Studies On Induction And Mechanism Of Resistance To TMV With Non-fungicidal Compounds On Tobacco

Tobacco Mosaic Virus Disease is a systemic virus disease, and also one of the most destructive diseases in the production of tobacco. A systematic study was carried out and determined at three different levels. One aspect was resistance of different tobacco cultivars,. Another was resistance induction to TMV with different non-fungicidal compounds on different tobacco cultivars. Still another aspect was the substantial changes of activities of Phenylalanine Ammonia Lysase (PAL), Peroxidase (POD), Polyphenol oxidase (PPO) activities and content of total phenolics compounds, total flavonoids and that of chlorophyll after induction and inoculation by non-fungicidal compounds and TMV on tobacco. The results showed: The resistance of different cultivars to TMV was very different. Among them, CVS5 and 9205 were resistant cultivars, G80 was susceptible cultivars, Duncan test showed the significance level of them was 0.05. The difference of CV87, Longyan85l, Zhongyan9o, CF8O, NC 82, Nc89, 9405 and 87-8340 was not significant. After inoculation with TMV, systemic resistance non-fungicidal compounds could induce on tobacco, delay the occurrence of disease, relieve the severity of disease. The further experiment was proceeded 4 concentrations and 3 treatment methods after the primary induction with 4 non-fungicidal compounds. The result showed that the comparative induction effect of the 4 compounds was different. Salicylic acid could best induce systemic resistance on different tobacco cultivars. The analysis of variance and Duncan test showed that different compounds with different concentrations and treatment methods could induce different resistance to TMV on tobacco. Induction and mechanism of resistance to TMV with non-fungicidal compounds on tobacco had been premarily studied. The content of total phenolics compounds, total flavonoids, chlorophyll and activities of PAL, POD, PPO were tested. The result showed: the systemic resistance could be induced to TMV by salicylic acid on tobacco. The activities of PAL, POD, PPO and content of total phenolic compound, total flavonoids, chlorophyll had shown distinct regular changes of the systemic acquired resistance (SAR) after induction and inoculation. The activity of PAL and content of total flavonoids had close relation with SAR of resistant or susceptible tobacco cultivars. SAR was found positively related to resistance. After induction and inoculation, the activity of PAL and content of total flavonoids increased greater and earlier on resistant cultivar than on susceptible one. They could be used as biochemical indexes to indicate inducted resistance. The activities of POD, PPO and content of total phenolic compounds were found positively related with SAR of resistant or susceptible cultivars to some extent. They could be used to indicate induced resistance as auxilary methods. The relation between chlorophyll content and SAR had not been confirmed and required further investigation. Name: Liu, Taiguo Specialty: Plant Pathology Advisor: Li, Yonghao...