110 research outputs found
Systematics of Hypocrea citrina and related taxa
Morphological studies and phylogenetic analyses of DNA sequences from three
genomic regions – the internal transcribed spacer (ITS) regions of the
nuclear ribosomal gene repeat, a partial sequence of RNA polymerase II subunit
(rpb2), and a partial sequence of translation elongation factor
(tef1) – were used to investigate the systematics of
Hypocrea citrina and related species. A neotype specimen is
designated for H. citrina that conforms to Persoon's description of a
yellow effuse fungus occurring on leaf litter. Historical information and
results obtained in this study provide the foundation for selection of a
lectotype specimen from Fries's herbarium for H. lactea. The results
indicate that (1) Hypocrea citrina and H. pulvinata are
distinct species; (2) H. lactea sensu Fries is a synonym of the older
name H. citrina; (3) H. pulvinata, H. protopulvinata, and
H. americana are phylogenetically distinct species that form a
well-supported polyporicolous clade; (4) H. citrina is situated in a
clade closely related to H. pulvinata; and (5) H.
microcitrina and H. pseudostraminea reside in a highly supported
clade phylogenetically distinct from H. citrina. Hypocrea protopulvinata,
H. microcitrina, H. megalocitrina, H. pseudostraminea, and a new species,
H. aurantiistroma, are reported and described from North America.
Variation in rpb2 and tef1 gene sequences suggests
geographical subgroupings between European and North American isolates of
H. pulvinata. The phylogenies inferred from ITS, rpb2, and
tef1 gene sequences are concordant. Hypocrea citrina var.
americana is elevated to species status, Hypocrea
americana
What is Scirrhia?
The ascomycetous genus Scirrhia is presently treated as a member of Dothideomycetidae, though uncertainty remains as to which family it belongs in Capnodiales, Ascomycota. Recent collections on stems of a fern, Pteridium aquilinum (Dennstaedtiaceae) in Brazil, led to the discovery of a new species of Scirrhia, described here as S.
brasiliensis. Based on DNA sequence data of the nuclear ribosomal DNA (LSU), Scirrhia is revealed to represent a member of Dothideomycetes, Capnodiales, Mycosphaerellaceae. Scirrhia is the first confirmed genus in Mycosphaerellaceae to have well developed pseudoparaphyses and a prominent hypostroma in which ascomata are arranged in parallel rows. Given the extremely slow growth rate and difficulty in obtaining cultures of S. brasiliensis on various growth media, it appears that Scirrhia represents a genus of potentially obligate plant pathogens within Mycosphaerellaceae
Pleosporales
One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
One Fungus = One Name: DNA and fungal nomenclature twenty years after PCR
Some fungi with pleomorphic life-cycles still bear two names despite more than 20 years of molecular phylogenetics that have shown how to merge the two systems of classification, the asexual “Deuteromycota” and the sexual “Eumycota”. Mycologists have begun to flout nomenclatorial regulations and use just one name for one fungus. The International Code of Botanical Nomenclature (ICBN) must change to accommodate current practice or become irrelevant. The fundamental difference in the size of fungi and plants had a role in the origin of dual nomenclature and continues to hinder the development of an ICBN that fully accommodates microscopic fungi. A nomenclatorial crisis also looms due to environmental sequencing, which suggests that most fungi will have to be named without a physical specimen. Mycology may need to break from the ICBN and create a MycoCode to account for fungi known only from environmental nucleic acid sequence (i.e. ENAS fungi)
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