Molecular phylogeny and re-assessment of some Scleroderma spp. (Gasteromycetes)

9 pages, 3 figures, 1 table.[EN] The fungal genus Scleroderma is cosmopolitan in temperate and tropical regions and forms ectomycorrhizal associations with a wide range of forest trees. To delimit phylogenetic Scleroderma species and identification, 43 basidiomes were chosen of different geographical origins and their rDNA internal transcribed spacer (ITS) were sequenced. Phylogenetic analyses of these sequences together with additional GenBank sequences identified 11 taxa. A strong phylogenetic pattern was observed related to a character of their basidiospore ornamentation.[ES] Las especies del género Scleroderma son cosmopolitas y forman ectomicorrizas con un amplio rango de hospedantes, tanto de zonas templadas como tropicales. Para delimitar las especies filogenéticas y la identificación de las mismas, se han seleccionado 43 basidiomas, de diferente origen geográfico, y se han secuenciado las regiones de transcripción interna del ADN ribosómico nuclear. Los análisis filogenéticos de estas colecciones, junto con secuencias obtenidas del GenBank, permiten identificar 11 especies, agrupadas en tres clados relacionados con el tipo de ornamentación de la basidióspora.CP is indebted to the Commission on Higher Education of Thailand, Royal Thai government for financial support and to the European Commission Human Potential Programme for supporting part of this study at the Real Jardín Botánico de Madrid (BIODIBERIA).Peer reviewe

Endophytic Xylariaceae from Thai Plants: A Research Review

Endophytic fungi are present in all plant species investigated, and members of the Xylariaceae are especially common in tropical plants. There is major interest in endophytic fungi, because of their excellent track record concerning the production of novel and often bioactive compounds including the anti-cancer drugs taxol and taxane. Studies in Thailand on endophytes over the past 20 years confirm the high presence of the Xylariaceae in many different Thai plants. Species of Xylaria stand out as the most frequent Xylariaceae isolated; although, Daldinia eschscholtzii has also been commonly isolated. DNA technology and chemical profiling have been shown to be invaluable in the identification of xylariaceous isolates which previously could not be identified to species level or even assigned to genera in many cases. Reference is made to those isolates which produce novel compounds or those exhibiting bioactive properties

Community structure and dynamics of ectomycorrhizal fungi in a dipterocarp forest fragment and plantation in Thailand

<p><b><i>Background</i></b>: Ectomycorrhizal (EcM) associations have been reported with trees of the plant family Dipterocarpaceae. We hypothesised that a dipterocarp forest fragment, with more host species, would yield a higher diversity of associated EcM fungal species than that of a <i>Dipterocarpus alatus</i> monoculture plantation.</p> <p><b><i>Aims</i></b>: To examine the above- and below-ground EcM community structure of a dry dipterocarp forest fragment and a <i>D. alatus</i> plantation in Thailand.</p> <p><b><i>Methods</i></b>: Sporocarps were collected and identified, and EcM root tips were collected in the dry and wet seasons and identified by terminal restriction fragment length polymorphism and internal transcribed spacer sequencing.</p> <p><b><i>Results</i></b>: Higher EcM fungal diversity was observed in the dry dipterocarp forest fragment than in the <i>D. alatus</i> plantation, with a larger number of species found in the wet seasons than the dry seasons. Sporocarp species richness was greater than root-tip EcM richness. Different dominant EcM taxa were observed in the above- and below-ground communities.</p> <p><b><i>Conclusions</i></b>: Our results suggest that host tree diversity may explain the greater EcM fungal diversity in the dry dipterocarp forest fragment than the <i>D. alatus</i> monoculture plantation. Seasonal dynamics also influences the composition of the EcM communities, with different dominant taxa and relative abundance in the dry and wet seasons. Further research would be of great help in providing useful information for management of dipterocarp forests as well as restoration of disturbed landscapes.</p

Solubilization and transformation of insoluble zinc compounds by fungi isolated from a zinc mine

Fungi were isolated from zinc-containing rocks and mining soil. They were screened for the ability to solubilize and transform three insoluble zinc compounds: ZnO, Zn3(PO)4, and ZnCO3. Fungi were plated on potato dextrose agar (PDA) medium which was supplemented with 0.5% (w/v) of insoluble zinc compounds. Of the strains tested, four fungal isolates showed the highest efficiency for solubilizing all the insoluble zinc compounds, producing clearing zone diameters > 40 mm. These were identified as a Phomopsis spp., Aspergillus sp.1, Aspergillus sp.2, and Aspergillus niger. Zinc oxide was the most easily solubilized compound and it was found that 87%, 52%, and 61% of the tested fungi (23 isolates) were able to solubilize zinc oxide, zinc phosphate, and zinc carbonate, respectively. Precipitation of zinc-containing crystals was observed in zinc oxide-containing agar medium underneath colonies of Aspergillus sp.1, and these were identified as zinc oxalate. It is suggested that these kinds of fungi have the potential application in bioremediation practices for heavy metal contaminated soils