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.
荒漠条件下甘草气孔振荡的水被动证据
王根轩1* 廖建雄1 吴冬秀2
（1. 兰州大学干旱农业生态国家重点实验室，兰州730000；2. 河南大学生物系，开封475001）
摘要: 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1 kPa 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，但是并不能显著改变气孔振荡强度（振幅/平均值）。气孔振荡强度与VPD和根阻力显著相关，但与呼吸速率无明显相关。在荒漠条件下，当VPD大于0.8 kPa和至少存在1/4全根阻力的条件下才可能出现气孔振荡。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。
关键词： 气孔振荡；甘草；水被动；气孔导度；水蒸汽压差
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