407 Czech J. Food Sci. Vol. 31, 2013, No. 4: 407–412 Mycotoxin Production, Chemotypes and Diversity of Czech Fusarium graminearum Isolates on Wheat Taťána SUMíKOVá 1 , Ludmila GABRIELOVá 2 , Ladislav KUčERA 3 , Martin ŽABKA 2 and Jana CHRPOVá 1 1 Department of Genetics and Plant Breeding Methods, 2 Department of Mycology and 3 Department of Molecular Biology, Crop Research Institute, Prague, Czech Republic Abstract Sumíková T., Gabrielová L., Kučera L., Žabka M., Chrpová J. (2013): Mycotoxin production, chemo- types and diversity of Czech Fusarium graminearum isolates on wheat. Czech J. Food Sci., 31: 407–412. Fusarium head blight (FHB) is a serious cereal disease in the Czech Republic. The most important pathogen associ- ated with FBH is Fusarium graminearum, which can produce trichothecenes, mainly deoxynivalenol (DON) and its derivates. A set of 103 F. graminearum isolates were isolated from naturally infected wheat ears collected from 20 localities (25 ears from one locality) within the Czech Republic, in the year 2004. The ears were evaluated for DON content by ELISA. Maximum detected value was 30.7 mg/kg. A group of PCR assays targeting the segments of the Tri7, Tri13 and Tri3 genes were used to determine the chemotypes of F. graminearum isolates. All the isolates belonged to DON producing chemotype. Further discrimination revealed that almost all (99.03%) isolates belonged to 15-ADON chemotype, and only one (0.97%) isolate belonged to 3-ADON chemotype. The genetic variability of the isolates was assessed from their AFLP fingerprints. The populations were highly heterogeneous both within and between locations, and no clear evidence for the association between AFLP profile and geographic origin was found out. Keywords: food contaminant; electroanalysis; sample preparation; deoxynivalenol; AFLP; Triticum aestivum L. F. graminearum Schwabe (teleomorph: Giberella zeae (Schwein.) Petch) is one of the major causa- tive pathogens of Fusarium head blight (FHB) in wheat and barley. Our current understanding of the phylogeny of the F. graminearum complex, based on multi-locus sequence data, has identified 15 dis- tinct species (Starkey et al. 2007; O’Donnell et al. 2008; Yli-Mattila et al. 2009, Sarver et al. 2011). These classifications are correlated to some extent with the geographical origin, choice of host, pathogenicity towards a range of cereal species, and mycotoxin chemotype. However, the division of F. graminearum complex into multi- ple species is not generally accepted (Leslie & Bowden 2008). The attempts to characterise the genetic variation existing within the populations of F. graminearum have taken advantage of a variety of genotyping methods, and an overall review of the population genetics of the species has been given by Miedaner et al. (2008). Natural epidemics of FHB are associated with the yield loss and compromised grain quality, the latter reflecting the presence of the trichothecene mycotoxins. F. graminearum strains usually express one of three sets of trichothecenes – nivalenol and its derivates (NIV chemotype), DON and 15-acetyl deoxynivalenol (15-ADON chemotype), and DON and 3-acetyl deoxynivalenol (3-ADON chemotype) (Ward et al. 2002). The biological function of these mycotoxins is not precisely understood, although it has been shown that DON and other trichothecenes are linked to the aggressiveness of F. graminearum and F. culmorum strains to- wards wheat (Maier et al. 2006). However, it is well known that trichothecenes present a serious health hazard for both humans and livestock. The Supported by the Ministry of Agriculture of the Czech Republic, Project No. MZE 0002700604.