Rice (Oryza sativa L. cv. Pathum Thani 1)
seeds were sown in 8 cm plastic pots
containing soil and grown in a greenhouse.
After sowing for 78 days (R 2 stage,
microsporogenesis) plants were applied with
0.001 μM 24-epibrassinolide (EBR, Ruina,
China). The EBR solution and its solvent
(0.01% ethanol) were prepared just before
use. Controls are non-stressed control (CK1,
0.01% ethanol) and stressed control (CK2,
0.01% ethanol). Fifteen ml solution was
sprayed by a hand spraying to 5 pots per
treatment. Prior to spraying, the solution
(EBR or Control) was mixed with surfactant
(0.025% Tween-20).