ABSTRACT
This paper studied the effect of polyethylene glycol (PEG) on regeneration and free proline accumulation of callus of Pogonatherum paniceum (Lam.) Hack. under motionless liquid culture condition and shake liquid culture condition. Callus of P. paniceum had the ability to resist the stress of PEG. The effects of PEG stress and culture conditions on the callus of P. paniceum appeared mainly in two aspects, delaying regeneration time and debasing regeneration rates. The shake liquid culture mainly delayed the regeneration time and PEG stress mainly debased the regeneration rates. Free proline accumulated in the two culture conditions, and the contents of proline were positively correlated with PEG concentrations and culture time. After stress removal, most of the callus could recover the ability of regeneration, and the free proline might pay an important part in the inhibition and recovery. So it must be chosen a more than 300 g x L(-1) PEG concentration and long than 3 weeks culture time in the selection of drought-resistant mutants of P. paniceum. The motionless liquid culture was more suitable for selection of drought-resistant mutants.