A way to make Cavendish banana plants temporarily resistant to Fusarium fungus could lead to new ways to protect them from Panama disease
Banana plants that produce the world’s most widely eaten variety of fruit have been made temporarily resistant to a devastating fungal disease that is spreading across the globe and destroying plantations. The hope is that the work could lead to ways to make bananas permanently resistant.
“The question is, can we continuously trigger this mechanism?” says Gert Kema at Wageningen University in the Netherlands. “We need to know more about it.”
The main banana exported to Western countries used to be a variety called Gros Michel. But in the 1920s, a strain of Fusarium fungus called tropical race 1 (TR1), which causes Panama disease, began wiping out plantations in banana-producing areas. By the late 1950s, growers had switched to the Cavendish banana, which isn’t as tasty as the Gros Michel but is highly resistant to TR1.
Now, however, another strain of Fusarium called TR4 that can kill many varieties, including the Cavendish, is spreading to more and more countries. In many places, bananas are a staple crop, so this fungus is a threat to food security as well as livelihoods.
Kema and his colleagues wondered if exposure to TR1 would protect Cavendish bananas against TR4. The team uprooted young plants and dunked them in a solution containing assorted types of TR1 fungus. At various time intervals from 30 minutes to 10 days later, they then immersed plants in a solution with spores.