Scientists aid vintage tomato cause
Vintage tomatoes that taste as good as they look could be making a comeback thanks to a genetic discovery.
Scientists have pinpointed the reason why tomatoes bred to attract the eye of shoppers tend to lack flavour.
The key is a gene linked to photosynthesis called GLK1 and manipulating it could see a return to the superior tasting tomatoes enjoyed by our grandparents, the experts said.
For about 70 years, commercial growers have selected tomato varieties whose fruit is a uniform light green before ripening. These "store ready" tomatoes can be harvested at the same time and turn red evenly as they ripen, making them appear attractive on supermarket shelves.
But the same trait leads to a reduction in sweet-tasting sugars and a loss of flavour, scientists have learned.
The new research focused on genes that control the development of chloroplasts, the plant cell structures responsible for photosynthesis.
Chloroplasts, which contain green chlorophyll, capture light energy from the sun and use it to make sugars and other organic molecules.
The US and Spanish scientists searched through a collection of mutant and wild tomato species established at the University of California, Davis, in the 1950s. They discovered the key role of a gene called GLK2 that stimulates chloroplast development and photosynthesis.
Tomatoes with active GLK2 are dark green before ripening and produce fruits of varying shades containing high levels of sugar but in the "uniform ripening" varieties, GLK2 is disabled and photosynthesis is less efficient.
Dr Ann Powell a UC Davis biochemist whose work is newly published in the journal Science, 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.