21 research outputs found
Systematics of Hypocrea citrina and related taxa
Morphological studies and phylogenetic analyses of DNA sequences from three
genomic regions â 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) â 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
Species diversity of Trichoderma in Poland
In the present study, we reinvestigate the diversity of Trichoderma in Poland utilizing a combination of morphological and molecular/phylogenetic methods. A total of 170 isolates were collected from six different substrata at 49 sites in Poland. These were divided among 14 taxa as follows: 110 of 170 Trichoderma isolates were identified to the species level by the analysis of their ITS1, ITS2 rDNA sequences as: T. harzianum (43 isolates), T. aggressivum (35), T. citrinoviride (11), T. hamatum (9), T. virens (6), T. longibrachiatum (4), T. polysporum (1), and T. tomentosum (1); 60 isolates belonging to the Viride clade were identified based on a fragment of the translation-elongation factor 1-alpha (tef1) gene as: T. atroviride (20 isolates), T. gamsii (2), T. koningii (17), T. viridescens (13), T. viride (7), and T. koningiopsis (1). Identifications were made using the BLAST interface in TrichOKEY and TrichoBLAST (http://www.isth.info). The most diverse substrata were soil (nine species per 22 isolates) and decaying wood (nine species per 75 isolates). The most abundant species (25%) isolated from all substrata was T. harzianum
The Trichoderma koningii aggregate species
The morphological concept of Trichoderma koningii is found to
include several species that differ from each other in details of phenotype
(including conidium morphology, growth rate) and biogeography. Phylogenetic
analysis utilizing partial sequences of the translation-elongation factor 1
alpha (tef1), as well as fragments of actin and calmodulin genes,
indicate that phenotypic characters typical of T. koningii evolved
independently in three well-separated main lineages. Combined molecular and
phenotype data lead to the development of a taxonomy with the recognition of
twelve taxonomic species and one variety within the three lineages. These
lineages include: (1) T. koningii and T. ovalisporum and the
new species T. caribbaeum var. caribbaeum, T. caribbaeum
var. aequatoriale, T. dorotheae, T. dingleyae, T. intricatum, T.
koningiopsis, T. petersenii and T. taiwanense; (2) the new
species T. rogersonii and T. austrokoningii, and (3) the new
anamorph T. stilbohypoxyli