Marker assisted breeding for thrips resistance in tomato
Which plant leaf characteristics are involved in thrips resistance in tomato?
In this project we developed together with Rijk Zwaan QTL’s for resistance. We showed that the resistance is based on metabolites in the leaf rather than on trichomes.
Thrips resistance in tomato
The plant ecology and phytochemistry group detected a thrips resistant tomato variety (RT). So far it is the only known cultivated tomato that is resistant against thrips. In this variety the trichome density is much higher than in e.g. the well-known commercial variety moneymaker. We started the project with the hypothesis that the resistance of RT was based on this high trichome density. The goal of the project was to develop molecular markers to assist the breeding program of Rijk Zwaan. We set up a cross between moneymaker and RT and successfully developed QTL’s for both thrips resistance and trichome density. Our analyses showed that resistance was not related to trichome density. In addition we determined metabolomics profiles of the leaves of resistant and susceptible genotypes. We found an NMR signal that was strongly related to resistance.
Why is it important?
Western flower thrips is one of the most important pests in horticulture worldwide leading to great economic losses. Because trough EU regulation many insecticides will be banned we urgently need to find alternatives. One strategy is to increase the resistance of the plants. So far this was not possible for tomato because no cultivated varieties were known that were resistant against thrips. For the first time now Rijk Zwaan will be able to include thrips resistance in its breeding program. If successful this will lead to a strong reduction in the use of pesticides.
Our current research in this project focusses on the isolation and identification of the compounds involved in thrips resistance in our resistant variety