Ribosomal DNA analyses challenge the status of Fusarium sections Liseola and Elegans Cees Waalwijk*', R. P. Baayen 1 , J. R. A. De Koning 1 & W. Gams 1 ' >DLO Research Institute for Plant Protection (IPO-DLO), P.O. Box 9060, 6700 GW Wageningen, The Netherlands -Centraalbureau voor Schimmelcultures, P.O. Box 273, 3740 AG Baarn, The Netherlands Waalwijk, C, R. P. Baayen, J. R. A. de Koning & W. Gams (1996). Ribosomal DNA analyses challenge the status of Fusarium sections Liseola and Elegans. - Sydowia48 (1): 90-104. The internal transcribed spacer (ITS) region of the ribosomal DNA (rDNA) of species in Fusarium sections Elegans, Liseola and Dlaminia and species considered to be related to these sections was analyzed by amplification and subsequent digestion with several restriction enzymes. Two distinct RFLPs were encountered among the species studied that differed from one another in size and in restriction pattern with Hhal, Hinfl and Pstl. RFLP pattern I was shared by F. oxysporum, F. anthophilum, F. napiforme, F. polyphialidicum, F. sacchari var. sacchari and var. elongatum, F. subglutinans, F. succisae and F. verticillioides. RFLP pattern II was shared by F. redolens, F. annulatum, F. beomiforme, F. dlaminii, F. fujikuroi, F. nygamai and F. proliferatum. Neither RFLP was encountered in species belonging to sections Fusarium, Sporotrichiella, Gibbosum or Martiella. Sequence analysis for F. oxysporum and F. redolens revealed that diversity was mainly located in the ITS2 region. The separation of the sections Elegans, Liseola and Dlaminia becomes debatable. Keywords: Fusarium, molecular taxonomy, ITS region, ribosomal DNA. The basis for all Fusarium systematics is the monograph of Wollenweber & Reinking (1935), who recognized 65 species grouped together into 16 sections. Their classification has been followed and their system further extended by Gerlach & Nirenberg (1982) and Nirenberg (1989), who recognized more than 90 species. A different interpretation was presented by Snyder & Hansen (1940, 1941, 1945) who reduced the entire genus to nine species, each corresponding to one or more of the sections described by Wollenweber & Reinking. With the work of Nelson & al. (1983), who considered 30 well- documented and 16 questionable species grouped into 13 sections, a certain convergence between the two schools was observed. One of the sections, Arachnites, encompasses species now excluded from the Corresponding author, e-mail: Waalwijk@ipo.dlo.nl 90 Verlag Ferdinand Berger & Söhne Ges.m.b.H., Horn, Austria, download unter www.biologiezentrum.