二斑叶螨对菜豆叶片几种生理指标的影响

Effect of Invasion by Tetranychus urticae on Some Biochemical Indexes of Leaves of Phaseolus vulgaris

[目的]测定二斑叶螨为害后菜豆叶片生理指标的变化。[方法]在供试菜豆4叶期后,每株菜豆接种20头二斑叶螨,隔0、3、5、10、15和20 d随机采集被害叶片10片,测定样品的叶绿素、可溶性蛋白、游离氨基酸和游离脯氨酸含量,并测定其过氧化氢酶活性和膜透性。[结果]菜豆叶片受二斑叶螨侵害后在取食部位形成褪绿斑,随着为害侵染天数的增加,该褪绿斑增多,20 d后,菜豆叶片发白直至死亡。生理指标测定表明,菜豆叶片叶绿素含量随着侵染时间的增加而降低,可溶性蛋白、游离氨基酸、游离脯氨酸、过氧化氢酶和电导率随着为害时间的延长而明显增加。[结论]该研究对探索植物对二斑叶螨侵染的反应机制,发展植物对二斑叶螨抗性具有指导意义。

[Objective] The study aimed to determine the change of physiological indexes in the leaves of Phaseolus vulgaris infected by Tetranychus urticae.[Method] In 4-leaf stage of tested pea-beans,each plant of pea-beans was accepted to the inoculation of 20 heads of T.urticae,10 slices of injured leaves were collected randomly in the interval of 0,3,5,10,15 and 20 d,the contents of chlorophyll,soluble protein and free amino acids and free proline in the leaf samples were determined and their hydrogen peroxidase activity and membrane permeability were also measured.[Result] The P.vulgaris leaves infected by T.urticae formed the chlorotic spots which were increased along with the increase of the infection days and after 20 d the P.vulgaris leaves became white until death.Determination on the physiological indexes showed that the chlorophyll content in the infected leaves was decreased with the increase of the infection days,and the contents of soluble protein,free amino acid and free proline,the activity of hydrogen peroxidase and the membrane permeability in the infested leaves were increased obviously with the delaying of the infection days.[Conclusion] The study showed the guiding significance for exploring the reaction mechanism of plant on T.urticae and to develop the resistance of plant against T.urticae.