Objective: To set up the fittest medium and optimum condition for plantlets to form microtubers.
Method: Plant hormones, concentration of sucrose, active carbon and light time influenced formation of adventitious root and microtuber in vitro from plantlet of Rehmannia glutinosa (85-5).
Result and conclusion: The plantlets were cultivated on the medium of microtuber induction after roots were induced on the 1/2MS medium with IBA 1 mg.L-1. The best medium was MS + 6-BA 2 mg.L-1 + NAA 0.1 mg.L-1 + Sucrose 5%. The fittest incubation temperature was 25 degrees C and the light length was (2,000-3,000 lx) 12 h.d-1. Active carbon and GA3 should not be added to the medium, which was not suitable for the induction of microtuber.