PV技术在油松侧柏苗木抗旱特性研究中的应用

An Application of PV Technique to Study Drought Resistance of Pinus tabulaeformis and Platycladus orientalis Seedlings

在人工气候室内,模拟大气干旱和土壤干旱,应用PV曲线研究了两年生油松苗和侧柏苗的水分参数(ψ_π^(100)、ψ_0、Va、Tw/Dw、ε^(max)、RWD^0等)及其在抗旱中的意义。结果表明,油松和侧柏具有相类似的水分生理特点,但在干旱条件下,油松具有高水势耐旱特征:较高的束缚水含量和比较坚硬厚实的细胞壁有利于保持体内水分,维持较高的水势和膨压;侧柏则具有低水势耐旱特征:细胞壁较大的弹性和一定的渗透调节能力有利于在水势降低时保持膨压,其原生质具有很强的耐脱水能力使之能在负膨压条件下生存。

Under the condition imitating atmospherical and soil drought in a walk-in Growth Chamber,water parameters of 2-year-old Pinus tabulaeformis and Platycladus orientalis seedlings were studied according to Pressure-Volume curve. The results show that they are of the similar property in water physiology. But under the condition of drought, the Pinus tabulaeformis seedling is characterized by drought tolerance at high water potential, a greater bound water content and stiffer and thicker cell wall being available for holding its water and keeping higher water potential and turgor. The Platycladus orientalis seedling is chacterized by drought tolerance at low water potential.a greater elasticity of cell wall and a certain osmotic adjustment ability being available for keeping turgor as water potential decreasing, and its plasma being of greater dehydration tolerance ability which allows the seedlings to survive at negative turgor.