Mycotoxigenicity of Fusarium isolated from banana fruits: Combining phytopathological assays with toxin concentrations

Abstract

Seven species of Fusarium isolated from rotten bananas were studied for their mycotoxigenicity. The first pathogenicity assay revealed symptoms of Fusarium rot infection when the Fusarium isolates were inoculated to wounded banana fruits. The second pathogenicity assay, where seedlings of Nicotiana were inoculated with Fusarium isolate filtrations, revealed evidence for the pathogenicity for six of the Fusarium species. One species, Fusarium oxysporum did not display any pathogenicity symptoms on Nicotiana seedlings. It neither produced the mycotoxins fumonisin, zearalenone and deoxynivalenol, which were produced by all of the other species. However, the mycotoxin concentrations did not correlate with the disease severity in the pathogenicity assay with banana fruits. We conclude that that pathogenicity is a complex issue regulated by many factors and several toxins and the pathogenicity assessment needs bioassays with a multi-mycotoxin approach.