Scientists have solved the mystery of tasteless tomatoes
“This study, which examines the reason for this situation, shows that tomatoes with better taste can make a comeback.”
12punto
Most tomatoes bought from supermarkets, or even farmers' markets, are tasteless. Scientists have discovered that a gene that gives tomatoes their flavor is missing in approximately 93 percent of modern, domesticated tomato varieties. This discovery by researchers could help the tomatoes you buy from the produce aisle regain their flavor.
Clifford Weil, head of the Plant Genome Research Program at the U.S. National Science Foundation, which supported the study reported by Popular Science Turkey, says, “You have likely heard many times that the tomatoes you buy from supermarkets and greengrocers are nothing like the old tomatoes.” “This study, which examines the reason for this situation, shows that tomatoes with better taste can make a comeback.”
THE DOMESTICATION DISASTER
An international research team combined genetic information collected from 725 cultivated and wild tomatoes into a pan-genome; that is, they converted this information into a genome containing the genetic data of all tomato varieties. They then compared this pan-genome with the genome of a domesticated tomato called Heinz 1706.
This tomato genome has served as a representative sample for all tomato genomes until now. Comparing the tomatoes side by side, the researchers noticed that the Heinz 1706 reference genome was missing approximately 5,000 genes carried by other tomato varieties.
Most of these missing genes also provide defense against pathogens in plants. Tomatoes did not lose these genes due to genetic modifications, but rather through the old-fashioned way of breeding, where growers selected for traits that made tomatoes resilient.
Zhangjun Fei, a plant geneticist at Cornell University, says, “During the domestication and improvement process of the tomato, humans mostly focused on traits that would increase production, such as fruit size and shelf life.” “Some genes related to other important characteristics of the fruit and stress tolerance were lost during this process.”
Identifying these previously unknown genes could help breeders develop better tomatoes.
James Giovannoni, a molecular biologist at Cornell University and the U.S. Department of Agriculture, explains: “These new genes could enable plant breeders to develop elite tomato varieties that carry genetic resistance to diseases. Currently, we are using pesticides or other costly and environmentally harmful measures against these diseases.”
THE RETURN OF FLAVOR
The analysis also revealed that the rare gene form that gives the fruit its tomato flavor is not present in most of today's domestic tomatoes. However, in the researchers' study published in the journal Nature Genetics, it was discovered that more than 90 percent of wild tomatoes carry the strong-flavor version of this gene.
The scientists' analysis also shows that this flavor gene, called TomLoxC, flavors tomatoes with carotenoids (the pigments that make tomatoes red). But there is good news for tomato enthusiasts as well. This flavor gene can return. The rare version of TomLoxC was previously present in only about 2 percent of tomato varieties. However, with breeders starting to focus more on taste in recent years, the number of tomato varieties carrying this gene is increasing.
This gene is now found in approximately 7 percent of tomatoes. According to Giovannoni, this means that breeders are selecting accordingly. The scientist hopes that this trend will become widespread.