Bananas at risk of extinction due to fungal pandemic

A toxic fungal epidemic is threatening banana fields in Southeast Asia and spreading around the world, prompting scientists to warn of the risk of banana extinction.

Bananas are threatened with extinction by Panama disease. Photo: Telegraph.

According to research published in the journal PLOS Pathogens, scientists at Wageningen University, the Netherlands, discovered a soil-borne fungus called Fusarium oxysporum f.sp. cubense, also known as Panama disease, that has the potential to wipe out the $11 billion global banana industry.

Tracing the genetic makeup of the fungus, the team found that a form of the Panama disease fungus called Tropical Race 4 was killing banana plants, the world's most popular banana variety.

Tropical Race 4 was discovered in Indonesia in the 1960s and then spread to Taiwan, China, and other Southeast Asian countries. In every country hit by the disease, banana exports declined over several decades. After a few years of widespread disease, the decline was inevitable, said study co-author Gert Kema, a banana expert at Wageningen University.

Panama disease attacks the vascular system of banana plants, causing them to wilt rapidly and turn yellow-brown due to lack of water. Part of the problem is that farmers cannot eradicate the fungus, only contain it. But efforts to contain the disease have not been effective.

The fungus has now spread to Pakistan, Lebanon, Jordan, Oman, Mozambique and the northeastern Australian state of Queensland, and could soon spread to Latin America, which produces more than three-fifths of the world's banana exports, Kema said.

In the 1800s, a similar Panama disease swept through the Gros Michel banana population, the most widely consumed banana variety at the time. The Gros Michel was wiped out, but British scientists kept a small population of a similar banana, the banana pepper, to study and prove that it was resistant to the original strain of the fungus.

For more than 50 years, bananas have been a popular item in grocery stores, but research has shown that while they are resistant to the Panama disease that wiped out Gros Michel, they are no match for the Tropical Race 4 strain.

To make matters worse, the world’s banana population lacks genetic diversity because each seed is cloned, meaning it doesn’t evolve. This leaves the plant defenseless against disease. Meanwhile, banana consumption is greater today than it was 40 years ago.

According to the research team, finding a new banana variety is not easy. "The development of new banana varieties requires large investments in research and development, along with the recognition of bananas as a global fruit and major cash crop, providing livelihoods for millions of farmers," the researchers concluded.

According to VNE