02 February 2021

Wired: “The banana is dying. The race is on to reinvent it before it’s too late”

Despite its ubiquity, the Cavendish is something of a genetic outlier among crops: because it has three copies of each chromosome, it is sterile and can only reproduce by creating clones of itself. This makes the Cavendish an ideal crop to grow at scale – farmers know how a plantation of Cavendish bananas will respond to pesticides, how fast its fruit will ripen, how many bananas each plant will yield. You know what’s going to happen to a Cavendish banana when you pick it, says Bebber. When you put it in a refrigerated container, you know exactly what’s going to come out of the other end most of the time. Cavendish plants are short, so they don’t blow over easily in a hurricane, are easy to spray with pesticides, and reliably produce lots of bananas.

So far, Latin America, which grows almost all of the world’s export bananas – including those for the US and Europe – has escaped TR4. But, Ploetz says, it’s only a matter of time. Our concern in Central America is that if somebody has an outbreak on their property, they are going to keep their mouths shut, and then it’ll have spread widely by the time people realise it’s there, he says.

Faced with a crisis that could see the Cavendish gone forever, a handful of researchers are racing to use gene-editing to create a better banana and bring the world’s first TR4-resistant Cavendish to the market. To get there, they will butt up against not only the limitations of technology, but resistance from lawmakers, environmentalists and consumers wary of GM crops. But as TR4 closes in on Latin America, gene-editing may be the last chance we have to save the one banana we have chosen above all others.

Matt Reynolds

For people who like bananas, an interesting insight into their biology and cultivation – coupled with an impending threat of extinction, from a pathogen, naturally. I am generally wary of attempts to solve issues with our food supplies through gene editing, but the banana could be an exception. Because it only reproduces through cloning, a single precise genetic modification to make this variety resistant to TR4 could rapidly replace vulnerable crops. At the same time, there is no danger of the spliced genes spreading to wild banana populations, because the plants themselves are sterile.

Gilad Gershon, CEO of Tropic Biosciences, with a Cavendish plant
Gilad Gershon, CEO of Tropic Biosciences, with a Cavendish plant. His initial goal is to use CRISPR to create slower ripening fruit – and then take on the challenge of a TR4-resistant banana. Dan Burn-Forti

Still, I would prefer to see scientists and companies try other approaches before deciding on gene editing. Surely among those over 1000 varieties there are others beside the Cavendish that could be grown at scale and prove a suitable replacement on the market. Diversifying the supply would shield producers to some extent from future disruptive events affecting their crops, like climate change and new diseases. After all, making one variety resistant to a particular fungus does not prevent other pathogens from attacking banana plantations. Gene enhancing would have to be repeated every time a new disease emerges, whereas cultivating diverse banana crops would allow producers to shift production to other variants as they search for solutions.

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