Yes! We have no bananas... (with disease), say scientists

THE 1943 Louis Prima hit Yes! We Have

No Bananas became the unofficial theme tune for rationing during the Second World War, when the Ministry of Food banned the import of the fruit to save ships. But now scientists have found a way to make sure bananas remain on grocery shelves.

Cambridge University has discovered how to graft species of banana together to transfer beneficial characteristics, such as disease resistance – a task which was believed impossible before now.

Dr Greg Reeves, of the University of Cambridge Department of Plant Sciences, and first author of the paper, said: “It’s an urgent challenge to make important food crops resistant to the diseases that are destroying them.”

The breakthrough comes at a crucial time when banana plantations are under threat from soil-borne pathogens including panama disease, which has been destroying crops for more than 30 years.

The world’s banana industry is based on a single variety, called the Cavendish – a clone that can withstand longdistance transportation, but has no genetic diversity, making it vulnerable to disease. Cavendish bananas are also sterile, so disease resistance cannot be bred into future generations.

Until now it was thought impossible to graft grass-like plants in the group known as monocotyledons because they lack a specific tissue type, called the vascular cambium, in their stem.

But scientists have found that when tissue is still embryonic in seeds, it can fuse sufficiently with a different species, allowing for grafting. It means

‘It is an urgent challenge to make important food crops resistant to diseases that are destroying them’

that species can be combined without the need for genetic modification.

There are an estimated 60,000 monocotyledons, including food staples like rice, wheat and barley. Being able to add helpful traits could bring huge benefits to the food industry.

The team has also shown it works in pineapple, onion, tequila agave and date palm by injecting fluorescent dye into the plant roots – from where it was seen to move up the plant and across the graft junction. The research was published in the journal