P. oryzae fungus inoculums was isolated from
blast-infected rice cv. Inpari 13 obtained in
Kuningan district, West-Java. Rice seeds cv. Inpari
13 used in this study were obtained from Muara
experiment station, Bogor, West Java. Pure cultures
of P. oryzae were grown on petri dishes containing
potato dextrose agar (PDA) medium and incubated
for one week at room temperature. Production of P.
oryzae spores was carried out by growing the
fungus on oat meal agar (OMA) medium, incubated
for 8-10 days at room temperature. Fungal colonies
were added with 2 μg/50 ml streptomycin to
eliminate aerial hyphae; Isolates were then
irradiated with fluorescent lamps 300 volts to
induce the growth of spores for 5-6 days; then
washed with 1 liter of sterile distilled water
containing 0.2% (v/v) Tween 20. Spores were
harvested by rubbing using a brush to the surface of
the fungus colony that has been sterilized by
immersion in absolute alcohol. Spore suspension
was then filtered and collected in sterile Erlenmeyer
flasks, and the spore density was observed using
Neubauer-haemocytometer