XVI International Botanical Congess

Auxotrophic and drug resistant mutants were used to examine horizontal genetic transfer in the asexual fungus Fo cubense, the causal agent of vascular wilt of banana.Horizontal transfer is a mechanism by which asexual fungi can generate genetic variability. As non-pathogenic fungal strains are used for biocontrol, a concern is the transfer of drug resistance or pathogenicity genes.A time course of het formation was done to assess horizontal transfer and determine a time of transmission.Equal number of spores of two biauxotrophic strains, one marked with fungicide resistance, were co-inoculated. Pairings were done in triplicate. Spores were screened daily to determine transfer of fungicide resistance. Horizontal transfer of drug resistance occurs within 48 hours and at a rate of 1 in 100,000 spores.