The most popular fruit in the world may be in serious danger of extinction.
A virulent and incurable strain of the plant-destroying fungus Fusarium oxysporum f.sp. cubense is spreading across the globe and ravaging banana crops in its wake. A study by researchers in the Netherlands appearing in the online scientific journal PLOS Pathogens concludes that the fungus strain, known as “Tropical Race 4” (TR4), has the very real potential to completely wipe out the Cavendish banana, the modern breed of banana commercially available in supermarkets.
Cavendish bananas were not always the most popular cultivar of bananas. From the late nineteenth to the early twentieth century, that honor belonged to the Gros Michel banana, the only major banana breed consumed in the United States at the time. However, the Gros Michel was almost completely wiped out by – guess what – the infestation of the fungal pathogen known as Panama disease. When the spread of the disease became uncontrollable, banana producers had to undergo the enormously painful and costly process of switching from one cultivar to another – the modern Cavendish banana, which was resistant to the strain that wiped out the Gros Michel.
Panama disease spreads through a soil-and-water-borne fungus that infects the plant’s roots. The death of the host happens due to the untreatable disease the fungus causes, which attacks the vascular system, causing the roots to rot and the plant to turn brown and wilt rapidly, killing the host and contaminating the surrounding area. Once it takes hold, its effects are devastating. The F. oxysporum fungus has been found lying dormant in the soil for up to 30 years. Though the Cavendish bananas were hardy against the TR1 strain that killed the Gros Michel, they are particularly susceptible to the new TR4 strain. Due to the lack of testing and lack of a cure, it is virtually impossible for producers to either treat or prevent the incredibly efficient and deadly disease.
For a long time the eventual spread of Panama disease and its destruction of the Cavendish banana was considered inevitable. But since the 1960s, although periodic outbreaks were still a serious problem, the fungus has largely been contained to East and Southeast Asia. Not anymore.
Gert Kema, scientist at Wageningen University and Research Center and one of the co-authors of the study, was quoted as saying the disease has spread to other regions at an alarming rate, and if it hits Latin America, the fruit is likely to go completely extinct.
Kema says that the fungus has now leapt to Pakistan, Lebanon, Jordan, Oman, and Mozambique, and Australia’s northeast Queensland –and is only a matter of time before it lands in Latin America, where some more than three-fifths of the planet’s exported bananas are grown.
The worst part: there is no way to kill the fungus or even contain the spread of it, and there are currently no acceptable replacements for the Cavendish. There is simply no other conclusion: the banana is slowly but surely moving toward extinction.
CNN reports that the problem is made worse by the fact that bananas have no genetic diversity, as commercial bananas are all clones of each other.
Today, the Cavendish is a universal foodstuff, much like a Big Mac: supermarket bananas are pretty much identical anywhere you buy them.
That’s because they have nearly no genetic diversity — the plants are all clones of one another. The Cavendish is a monoculture, which means it’s the only variety that most commercial growers plant every year. Which is also why it is now under threat itself, from a new strain of the Panama disease. And once it infects one plant, it can infect them all.
The scientists who authored the study warn that developing a solution to the problem will require very serious effort.
“Developing new banana cultivars, however, requires major investments in research and development and the recognition of the banana as a global staple and cash crop (rather than an orphan crop) that supports the livelihoods of millions of small-holder farmers.”
Bananas are the most consumed fruit in the world and are vital to human health, but within a few decades bananas as we know them may soon be a thing of the past.
(Photo by Sandra Mu/Getty Images)