Despite careful quarantine measures, an invasive pathogen known as Fusarium fungus is threatening Cavendish banana plants worldwide. This puts the popular fruit at risk of extinction, again. While Cavendish bananas are widely exported around the world, a tastier, bigger and more resilient banana known as the Gros Michel once filled supermarket shelves. But in the 1960s an incurable and invasive pathogen virtually wiped out the beloved fruits.

That's when humans turned to the more bland Cavendish bananas, which at the time seemed to resist the fungal infection responsible for what is known as Panama disease. But now, a new and stronger strand of the pathogen is wreaking havoc on Cavendish crops and researchers fear the bananas may face the same fate as their tasty ancestors did years ago.

The new Fusarium fungus is known as Tropical Race 4 (TR4) and is a soil-borne pathogen that enters banana plants through their roots and kills them. When a plot of land is contaminated with the fungus it is no longer possible to cultivate there because new growth will become infected. The spread of TR4 has plagued plantations in countries such as Jordan, Mozambique, China, the Philippines, Pakistan and Australia. Currently, there is no way of combating the disease, so a farmings only hope is that quarantine methods will at least slow the rate of infestation. (Scroll to read more...)

Wageningen University researchers recently analyzed DNA of infected specimens in an attempt to trace how Panama disease has spread so widely around the world. Their analysis revealed that each strain of the fungus is genetically identical, meaning they are clones which makes it increasingly difficult to control its diversification.

What's worse is Cavendish bananas are also monoculture, which means they too also clones of one another and lack genetic diversity. It follows then that since they can't sexually reproduce, they also can't evolve a defense against the devastating pathogen.

"The Cavendish banana is very susceptible to TR4. Therefore, the fungus can spread easily due to the worldwide monoculture of Cavendish bananas," Gert Kema, banana expert at Wageningen University, explained in the university's release. "That's why we have to intensify awareness campaigns to reach small and large-scale growers in order to help them with developing and implementing quarantine measures preventing the fungus from continued spreading."

Their findings were recently published in the journal PLOS Pathogens

Related Articles

Paleo Peaches? First Fossil Peaches Discovered In China

Irish Potato Famine: Devastating Pathogen Originated In South America

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Samantha on Twitter @Sam_Ashley13