You have eaten precisely the same kind of banana hundreds, likely thousands, of times before. Sometimes it has been comically large; at others, helpfully palm-sized for convenient snacking. Riper or greener, bashed around in transit or fresh from the market, in sickness or in health—from a genetic perspective, it’s been the same old banana time after time after time. And that’s a problem.
Virtually every supermarket banana in the world is a Cavendish, a strain chosen for its hardiness and easy cultivation. In the 1950s, it replaced the Gros Michel, a comparable banana that was all but wiped out by the soil-dwelling fungus Panama disease. Also known as Fusarium fungus, the blight blackens bananas from the inside out. Once it’s infected a plantation, its fruit is toast. Even decades after bananas have gone, the spores hang around in the soil, with the potential to re-infect crops all over again.
For the past 30 years, the fungus has wreaked havoc on banana plantations in Southeast Asia, the Middle East, and Africa. Now, Colombia’s agriculture and fishing institute has declared a national emergency after the fungus was found in the northeastern province of La Guajira in June. Nearly 170 hectares (420 acres) of plantations have since been quarantined.
It’s never good news when a crop gets sick. But for the Cavendish banana, it’s especially worrying. That’s because the banana is based on a single genetic clone, producing a worldwide monoculture extremely vulnerable to epidemics.
It doesn’t have to be that way, of course. There are more than 1,000 varieties of banana around the world. Though not all are as tasty or as robust as the Cavendish, their genetic diversity lends them something very important: defenses against dis ease. At the same time, a dearth of research and development on a backup banana has left Colombia’s third-largest agricultural export wide open to attack.
The world loves bananas. Huge commercial pressure means you’ll probably always be able to pick up a bunch of those friendly yellow guys at the grocery store. But if the Cavendish does go down, as it threatens to do, agricultural scientists will be working flat out to find a replacement.
An alternative might involve using the genome sequences of the banana and the Fusarium fungus to engineer a Cavendish 2.0, with resistance to the blight. Whether it can cope with other, as yet unknown infections is an open question.