| 1. |
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| 2. |
- Articus, Kristina, et al.
(författare)
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Ribosomal DNA and beta-tubulin data do not support the separation of the lichens Usnea florida and U-subfloridana as distinct species
- 2002
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Ingår i: Mycological Research. - 0953-7562 .- 1469-8102. ; 106, s. 412-418
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Tidskriftsartikel (refereegranskat)abstract
- The lichens Usnea florida and U. subfloridana have since long been recognised as distinct species. They show many similarities in morphology, but have different reproductive strategies. Usnea florida is always provided with many apothecia and produces no specialised asexual propagules. Usnea subfloridana has soralia, isidiomorphs and occasionally apothecia. Phylogenetic analyses based on continuous sequences of the ITS and LSU regions of the nuclear ribosomal DNA and the gene coding for beta-tubulin, show that specimens of the two species form one monophyletic group of intermixed specimens, and not two groups corresponding to morphology, which Would have been expected if two species were at hand. The 'species pair' concept in lichenology is discussed. Other Usnea species included in the study are: U. articulata, U. barbata, U. ceratina, U. filipendula. U. hirta, U. rigida and U. wasmuthii.
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| 3. |
- Attitalla, Idress Hamad, et al.
(författare)
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A rapid molecular method for differentiating two special forms (lycopersici and radicis-lycopersici) of Fusarium oxysporum
- 2004
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Ingår i: Mycological Research. - 0953-7562 .- 1469-8102. ; 108:7, s. 787-794
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Tidskriftsartikel (refereegranskat)abstract
- Two pathogenic special forms (f. sp.) of the Fusarium oxysporum species complex f. sp. lycopersici (Fol) and f. sp. radicis-lycopersici (Forl) are morphologically indistinguishable. Although they are pathogenic to the same host genus Lycopersicon (tomato), and infect the same tomato cultivar, they form distinct diseases; Fol causes wilt and Forl causes crown rot and root rot. These two special forms apparently exist as genetically isolated populations, based on vegetative compatibility and molecular variation at the DNA level. In seeking efficient diagnostic tools for differentiating Fol and Forl isolates, we examined three techniques: isozyme analysis, mitochondrial DNA (mtDNA) RFLP by HaeIII-digestion of total genomic DNA, and an osmotic method using high performance liquid chromatography (HPLC) to detect fungal pigments. The isolates were collected from geographically widespread locations. Distinct HPLC-profile differences were found between an endophytic non-pathogenic isolate and the other pathogenic isolates. However, the direct mtDNA RFLP technique proved to be an efficient diagnostic tool for routine differentiation of Fol and Forl isolates.
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| 4. |
- Blaudez, D., et al.
(författare)
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Differential responses of ectomycorrhizal fungi to heavy metals in vitro
- 2000
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Ingår i: Mycological Research. - : Elsevier. - 0953-7562 .- 1469-8102. ; 104:11, s. 1366-1371
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Tidskriftsartikel (refereegranskat)abstract
- Thirty-nine ectomycorrhizal isolates of Paxillus involutus, Pisolithus tinctorius, Suillus bovinus, S. luteus and S. variegatus were tested on cadmium, copper, nickel and zinc amended media to determine their in vitro tolerance, measured as inhibition of biomass production. Twenty-one isolates were from heavy metal polluted sites, whereas the others were from non-contaminated soils. There was a strong interspecific variation in metal tolerance. S. luteus, S. variegatus and P. tinctorius were more tolerant of Cu, Cd and Zn when compared with P. involutus, whereas the reverse was true for Ni. A high intraspecific heterogeneity in metal tolerance was also found. EC50 values for isolates originating from polluted sites were not statistically different from EC50 values for isolates originating from non-contaminated sites. The findings are discussed in relation to the potential benefits of ectomycorrhizal fungi in protecting their host plants from metal contamination.
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| 5. |
- Collins, Catherine M., et al.
(författare)
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Molecular cloning and expression analysis of two distinct beta-glucosidase genes, bg1 and aven1, with very different biological roles from the thermophilic, saprophytic fungus Talaromyces emersonii
- 2007
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Ingår i: Mycological Research. - : Elsevier BV. - 0953-7562 .- 1469-8102. ; 111, s. 840-849
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Tidskriftsartikel (refereegranskat)abstract
- Recent sequencing of a number of fungal genomes has revealed the presence of multiple putative beta-glucosidases. Here, we report the cloning of two beta-glucosidase genes (bg1 and aven1), which have very different biological functions and represent two of a number of beta-glucosidases from Talaromyces emersonii. The bg1 gene, encoding a putative intracellular beta-glucosidase, shows significant similarity to other fungal glucosidases from glycosyl hydrolase family 1, known to be involved in cellulose degradation. Solka floc, methyl-xylose, gentiobiose, beech wood xylan, and lactose induced expression of bg1, whereas glucose repressed expression. A second beta-glucosidase gene isolated from T. emersonii, aueni, encodes a putative avenacinase, an enzyme that deglucosylates the anti-fungal saponin, avenacin, rendering it less toxic to the fungus. This gene displays high homology with other fungal saponin-hydrolysing enzymes and beta-glucosidases within GH3. A putative secretory signal peptide of 21 amino acids was identified at the N-terminus of the predicted aven1 protein sequence suggesting that this enzyme is extracellular. Furthermore, T. emersonii cultivated on oat plant biomass was shown to deglucosylate avenacin. The presence of the avenacinase transcript was confirmed by RT-PCR on RNA extracted from mycelia grown in the presence of avenacin. The expression pattern of aven1 on various carbon sources was distinctly different from that of bg1. Only methyl-xylose and gentiobiose induced transcription of aven1. Gentiobiose induces synthesis of a number of cellulase genes by T. emersonii and it may be a possible candidate for the natural cellulase inducer observed in Penicillium purpurogenum. This work represents the first report of an avenacinase gene from a thermophilic, saprophytic fungal source, and suggests that this gene is not exclusive to plant pathogens.
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| 6. |
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| 7. |
- Gadjieva, Rena
(författare)
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Hebeloma species associated with Cistus
- 2009
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Ingår i: Mycological Research. - : Elsevier BV. - 0953-7562 .- 1469-8102. ; 113, s. 153-162
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Tidskriftsartikel (refereegranskat)abstract
- The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously unknown species H. plesiocistum Spec. nov. is described. We also provide a key to the known Hebeloma associates of Cistus. Molecular analyses based on ITS sequence data further illustrate the distinctness of the newly described species and difficulties in the species delimitation with view to H. erumpens. Specific associations with Cistus may have evolved more than once within the genus Hebeloma. (C) 2008 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
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| 8. |
- Hibbett, D. S., et al.
(författare)
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A higher-level phylogenetic classification of the Fungi
- 2007
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Ingår i: Mycological Research. - : Elsevier BV. - 0953-7562 .- 1469-8102. ; 111, s. 509-547
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Tidskriftsartikel (refereegranskat)abstract
- A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community. The classification includes 195 taxa, down to the level of order, of which 16 are described or validated here: Dikarya subkingdom nov.; Chytridiomycota, Neocallimastigomycota phyla nov.; Monoblepharidomycetes, Neocallimastigomycetes class. nov.; Eurotiomycetidae, Lecarioromycetidae, Mycocaliciomycetidae subclass. nov.; Acarosporales, Corticiales, Baeomycetales, Candelariales, Gloeophyllales, Melanosporales, Trechisporales, Umbilicariales ords. nov. The clade containing Ascomycota and Basidiomycota is classified as subkingdom Dikarya, reflecting the putative synapomorphy of dikaryotic hyphae. The most dramatic shifts in the classification relative to previous works concern the groups that have traditionally been included in the Chytridiomycota and Zygomycota. The Chytridiomycota is retained in a restricted sense, with Blastocladiomycota and Neocallimastigomycota representing segregate phyla of flagellated Fungi. Taxa traditionally placed in Zygomycota are distributed among Glomeromycota and several subphyla incertae sedis, including Mucoromycotina, Entomophthoromycotina, Kickxellomycotina, and Zoopagomycotiria. Microsporidia are included in the Fungi, but no further subdivision of the group is proposed. Several genera of 'basal' Fungi of uncertain position are not placed in any higher taxa, including Basidiobolus, Caulochytrium, Olpidium, and Rozella. (c) 2007 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.
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| 9. |
- Ihlen, Per G.
(författare)
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Taxonomy of the non-yellow species of Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) in the Nordic countries, with hyaline and muriform ascospores
- 2004
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Ingår i: Mycological Research. - 0953-7562 .- 1469-8102. ; 108:5, s. 533-570
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Tidskriftsartikel (refereegranskat)abstract
- The taxonomy of the non-yellow species of the genus Rhizocarpon (Rhizocarpaceae, lichenized Ascomycota) occurring in the Nordic countries, with hyaline and muriform ascospores, has been revised. Rhizocarpon amphibium, R. anaperum, R. distinctum, R. furfurosum, R. lavatum, R. petraeum, R. postumum, R. reductum, R. roridulum, R. rubescens, R. subgeminatum, R. sublavatum (reported from the study area for the first time), R. subpostumum, R. suomiense, R. timdalii, and R. umbilicatum are recognized. Their morphology, anatomy, secondary chemistry, ecology, and distribution in the Nordic countries are investigated and discussed. Distribution maps and a key to the species are provided. The most important characters for separating the treated species are pruinose/epruinose thallus, number of ascospores in asci, ascospore size and number of cells per ascospore in optical view, insoluble lichen pigments of the epihymenium and the proper excipulum, and lichen substances. Seven names are lectotypified and two are neotypified.
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| 10. |
- James, Timothy Y, et al.
(författare)
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Trikaryon formation and nuclear selection in pairings between heterokaryons and homokaryons of the root rot pathogen Heterobasidion parviporum
- 2009
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Ingår i: Mycological Research. - : Elsevier BV. - 0953-7562 .- 1469-8102. ; 113:5, s. 583-590
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Tidskriftsartikel (refereegranskat)abstract
- Pairings between heterokaryons and homokaryons of Agaricomycete fungi (he-ho pairings) can lead to either heterokaryotization of the homokaryon or displacement of the homokaryotic nucleus through migration of nuclei from the heterokaryon into the homokaryon. in species of Agaricomycetes with multinucleate cells (> 2 nuclei per cell), he-ho pairings could result in the stable or transient formation of a hypha with three genetically different nuclei (trikaryons). in this study, he-ho pairings were conducted using the multinucleate Agaricomycete Heterobasidion parviporum to determine whether trikaryons can be formed in the laboratory and whether nuclear genotype affects migration and heterokaryon formation. Nuclei were tracked by genotyping the heterokaryotic mycelium using nucleus-specific microsatellite markers. The data indicated that certain nuclear combinations were favored, and that nuclei from some strains had a higher rate of migration. A high percentage of trikaryons (19 %) displaying three microsatellite alleles per locus were identified among subcultures of the he-ho pairings. Using hyphal tip and conidial isolation, we verified that nuclei of three different mating types can inhabit the same mycelium, and one of the trikaryotic strains was judged to be semi-stable over multiple sub-culturing steps, with some hyphal tips that retained three alleles and others that reduced to two alleles per locus. These results demonstrate that nuclear competition and selection are possible outcomes of heterokaryon-homokaryon interactions in H. parviporum and confirm that ratios of component nuclei in heterokaryons are not strictly 1:1. The high rate of trikaryon formation in this study suggests that fungi with multinucleate cells may have the potential for greater genetic diversity and recombination relative to dikaryotic fungi.
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