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Some Alternaria species are able to produce plant pathogenic as well as toxic metabolites. In both agriculture and the food industry it is important know if toxigenic Alternaria are present to rapidly employ the correct corrective actions. The purpose of this work was to establish a real-time PCR method, which can detect and quantify apple pathogenic and toxigenic Alternaria. An AM-toxin I primer set, which could recognize Alternaria DNA only, was designed by using primers complementary to the AM-toxin I gene. The method could detect small amounts of DNA (4 pg) and still obtain a large dynamic range (4 decades) without interference from apple material. Eight Alternaria isolates were analyzed for the presence of AM-toxin I gene and their production of secondary metabolites. Then analyses showed that all eight isolates contained the AM toxin gene and were able to produce the plant pathogenic tentoxin in addition to AM toxin I. The analyses also showed the production of tenuazonic acid, alternariols, Altenuene, altenusin and/or altertoxin I in pure culture. Analyses of inoculated apples showed that both the AM-toxin gene and alternariol monomethyl ether could be detected. Morphological analyses suggested that the eight Alternaria strains, though they all carried the AM toxin genes, probably belong to different but closely related un-described Alternaria taxa in the A. tenuissima species-group based on morphological and chemical differences.

Rapid identification of filamentous fungi is becoming increasingly important in food mycology both for monitoring the production process and for the identification of food spoilers. This paper describes the development and trial of two specifie PCR primer sets. A 336 bp fragment from species belonging to Penicillium subgenus Penicillium was amplified by the primers ITS 212d and ITS 549. The other primer set, ITS 183 and ITS 401 specifically identified two species. Penicillium roqueforti and P. carneum, both known as spoilers in the bread industry, by amplification of a 300 bp fragment. The future perspectives of PCR based identification of filamentous fungi in food are discussed.