The banana is among the world's most beloved fruits, yet its cultivation faces a serious threat: a persistent fungal disease. Called Fusarium wilt, it destroys plantations and worries farmers in many regions.
A solution could emerge from a wild banana called Calcutta 4, according to research by a team at the University of Queensland. Their work has isolated a region of the genome that offers natural protection against the STR4 strain of the fungus, thus opening a path to obtaining more resilient bananas.
To achieve this discovery, scientists crossed the wild banana Calcutta 4 with susceptible varieties. The resulting plants were then exposed to the pathogenic fungus. By comparing the DNA of the spared specimens with that of the diseased plants, the team successfully located the responsible gene precisely on chromosome 5. This work, combining genetics and sequencing, required several years.
The presence of this gene on chromosome 5 is a major step. Indeed, it is the first such precise mapping of resistance to Fusarium wilt in a wild banana. Now, breeders can target this genomic region to design commercial varieties capable of combating the disease.
The researchers' next goal is to develop molecular markers to easily track this resistance trait. Thanks to this, farmers will be able to identify healthy plants. This method will accelerate selection, reduce costs, and should lead to naturally resistant bananas.
This project involved five years of work, with each generation of bananas requiring at least twelve months of growth before evaluation. Its funding combines contributions from the banana industry and support from the Australian government.