For the pathogenicity assay on rice seedlings, seeds of
cultivar Koshihikari were dipped into water at 30 C for
2 days to stimulate germination, then transferred into a cell
suspension (OD610 = 0.2) of a bacterial strain obtained
from PSA. After incubation at 30 C for 1 day, the inoculated
seeds were sown in soil and incubated at 30 C for
10 days. Disease severity was evaluated as previously
described (Iiyama et al. 1995): 0 = no symptoms,
1 = only slight chlorosis without growth inhibition;
2 = slight growth inhibition accompanied with slight
necrosis, curling with slight chlorosis; 3 = moderate
growth inhibition with some degree of necrosis