基于电阻抗图谱法的月季白粉病检测技术研究OA

Rosa chinensis is an important cut flower and garden plant worldwide.Podosphaera pannosa,the cause of rose powdery mildew,significantly affects the ornamental and economic value of roses.To reduce the damage caused by rose powdery mildew and enhance the early detection and warning capabilities of the disease,two-year-old rose varieties"Fairyland"(highly resistant)and"Red Hat"(susceptible)were used as test materials.They were inoculated with Podosphaera pannosa,and the electrical impedance spectroscopy(EIS)spectra and parameters,activities of pathogenesis-related proteases,and contents of starch and soluble sugar in rose leaves were measured.The correlations between EIS parameters and physiological indicators were analyzed to explore suitable EIS parameters for rose powdery mildew,providing a new technical method for rapid detection of rose powdery mildew.The results showed that:(1)As the disease severity increased in both varieties,the arc of the EIS spectra gradually increased.The susceptible variety"Red Hat"showed significant differences from the control 3 days after inoculation,while the highly resistant variety"Fairyland"showed significant differences from the control 5 days after inoculation.(2)Before inoculation,the activities of chitinase,β-1,3-glucanase,and polyphenol oxidase in the highly resistant variety"Fairyland"were higher than those in the susceptible variety"Red Hat",indicating that the highly resistant variety had higher activities of pathogenesis-related proteases.(3)After inoculation,the activities of chitinase,β-1,3-glucanase,and polyphenol oxidase in the highly resistant variety"Fairyland"were higher than those in the susceptible variety"Red Hat",and the activities of both varieties were higher than those in the control.(4)After inoculation with powdery mildew fungus,the EIS parameters of both varieties showed significantly correlated with physiological parameters.Ψ had was highly significantly correlated with physiological parameters,with correlation coefficients of r=0.688(P＜0.01)for both chitinase activity and soluble sugar content,and r=0.555(P＜0.01)for β-1,3-glucanase activity.Therefore,Ψ can be used as the best EIS parameter to reflect the resistance of rose to powdery mildew.