Humble banana gets its genome decoded

Bananas is a vital source of food widely enjoyed around the world. It's also a staple food in some of the poorest countries, but it faces pests and diseases that threaten to wipe it out across the globe.

To save the fruit from imminent demise and help breeders grow a healthier and better-tasting banana, a team of French researchers carried out the genome sequencing of a variety, which is a simpler relative of the Cavendish.

"The banana is very important, especially for tropical and subtropical countries," Angelique D'Hont, a geneticist at CIRAD, an agricultural research center in Montpelier, France, was quoted as saying by the Discovery News.

"Because the future of the banana is in danger, the sequence will help to produce resistant bananas and avoid the utilisation of pesticides. It will be much easier now to identify genes which are important," D'Hont said.

To decipher banana's genetic strengths and weaknesses, D'Hont and a team of colleagues spent two years sequencing the Musa acuminate variety. Once they put together the sequence, the team discovered several genes that may be involved in pest resistance.

Among other findings, the team identified genes involved in ripening after the application of ethylene, which is often added to green bananas during transport.

The sequence also revealed that the banana duplicated its entire genome three times (making an extra copy of every single gene in its genome) -- including once 100 million years ago and once 60 million years ago.

Even though all bananas are clones of each other, the original gene forms that came from mother and father plants remain different from each other -- unlike in seeded crops that tend to become inbred, said Simon Chan, a plant biologist at the University of California.

What's more, bananas have three copies of each chromosome just like other seedless plants. And for many genes, all three copies are different, the team reported in the journal Nature. (More)