Gene sequence analysis of an opportunistic wheat pathogen, an isolate ofFusarium proliferatum

A fungal endophyte of wheat causing seedling necrosis when plants are grown under stressed conditions was identified as a Fusarium proliferatum (Matsushima) Nirenberg isolate (NRRL 31017). The wheat isolate grew rapidly on potato dextrose agar as lanose to cottony colonies and rarely produced macroconidia under ultraviolet light. Microconidia were produced both in false heads and chains; sporodochia and chlamydospores were not found. Phylogenetic analysis of the nucleotide sequences of the genes for β-tubulin, mitochondrial small subunit ribosomal DNA, calmodulin, and elongation factor 1-α from the wheat isolate showed affinity with other F. proliferatum isolates. The closest relationship was with an isolate with ligninolytic potential obtained from forest litter in Spain (F. proliferatum MUCL 31970). Nucleotide sequences of genes encoding laccases, which are quite divergent between fungal species, showed 99% identity between the wheat and the forest litter isolates.