Dirty panicle pathogens inoculation
Pure cultures of Bipolaris oryzae, C. lunata and Alternaria padwickii
isolated from discolored rice seeds were used for rice plant
inoculation. Each pathogen was grown on autoclaved rice seeds
contained in a plastic bag and incubated under near ultraviolet
light for 10 d or until the spores could be observed (modified from
Chamswarng and Intanoo, 2002). Spore suspensions were prepared
and the spore concentration was adjusted to 1 104 spores/
mL using a haemacytometer. Inoculation was performed by
spraying the spore suspension on the whole rice plants at the early
stage of panicle formation.