Saving Cavendish: Team grows world-first Panama disease-resistant bananas

QUT researchers have developed and grown modified Cavendish bananas resistant to the devastating soil-borne fungus Fusarium wilt tropical race 4 (TR4), also known as Panama disease. 

In a world-first GM field trial conducted in heavily TR4-infested soil, one Cavendish line transformed with a gene taken from a wild banana remained completely TR4 free, while three others showed robust resistance.

Cavendish Grand Nain were modified with the RGA2 gene, taken from the TR4-resistant wild, south-east Asian banana subspecies, Musa acuminata ssp malaccensis.

One modified Cavendish line (RGA2-3) remained TR4-free for the three years of the trial. Three other lines modified with RGA2 showed strong resistance, with 20% or fewer plants exhibiting disease symptoms in three years

By contrast, 67%-100% of control banana plants after three years were either dead or TR4-infected, including a Giant Cavendish variant 218 generated through tissue culturing in Taiwan and reported to be tolerant to TR4.

The field trial, which ran from 2012 to 2015, was led by Distinguished Professor James Dale, from QUT's Centre for Tropical Crops and Biocommodities. It was conducted on a commercial banana plantation outside Humpty Doo in the Northern Territory previously affected by TR4. The soil was also heavily reinfested with disease for the trial.

Professor Dale said the outcome was a major step towards protecting the US$12 billion Cavendish global export business, which is under serious threat from virulent TR4. "These results are very exciting because it means we have a solution that can be used for controlling this disease," he said.