Fitopatologia - Artigos

URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11741

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    Novel fungi from an ancient niche: cercosporoid and related sexual morphs on ferns
    (Persoonia, 2016-02-01) Guatimosim, E.; Schwartsburd, P.B.; Barreto, R.W.; Crous, P.W.
    The fern flora of the world (Pteridophyta) has direct evolutionary links with the earliest vascular plants that appeared in the late Devonian. Knowing the mycobiota associated to this group of plants is critical for a full understanding of the Fungi. Nevertheless, perhaps because of the minor economic significance of ferns, this niche remains relatively neglected by mycologists. Cercosporoid fungi represent a large assemblage of fungi belonging to the Mycosphaerellaceae and Teratosphaeriaceae (Ascomycota) having cercospora-like asexual morphs. They are well-known pathogens of many important crops, occurring on a wide host range. Here, the results of a taxonomic study of cercosporoid fungi collected on ferns in Brazil are presented. Specimens were obtained from most Brazilian regions and collected over a 7-yr period (2009–2015). Forty-three isolates of cercosporoid and mycosphaerella-like species, collected from 18 host species, representing 201 localities, were studied. This resulted in a total of 21 frond-spotting taxa, which were identified based on morphology, ecology and sequence data of five genomic loci (actin, calmodulin, ITS, LSU and partial translation elongation factor 1-α). One novel genus (Clypeosphaerella) and 15 novel species (Cercospora samambaiae, Clypeosphaerella sticheri, Neoceratosperma alsophilae, N. cyatheae, Paramycosphaerella blechni, Pa. cyatheae, Pa. dicranopteridis-flexuosae, Pa. sticheri, Phaeophleospora pteridivora, Pseudocercospora brackenicola, Ps. paranaensis, Ps. serpocaulonicola, Ps. trichogena, Xenomycosphaerella diplazii and Zasmidium cyatheae) are introduced. Furthermore, 11 new combinations (Clypeosphaerella quasiparkii, Neoceratosperma yunnanensis, Paramycosphaerella aerohyalinosporum, Pa. dicranopteridis, Pa. gleicheniae, Pa. irregularis, Pa. madeirensis, Pa. nabiacense, Pa. parkii, Pa. pseudomarksii and Pa. vietnamensis) are proposed. Finally, nine new host associations are recorded for the following known fungal species: Cercospora coniogrammes, Cercospora sp. Q, Ps. abacopteridicola, Ps. lygodiicola and Ps. thelypteridis.
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    The forgotten Calonectria collection: Pouring old wine into new bags
    (Studies in Mycology, 2016-11-22) Lombard, L.; Wingfield, M.J.; Alfenas, A.C.; Crous, P.W.
    The genus Calonectria with its Cylindrocladium asexual morphs has been subject to several taxonomic revisions in the past. These have resulted in the recognition of 116 species, of which all but two species (C. hederae and C. pyrochroa) are supported by ex-type cultures and supplemented with DNA barcodes. The present study is based on a large collection of unidentified Calonectria isolates that have been collected over a period of 20 years from various substrates worldwide, which has remained unstudied in the basement of the CBS-KNAW Fungal Biodiversity Centre. Employing a polyphasic approach, the identities of these isolates were resolved and shown to represent many new phylogenetic species. Of these, 24 are newly described, while C. uniseptata is reinstated at species level. We now recognise 141 species that include some of the most important plant pathogens globally.