Study On Relativity Between The Cappacitive Property And Water Content Of Winter Wheat Under Water Stress

Physiologically, physicochemical property of the liquid in plant body changes under the condition of drought, such as water volume declines, the body liquid becomes thick and media varied. Certainly, all these changes will be represented in capacitance characteristics. In this study, we analyzed the correlation between the capacitance characteristics and physiological characters of winter wheat under water stress.Studying the undamaged contact test method, we ascertain the range and testing condition in testing capacitance characteristics of winter wheat. On this basis, we study the impact of drought on the capacitance characteristics of winter wheat leaf and the relationship between capacitance characteristics and physiological characteristics. Main conclusions draw from above studies are:(1) The best measuring frequency screened is 5 KHz. Then we measure capacitance value of Shan-253, Handan-6050, Xiaoyan-22, Zhoumai-18, Chinese Spring and Changzhi-6878 with this frequency. When the osmotic potentials in PEG6000 liquid are 0, -0.1MPa, -0.2MPa, -0.3MPa, -0.4MPa, -0.5MPa, -0.6MPa and -0.7MPa, find the smaller the osmotic potentials is, the more significance of the changes for capacitance value is, and the smaller the capacitance value is. And the longer the time of water stress is, the smaller the capacitance value is.(2) When the measuring frequency of measuring meter is 5KHz and the osmotic potentials is -0.5MPa, we find that the tendencies of the capacitance value change with time among different winter wheat are: the varieties of wheat with stronger drought resisting——Handan-6050, Xiaoyan22 and Changzhi-6878 have bigger changes of the capacitance value than the varieties of wheat with weaker drought resisting——han-253, Zhoumai-18 and Chinese Spring.(3) Analysis of the correlation between capacitance value and water volume of leaf, free water/bound water, free proline content, catalase activity with the osmotic potentials -0.5MPa, results show that capacitance value are positive correlation significantly with water volume and free water/bound water, while there are negative correlation significantly between capacitance value and free proline content, catalase activity.