中文摘要：

植物细胞外电势差信号能够反映植物生理信息,通过插入黄杨树干和土壤金属电极,然后测定这种细胞外电势差,并借助小波变换方法,探究其对根系吸水过程的响应.结果表明：加水后必然产生动作电位信号,在土壤含水量相似的条件下,加水量越大,动作电位信号越强,而在加水量相当的条件下,土壤含水量越低,动作电位信号越强;树干-土壤之间的电势差在加水后波动幅度增加,并呈衰减趋势,当波动幅度衰减到几毫伏量级时,树干-土壤之间的电势差出现日变化规律,即在正午左右电势差出现极值.

英文摘要：

Previous studies have shown that extracellular electric potential difference signals could reveal the physiological information of plant.When the plant is stimulated by the change of environment,such as water absorption and temperature variation,electrical signals that could be obtained by the instruments will generate and transport by cells.In this study,metal electrodes are inserted into a boxtree trunk and the soil around the tree to capture the action potential（AP）.Water irrigation is chosen as a stimulation method and irrigation events are repeated in different soil conditions.Since the measured electrical signal is slightly disturbed by noise and the plant electrical signal has a property of low frequency,wavelet transform method is applied to seek the information of AP transmission.During the AP signal is transporting,electric potential difference is measured in high frequency at the same time to catch the AP,with the aim to explore the electrical response of water absorption of root.The results indicate that： Irrigation events with different volume of water give rise to action potential under various conditions of soil condition.When the volume of irrigation water is similar,the larger volume creates the stronger action signal.Meanwhile,while the water amount is close,the lower soil moisture content brings the stronger action signal.This suggests that the stronger stimulation of the environment results the more powerful signal.Moreover,the fluctuation range of electric potential difference measured between trunk and soil increases immediately after irrigation,and then it has an attenuation trend in the following few days.As the fluctuation range drops to few millivolts,the diurnal variation phenomenon of the electric potential difference between trunk and soil comes up.The appearance of diurnal variation shows that the effect of water irrigation totally finishes.