Using genetic modification, Australian researchers have created a Cavendish banana that is resistant to the Panama disease. Gert Kema, one of the contributors to the research, speaks of a breakthrough.
The researchers found a gene in a resistant group of bananas and planted this gene – RGA2 – using genetic modification into a Cavendish banana, the world’s foremost banana group. This banana is under threat by the tropical race 4 (TR4) fungal pathogen, also known as the Panama disease.
The monoculture on banana plantations allows TR4 to spread exceptionally quickly. The fungus has destroyed plantations in Indonesia, Malaysia, China, the Philippines, Australia and Mozambique, and it is currently making its way in various countries, including Pakistan, Jordan and Lebanon. Once a plantation has been contaminated with the fungus, it will remain permanently unusable for banana crops. No effective chemical fungicides are available.
Over a period of three years, the Australian researchers tested Cavendish bananas with the RGA2 gene on a former banana plantation in Northern Australia which had been contaminated by the fungal disease. On 14 November, they reported in Nature Communications that the control group lacking the gene became diseased, while the bananas that did sport the gene did not. ‘This is an absolute breakthrough. We are ecstatic about the results’, says Gert Kema, professor of Tropical Phytopathology at WUR. ‘But this is just the beginning.’
The EU currently does not allow import of genetically modified bananas. An important detail, however, is that the RGA2 gene also naturally occurs in Cavendish bananas, albeit in a weaker form. The researchers will now carry out follow-up research with Cavendish bananas to find cultivars with a good harvest and resistance against tropical race 4. However, gene editing is also a viable option. Using this method, they hope for a focused increase of the resistance gene’s activity in the Cavendish.
According to Kema, who carried out part of the analyses in this study, more needs to be taken. Resistances in monocultures are breached sooner or later. ‘The next step is to ensure more variation in the production of bananas.’