Our cherished banana is in trouble, but scientists are on the case to find its saving grace. A new scientific expedition uncovered wild species with features that might safeguard its future.

Image Credit: Bartosz Luczak via Shutterstock / HDR tune by Universal-Sci

Due to the fact that there exists only a limited range of genetic diversity in bananas, they are in danger of becoming extinct. With a lack of genetic 'reserve,' so to say, threats like pests and diseases like the Panama disease are extremely hazardous. Add to that an increase in abiotic threats common in the modern age (such as climate change-induced droughts), and we have a toxic cocktail jeopardizing the future of the species.

Conservation efforts are on their way as banana germplasm gets stored in several regional and national gene banks. However, banana cultivars are generally seedless, and their long-term preservation is therefore restricted by the vegetative nature of the plant's reproductive system.

So as a result, bananas are mainly conserved in three ways; As plantlets in test tubes, by cryopreservation (plant tissue cooled to an extreme -196 Celcius), and alive, planted in designated fields.

Notwithstanding these conservation efforts, at any rate, there still remains a minimal range of genetic diversity. That is where a recent expedition, made by a group of researchers collaborating with the Papua New Guinean National Agricultural Institute, comes into play.

The banana finds its primeval beginnings in Papua New Guinea, where it was cultivated by indigenous communities many thousands of years ago (approximately 5000 bc). Back then, the banana looked very different from what we are used to seeing in supermarkets today. Contrary to the modern banana, peeling back its skin exposed many large, hard seeds that allowed for easy reproduction in the wild.

Wild banana species commonly contain hard seeds, akin to its ancient ancestors - Image Credit: s.Carpentier

In the present, a wide variety of wild bananas still grow across the many rainforests of New Guinea. Nevertheless, as deforestation and fires damage more and more of the tropical and subtropical forests throughout the South Pacific, we risk losing both the ancestors and the possible future of the banana.

The research team spent many days collecting searching for these wild banana species, which is no easy feat. It turns out that the wild relatives of the banana are called wild for a reason. While they might have desirable features, some species remain uncultivated as they are not edible for humans. Even specialized scientists can't always distinguish wild species in the field. In addition, the plants might not even be in the brief stage where seeds or genetic material are available when they are found.

In the end, the team accumulated 31 bunches of 8 different species while carefully remarking their adjustments to their respective surroundings. The collected samples were delicately transported to the International Musa Germplasm Transit Center (ITC) Belgium, where genebank samples were meticulously stored. Follow up experiments were conducted on the samples in order to better understand the freshly collected material.

According to Sebastian Carpentier, one of the researchers, it is crucial to continue to accumulate more wild banana species and screen them for resistance to pests and diseases as he reckons there is potential to fend these off. Additional points of interest include health benefits (wild bananas have been used in traditional medicine, but this is not well-documented) and the possibility of improving the yield of banana plants.

Many wild banana species remain in the rainforests of Papa New Guinea - Image Credit: Ethan Daniels via Shutterstock - HDR tune by Universal-Sci

One finding following the expedition can already be put to good use as it turns out. In the wake of field observations of a banana species called 'Musa balbisiana,' the scientists have gained insights on water use efficiency, which might help breeders adapt bananas to withstand future droughts. This is a big deal as it turns out that currently, about 65% of banana harvests are lost due to droughts.

If you are interested in a more detailed account of the studies following the Papua New Guinean expedition, be sure to check out the two studies published in the science journals 'plants' and 'crop science' listed below.

Sources and further reading: