungi. Later, this biotrophic mycoparasitic strain was found to establish biotrophic fusion and haustorial contact relations with F. avenaceum, F. oxysporum, and two F. graminearum chemotypes. Since, 3-Acetyldeoxynivalenol-producing F. graminearum is one of the most highly toxigenic and aggressive wheat pathogens in Saskatchewan and North America, therefore, this pathogen strain was chosen for tritrophic interaction study. Under controlled conditions in the phytotron, S. mycoparasitica improved seedlings growth when these were challenged with F. graminearum as compared to seedlings only inoculated with the Fusarium pathogen. In conclusion, S. mycoparasitica could be a potential candidate for biological control of Fusarium diseases in wheat

Interactions between Xylotrophic Mushrooms and Mycoparasitic Fungi in Dual-Culture Experiments

Seventeen wood-decaying mushroom species (Coriolus versicolor, Flammulina velutipes, Ganoderma sp., Hypholoma fasciculare, H. sublateritium, Kühneromyces mutabilis, Lentinula edodes, Lentinus tigrinus, Pholiota alnicola, Ph. aurivella, Ph. destruens, Pleurotus cornucopiae, Pl. ostreatus, Polyporus subarcularius, Po. squamosus, Po. varius and Schizophyllum commune) were paired with three Trichoderma species (T. harzianum, T. pseudokoningii, and T. viride) and Clonostachys rosea in dual-culture experiments on an agar-based medium. Xylotrophic mushrooms and mycoparasitic fungi in general showed similar competitive ability; deadlock, or mutual inhibition after mycelial contact, was observed in 45.6% of pairings, while stable inhibition at a distance occurred in 4.4% of pairings. Replacement, or overgrowth of xylotrophic mushroom by a mycoparasitic fungus was observed in 29.4% of pairings; the opposite, overgrowth of the xylotrophic mushroom on the mycoparasitic fungus in 20.6%. of pairings. Of the xylotrophic mushrooms, Pl. ostreatus, Ganoderma sp., F. velutipes and H. fasciculare, showed the highest competitive ability against mycoparasitic fungi. Of the mycoparasitic fungi, T. harzianum showed the strongest competitive activity against xylotrophic mushrooms

Recent advances toward the sustainable management of invasive Xylosandrus ambrosia beetles

We provide an overview of both traditional and innovative control tools for management of three Xylosandrus ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history of damage in forests, nurseries, orchards and urban areas. Xylosandrus compactus, X. crassiusculus and X. germanus are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor Xylosandrus species. Conventional pest control methods are mostly ineffective against Xylosandrus beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling Xylosandrus damage

Hongos micoparásitos II. Especies del Estado de México

The mycoparasitic species: Cladobotryum mycophilum, Mycogone perniciosa, Sepedonium ampulosporum, Streptomyces sp., Apiocrea hyalina and Hypomyces macrosporus, all are reported for the first time in several places in the State of Mexico. It is included a table of mycoparasitic species and their hosts. New records of mycoparasitic fungi genera are reported: Cladobotryum mycophilum and Streptomyces sp., as well as for the hosts: Amanita pantherina, Boletellus chrysenteroides, Hygrophorus sp., Inocybe calamistrata and Pleurotus ostreatus