荒漠条件下甘草气孔振荡的水被动证据

生长在中国西北干旱荒漠的甘草（Glycyrrhiza inflata Batalin)，当白天大气水蒸汽压差（ＶＰＤ）高于１kPa时，其气孔导度随时间的变化趋势为从稳态转为振荡态。通过茎木质部注射代谢抑制剂（ＮaN3或羰基氰化物－间－氯苯腙（ＣＣＣＰ）使气孔导度有些微降低，但是并不能显改变气孔振荡强度（振幅／平均值）。气孔振荡强度与ＶＰＤ和根阻力显相关，但与呼吸速度无明显相关，在荒漠条件下，当ＶＰＤ大于０．８kPa和至少存在１／４全根阻力的条件下才能出现气孔振荡。结果说明荒漠干旱条件诱发的甘草气孔振荡可能主要是一种水被动过程 。

Evidence of Hydropassive Movement in Stomatal Oscillations of Glycyrrhiza inflata under Desert Conditions

Stomatal conductance was found to change from steady_state to a state of oscillations during daytime when vapour pressure deficit (VPD) increased to a value of 1 kPa in Glycyrrhiza inflata Batalin grown under the conditions of arid desert in north_west China. The injected metabolic inhibitors (NaN 3 or carbonyl cyanide_m_chlorophenyl_hydrazone (CCCP)) slightly reduced the stomatal conductance but did not significantly decrease the intensity of stomatal oscillations (amplitude/average). The oscillation intensity was found to be significantly correlated with VPD and root resistance, but not with the respiration rate. There might exist a minimum threshold of VPD (0.8 kPa) and root resistance (1/4 relative value) that induced stomatal oscillations. These results suggested that stomatal oscillations induced by atmospheric drought stress and root resistance were mainly a type of hydropassive movement.