Scientists from the African Agricultural Technology Foundation (AATF) are developing a gene that they hope will lead to new banana varieties resistant to bacterial wilt.

The gene has only previously been used to combat diseases in tomatoes, broccoli, orchids, tobacco and rice. But according to Peter Werehire of the AATF, in the last five years, the disease has spread throughout the eastern and central African countries of Uganda, Eastern Congo, Kenya, Tanzania and Rwanda.

“The National Agricultural Research Organisation and the International Institute of Tropical Agriculture sought to access candidate genes for conferring resistance against the wilt,” said Werehire. “One such gene was the plant ferrodoxin-like protein gene from sweet pepper.”

The highly infectious wilt disease is caused by Xanthomonas campestrispv. Musacearum, and is spread through the use of infected banana-planting materials and cutting tools, and can even be spread by animals. “When the disease strikes, the leaves of the infected plants first turn dull green before they become scalded,” said Werehire. “The plants start wilting, and the bunches show uneven and premature ripening of fruit.”

It has been found to be very destructive, with incidence of 70-80 per cent common in plantations and even yield losses of up to 90 per cent on some farms.

In Uganda, for example, the potential national loss is estimated at $360 million (£181m) annually. Early laboratory tests revealed by the Nairobi-based AATF indicate that the scientists’ transgenic banana plants appear to be resistant to the wilt.

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