ResearchPad - fungiculture https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Mycelial biomass estimation and metabolic quotient of <i>Lentinula edodes</i> using species-specific qPCR]]> https://www.researchpad.co/article/elastic_article_15715 Lentinula edodes, commonly known as shiitake, is an edible mushroom that is cultivated and consumed around the globe, especially in Asia. Monitoring mycelial growth inside a woody substrate is difficult, but it is essential for effective management of mushroom cultivation. Mycelial biomass also affects the rate of wood decomposition under natural conditions and must be known to determine the metabolic quotient, an important ecophysiological parameter of fungal growth. Therefore, developing a method to measure it inside a substrate would be very useful. In this study, as the first step in understanding species-specific rates of fungal decomposition of wood, we developed species-specific primers and qPCR procedures for L. edodes. We tested primer specificity using strains of L. edodes from Japan and Southeast Asia, as well as related species of fungi and plant species for cultivation of L. edodes, and generated a calibration curve for quantification of mycelial biomass in wood dust inoculated with L. edodes. The qPCR procedure we developed can specifically detect L. edodes and allowed us to quantify the increase in L. edodes biomass in wood dust substrate and calculate the metabolic quotient based on the mycelial biomass and respiration rate. Development of a species-specific method for biomass quantification will be useful for both estimation of mycelial biomass and determining the kinetics of fungal growth in decomposition processes.

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<![CDATA[Identification of Degenerate Nuclei and Development of a SCAR Marker for Flammulina velutipes]]> https://www.researchpad.co/article/5989d9ecab0ee8fa60b6cdb2

Flammulina velutipes is one of the major edible mushrooms in the world. Recently, abnormalities that have a negative impact on crop production have been reported in this mushroom. These symptoms include slow vegetative growth, a compact mycelial mat, and few or even no fruiting bodies. The morphologies and fruiting capabilities of monokaryons of wild-type and degenerate strains that arose through arthrospore formation were investigated through test crossing. Only one monokaryotic group of the degenerate strains and its hybrid strains showed abnormal phenotypes. Because the monokaryotic arthrospore has the same nucleus as the parent strain, these results indicated that only one aberrant nucleus of the two nuclei in the degenerate strain was responsible for the degeneracy. A sequence-characterized amplified region marker that is linked to the degenerate monokaryon was identified based on a polymorphic sequence that was generated using random primers. Comparative analyses revealed the presence of a degenerate-specific genomic region in a telomere, which arose via the transfer of a genomic fragment harboring a putative helicase gene. Our findings have narrowed down the potential molecular targets responsible for this phenotype for future studies and have provided a marker for the detection of degenerate strains.

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<![CDATA[Rediscovery of the enigmatic fungus-farming ant "Mycetosoritis" asper Mayr (Hymenoptera: Formicidae): Implications for taxonomy, phylogeny, and the evolution of agriculture in ants]]> https://www.researchpad.co/article/5989db5aab0ee8fa60bdf6b2

We report the rediscovery of the exceedingly rarely collected and enigmatic fungus-farming ant species Mycetosoritis asper. Since the description of the type specimen in 1887, only four additional specimens are known to have been added to the world's insect collections. Its biology is entirely unknown and its phylogenetic position within the fungus-farming ants has remained puzzling due to its aberrant morphology. In 2014 we excavated and collected twenty-one colonies of M. asper in the Floresta Nacional de Chapecó in Santa Catarina, Brazil. We describe here for the first time the male and larva of the species and complement the previous descriptions of both the queen and the worker. We describe, also for the first time, M. asper biology, nest architecture, and colony demographics, and identify its fungal cultivar. Molecular phylogenetic analyses indicate that both M. asper and M. clorindae are members of the genus Cyphomyrmex, which we show to be paraphyletic as currently defined. More precisely, M. asper is a member of the Cyphomyrmex strigatus group, which we also show to be paraphyletic with respect to the genus Mycetophylax. Based on these results, and in the interest of taxonomic stability, we transfer the species M. asper, M. clorindae, and all members of the C. strigatus group to the genus Mycetophylax, the oldest available name for this clade. Based on ITS sequence data, Mycetophylax asper practices lower agriculture, cultivating a fungal species that belongs to lower-attine fungal Clade 2, subclade F.

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<![CDATA[Networks Depicting the Fine-Scale Co-Occurrences of Fungi in Soil Horizons]]> https://www.researchpad.co/article/5989db16ab0ee8fa60bcd33d

Fungi in soil play pivotal roles in nutrient cycling, pest controls, and plant community succession in terrestrial ecosystems. Despite the ecosystem functions provided by soil fungi, our knowledge of the assembly processes of belowground fungi has been limited. In particular, we still have limited knowledge of how diverse functional groups of fungi interact with each other in facilitative and competitive ways in soil. Based on the high-throughput sequencing data of fungi in a cool-temperate forest in northern Japan, we analyzed how taxonomically and functionally diverse fungi showed correlated fine-scale distributions in soil. By uncovering pairs of fungi that frequently co-occurred in the same soil samples, networks depicting fine-scale co-occurrences of fungi were inferred at the O (organic matter) and A (surface soil) horizons. The results then led to the working hypothesis that mycorrhizal, endophytic, saprotrophic, and pathogenic fungi could form compartmentalized (modular) networks of facilitative, antagonistic, and/or competitive interactions in belowground ecosystems. Overall, this study provides a research basis for further understanding how interspecific interactions, along with sharing of niches among fungi, drive the dynamics of poorly explored biospheres in soil.

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<![CDATA[Fusarium: Molecular Diversity and Intrinsic Drug Resistance]]> https://www.researchpad.co/article/5989db2dab0ee8fa60bd1b3f ]]> <![CDATA[Fungal Volatiles Can Act as Carbon Sources and Semiochemicals to Mediate Interspecific Interactions Among Bark Beetle-Associated Fungal Symbionts]]> https://www.researchpad.co/article/5989da21ab0ee8fa60b7f056

Mountain pine beetle (Dendroctonus ponderosae) has killed millions of hectares of pine forests in western North America. Beetle success is dependent upon a community of symbiotic fungi comprised of Grosmannia clavigera, Ophiostoma montium, and Leptographium longiclavatum. Factors regulating the dynamics of this community during pine infection are largely unknown. However, fungal volatile organic compounds (FVOCs) help shape fungal interactions in model and agricultural systems and thus may be important drivers of interactions among bark beetle-associated fungi. We investigated whether FVOCs can mediate interspecific interactions among mountain pine beetle’s fungal symbionts by affecting fungal growth and reproduction. Headspace volatiles were collected and identified to determine species-specific volatile profiles. Interspecific effects of volatiles on fungal growth and conidia production were assessed by pairing physically-separated fungal cultures grown either on a carbon-poor or -rich substrate, inside a shared-headspace environment. Fungal VOC profiles differed by species and influenced the growth and/or conidia production of the other species. Further, our results showed that FVOCs can be used as carbon sources for fungi developing on carbon-poor substrates. This is the first report demonstrating that FVOCs can drive interactions among bark beetle fungal symbionts, and thus are important factors in beetle attack success.

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