Inhibitory Of Different Treatment Methods On PVYros And TuMV

Potato virus Y(PVY)and Turnip mosaic virus(Tu MV)are members of Potyviridae and potyvirus.They have a wide range of virus hosts and have seriously threatened the industrial development of potato,tobacco and other crops.This thesis studied the inhibitory effects of different treatment methods,including 22/30℃ poikilothermic treatment,nitrite passivation and plant extract treatment on the two viruses.The results are as follows:(1)The results of Nicotiana benthamiana infected by PVYros treated at 22/30℃showed that the symptoms of the upper leaves of the treated plants gradually decreased and disappeared completely after 12 days.The virus content reached a healthy level by Western blot.The results showed that 22/30℃ poikilothermic treatment could significantly inhibit virus proliferation.After 30 days,the new leaves of the treated plants had no symptoms of virus infection and no virus accumulation was detected.The plants treated at 22/30℃ were cultured at 22℃ for 70 days,and the new leaves without virus infection symptoms were inoculated on healthy Nicotiana benthamiana plants again to detect whether the new leaves had virus infection.The results showed that the plants did not show virus infection symptoms and virus accumulation 7 days after inoculation.The results showed that the variable temperature pretreatment could significantly inhibit the infection(2)In order to verify whether the new leaves of symptomatic recovery plants have cross protective effect on PVYros and Tu MV,the new leaf tissues were inoculated in Benshi tobacco,and PVYros and Tu MV were challenge inoculated 7 days later.No obvious symptoms of virus infection and virus accumulation were observed in the treated plants after challenge inoculation.This showed that the new leaves recovered after 22/30℃temperature change treatment had a good cross protection effect on PVYros and Tu MV.The study on the preventive effect of new leaves of symptom recovery plants on PVYros found that only one of the 12 strains of Nicotiana benthamiana inoculated with new leaves showed virus infection symptoms.It shows that it has good preventive effect.(3)PVYros and Tu MV viruses were pretreated with nitrite,and then inoculated into normal Nicotiana benthamiana plants to study the inactivation effect of nitrite on the virus.The results showed that after nitrite treatment,both viruses could not infect Nicotiana benthamiana,showed no symptoms of virus infection,and could not detect virus accumulation.It shows that nitrite has a certain passivation effect on PVYros and Tu MV.(4)The inhibitory effects of plant extracts on Tu MV and PVYros were studied.The results showed that the four plant extracts(Cnidium monnieri,onion,Allium mongolicum and reed)showed certain preventive,therapeutic and passivation effects on Tu MV.Among them,onion extract had significant preventive effect on Tu MV,and only one of the six inoculated Nicotiana benthamiana was infected.Osthol extract had significant passivation effect,and only 1 of the 6 inoculated Nicotiana benthamiana strains developed disease.In the treatment test of four plant extracts,3 of the 6 plants inoculated respectively were infected.The inhibitory effect of four plant extracts on PVYros was not obvious,and the number of diseased plants was higher than that of ningnanmycin treatment.