腐烂茎线虫对当归细胞结构和生理特性的影响

为了明确当归受到腐烂茎线虫(Ditylenchus destructor)侵染后其根部细胞结构和叶部生理特性的变化,本试验以‘岷归1号’和腐烂茎线虫为材料,采用田间自然发病条件测定了腐烂茎线虫侵染后当归根部细胞结构,以及叶部生理特性的变化规律。徒手切片光学显微镜观察结果表明,腐烂茎线虫侵染后,根部发病部位细胞受到严重破坏和断裂。当归病叶片叶绿素含量降低,达到1.18 mg/g,电解质渗漏电导率升高,为76.19 ws/cm。当归病叶的净光合速率、气孔导度和蒸腾速率均降低,胞间CO₂浓度升高;当归病叶光饱和点、最大净光合速率、暗呼吸速率和CO₂饱和点均降低,而光补偿点和CO₂补偿点均升高。同时当归病叶营养元素氮、磷、钾、锌、锰、铁的含量降低,分别为2.41、5.71、36.07、33.53、112.37、1318.03 g/kg,而铜、钙、镁的含量增加,分别达到8.07、538.13、33.13 g/kg。本研究为阐明当归麻口病的发病机制提供了理论依据。

Ditylenchus destructor: Effects on the Cell Structure and the Physiological Characteristics of Angelica sinensis

To determine the changes of root cell structure and leaf physiological characteristics of Angelica sinensis after infected with Ditylenchus destructor, ‘Mingui 1’ and D. destructor were used in this study. The cell structure of roots and the physiological characteristics of leaves were tested in filed by natural diseased condition. Microscopic observation showed that the cell structure of the diseased roots were seriously damaged and broken after infected with D. destructor. The chlorophyll content in diseased leaves decreased to 1.18 mg/g, while the electrolyte leakage conductivity increased to 76.19 ws/cm. The net photosynthetic rate, the stomatal conductance and transpiration rate decreased, whereas the concentration of intercellular CO₂ increased. Moreover, compared with the control, the light saturation point, the maximum net photosynthetic rate, the dark respiration rate and the CO₂ saturation point decreased, while the light compensation point and the CO₂ compensation point increased. The content of nitrogen, phosphorus, potassium and some nutrient elements including Zn, Mn, Fe decreased to 2.41, 5.71, 36.07, 33.53, 112.37 and 1318.03 g/kg, respectively, while the content of Cu, Ca, Mg increased to 8.07, 538.13 and 33.13 g/kg, respectively. The results could provide a theoretical basis for elucidating the pathological mechanism of A. sinensis disease caused by D. destructor.