Development of germplasm and breeding methods for tomato improvement
Research and development of germplasm and breeding methods for tomato
improvement and disease and insect control
Researchers developed tomato lines with unique combinations of genetic resistance to bacterial and fungal diseases. The team also identified a wild tomato species that naturally repels insects and used those traits to produce more resistant market tomatoes. Seed companies can now use the 10 new lines of fresh market tomatoes released by this team, to improve their commercial tomato lines.
Fresh market field tomatoes are susceptible to a variety of bacterial and fungal diseases that can damage crops and cause farm losses, including bacterial speck, bacterial spot, late blight, early blight and Septoria leaf spot. In addition, insects can carry and transmit viral diseases devastating to tomatoes: western flower thrips carry and spread tomato spotted wilt virus, and sweet potato white flies spread tomato yellow leaf curl virus, among others. To protect food supplies and enable farmers to reduce the use of control chemicals such as insecticides, fungicides and copper, there is a need for new tomato varieties that are naturally resistant to disease and pests.
We developed tomato lines with unique combinations of genetic resistance to bacterial and fungal diseases. We also identified a wild tomato species native to Peru, Solanum pennellii, that naturally repels insects. The species produces a compound called acylsugars which repels insects, safely and naturally deterring a wide variety of pests and preventing them from feeding, transferring disease and laying eggs where larvae might damage plants. We crossed S. pennellii with traditionally grown market tomatoes, breeding to retain the beneficial acylsugars while removing undesirable traits such as small and off-flavor fruit and excess branches. In laboratory and field trials, the tomato lines with acylsugar control protected against not only western flower thrips and sweet potato white fly, but also green peach aphid, potato aphid, leaf miner species, greenhouse whiteflies, tobacco thrips and psyllids; most of these insect species also transmit disease.
We completed and released 10 new lines of fresh market tomatoes with genetic resistances to bacterial and fungal diseases. Seed companies may now use these lines to transfer these resistances to their commercial lines and hybrids. The combination of so many resistances in a good quality fresh market tomato background, combined with markers for identification and transfer of each of these resistances, will greatly assist seed companies in transferring these resistances to commercial tomato lines and resulting commercial hybrids. This work is already having commercial impact: two seed companies have completed licenses for use of these lines in hybrids to be released starting in the 2023 or 2024 growing seasons, and other companies are working on new commercial hybrids. Twenty elite insect-resistant lines will be released in April 2023, enabling seed companies to transfer this uniquely valuable trait to commercial tomatoes.
Reduction in use of control chemicals reduces the risk of chemical residue in the environment and in produce, as well as reducing risk to workers and residents in farms and farming communities. Fungal and bacterial resistant lines reduce the need for fungicide and copper application by over 75% in Northeast production conditions. Insect resistant lines could eliminate the need for insecticides.
- Funding Source: Hatch
- Statement Year: 2022
- Status: Completed Project
- Topics: Disease resistance, pest control, tomato varieties