MORGANTOWN, WV — Always near the top of the list for having the most pesticide residue, tomatoes have few ways of protecting themselves from pests.
Now, one West Virginia University researcher is confident he will be able to develop a tomato that requires little to no pesticides.
Vagner Benedito, associate professor of biochemical genetics in the Davis College of Agriculture, Natural Resources and Design, is working to understand the genetics of economically-important traits in the world's most popular produce.
"Some wild tomatoes that are closely related to domesticated tomatoes have resistance to insects in very high levels," Benedito said. "This trait, which is insect resistance, is linked to a structure on the leaves of plants called glandular trichomes that have specific chemicals that will give resistance to a very broad range of pests.
Glandular trichomes are small, hair-like growths that give tomatoes their "fuzzy" feeling.
Backed by a $400,000 National Institute of Food and Agriculture grant, Benedito is working to understand the genes that make both trichomes and eventually bring the insecticide-resistant trait to the domesticated tomato.
He's collaborating on the project with Eloisa Vendemiatti, a postdoctoral researcher, and world-renowned tomato geneticist Lázaro Perez from the University of Sao Paulo in Brazil.
"The final product I'm quite curious and excited about," Benedito said. "The tomato crop will not require a lot of pesticides as it does today. And, ultimately, we will have tomatoes that are resistant to pests."
To create a pest-resistant version, the researchers will cross a wild tomato with a Micro-Tom, a dwarf variety that grows quickly.
They'll analyze trichome four, one of several types of small, hair-like growths on the outside of plants, and the acylsugar it produces. Acylsugar is a fat-laden compound insects avoid, helping create pest resistance in the plant.
Plants that meet specific levels of pest resistance will be back-crossed with the micro-tomato to hopefully produce a tomato with the likeness of the micro-tomato and the pest-resistance of the wild tomato.
"Once we understand the genetics behind the development of type-4 trichomes in tomatoes, we can even bring this to a more important crop like the potato. Potatoes have a major problem with pests," he said, referencing a USDA statistic that shows the tomato is only second to the potato as the most consumed vegetable in the U.S.
Before the science can be applied to other crops, however, the development of the tomato alone is four years away.
The most important aspects of the research to Benedito are identifying pest-resistant genes, getting a genotype resistant to pests and making those new varieties available to breeders, and ultimately, to farmers and gardeners.
"Our research is to make tomato cropping more environmentally friendly and sustainable. We want to make produce safer to consume by reducing pesticide use," he added.
The key to making the new varieties widely available is for Benedito and his team to provide breeding tool kits to crop breeders.
They can then utilize genetic markers and select plants that are resistant to insects without having to do tests for broad spectrum resistance themselves. This will enable breeders to make any type of tomato pest resistant.
"We aim for the breeder, but the trait is important for everybody: for the farmer, the consumer. We do it for the breeder so they can deliver the final product like seeds that the farmer will buy," Benedito said.