露点水势仪用于植物活体原位水势测定的技术改进  

Improved Protocol for the in Situ Measurement of Water Potential of Plants with a Thermocouple Psychrometer

作　　者：朱建军[1] 柏新富[1] 刘林德[1] 

机构地区：[1]鲁东大学生命科学学院,烟台264025

出　　处：《植物学报》2013年第5期531-539,共9页Chinese Bulletin of Botany

基　　金：国家重点基础研究发展规划(No.2009CB421300);山东省自然科学基金(No.ZR2012CM007);山东省高等学校科技计划(No.J09LC06)

摘　　要：提出露点水势仪用于植物活体原位水势测定技术的优化方案,并通过不同植物的实测进行了验证,同时将露点水势仪的测定结果与压力室的测定结果进行了横向比较。实验表明,改进后的测定技术可获得更为可靠的测定结果。优化方案主要包括用氧化铝微晶粉末磨除叶片的角质层,采用湿度测量模式以随时监测探头是否受污染和确定热电偶的通电冷却时间,记录和读取测量结果等措施。同时介绍了被污染探头的清洗、误差来源和减小误差的方法等。改进后的方案能够快速、准确地完成活体植物水势的原位测定,消除用叶圆片代替活体测定带来的由于细胞破损而使细胞浆外流污染对叶片实际水势的干扰影响。We present an improved protocol for the in situ measurement of water potential of plants with an L-51 leaf chamber combined with an HR-33T microvoltmeter. The protocol was verified with several plants grown in different envi- ronments. To facilitate the diffusion of vapour to the thermocouple junction of the L-51 leaf chamber, a swab wetted with a droplet of distilled water and attached with fine aluminium powder （10-15 IJ in particle diameter） was used for removing the cuticle of plant leaves. For more accurate readout of data, a data acquisition and recording device and computer software were used to record and analyse the results. Results with this protocol were in good agreement with those ob- tained with a Schollander bomb. Details for determining cooling time during the measurement and sensor contamination as well as the method and prototol for cleaning the contaminated sensor are given with examples and illustrations. Error evaluation and measures to minimize those errors caused by abrupt temperature fluctuations, especially for field meas- urements, are also proposed. With the new protocol, the in situ measurement of plant water potential can yield faster, more accurate and reliable results, because the impact of cell sap from damaged cells on water potential is eliminated.

关 键 词：原位水势 植物 露点水势仪 热电偶 

分 类 号：Q945[生物学—植物学]