The ITS region as a taxonomic discriminator between Fusarium verticillioides and Fusarium proliferatum I. VISENTIN a , G. TAMIETTI a , D. VALENTINO a , E. PORTIS b , P. KARLOVSKY c , A. MORETTI d , F. CARDINALE e, * a DiVaPRA, Plant Pathology, University of Turin, via L. da Vinci 44, 10095 Grugliasco (TO), Italy b DiVaPRA, Plant Genetics and Breeding, University of Turin, via L. da Vinci 44, 10095 Grugliasco (TO), Italy c Molecular Phytopathology and Mycotoxin Research Unit, University of Go ¨ttingen, Grisebachstrasse 6, D-37077 Go ¨ttingen, Germany d ISPA, National Research Council, Via Amendola, 122/O – 70126 Bari (BA), Italy e Dept. of Arboriculture, University of Turin, via L. da Vinci 44, 10095 Grugliasco (TO), Italy article info Article history: Received 6 April 2009 Received in revised form 15 July 2009 Accepted 16 July 2009 Available online 23 July 2009 Corresponding Editor: Stephen W. Peterson Keywords: Fusarium proliferatum Fusarium verticillioides ITS Maize PCR abstract The maize pathogens Fusarium verticillioides (Fv) and Fusarium proliferatum (Fp) are morpho- logically very similar to one another, so Fp isolates have been often mistaken as Fusarium moniliforme (the former name of Fv). The only presently accepted morphological discrimina- tor between these species is the presence/absence of polyphialides. Here, a collection of 100 Fusarium strains, isolated from infected maize kernels on plants grown in north-western Italy, were assigned as Fv or Fp on the basis of the presence/absence of polyphialides. This classification was tested on a subset of isolates by sexual crosses, ITS and calmodulin sequencing and AFLP profiling. An ITS-RFLP assay was extended to the full collection and to a number of Fv and Fp isolates of different geographical origin and hosts. The ITS region is proposed as taxonomically informative for distinguishing between Fp and Fv. ª 2009 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. Introduction Fusarium verticillioides (Fv) (sexual stage Gibberella moniliformis) and Fusarium proliferatum (Fp) [sexual stage Gibberella interme- dia] are both common as pathogens of maize worldwide, caus- ing [in conjunction with Fusarium subglutinans] ear, stalk and root rot (Bottalico 1998; Leslie et al. 1990; Nelson et al. 1981). They can be particularly aggressive in temperate climates (Munkvold 2003), and maize produced in northern Italy is of- ten heavily contaminated. Infection can be spread by both soil- and seed-borne inoculum, but usually invasion of the growing plant occurs through the silk or the kernels damaged by insects (Munkvold 2003). Ear rot not only reduces grain yield, but also grain quality, since both Fv and Fp produce my- cotoxins within the infected kernel. In particular, significant quantities of the class B fumonisins (FB) are frequently detected in maize grown in northern Italy (Bottalico et al. 1989; Moretti et al. 1995). Over 20 natural analogues of fumoni- sins are known, but it is fumonisin B1 (FB1) which is the com- monest and most dangerous one, and the one which was associated with severe mycotoxicosis in both domesticate an- imals and humans (Rheeder et al. 2002). Kernels can become heavily contaminated long before harvest, so an understand- ing of the epidemiology of ear, stalk and root rot is necessary * Corresponding author. Tel.: þ39 011 670 8875; fax: þ39 011 236 8875. E-mail address: francesca.cardinale@unito.it journal homepage: www.elsevier.com/locate/mycres mycological research 113 (2009) 1137–1145 0953-7562/$ – see front matter ª 2009 The British Mycological Society. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.mycres.2009.07.011