In vitro antibacterial activity of Magnolia tamaulipana against tomato phytopathogenic bacteria

The tomato (Solanum lycopersicum Linnaeus) is one of the most important vegetable crops in the world. Still, there are phytopathogenic bacteria that cause a decrease in the yield or can kill the plant, like Pseudomonas syringae pv. tomato (Pst), Xanthomonas vesicatoria (Xv), Clavibacter michiganensis subsp. michiganensis (Cmm), Ralstonia solanacearum (Rs) and Agrobacterium tumefeciens (At). Synthetic chemical fungicides are primarily used to control plant pathogenic bacteria, but their rapid growth makes them resistant to control. This research work is aimed at assessing the in vitro antibacterial activity of the ethanolic extract of Magnolia tamaulipana Vazquez leaves against Rs, Pst, Xv, Cmm, and At, as well as obtaining information about this plant species' chemical composition. The extract inhibited the growth of the five phytopathogenic bacteria that were tested. The growth inhibition rate ranged between 8.22 and 100%. The inhibitory concentration, IC50(90), required to inhibit 50 (90%) of Pst, Xv, Cmm, and At bacterial growth, was 34.71 (39.62), 23.09 (441.88), 64.75 (176.73) and 97.72 (535.48) ppm, respectively. The phytochemical analysis detected the presence of phenols, tannins, terpenes, saponins. M. tamaulipana ethanolic extract has antimicrobial properties and it must be considered a new control agent.