Bananas are facing potential extinction, researchers have cautioned, as a deadly tropical disease sweeps across crops worldwide. Known as Panama disease, or Fusarium oxysporum f.sp. cubense, the fungal infection has already spread throughout Asia, Africa, the Middle East, Australia and Central America.
Should the infection reach South America, researchers warn the Cavendish banana – the species most commonly sold and consumed worldwide – could face extinction.
Chemical treatment has proved ineffective at halting the spread of the disease, with experts only able to stop the fungus by quarantining vast swathes of farmland.
Cavendish bananas are genetically identical to one another, which allows Panama disease to rapidly decimate entire harvest yields.
Some five billion Cavendish bananas are eaten each year in the UK alone.
Salvation for banana crops could come in the form of a rare Madagascan tree, which grows an unpalatable, wild species of banana that is immune to Panama disease.
Plant biologists are rushing to create a hybrid of the two species of banana in the hope of creating a infection-resistant strain.
Quarantine has showed some effectiveness as a way of limiting the spread of the fungus, but it is not a perfect method.
Whilst a portion of land may be sacrificed to protect an even larger area becoming riddled with the destructive fungus, spores remain dormant in the soil for decades, ready to flare up when the right conditions arise later on.
There are only five of the more hardy Madagascan banana trees in existence.
Richard Allen, senior conservation assessor at the Royal Botanic Gardens at Kew, told the BBC that the rare disease-resistant species found in Madagascar (Ensete perrieri) has certain traits which make it more durable than the Cavendish banana.
The climate on the island is believed to have played a role in creating a banana that has evolved to have an innate tolerance to drought and disease.
‘It doesn’t have Panama disease in it, so perhaps it has genetic traits against the disease,’ Mr Allen said.
‘We don’t know until we actually do research on the banana itself, but we can’t do the research until it’s saved.’
Panama disease is resilient to fungicidal treatments, with infected fields often becoming ruined once a single plant gets infected.
On an expedition to the island off the coast of Africa, scientists from the Royal Botanic Gardens found only a handful of the more resistant bananas in existence.
Unlike the Cavendish banana, which is what is grown commercially and eaten worldwide, the Madagascar banana produces seeds and is distasteful.
It is thought that combining the two strains of banana could produce a best-of-both scenario, with the hybrid being both edible and durable.
The Madagascar banana grows on the edge of forests, where it is vulnerable to the climate.
Damage from severe weather, as well as logging, forest fires and deforestation for farmland are all endangering the Madagascan plant.
As a result, it has now been listed on the official Red List of the IUCN (International Union for Conservation of Nature).
Dr Hélène Ralimanana, of the Kew Madagascar Conservation Centre, says the Madagascan plant is part of the island’s rich floral heritage.
‘It is very important to conserve the wild banana because it has large seeds which can offer an opportunity to find a gene to improve the cultivated banana,’ she said.
Dr Gert Kema, expert in global plant production at the Wageningen University in the Netherlands, told MailOnline: ‘Cavendish is now collapsing and there is nothing to replace it.On top of that many local cultivars – or varieties – are equally susceptible.’
Halting exports bananas from affected countries could be one way to help curb the spread of disease.
Cavendish bananas are named for the family of the house they were first grown in – Chatsworth House in Derbyshire.
Steve Porter, Head Gardener at Chatsworth, told MailOnline: ‘We are hopeful that the work being done by scientists around the world to find a cure for the disease threatening the Cavendish banana will be successful.
‘We’re proud of the banana’s heritage at Chatsworth and still grow them in our greenhouses so any development that can safeguard the future of the Cavendish banana for future generations is very welcome.’
In the 1950s, Panama disease devastated a type of banana known as the ‘Gros Michel’ (often known as Big Mike).
The Daily Mail
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