Mycotoxin Production by Fusarium proliferatum and Fusarium fujikuroi Causing Stem Rot of Hylocereus polyrhizus in Malaysia

Abstract

Fusarium proliferatum and Fusarium fujikuroi are the causative pathogens of stem rot in red-fleshed dragon fruit (Hylocereus polyrhizus). Both species are toxigenic fungi that produce several mycotoxins, including fumonisin B1 (FB1), moniliformin (MON), and beauvericin (BEA). These mycotoxins exert phytotoxic effects and are involved in pathogenesis in the host plants. In this study, we investigated the ability of F. proliferatum and F. fujikuroi to produce FB1, MON, and BEA. Polymerase chain reaction amplification using FUM1-specific primers detected the gene in all 44 isolates tested, indicating that all isolates produced FB1. Isolates of F. proliferatum and F. fujikuroi produced variable concentrations of FB1, ranging from 11.97–236.80 µg/g. MON and BEA were also produced at 0.48–174.84 µg/g and 0.28–70.02 µg/g, respectively by isolates of F. proliferatum and F. fujikuroi. These results suggest that the three mycotoxins play roles in stem rot disease development and symptom manifestation, as all isolates tested were pathogenic and led to stem rot in H. polyrhizus.