Breeding tomatoes to have the perfect color ruins their flavor, a genetic study has shown, explaining why many people believe supermarket tomatoes are tasteless.
For about 70 years tomato growers have sought to produce varieties in which all the fruit ripens at once and develops the same even, red coloring so that it will look more appealing to shoppers.
But the breeding process which produced this color has accidentally disabled a key gene used in photosynthesis, causing a reduction in the sugars which give the fruit its sweet taste, scientists have found.
In contrast, tomatoes with active copies of the gene ripen at different rates and come in varying shades, but contain higher levels of sugar, they reported in the Science journal.
Tweaking the gene in supermarket varieties so that it becomes active again could bring about a return to the sweet tomatoes enjoyed by previous generations.
Dr Ann Powell of the University of California Davis, who led the study, said: "This information about the gene responsible for the trait in wild and traditional varieties provides a strategy to recapture quality characteristics that had been unknowingly bred out of modern cultivated tomatoes.
"Now that we know that some of the qualities that people value in heirloom tomatoes can be made available in other types of tomatoes, farmers can have access to more varieties of tomatoes that produce well and also have desirable color and flavor traits."
