Blood orange

Scientists at the John Innes Centre in Norwich, England, say they have identified the 'ruby' gene that turns Sicilian blood oranges red.

The gene is believed to be the source of health benefits that make blood oranges a potent weapon in the fight against obesity and heart disease.

The fruit is currently more expensive for consumers than its 'blond' relatives because it requires a cold period during ripening and as a result is largely grown commercially only on the Italian island of Sicily.

Professor Cathie Martin, the leader of the research team, said: "Our improved understanding of this trait could offer relatively straightforward solutions to growing blood oranges reliably in warmer climates through genetic engineering."

Prof. Martin told a press conference it should take seven years to genetically engineer blood orange varieties that could thrive in other orange-growing areas such as Brazil and Florida.

The study is published in the latest issue of The Plant Cell journal.