Preliminary Studies On Mechanism Of Physiological And Biochemical And The Inheritance Of Tobacco Resistance To CMV

This paper studied the correlation of disease index between seedling which was inoculated with CMV and adult plant which was inoculated with CMV in net room or infected in nature, Jintai No.18,Tiebazi,Xinnong No.3-1,NC89,Yunyan85 etc.7 different tobacco cultivars were used on trail. On the one hand, selected 3 different varieties to study tobacco & CMV interaction in the physiological and biochemical mechanisms of tobacco preliminary at seedlings, on the other hand, the two parents and F1 generation were used to discuss the inheritance of resistant after artificial inoculation with CMV preliminary at seedlings. The result indicated that:1. The disease index between seedling after artificial inoculation and adult were highly positive correlation. Seedling disease index and the adult disease index after artificial inoculation or infection in nature were significant positive correlation (r=0.975**;r=0.987**); And adult inoculated disease index and natural incidence of disease index was significant positive correlation (r = 0.974 **).So seedlings artificial inoculation can be used as the supplementary means to identify and screen excellent anti-CMV materials rapidly at seedling.2. Activities of POD, SOD, CAT and APX activity of susceptible varieties were higher than that of resistant varieties in CK. After inoculation with CMV, in the first day ,the enzymes activities of different varieties were increased, the increase amplitude of SOD activity in the resistance response were higher than that of the susceptible response; the increase amplitude of POD,CAT and APX activity in the resistance response were higher than that of the susceptible response. SOD activity change ratio after inoculation in the susceptible varieties were higher than that of the resistance varieties at prophase (1-5 d) (Tiebazi>XinnongNo. 3-1>NC89), POD and APX activity rate of change in the average level was also the case. Therefore, the change ratio of SOD(1-5d),POD and APX can be regarded as the supplementary means of the tobacco identification of resistance to CMV. CAT activity after inoculation disordered, it whether can be used as indicators of tobacco resistance identification has yet to be studied further.3. CK processing, the better resistance to CMV, the higher of PPO and PAL activity, that is when tobacco wasn't inoculated CMV, PPO and PAL activity and tobacco resistance were positive correlation. After inoculation, the resistance of different varieties had increased, the increase amplitude of PPO and PAL activity in the susceptible varieties were higher than that of the resisitance varieties, and from the reaction time, the former was faster than the latter. PPO and PAL activity and the resistance were positive correlation after inoculation.4. MDA content, the chlorophyll content and root activity of tobacco were close to tobacco resistance to CMV after inoculation, and they can be used as physiological indexes which was the measure of resistance to CMV. The content of MDA were higher than CK after the inoculation with CMV in different resistant varieties, and the increase amplitude of susceptible varieties were higher than that of resistant varieties; Chlorophyll content of resistant varieties had a increase stage or very small decrease amplitude at prophase after inoculation, but CMV gradually invaded to reduce chlorophyll content with the extension of inoculation, and the decrease amplitude of resistant varieties were less than susceptible varieties; Either resistant varieties or susceptible varieties the root activity were enhanced, and the increase amplitude of the root activity in resistant varieties were higher than that of susceptible varieties, however, the time of maintaining high root activity is very transient, the root activity of resistant varieties increased slowly at the beginning, then gradually growing quickly, and maintain a longer time. The root of tobacco were damaged with the further invaded, subsequently, the root of activity declined, and the decrease amplitude of susceptible varieties were higher than that of resistant varieties.5. After inoculation with CMV of Yunyan 85, Jintai No.18 and the F1 hybrid generation YJ, the defense enzyme activities, MDA content, and other physiological indexes, and the change ratio of F1 were between the two parents, that is the resistance of tobacco to CMV was controlled by quantitative genetic,Its deeper levels of discussion will need to further research on the molecular level.