Rep-PCR based genomic fingerprinting of isolates of Leptosphaeria maculansfrom Poland

Leptosphaeria maculans, the ascomycete fungus which causes blackleg disease of oilseed rape, has been considered for a long time as a single species d ivided into 'aggressive' and 'non-aggressive' pathogenicity groups which di ffer in their economic importance. However, the development of accurate bio chemical and molecular characterisation methods has demonstrated that the w orld-wide L. maculans population actually comprises at least two species. T he aim of this research was to assess the ability of rep (repetitive elemen t based)-PCR genomic fingerprinting methods, initially developed for bacter ial identification, to characterise a collection of 90 isolates of L. macul ans from Poland, in comparison with reference isolates from the IBCN (Inter national Blackleg of Crucifers Network) collection. REP (repetitive extrage nic palindromic)-, ERIC (enterobacterial repetitive intergenic consensus)-, and BOX primers for rep-PCR genomic fingerprinting, and primers derived fr om LMR1, a L. maculans specific repeated element, were tested. Rep-PCR and LMR1-based analyses were able to discriminate the different components of t he species complex and to evaluate the genetic diversity within each member of the complex. These analyses suggested that Polish populations of L. mac ulans mainly belong to the 'non-aggressive' species, rather than the 'aggre ssive' species which is prevalent in Western Europe, Canada and Australia.