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1 year ago
22
Nearly half of the world's bananas are on the brink of extinction as a fungal disease threatens plantations across the globe.
Cavendish crops in Asia, Africa, the Middle East, Australia and Central America have already been infected by the Panama disease, a soil-born fungus.
The disease causes the plants to wilt by targeting their vascular system and reducing the amount of water they take in from the soil.
Experts recently identified early signs of the 'catastrophic' fungus in South America, where most exported Cavendish bananas are grown in our supermarkets.
Cavendish crops in Asia, Africa, the Middle East, Australia and Central America have already been infected by the Panama disease, a soil-born fungus.
Cavendish bananas account for 47 percent of global banana production and exports.
However, this type of banana was grown to replace another that was eradicated by the disease.
Gros Michel, also called Big Mike, was the main type until the 1950s.
The United Fruit Company popularized Gros Michael but introduced Cavendish in 1947 when the banana plantations began to die off.
Cavendish was immune to the strand, allowing it to dominate the market.
However, in 1997, scientists found a new strain called TR4 in Australia that could infect Cavendish, and the fungus traveled throughout the continent by 2015.
Experts recently identified the 'catastrophic' fungus in South America, where most exported Cavendish bananas are grown in our supermarkets
James Dale, a professor and leader of the banana biotechnology program at the Queensland University of Technology, told Insider: 'Since then, it has spread to India and China, the world's largest producers of bananas.
'It has also spread to the Middle East and Africa and very recently was found in South America.'
Panama TR4 is easily spread by people, vehicles, machinery and animals by the movement of infected banana plants, planting material, and contaminated soil and water.
The infection is apparent when leaves begin to turn yellow, which then leads to wilting and browning.
The stem of banana plants will then rot on the inside, which appears as a discoloration when cut open.
The infection is apparent when leaves begin to turn yellow, which then leads to wilting and browning
The stem of banana plants will then rot on the inside, which appears as a discoloration when cut open
Scientists are working on a TR4-resistant Cavendish or a resistant replacement for Cavendish, which is done by developing a genetically modified version.
This is possible using CRISPR-Cas9, a precise technique that allows academics to alter and remove sections of DNA, allowing the total eradication of the disease.
A team of researchers at Queensland University of Technology (QUT) is also developing a genetically modified variety of Cavendish bananas called QCAV-4.
QCAV-4 bananas, developed in partnership with government and industry, have been grown in field trials in the Northern Territory for over six years and have proven highly resistant to Panama Disease TR4.
The fruit is a Cavendish Grand Nain banana that has been bioengineered with a single gene, RGA2, from the wild southeast Asian banana.
'I would say with certainty that there will be a solution before the export market for Cavendish is severely affected,' Dale told Insider.
WHAT IS THE HISTORY OF THE CAVENDISH BANANA?
The Cavendish banana is currently the world's main commercial crop.
It was first grown in large volumes by the Peak District stately home of Chatsworth house.
According to folklore, Chatsworth's first head gardener, Joseph Paxton was inspired to grow a banana by one he saw depicted on Chinese wallpaper in a bedroom at Chatsworth.
For nearly a hundred years the story was thought to be a myth, as nobody could find the painted banana.
Joseph Paxton was successfully growing bananas at Chatsworth by 1835 after obtaining one from Mauritius.
There was great excitement at Chatsworth in November 1835 when the banana plant flowered. By the following May, it was loaded with more than 100 fruit.
Within a few years, he had enough plants to offer them to enthusiasts from all over the country.
The banana variety known as Gros Michel was initially the world leader and had the edge until the Second World War.
But the Dwarf Cavendish had certain characteristics which gave it an advantage.
The one property which enabled the Cavendish variety to take the crown as top banana was its greater resistance to disease.
The Gros Michel was virtually wiped out worldwide by Panama disease, also known as banana wilt, caused by a fungus.
Within a decade, the Dwarf Cavendish and its varieties had become the main commercial crop around the globe.
The Cavendish banana is currently the world's main commercial crop. It was first grown in large volumes by the Peak District stately home of Chatsworth house in the 19th century (right) and is still grown there today (left)
