Location: Plant Genetic Resources Conservation Unit
Project Number: 6046-21000-012-031-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Jun 1, 2022
End Date: May 31, 2023
The USDA maintains a collection of seed of approximately 850 accessions of eggplant (Solanum melongena) and several of its related species including Solanum aethiopicum (Scarlet eggplant) and Solanum macrocarpon (African eggplant) in a genebank (S9) located in Griffin, GA. The accessions of these Solanum species were acquired from 18 countries over a period of 60 years. The USDA genebank is responsible for the maintenance of these plant materials and for the distribution of seed of them. Materials in this collection often serve as the basis for the improvement of the crop and are made available nationally and internationally in support of research, breeding and educational programs. The seed inventories of the materials in the USDA eggplant collection (S. melongena and related species) have not been previously indexed for any plant virus. Eggplant (Solanum melongena and related species) is susceptible to various members of the Tobamovirus group. Tobamoviruses are very stable and can survive in plant debris for a number of years. Seed-borne members of the Tobamovirus group of viruses infecting eggplant include the well-known Tobacco Mosaic Virus (TMV), Tomato Mosaic Virus (ToMV), Tomato Mottle Mosaic Virus (ToMMV), Tobacco Mild Green Mosaic Virus (TMGMV), and possibly others. These viruses are readily spread through the dissemination of infected seed as well as mechanically as plants are handled. The objective is to to screen the USDA/ARS collection of eggplant (including S. melongena, Solanum aethiopicum and Solanum macrocarpon) for the presence of Tobamoviruses.
We propose to sample each distribution inventory of eggplant and its related species in the USDA/ARS germplasm collection in Griffin, GA (822 total samples) for the presence of Tobamoviruses using a PCR-based assay capable of detecting multiple members of the Tobamovirus Group. This assay is capable of detecting a single infected seed in a bulked sample of > 100 seeds. One hundred (100) seeds of each genebank accession will be packaged and labeled in Griffin and sent to the Cooperator. Each sample will be tested for the presence Tobamoviruses. While no problems are likely to be encountered, there is a high probability that one or more viruses will be detected. The proposed testing scheme will not identify a specific virus. Hence, further analysis of seed samples (those testing positive) would be required in order to identify the virus involved.