Bananas are in an existential crisis

Bananas are the most popular fruit in the world. It’s easy to why, as they are inexpensive, extremely portable, make great additions to breakfast cereal and oatmeal, and even when they are overripe they can still be used in quick breads or popped into the freezer to be used in smoothies. As a testament to their popularity, the EYB Library houses over 7,200 online recipes that include bananas. However, the world’s most popular variety – the Cavendish – is on the brink of extinction due to a fungus that is attacking banana plantations in every growing region around the world. The fungal disease, known as fusarium oxysporum (aka TR4), attacks the roots of the plant and causes it to rot and die.

A similar disease nearly caused the extinction of the Gros Michel banana in the 1950s, which is why the Cavendish became the dominant variety due to its disease resistance. Scientists recently discovered how the latest strain of TR4 has evolved to affect the sturdy Cavendish banana. They have isolated a gene involved in nitric oxide production that appears to be responsible for making the disease more virulent and able to attack the Cavendish plants. Understanding this disease mechanism will open the door to its mitigation and control.

Although this is good news, scientists emphasize that relying so heavily on only one variety of banana worldwide is a problem because it makes the crop susceptible to disease that could wipe it out entirely. “When there’s no diversity in a huge commercial crop, it becomes an easy target for pathogens,” says Li-Jun Ma, professor of biochemistry and molecular biology at UMass Amherst. He suggests purchasing other types of bananas to help spur diversity. Nearly 1,000 varieties of bananas exist, although it is difficult to find anything but the Cavendish in most supermarkets. Food cooperatives and mail order may be the best sources for alternate varieties if you don’t live near a banana-growing region.