| Australian Broadcasting Corporation
DARWIN - Scientists are racing to find and save the living ancestors of modern-day, cultivated bananas that grow in the rainforests of Papua New Guinea.
These wild bananas have genes capable of protecting one of the world's most popular fruits from climate change, pests and diseases.
However, deforestation and fires are destroying tropical forests across the South Pacific, and scientists say there is a risk of losing both the ancestors and the possible future of commercial bananas.
Bananas are second only to tomatoes in popularity as a fruit, with the global industry worth more than $US31 billion last year.
The Australian Banana Growers Council says the industry is worth $1.3 billion a year to the national economy.
Belgium-based scientist Sebastien Carpentier led an expedition to Papua New Guinea last year to collect and conserve the genetics of these wild bananas.
"Papua New Guinea contains very unique species that only occur on the island of Papua, and it is one of the main ancestors of the commercial bananas we have now," he said.
Dr Carpentier is the team leader of banana characterisation and evaluation with the Alliance of Bioversity International and the International Centre for Tropical Agriculture (CIAT).
His job is to save these unique bananas before they disappear from the natural world.
"We see that a lot of forests are disappearing," Dr Carpentier said.
"Times start to change when people start doing commercial agriculture or mining and start destroying whole areas of forest, then, of course, the species cannot survive and will disappear."
Dr Carpentier said the most recent expedition uncovered some unusual varieties, such as endangered plants that grow 15 metres tall and bear fruit with hard seeds, instead of the typical soft, yellow flesh of commercial bananas.
Genetic diversity is key to protecting cultivated varieties, such as cavendish and ladyfinger, from the adverse effects of climate change and pests and diseases, according to Dr Carpentier.
For example, the variety Musa balbisiana has superior water use efficiency and was found persevering in open land recovering from fires, so its genetics could help breeders adapt bananas to resist future droughts.
"The reason why we have nice, delicious bananas is because farmers protect them — they would be quite vulnerable if you left them," Dr Carpentier said.
"[Wild bananas] contain unique genes, since they are exposed to the natural threats of the environment and only the fittest survives."
Dr Carpentier said one of the greatest threats to worldwide banana production, the Panama disease, has devastated industries in some countries.
"If forests disappear and you cannot go back to individual plants that contain unique traits, in the long term you might lose the crop, because the bananas we have now are very vulnerable," he said.
The specimens collected from the wild are stored in the world's largest banana gene bank in Leuven, Belgium.