Development And Reproduction Of M. Persicae (Sulzer) Feeding On Tobacco Infected PVY At Different Temperature

Myzus persicae(Sulzer),which also named Green peach aphid,is one of the most important pests on tobacco,and it is the most main insect vector of Potato Virus Y(PVY),which can transmit PVY to tobacco.According to study and investigations over the last few years,the harm of PVY on tobacco is increasing year-by-year.The present studies were to isolate and identify tobacco PVY in Chongqing,and investigate the ability of Myzus persicae(Sulzer)to transmit tobacco PV).The effect of tobacco PVY and temperature on population and life-table parameters of M.persicae (Sulzer)was also investigated.The main results are as follows:1 The isolation and identification of PVYPVY was isolated by using indicating plant(Nicotiana sumsam)and necrosis spotted host (Chenopodium amarauticolar),and was identified biology and serology by using the genetic lineage of differential host and indirect ELISA.Different symptoms were observed in different hosts.The systemic mosaic symptom was found in y85,y87,Nicotiana tabacu,Nicotiana glutinasa and Nicotiana sumsam;Necrosis spot was observed in Chenopodium amarauticolar.The symptom of infection was not found in Comphrana globosa.The OD of virus sample was over 0.5,and the ratio of virus sample to negative control was more than 2.That means the virus is PVY.2 The ability of transmitting tobacco PVY by Myzus persicae(Sulzer)The mortality method of the source plants was conducted to investigate the PVY obtaining time, spreading time,and spreading numbers and effect of virus by the aphids.The results showed that virus can be picked up or spread by aphid within 0.5 minutes,the incidence of a disease obviously increased with increasing of time of picking up and spreading virus within three minutes.The incidence of a disease increased slowly for more than three minutes.Transmission of the PVY was achieved by one adult aphid.The incidence of a disease increased obviously with increasing of aphid number for no more than three aphids per plant;but a slow increase of the incidence was found at the number of aphids per plant over three.All of the nymphae(2^nd-3^rd),the apterous and the alatate can transmit PVY,and the ability of transmitting PVY was in the order of alatate＞apterous＞nymphae(2^nd-3^rd).3 Development and reproduction of M.persicae(Sulzer)feeding on tobacco infected PVY at different temperatureThe growth and reproduction of M.persicae(Sulzer)were investigated in healthy and infected PVY tobacco under different constant temperature(19℃,22℃,25℃,28℃and 31℃).The results indicated that the duration and number of reproduction,post-reproduction duration,adult longevity and generation duration all decreased with increasing of temperature in healthy tobacco.The highests of reproduction duration,adult longevity and reproduction number were observed at 19℃, which were 20.705d,24.589d and 47.10,while the lowests were found at 31℃,which were 4.061d, 7.242d and 6.06.Furthermore,the highests of finite rate of increase(λ)and intrinsic rate of natural increase(rm)were found at 25℃.That suggested that the most suitable temperature for growth and reproduction of M.persicae(Sulzer)was at 25℃.The duration and number of reproduction,post-reproduction duration,adult longevity and generation duration all decreased with increasing of temperature in infected PVY tobacco.The highests of reproduction duration,adult longevity,reproduction number and the net reproductive rate (R0)were recorded at 19℃,and reproduction duration,adult longevity and reproduction number were 19.013d,21.191d and 38.347,while the lowests of reproduction duration,adult longevity, reproduction number and the net reproductive rate(R0)were found at 31℃,and reproduction duration,adult longevity and reproduction number were 2.694d,5.611dand 2.722.Significant difference of M.persicae(Sulzer)was observed between healthy and infected PVY tobacco at the same of temperature.The duration and number of reproduction,adult longevity and generation duration of M.persicae(Sulzer)in healthy tobacco were greater than infected PVY tobacco.It suggested that healthy tobacco is more favorable for M.persica(Sulzer)growth than infected PVY tobacco.