Chinese scientists have successfully identified the genetic mechanism that influences tomatoes’ shape and used that knowledge to develop fresh tomatoes that can better withstand mechanical harvesting, according to a study published in Nature Plants on September 18.
Sixty years ago, a mutation was observed in tomatoes that caused the fruits to change from a round to a blockier shape. The mutation, called fs8.1 dramatically improved the stress tolerance of tomatoes, opening the door to tomato harvesting by machines instead of by hand.
Now, researchers led by Prof. LI Chuanyou from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences report that they were able to successfully clone, functionally characterize, and apply the fs8.1 mutation from processing tomatoes to fresh tomatoes.
Until now, scientists had not identified the specific gene responsible for the fs8.1 mutation. Now, they have identified the gene, and demonstrated that the mutation changes the rate of cell proliferation in different parts of the tomato. Specifically, the fs8.1 mutation promotes cell proliferation in the ovary wall more than in the columella, resulting in an elongated fruit shape.
Until now, fs8.1 has been absent in fresh market varieties. Introducing it to fresh market varieties offers opportunity to enhance production efficiency without compromising quality, explained the release:
“Compared to the fruit of processing tomato, the fruit of fresh market tomato is of higher quality in terms of nutrition and flavor. However, fresh market tomato fruit may experience severe soft-fruit-related deterioration during harvest, transportation and storage. Natural ripening-related mutations have been used to improve fruit firmness. However, they often adversely affect color, flavor and nutritional quality. fs8.1 does not affect fruit ripening. Thus, cloning of FS8.1 offers a potential way to redesign fresh market tomatoes for mechanized production without compromising quality.”
While fresh market tomatoes that included fs8.1 show enhanced compression resistance, their key quality parameters – total soluble solid content and levels of sugar, acids and lycopene – remained unchanged.
The study was funded by the National Key R&D Program of China and the National Natural Science Foundation of China.
