Search results for "Spacer"
showing 10 items of 247 documents
Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of…
2009
This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatellite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species …
A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.
2008
Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …
ITS region of the rDNA of Pythium longandrum, a new species; its taxonomy and its comparison with related species.
2001
Pythium longandrum (F-73.0) was isolated, from soil samples taken in Lille in northern France. Morphologically the fungus resembles closely Pythium rostratum, however its antheridial characters are unique. The oogonia of this species are provided with hypogynous and monoclinous antheridia. The antheridial cells are inflated and are probably the largest and longest for the genus. The internal transcribed spacer region of its nuclear ribosomal DNA indicates that it is entirely different from all other species of Pythium. This new species is characterized by its spherical to elongated sporangia, smooth-walled oogonia and hypogynous to monoclinous antheridia bearing long antheridial cells close…
Pythium campanulatumsp. nov., isolated from the rhizosphere of maize, its taxonomy, ITS region of rDNA, and comparison with related species
2003
Pythium campanulatum sp. nov. was isolated from some soil samples taken in the rhizosphere of maize (Zea mays) in north-eastern India. This species is characterized by the absence of zoospores and sporangia, antheridial branches wrapping around the oogonia leaving one to two campanulate antheridial cells after fertilization, and aplerotic oospores. The ITS region of its rDNA is comprised of 922 bases. This oomycete is closely related to Pythium orthogonon, Pythium nunn and Pythium toruloides. However, it has its own characteristic features and is completely devoid of zoospores. Taxonomic description of this new species and its comparison with related oomycetes, together with the sequence of…
Pythium glomeratum, a new species isolated from agricultural soil taken in north-eastern France, its ITS region and its comparison with related speci…
2003
Pythium glomeratum sp. nov. is described here. It was isolated from soil samples taken in the northern France in 1992, was wrongly identified as Pythium heterothallicum and was kept aside. Recently, the ITS region of the rDNA of this oomycete was amplified and sequenced. The differences between the sequence and a more detailed study of the morphological characters of these two species, revealed that both are related but different species. P. glomeratum is characterized by the presence of branched antheridia that wrap around the oogonia, aplerotic to almost plerotic oospores, and the lack of zoosporangia and zoospores. Taxonomical description of this new species, its comparison with related …
A new species of Pythium isolated from a vineyard in France.
2006
Pythium apiculatum sp. nov. is a new oomycete characterized by the presence of both ornamented and smooth-walled oogonia. The ornamentations are blunt, and at times, bent. The oomycete was isolated from soil samples taken in a vineyard in the Burgundian region of France. Morphologically, it resembles some species having ornamented oogonia like Pythium radiosum, Pythium echinulatum, and resembles, also the species having smooth-walled oogonia like Pythium hypogynum and Pythium acrogynum. However, the oomycete has its own distinguishing characteristics which, when combined with molecular features, enables us to describe it as a new species. The taxonomic description of this new oomycete, its …
A new species of Pythium with inflated sporangia and coiled antheridia, isolated from India
2008
Pythium kashmirense sp. nov. was isolated from soil samples taken on the Himalayas at the height of 5300 feet in the Shivalik Hill Range of the northern Indian state of Jammu and Kashmir. The oomycete has filamentous-inflated type sporangia and its antheridial filaments form loose loops around the female gametangia, and coil around the oogonial stalks. The new species is closely related to Pythium plurisporium, Pythium periilum, Pythium inflatum, and Pythium folliculosum. All of these oomycetes have filamentous-inflated type sporangia. However, P. kashmirense has its own distinguishing characteristics which can easily differentiate it among these related species. The sequences of the intern…
Independent host switching events by digenean parasites of cetaceans inferred from ribosomal DNA
2015
Cetaceans harbour a unique fauna of digeneans whose origin and relationships have sparked considerable debate during recent decades. Disparity in the species reported indicates that they do not share close affinities, but their unusual morphology has made their taxonomic identities and phylogenetic positions uncertain. Here we use sequence data to investigate the phylogenetic relationships of the main species of flukes infecting cetaceans. We sequenced the 18S, 28S and internal transcribed spacer 2 rDNA of digenean species representing all known families reported from cetaceans: Braunina cordiformis (Brauninidae), Ogmogaster antarcticus (Notocotylidae), Pholeter gastrophilus (Heterophyidae)…
Parallel evolution of flower reduction in two alpineSoldanellaspecies (Primulaceae)
2014
The European endemic Soldanella has traditionally been divided into two morphologically well-defined sections. Section Tubiflores contains two species growing in high-elevation habitats, whereas most of the 14 species of section Soldanella inhabit montane forests. Section Tubiflores has a reduced floral morphology compared with section Soldanella. A previous phylogenetic study based on internal transcribed spacer (ITS) and AFLP data has revealed that, although the genus Soldanella itself is monophyletic, both sections are paraphyletic. Soldanella alpina (section Soldanella) forms a clade with S. minima and S. pusilla (section Tubiflores), and the grouping of S. alpina with S. pusilla has be…
Phylogeny and quaternary history of the European montane/alpine endemicSoldanella(Primulaceae) based on ITS and AFLP variation
2001
Soldanella contains 16 species of herbaceous perennials that are endemic to the central and south European high mountains. The genus is ecogeographically subdivided into forest/montane and alpine species. Evolutionary relationships and large-scale biogeographic patterns were inferred from parsimony analyses of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA, and genetic distance analyses based on amplified fragment length polymorphism (AFLP) markers. The ITS region proved useful for examining subgeneric relationships and testing hypotheses on genus-wide divergence times, whereas the AFLP markers were suitable for studying relationships among closely related taxa and b…