Therefore, a brief protocol for an inoculum free method for screening rice varieties against
bakanae disease may be suggested as follows: (i) Dry seeds have to be inoculated into 100 ppm
aqueous solution of GA3., (ii) subsequently these have to be incubated at 30 - 35ºC for 10 days
under florescent tube light on the laboratory table. and (iii) a known susceptible variety should be
included simultaneously.
In 2008, it was reported from China by Ma et al. that rice materials carrying dwarf gene such
as sd1 were not only sensitive to GA3 but also susceptible to rice bakanae disease. Materials
carrying dwarf genes d29, sd6 or sdq(t) were insensitive to GA3 and resistant to bakanae. The
present study indicated that GA3 insensitive dwarf and semi-dwarf rice materials might be useful
resources for improvement of bakanae resistance in rice breeding programs. The method describe herein is a quick one and would not require the maintenance of living culture plates of the
pathogen.