Comparison between Polish and United Kingdom populations of Leptosphaeria maculans, cause of stem canker of winter oilseed rape

Thirty-eight isolates of Leptosphaeria maculans (20 from Poland and 18 from the UK) were compared for growth rate on agar media, pigment and sirodesmi n production in liquid media, pathogenicity to oilseed rape plants and PCR banding patterns. Most isolates collected from different geographical locat ions in Poland belonged to the Tox(0) group, whereas all except one of the UK isolates were classified as Tox(+). Great differences in fungal culture morphology were observed between Tox(+) and Tox(0) isolates with wide varia tion within the Tox(0) group. All Tox(+) isolates produced sirodesmin PL in large amounts and several other structurally related phytotoxins in smalle r amounts. HPLC analysis showed great differences in the patterns of second ary metabolite production between the groups and within each of them, parti cularly within Tox(0). Similarly, DNA banding patterns obtained in the PCR reaction using Eric1R/Eric 2, Rep 1RI/Rep 21 and BOX A1R starters were dist inct for both groups with some variation within the Tox(0) group.