白粉病菌入侵对不同抗性南瓜品种的病理和生理影响

为了寻找简便有效的品种鉴定方法,采用透明染色法比较了不同抗性南瓜品种接种白粉病菌(Podosphaera xanthii)后的组织病理表现,并用电泳分离法分析了这些品种染病前后过氧化物酶(POD)、多酚氧化酶(PPO)和超氧化物歧化酶(SOD)的同工酶谱变化.结果显示:在抗病南瓜品种上,白粉病菌生长缓慢,分生孢子形成较晚,叶片受侵染部位H2O2生成较多;接种后,所有抗病南瓜品种POD和PPO同工酶谱带均显著增强,而感病南瓜品种POD和PPO同工酶谱带无明显变化.因此,在筛选抗白粉病的南瓜品种时,可以把接种后POD和PPO酶活激发与否作为鉴别是否为抗病品种的依据之一.

Changes of Histopathology and Isozymes in Susceptible and Resistant Pumpkin Cultivars Penetrated by Podosphaera xanthii

Screening of resistant varieties and application of resistant cultivars are necessary and available for crop protection.Identification of resistant pumpkin cultivars was limited by traditional screening method.To accelerate the speed of identification and find a new screening method,various pumpkin cultivars with different resistant levels to Podosphaera xanthii were studied on the histopathology by staining assays in this investigation.Isozymes of peroxidase(POD),polyphenol oxidase(PPO) and superoxide dismutase(SOD) in healthy and inoculated cultivars were analyzed by native-PAGE.Results showed that mycelial growth and conidial formation of Podosphaera xanthii were inhibited on resistant pumpkin cultivars.Moreover,H2O2 burst occurred in resistant cultivars at interaction sites 24 hours after inoculation.The intensity of POD and PPO isozyme bands in resistant cultivars was greatly enhanced at 48 hours after inoculation, while in susceptible cultivar these isozyme bands had no changes after inoculation. This research indicated that resistant pumpkin varieties could be simply identified by the enhancement of POD and PPO isozyme bands after inoculation.