Abstract: In a pot experiment with 4-year-old apple root stock (Malus hupehensis), this paper studied the effects of foliar-spraying exogenous glycinebetaine (GB) on the leaf ultraweak luminescence (UWL), contents of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), endogenous GB and proline (Pro), and activities of superoxide dismutase (SOD) and peroxidase (POD) under drought stress. The results showed that UWL intensity increased under slight- and mid drought stress,but decreased with increasing drought stress till lower than the control. Under slight- and mid drought stress, foliar-spraying GB improved the UWL intensity by 35.27% and43.95%，respectively, decreased H₂O₂ and MDA contents, increased SOD and POD activities, and promoted the accumulation of GB and Pro. The exogenous GB and its induced Pro accumulation could increase the anti-oxidative capability of M. hupehensis leaves, and protect the leaf cells from oxidative damage under drought stress.

Key words: Chorthippus dubius, Biology, Spatial pattern, Population dynamics