Study on the Antibacterial Activity of the Extracts from 4 Kinds of Plant Leaves Against Ralstonia solanacearum

Ralstonia solanacearum is a devastating soil-borne pathogen, which is difficult to control. The inhibition effects of the extracts from Bauhinia purpurea, Sphagneticola trilobata, Lantana camara and Mangifera indica leaves on Ralstonia solanacearum were investigated by measuring the inhibition zone, antibacterial rate and minimal inhibitory concentration. The results showed that the antibacterial effect of the extract from Sphagneticola trilobata leaves was the best, and the inhibition zone ranged from 15.00 mm to 18.13 mm, which was highly sensitive. The antibacterial rate reached 79.63% at the concentration of 0.40 g·mL^-1, which was significantly higher than that of other treatment groups. The inhibition zone of the extract from Bauhinia purpurea and Lantana camara leaves ranged from 10.67 mm to 15.57 mm, which were moderately sensitive, and their antibacterial rates were 58.33% and 60.37%, respectively. The antibacterial effect of the extract from Mangifera indica leaves was the lowest.