FIGURE 3.

Population, behaviour, and virulence of Ralstonia pseudosolanacearum strains OE1‐1, ΔphcB, ΔphcA, ΔphcR, and ΔphcQ in 8‐week‐old tomato plants inoculated by the root‐dip method. (a) Populations of R. pseudosolanacearum strains in tomato roots. Data are presented as the mean ±SD of five trials. Asterisks indicate values significantly different from those of wild‐type strain OE1‐1. cfu, colony‐forming unit. (b) Behaviour of R. pseudosolanacearum strains in tomato roots and stems 10 days after root‐dip inoculation as determined by a plate‐printing assay (Hayashi et al., 2019). (c) Virulence of R. pseudosolanacearum strains. Plants were rated according to the following disease index scale: 0, no wilting; 1, 1%–25% wilting; 2, 26%–50% wilting; 3, 51%–75% wilting; 4, 76%–99% wilting; and 5, dead. For each bacterial strain, three replicate experiments conducted using independent samples with 12 technical replicates per experiment produced similar results. Results of a single representative sample are provided. Data are presented as the mean ±SD of 12 replicates