A preliminary report on soil dematiaceous hyphomycetes from the three river gorge regions in eastern Tibet
GENG Yue-Hua ZHANG Tian-Yu* WANG Hong-Feng
Department of Plant Pathology, Shandong Agricultural University, Tai’an 271018, China
菌物学报 15 January 2008, 27(1): 39-47
Abstract: A total of 47 isolates of soil dematiaceous hyphomycetes belonging to 29 species in 15 genera were found from the gorge regions of three rivers (the Jinsha River, the Nu River and the Lantsang River) in eastern Tibet. Most of the genera and species found are new for the regions. Among them Eladia tibetensis is a new species, and Scytalidium acidophilum and S. circinatum are new records to China. Latin description is given for the new species. Brief descriptions and illustrations of the new records are also given based on Chinese isolates. The other 26 species being previously known from China in several genera are also listed. Dried cultures and living cultures studied have been deposited in Herbarium of Shandong Agricultural University: Plant Pathology (HSAUP).
Key words: taxonomy, soil fungi, Eladia tibetensis sp. nov., new records to China
1 INTRODUCTION
Qinghai-Tibet Plateau is commonly called the roof of the world and Tibet is the main body of it. Owing to the influence of the monsoon from Indian Ocean, the climate is relatively warm and moist in eastern Tibet. The rich fungal resources in this region have long held the interest of foreign and Chinese mycologists. The earlier investigators for the regions include M. Wilson in 1919-1921, F. Ludlow, G. Sherriff and G. Taylor in 1938, F. Ludlow, G. Sherriff and H. H. Elliot in 1947 (see Tai 1979), F. Petrak (1947) and others. Since 1956 the Chinese Academy of Sciences has organized many scientific surveys in Tibet. Up to 1983, 161 species in 39 genera of deuteromycete fungi, including 122 species in 23 genera of hyphomycete fungi have been reported from Tibet by Chen (1974), Wang (1980), Chen (1979, 1980), Zheng & Chen (1980), Zang (1979, 1980) and others (Anon. 1983). Among the fungi reported, only 33 species of 13 genera belong to dematiaceous hyphomycetes. In the published volumes of Flora Fungorum Sinicorom more hyphomycete fungi have been reported by Qi (1997), Liu & Guo (1998, 2003, 2005), T. Y. Zhang (2003), Z. Y. Zhang (2003, 2006), and others from Tibet. As a part of an effort to reveal the fungal diversity in respect to the soil dematiaceous hyphomycetes in China, the authors focus their attention on the gorge regions of three rivers (the Jinsha River, the Nu River and the Lantsang River) in eastern Tibet. The topography in this area is complicated. As a consequence of the incision by the three rivers, the peak-valley difference in height is very conspicuous. The vertical zonation is marked and the vegetation complicated. The soil abounds with organic matter and humus. The unique topography, vegetation and climate proved to be favorable to the diversity of fungus species.
2 MATERIALS AND METHODS
2.1 Soil sample collection
Each sample was collected from many points (surface layer 2-10cm) in one ecosystem of one site, after mixing thoroughly, took about 100g of soil and put the soil into a plastic bag as one sample. After bringing them back put the samples into 0-4℃ freezer. Isolations were fulfilled within two months.
2.2 Isolation and single spore culture making
Soil plate method and soil-dilution plate method were adopted. For obtaining the aimed fungi as many as possible, the TWA (tap water agar) + W (wheat straw) + NS (natural substratum: the maceration extract made from the original soil sample) medium was used for isolation. The single spore cultures were made for each fungal isolate.
2.3 Culturing and identification
The single spore isolates were incubated at 20-23℃. Identifications were carried out mainly according to the morphological characters of each pure culture.
2.4 Dried culture making
“Drying down cultures for the herbarium” traditionally used in the International Mycological Institute (IMI), England was followed.
