高温与空气湿度交互对花期番茄植株水分生理的影响

以番茄品种“金冠5号”为试材，在人工气候箱内进行正交试验，设计日最高气温（℃）/最低气温（℃）分别为32/22、35/25、38/28、41/31共4个温度处理水平，空气相对湿度分别为50%±5%、70%±5%、90%±5%，处理天数为3、6、9、12d，并以28/18、50%±5%为对照（CK），测定不同处理下番茄苗叶片生理指标的变化。结果表明：在32～41℃高温处理下，叶片气孔导度Gs、蒸腾速率Tr在日最高气温35℃时最高，分别为0.109μmol·m-2·s-1、0.21μmol·m-2·s-1；叶水势ψw、根系活力Rv、根冠比R/S、净光合速率Pn和水分利用效率WUE均随胁迫温度的升高而逐渐降低，日温41℃时较CK降低163.76%、66.63%、28.59%、73.90%和65.11%。高温条件下提高湿度至70%后，ψw、Gs、Pn、Tr和WUE分别较50%处理均有显著提高，且可以在28d内基本恢复至CK水平，在恢复期内根系恢复良好且保持较高WUE；但湿度提高至90%后，Gs和ψw有所上升，而Pn、Rv、R/S、WUE未能显著提高，且在恢复期内WUE较低。故在35℃及以上的高温环境中，提高空气湿度至70%可有效降低高温对番茄的危害，也有利于番茄灾后恢复。

Effects of High Temperature and Different Air Humidity on Water Physiology of Flowering Tomato Seedlings

Used tomato variety “Jinguan 5” as the test material, and orthogonal test was carried out in the artificial climate chamber to design the daily maximum temperature(℃)/lowest temperature(℃). For the 32/22℃, 35/25℃, 38/28℃, 41/31℃ levels, the relative humidity of the air is 3 levels: 50%±5%, 70%±5%, 90%±5%, and the treatment days is 3, 6, 9, 12 days, and set 28/18℃, 50%±5% as control (CK), the changes of physiological indices of tomato under different treatments were determined. The results showed that under the high temperature treatment of 32?41℃, the stomatal conductance (Gs) and transpiration rate (Tr) were the highest at 35℃, respectively, 0.109μmol·m-2·s-1, 0.21μmol·m-2·s-1; leaf water potential (ψw), root system vigorous (Rv), root-shoot ratio (R/S), net photosynthetic rate (Pn) and water use efficiency (WUE) decreased with increasing stress temperature, and decreased by 163.76%, 66.63%, 28.59%, 73.90% and 65.11% at 41℃ compared with CK. After increasing the humidity to 70% under high temperature conditions, ψw, Gs, Pn, Tr and WUE were significantly improved compared with 50% treatment and can basically recover to CK level within 28 days, the root system also recovered better and maintained a higher WUE during the recovery period; but after increased the humidity to 90%, Gs and ψw increased, but Pn, Rv, R/S, WUE failed to increase significantly, and WUE was lower during the recovery period. Therefore, in the high temperature environment of 35℃ and above, increasing the humidity of the air to 70% can effectively reduce the damage of high temperature to tomato, and it was also conducive to tomato recovery. This study provides a theoretical basis for the optimal management of summer greenhouse tomato.