At last! Scientific confirmation of what anyone with a palate already knew: Supermarket tomatoes, by and large, are as tasty as raw potatoes, which is to say they basically have no flavor at all.
As humans have tried to develop a tough-skinned, slow-ripening commercial tomato that would survive the rigors of long-distance transport, it appears the flavor genes got left behind, says molecular biologist James Giovannoni.
Consumers have been grousing about Flavorgate for years, Giovannoni said, especially when they compare the supermarket varieties to the tomatoes that Grandma used to grow, or even the ones they grew last summer in their yards.
“Lots of people don’t know what a fresh peach should taste like because they’ve never grown one, but tomatoes are a little unique,” he said. “If you’re growing anything at your home, it’s probably a tomato plant, even if it’s on your balcony, so people know what a good tomato should taste like.”
But now breeders have a key for reinserting some flavor into their tomatoes, while still keeping them market tough.
Giovannoni, of the USDA’s Agricultural Research Service Plant, Soil and Nutrition Research Laboratory, and fellow researcher Zhangjun Fei, a bioinformatics scientist at the Boyce Thompson Institute, both in Ithaca, have constructed a pan-genome — basically the entire set of genes — for 725 different cultivated tomatoes and their wild relatives, discovering 5,000 previously undocumented genes.
Turns out wild tomatoes have lots of flavor but they’re also tiny, around the size of a pea, Giovannoni said. Humans began cultivating larger mutants of the wild variety, that originated in South America.
The researchers discovered one particular gene — dubbed TomLoxC — that is present in 91% of the tasty wild varieties, primarily Solanum pimpinellifolium, aka currant tomatoes, which are sometimes used as a garnish in fancy restaurants, Giovannoni said, served on a stem like a cluster of tiny grapes to add a little pop of tomato flavor.
But — surprise, surprise — TomLoxC was present in only about 2% of cultivated varieties, including heirlooms.
Now that researchers have teased out a critical flavor gene, breeders can start adding it to the mix when they create new commercial varieties. And now that they know what genes provide specific qualities, they can test their new plants when they’re only a few inches tall, to see if they include all the qualities they want, from long shelf life to TomLoxC aromatics.