The Plant Pathology Journal

Fig. 5.

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Fig. 5. Virulence of Acidovorax citrulli isolates after inoculation into fully ripe watermelon fruits. Watermelon fruits were inoculated with 106 cfu/ml of A. citrulli isolates using a pipette at a depth of 0.5 cm from the surface and incubated at room temperature for 40 days. (A) Symptoms in the surface of or inside the watermelon fruits at 24 days after inoculation (dai) with 106 cfu/ml of each indicated isolate. The mark at the bottom right represents the extent of disease. (B) Confirmation of the presence of inoculated bacteria by PCR using a 16/25S rRNA gene primer set. The fruit extract was cultured on medium for 24 h at 26°C, and colonies on medium were used for PCR. M, 1 kb ladder marker; P, Ac0 genomic DNA (positive control); N, H2O (negative control). (C) Percentage of infected seeds collected from watermelons inoculated with Ac1 isolate (106 cfu/ml). All seeds were collected at 10 dai and 40 dai, and bacterial titers inside each seed were counted. The percentage of seeds with each range of bacterial titer was calculated by the following equation: (number of seeds with each range of bacterial titer/total seed number) × 100.
Plant Pathol. J. 2020;36:29-42
© 2020 Plant Pathol. J.