1 6 Mycologia, 91 (2), 1999, pp. 263-268. © 1999 by The Mycological Society of America, Lawrence, KS 66044-8897 Fusarium miscanthi sp. nov. from Miscanthus litter W. Gams l Centraalbureau voor Schimmelcultures, Po. Box 273, 3740 AG Baarn, Netherlands M. Klamer Dept. of Mycology, University of Copenhagen, Oester Fanmagsgade 2D, DK-1353 Copenhagen K, Denmark K. O'Donnell Microbial Properties Research, National Center for Agricultural Utilization Research, Agricultural Research Service, United States Department of Agriculture, Peoria, Illinois 61604 Abstract: Fusarium miscanthi sp. nov. was isolated from straw of Japanese silver grass, Miscanthus sinen- sis, buried in a Danish soil. It is characterized by long chains of microconidia which can be either pyriform or fusiform and are produced on polyphialides. Peri- thecia were not obtained in mating experiments. A strongly supported F miscanthi-F nisikadoi clade forms a putative sister group to the Fusarium oxys- porum complex. These two clades form a strongly supported sister group to the Gibberella fujikuroi com- plex. Presumably F miscanthi has been introduced into Denmark from Asia together with the grass. Key Words: Gibberella, litter bag, morphology, new species, phylogeny, rD A I lTRODCCTIO Miscanthus sinensis Andersson (eulalia or Japanese silver grass), a grass native to Japan, was introduced to Denmark as an ornamental in 1935 (Linde-Laur- sen 1993). In recent years, species of Miscanthus have been used in composting experiments directed at de- veloping a new growing medium for horticulture. In this connection, a decomposition experiment was ini- tiated using litter bags in order to study the natural decomposition of Miscanthus in a Danish agricultural soil. A species of Fusarium was isolated from straw pieces after being buried in the soil from May to Dec 1996. This species could not be identified with the atlases and keys by Gerlach and irenberg (1982) and irenberg and O'Donnell (1998). Subsequently, Accepted for publication September 28, 1998. 1 E-mail: Gams@CBS.KNAW. TL 263 the species was found again in Apr 1997 when fungi were isolated from stubble and fresh straw material of M. sinensis grown at an experimental field in Ar- slev, Funen, Denmark. MATERIAL A.'\iD METHODS Taxonomic methods.-Isolates were grown on potato-dex- trose agar (PDA, Difco) in darkness for assessing the car- dinal temperatures for growth, and at 24 C for description of colony habit. For microscopic examination strains were grown on synthetic low-nutrient agar (S A; irenberg 1976, 1990) mostly without the addition of pieces of filter paper at 24 C in darkness (D) and in natural day-night rhythm (DL) at approx. 21 C. Carnation leaf (CLA), potato- carrot (PCA) and oatmeal (OA) (Anonymous 1996) agars were also used for comparison. Color descriptions are stan- dardized according to Kornerup and Wanscher (1978). Camera-Iucida drawings were made in water mounts from S A (DL) cultures; photographs of conidial arrangement in situ were made in the same cultures. The dimensions of 30 conidia were measured in water mounts and ranges of commonly observed dimensions and extreme values (be- tween parentheses) are given. Mating experiments.-A mating experiment was performed using a modification of the procedure described by Klittich and Leslie (1988): All strains were inoculated on carrot agar (CA) plates and S A slants at the same time. Mter 7 d, conidia from the S A slant were suspended in about 3 mL of a 2.5% Tween 80 solution, and 1 mL of this suspension was spread over the surface of the CA plates. All strains were crossed pairwise in all possible combinations, using all strains as both 'male' or 'female'. One set of plates was incubated in darkness at 20 C, the other under near-UV light also at 20 C. Molecular and phylogenetic methods.-To obtain genomic D A, mycelium was grown in yeast-malt broth, lyophilized, and extracted using a CTAB (hexadecyltrimethyl-ammoni- urn bromide; Sigma Chemical Co., St. Louis) procedure de- scribed in O'Donnell and Cigelnik (1997). Primers and re- agents described in White et al (1990) and O'Donnell et al (1998) were used in the polymerase chain reaction (PCR) amplification and sequencing portions of the nuclear large subunit 28S rD A, mitochondrial small subunit (mtSSU) rDl A, and the f3-tubulin gene. Applied Biosystems 373 and 377 DNA sequencers were used to analyze the sequencing reaction mixtures. See TABLE I for GenBank accession num- bers of the sequences generated for Fusarium miscanthi and for other species included in the analysis. Alignments and the single most-parsimonious tree have been deposited in