Eggplant accessions (Solanum melongena) for resistance to bacterial wilt disease and for use as a rootstock for grafted tomato in Mali and Burkina-Faso

W. Bihon, J. Tignegre, J. Chen, R. Manickam, A. Camara, L. Ouedraogo, K. Ndiaye, R. Srinivasan, L. Kenyon
Bacterial wilt (BW) caused by the Ralstonia solanacearum species complex leads to high economic losses in solanaceous vegetables production around the world. Management of this disease is difficult because of its high genetic diversity, broad host range, ability to survive in the soil for several years and its ability to cause latent infection. Several methods, including resistant cultivars, soil disinfection and the recent introduction of grafting onto resistant rootstocks have been used to control the disease. Vegetable grafting, the joining of rootstock (resistant to soil-borne pathogen) and the scion (with horticultural and consumer traits of interest) of closely related species has been introduced in different parts of Africa. However, for successful grafting in BW management, it is necessary to have a rootstock that is both resistant to the local strains of the disease and graft-compatible with the intended scion genotype. The aim of this study was to screen nine eggplant accessions (Solanum melongena L.), previously identified as showing some resistance to BW in Taiwan, for BW resistance under open field conditions in Mali and Burkina-Faso, and to study the graft-compatibility with tomato of selected rootstocks. Field experiments were laid out in a completely randomized block design replicated four times at Samanko experimental site, Mali and replicated three times at Bobo-Dioulasso, Burkina-Faso and three times at Baguineda, Mali. Disease incidence and yield data were subjected to analysis of variance and means separated by LSD at 5% probability. The result showed that VIO41945 (in Samanko), VIO34845 and VIO41943 (in Bobo-Dioulasso), and VIO45276 and VIO41943 (in Baguineda) were the most resistant and adaptable accessions that could be used for grafting with tomato, but resistance to BW varies with location. This shows the importance of multilocation testing of rootstocks for soilborne pathogens prior to use for grafting. Graft compatibility testing using four of the eggplant accessions with tomato (‘Roma’) showed the potential of grafting as an integrated pest management component to manage bacterial wilt disease.
Bihon, W., Tignegre, J., Chen, J., Manickam, R., Camara, A., Ouedraogo, L., Ndiaye, K., Srinivasan, R. and Kenyon, L. (2022). Eggplant accessions (Solanum melongena) for resistance to bacterial wilt disease and for use as a rootstock for grafted tomato in Mali and Burkina-Faso. Acta Hortic. 1348, 253-260
DOI: 10.17660/ActaHortic.2022.1348.35
Ralstonia pseudosolanacearum, Solanum lycopersicum, rootstock-scion compatibility, vegetable grafting, Solanacea

Acta Horticulturae