J Appl Genetics (2012) 53:237–247 DOI 10.1007/s13353-012-0087-z MICROBIAL GENETICS · ORIGINAL PAPER Genetic variation of Fusarium oxysporum isolates forming fumonisin B1 and moniliformin Lidia Irzykowska & Jan Bocianowski & Agnieszka Waśkiewicz & Zbigniew Weber & Zbigniew Karolewski & Piotr Goliński & Marian Kostecki & Witold Irzykowski Received: 2 December 2011 / Revised: 21 January 2012 / Accepted: 27 January 2012 / Published online: 25 February 2012 # The Author(s) 2012. This article is published with open access at Springerlink.com Abstract Thirty single-spore isolates of a toxigenic fungus, Fusarium oxysporum, were isolated from asparagus spears and identified by species-specific polymerase chain reaction (PCR) and translation elongation factor 1-α (TEF) sequence analysis. In the examined sets of F. oxysporum isolates, the DNA sequences of mating type genes (MAT) were identified. The distribution of MAT idiomorph may suggest that MAT1-2 is a predominant mating type in the F. oxysporum population. F. oxysporum is mainly recognised as a producer of monili- formin—the highly toxic secondary metabolite. Moniliformin content was determined by high-performance liquid chroma- tography (HPLC) analysis in the range 0.05–1,007.47 μg g−1 (mean 115.93 μg g−1) but, also, fumonisin B1 was detected, in the concentration range 0.01–0.91 μg g−1 (mean 0.19 μg g−1). L. Irzykowska (*) : Z. Weber : Z. Karolewski Department of Phytopathology, Poznan University of Life Sciences, Dąbrowskiego 159, 60-594 Poznań, Poland e-mail: irzyk@up.poznan.pl J. Bocianowski Department of Mathematical and Statistical Methods, Poznan University of Life Sciences, Wojska Polskiego 28, 60-637 Poznan, Poland A. Waśkiewicz : P. Goliński : M. Kostecki Department of Chemistry, Poznan University of Life Sciences, Wojska Polskiego 75, 60-625 Poznań, Poland W. Irzykowski Institute of Plant Genetics Polish Academy of Science, Strzeszyńska 34, 60-479 Poznań, Poland There was no association between mating types and the mycotoxins biosynthesis level. Additionally, a significant intra-species genetic diversity was revealed and molecular markers associated with toxins biosynthesis were identified. Keywords Fusarium oxysporum . Fumonisin B1 . Moniliformin . Mating type idiomorphs . Genetic fingerprinting . HPLC analysis Introduction Asparagus (Asparagus officinalis L.) is a worldwide well- known vegetable not only due to its high nutritional value, but also because of the biologically active compounds present, including protodioscin and rutin, with a strong cytotoxic ac- tivity against many cancer cell lines (Kinghorn et al. 2003; Chin and Garrison 2008). However, the asparagus is often infected by fungi of the Fusarium genus, a causal agent of crown and root rot which decreases the quantity and quality of the yield. A visible chlorosis and wilting of the individual stalks, progressive discolouration of plants and destruction of roots and crown are the main symptoms of this serious disease (Logrieco et al. 2003). F. oxysporum Schlechtend. emend. Snyder & Hansen and F. proliferatum (Matsus.) Nirenberg are the most severe asparagus pathogens (Blok and Bollen 1995; von Bargen et al. 2009). Both species are well-known mycotoxins producers, so their precise identification is of prime concern. New molecular methods have been applied to complement, support and confirm identification based on morphological characters (Geiser et al. 2004). F. oxysporum is identified worldwide and is known to be phylogenetically diverse and recognised as a moniliformin