April 19, 2023 – Researchers at the Hebrew University of Jerusalem (HU) succeeded in developing tomato varieties that require less water and produce a high yield, even in extreme drought conditions.

The study, published in the Proceedings of the National Academy of Sciences (PNAS) journal was led by doctoral student Shai Torgeman and Prof. Dani Zamir from the Hebrew University Robert H. Smith Faculty of Agriculture, Food, and Environment.

The researchers identified interactions between two regions of the tomato genome that resulted in a 20-50% increase in the overall tomato yield under irrigated conditions as well as in droughts.

“The unique structure of the new population, which enables precise mapping of the tomato genes, has the potential for extensive application in other plants and could increase productivity,” the researchers say.

Tomatoes grown in open field conditions need protection from pests and fertilization and must be watered over time. However, the climate crisis and the severe water shortages around the world require alternative varieties and new cultivation methods that also guarantee adequate profits for farmers.

The researchers crossbred two tomato species – a wild tomato from the deserts of western Peru and the cultivated tomato – to identify which regions of the genome affect important agricultural traits, such as yields. Individually, one genome didn’t affect the crop, but when these genome regions appeared together, there was a significant contribution to fertility even in dry conditions.

“Studies of complex traits in plants, such as yield and resistance to drought conditions, have been based on significantly smaller populations of 200~ species,” explained Torgeman. “This makes it impossible to identify all the interactions (epistasis) between the genes, as well as their influence on important agricultural traits. In this study, we genetically crossed two different species of tomato, and proved that by using a larger population and a genetic map that includes thousands of markers, it is possible to identify areas in the genome that have interaction between them that increases the yield.”

“Studies of complex traits in plants, such as yield and resistance to drought conditions, have been based on significantly smaller populations of 200~ species,” says Torgeman. “This makes it impossible to identify all the interactions (epistasis) between the genes, as well as their influence on important agricultural traits. In this study, we genetically crossed two different species of tomato, and proved that by using of a larger population and a genetic map that includes thousands of markers, it is possible to identify interactions that increase the yield.”

Zamir’s lab has conducted DNA sequencing and extensive data analysis of 1,400 plants over the past four years. The researchers are seeking to commercialize these new tomato varieties.

“With global warming and farmers need tomatoes that can cope with these changing weather conditions,” Torgeman says. “Global warming does not only cause higher temperatures but also extreme weather like sudden torrential downpours or drought, so we need plants that have improved capabilities.”

The research was conducted as part of the scientific cooperation with the European Union in the ‘Horizon 2020’ program.