植物叶片电容与含水量间关系研究
摘要以北方地区常见的抗旱树种毛白杨(Populus tomentosa Carr.)、加杨(Populus canadensis Moench.)和杜仲(Eucommia ulmoides Oliv.)为材料,研究水分胁迫对植物叶片的电容值、含水量和水势的影响。结果表明:随着胁迫时间的延长叶片组织的含水量降低,电容值及水势值亦逐渐下降,且电容值与含水量、电容值与水势间均存在显著的相关关系。在1 000Hz频率下,3种植物的叶片电容值与含水量之间的关系曲线图较为理想,拟合并建立了两者之间的数学模型。
关键词电容;含水量;水势;毛白杨;加杨;杜仲
Studyon the Relationshipbetween CapacitanceandWaterContentofPlantLeaves
XUAN Qi-danFENG Xiao-wangZHANG Wen-jie *
(College of Science,Beijing Forestry University,Beijing 100083)
AbstractCommon tree species in northern area of Populus tomentosa Carr.,Populus canadensis Moench.,and Eucommia ulmoides Oliv. were used to study the influence of water stress on leaf capacitance value,water content and water potential. The results showed that with the stress time extension,the leaf water content reduced,capacitance value and water potential also decrease gradually;capacitance value and water content,capacitance values and water potential had a significant relationship. At 1 000Hz,the relationship curve of water content and capacitance value of these three kinds of plants leaves was more desirable. By way of regression,a mathematic model was established.
Key wordscapacitance;water content;water potential;Populus tomentosa Carr.;Populus canadensis Moench.;Eucommia ulmoides Oliv.
水分是植物生长的必需条件,根系从土壤中吸收水分后,再通过叶面的蒸腾作用将水分散发到大气中,因此叶片的水分含量能够敏感地反映出植物的受旱情况
[1]。植物水分与抗旱生理研究一直是植物生理学研究的重要领域,植物组织含水量是判定植物抗旱性的一个重要生理指标。目前,对于含水量的测定主要是通过烘干法来进行的,此方法准确可靠,但其测量过程繁琐,所用时间较长且不易获得连续数据,并且对同一植物组织只能测定1次,这就使得众多科技工作者一直致力于寻找简便、快捷的方法对植株的抗旱性给予准确的评价。而植物组织电特性的测量则有可能实现快速无损检测植物组织的含水率。植物的电特性是植物组织所在空间的电磁场及电流分布的一些特性,如阻抗特性、介质特性[2]等。近年来,多