Scientists have pinpointed crucial genetic resistance to fight a funal disease which threatens the global banana supply in a wild subspecies of the fruit.
In a valuable step forward for banana breeding programs, Dr Andrew Chen and Professor Elizabeth Aitken from The University of Queensland have identified the genomic region that controls resistance to Fusarium wilt Sub Tropical Race 4 (STR4).
“Fusarium wilt – also known as Panama disease – is a destructive soil-borne disease which impacts farmed Cavendish bananas worldwide through its virulent Race 4 strains,” Dr Chen said.
“Identifying and deploying natural resistance from wild bananas is a long-term and sustainable solution to this pathogen that wilts and kills the host plant leaving residue in the soil to infect future crops.
“We’ve located the source of STR4 resistance in Calcutta 4 which is a highly fertile wild diploid banana by crossing it with susceptible bananas from a different subspecies of the diploid banana group.
“After exposing the new progeny plants to STR4, we examined and compared the DNA of the ones which succumbed to the pathogen and those that didn’t.
“We mapped STR4 resistance to chromosome 5 in Calcutta 4 .
“This is a very significant finding; it is the first genetic dissection of Race 4 resistance from this wild subspecies.”
The complex and challenging School of Agriculture and Food Sustainability project took 5 years to complete.
Each generation of banana crosses needed to be grown for at least 12 months before it could be challenged, examined and then used for further breeding once it flowered.
The team used a combination of forward genetics (population development and disease screening), genome sequencing and bulked segregant analysis.
Dr Chen said the discovery will help develop Fusarium wilt resistant commercial banana varieties.
“While Calcutta 4 provides crucial genetic resistance, it isn’t suitable as a commercial cultivar because it doesn’t produce fruit which are good to eat,” he said.
“The next step is to develop molecular markers to track the resistance trait efficiently so plant breeders can screen seedlings early and accurately before any disease symptoms appear.
“This will speed up selection, reduce costs and hopefully ultimately lead to a banana that is good to eat, easy to farm and naturally protected from Fusarium wilt through its genetics.”
STR4 affects bananas in subtropical regions around the world. It is a genetic variant of Tropical Race 4 (TR4) which is found in Australia.
This research was supported by Hort Innovation through the banana industry levy funds and contributions from the Australian Government and will directly inform future Hort Innovation investments aimed at translating these genetic discoveries into practical tools for banana breeding and industry adoption.
The research is published in Horticulture Research .
Images available via Dropbox .
Horticulture Research
Experimental study
Not applicable
Identification of a QTL conferring resistance to the Subtropical Race 4 of Fusarium oxysporum f. sp. cubense in Calcutta 4 (Musa acuminata ssp. burmannica)
9-Jan-2026
The authors declare no conflicts of interest.