First Report of Panama disease in Cavendish bananas caused by Tropical Race 4 in Colombia

we are reporting a feared and new incursion for this devastating pathogen, which now completed another intercontinental leap into Colombia, one of the major banana exporters to the United States and Europe. It has spread across South-East Asia, the Indian subcontinent, the Middle East and Africa and now finally to Latin America. The incursion of TR4 threatens not only the global banana export trade but also the livelihoods of millions of small farmers in this region. We completed Koch’s postulates in the sequence of experiments to diagnose TR4. We collected 22 samples in Colombia, corresponding to three farms, we first used three independent diagnostic methodologies (PCR, qPCR and LAMP) on plant tissue, then isolated multiple single-spore isolates which also underwent these diagnostic PCRs. three of these were used for inoculation trials along with controls. All inoculated plants developed symptoms and samples from these plants were again positive in the diagnostic PCRs. Simultaneously, we sequenced same three of the strains that were used for the inoculations and compared these with the database that we have developed over the years and which contains over 1,000 Fusarium strains causing Panama disease in a wide collection of banana germplasm, including many TR4 strains from all aforementioned locations as well as over 100 TR4 strains from the center of origin in Indonesia. All data unequivocally confirmed that the strains causing Panama disease in Cavendish banana in Colombia belong to F. odoratissimum previously known as Fusarium oxysporum f.sp. cubense Tropical Race 4 TR4