Panama disease: why bananas are at risk of extinction

A team of UK scientists is exploring gene-editing
technology as a potential solution to an unstoppable fungal disease
decimating the world’s banana plantations.

A fungal disease called “fusarium wilt”, or
Panama disease, “has been attacking plantations in Australia,
south-east Asia and parts of Africa and the Middle East”, The
Guardian reports – and there are fears it could spread to the
banana-growing heartlands of Latin America.

Traditional fungicides are unable to prevent the
spread of the virulent strain, and breeding a new variety of the
fruit is not an option because banana crops are cloned rather than
bred.

Start-up Tropic Biosciences, based in Norwich, has used
cutting-edge gene editing techniques to develop a banana cell which
it believes would be resilient to Panama disease.

“Gene editing makes a lot of sense, because the only
way you can change the banana now is through genetics,” CEO Gilad
Gershon told Fast Company.

“If we don’t [take] this type of role and save the banana, I’m
not sure there’s any other way to do it.”

Field trials of the genetically engineered
species are to begin this year in central America, the Philippines
and Turkey.

When Panama disease last struck on this scale, in the 1950s, it
wiped out the world’s dominant banana species, the Gros Michel –
generally regarded as more flavourful than the Cavendish bananas we
eat today.

The 1923 vaudeville novelty song Yes! We
Have No Bananas is thought to have been inspired by the
shortages caused by early outbreaks.

The disease spread beyond Panama, and by the
1950s, Gros Michel plantations had been decimated beyond
redemption. A more resistant strain of banana, the Cavendish,
quickly took over as the pre-eminent species.

Cavendish bananas now account for 99.9% of all bananas
exported around the world. But monoculture – the cultivation of one
variety of crop to the exclusion of all others – is a ticking time
bomb, environmental scientist Jackie Turner warned earlier this
month in digital magazine Aeon.

“When a population lacks genetic diversity, its
members have a heightened risk of succumbing to disease,” she
wrote. “Staking the fate of a fruit on monoculture is dangerous in
the extreme.”