一种测定葡萄新梢木质部水势的新方法

【目的】为了能够连续、即时测定葡萄新梢木质部水势,【方法】以无核白鸡心葡萄为试材,通过同时测定葡萄叶柄木质部导管平均流量和流速,应用变形的哈根-泊萧叶方程,研究了这种连续、即时测定葡萄新梢木质部水势的新方法。【结果】结果表明,在直径为4 mm的葡萄叶柄上,用此新方法测得的葡萄叶柄两端压力差与实际所加压力差吻合的很好,说明此新方法可用于连续、即时测定葡萄叶柄两端压力差。用此新方法在葡萄新梢上测定发现,葡萄新梢木质部水势日变化初步显现"倒双峰曲线",并且葡萄新梢木质部水势与叶水势之间成线性正相关。【结论】此新方法能够连续、即时测定葡萄新梢木质部水势。

A new method for measurement of xylem water potential of grape shoot

【Objective】 The objective of this study is to measure the xylem water potential of grapevine shoot real-timely and continually.【Method】 The novel method for measuring xylem water potential of grapevine shoot(Vitis vinifera L.’Centennial Seedless’) through simultaneously measuring petiole xylem vessels’ average flow rate and velocity and then placing into a transformed Hagen-Poiseuille equation was studied.【Result】 The results showed that the pressure difference between the two ends of excised grapevine petioles in 4 mm diameters measured with the new method agreed well with the actual applied ones.This showed that the pressure difference between the two ends of grapevine petioles could be real-timely and continually measured out with the new method.The diurnal variations of grapevine shoot xylem water potential measured with the new method seemed to present an inverted double-peak curve.And the shoot xylem water potential was positively and linearly correlated with the leaf water potential of grapevine.【Conclusion】The studies suggested that the xylem water potential of grapevine shoot could be real-timely and continually measured out with the new method.