Researchers from Brazil, the U.S. and Germany have created a new crop from a wild plant within a single generation using CRISPR-Cas9, a modern genome editing process.
Starting with a wild tomato, researchers have introduced crop features without losing the valuable genetic properties of the wild plant, according to a news release.
The results have been published in the current issue of Nature Biotechnology.
“This new method allows us to start from scratch and begin a new domestication process all over again,” biologist professor Jorg Kudla, from the University of Munster, said in a news release.
“In doing so, we can use all the knowledge on plant genetics and plant domestication which researchers have accumulated over the past decades. We can preserve the genetic potential and the particularly valuable properties of wild plants and, at the same time, produce the desired features of modern crops in a very short time.”
Altogether, the researchers spent about three years working on their studies, according to the release.
The release said the researchers chose Solanum pimpinellifolium as the parent plant species, a wild tomato relative from South America, and the progenitor of the modern cultivated tomato.
The wild plant’s fruits are only the size of peas and the yield is low — two properties which make it unsuitable as a crop. On the other hand, the fruit is more aromatic than modern tomatoes, which have lost some of their taste due to breeding.
Moreover, the wild fruit contains more lycopene, an antioxidant.
The researchers modified the wild plant by using multiplex CRISPR-Cas9 so that the offspring plants bore small genetic modifications in six genes — genes that have recognized to be the genetic key to features in the domesticated tomato.
In particular, the release said researchers changed the wild tomato in several ways:
- The fruit is three times larger than that of the wild tomato, bout the size of a cherry tomato;
- There is 10 times the number of fruits, and their shape is more oval than the round wild fruit;
- The plants also have a more compact growth; and
- The lycopene content in the new breed of tomato is more than twice as high as in the wild parent — and no less than five times higher than in cherry tomatoes.
“This is a decisive innovation which cannot be achieved by any conventional breeding process with currently cultivated tomatoes,” Kudla said in the release. “Lycopene can help to prevent cancer and cardiovascular diseases. So, from a health point of view, the tomato we have created probably has an additional value in comparison with conventional cultivated tomatoes and other vegetables which only contain lycopene in very limited quantities.”
So far, he adds, breeders have tried in vain to increase the lycopene content in cultivated tomatoes.
In cases in which they were successful, however, this was at the expense of the beta-carotene content — which also protects cells and is therefore a valuable ingredient.