Specific detection of Fusarium langsethiae and related species by DGGE and ARMS-PCR of a beta-tubulin (tub1) gene fragment.

Fusarium langsethiae was recently described as a new toxigenic Fusarium species, which morphologically resembles Fusarium poae, but exhibits a mycotoxin pattern related to Fusarium sporotrichioides. To develop tools for early and specific detection of F. langsethiae and distinguishing it from related species of section Sporotrichiella and Discolor (F. poae, F. sporotrichioides, Fusarium kyushuense, Fusarium robustum, Fusarium sambucinum and Fusarium tumidum) sequence variations in their beta-tubulin-encoding (tub1) gene were employed to design two PCR-based methods, denaturing gradient gel electrophoresis (DGGE) and amplification refractory mutation system (ARMS)-PCR. DGGE reliably separated all these strains, even from mixtures and in the presence of DNA from their natural hosts Zea mais, Triticum aestivum and Avena sativa. In addition, a tetraprimer ARMS-PCR, which employs two primer pairs to amplify, respectively, two different fragments of tub1 in a single PCR reaction resulted in rapid differentiation between F. langsethiae, F. sporotrichioides and F. poae according to the number of amplicons (four, two and one, respectively). These two methods will thus be worthwhile tools in the specific detection of F. langsethiae in infected crops.