| Myzus persicae (Sulzer) also named Green peach aphid is one of the most important pest on tobacco, it has caused tremendous economic losses on the production of tobacco. For example, it had caused direct and indirect economic losses about 20 millions at Chongqing in 2003. It is also the most main insect vector of Cucumber Mosaic Virus (CMV) , by transmitting CMV to tobacco . In recently study ,it showed that the harm of CMV on tobacco raised year-by-year . In order to control pest and dieases , ensure output and quality of tobacco , the CMV infecting tobacco at Wulong county was isolated by a series of experiments . At the same time , the interaction with M. persicae , temperature and bobacco infected CMV were evaluated in this paper. Through this project , major detoxification and target enzyme of M. persicae were studied , as well as other ralated factors , such as energy sourses . The main results are as follows:1.The isolation and identification of CMVCMV infecting tabacco was isolated by using indicating plant (Nicotiana glutinasa) and dpot host (Chenopodium qunoia), and was identified by a series of indicating plants, indirect ELISA and RT-PCR. There were different symptoms on different indicating plants .The symptom of mosaic was presented on Nicotiana tabacum , Nicotiana glutinasa, Nicotiana sumsam, K326, Cucumis floridana and Citrullus vulgaris, the symptom of spot was presented on Chenopodium qunoia and Chenopodium amarauticolar. The OD of virus sample was bigger than 0.5, and the ratio between virus sample and negative control was bigger than two. RNA distilled from CMV was pure and acquired DNA segment the length of 757 bp . It means that the unknowed virus is CMV.2. Development and reproduction of M. persicae feeding on tobacco infected CMV at different temperatureThe developmental duration and reproduction of M. persicae that are reared on the tobacco infected CMV are researched under the different temperature . There are five temperature which contains 19℃,22℃,25℃,28℃and 31℃.When increase the temperature , the adult longevity and generation duration increased, the fecundity weakened . Under the five temperature , its adult longevity and generation duration were the longest at 19℃and the shortest at 31℃When feeding on the tobacco infected cucumber mosaic virus , its fecundity was the highest at 19℃and the lowest at 31℃. Based on the parameters of the life table ,of the 5 temperature studied , the temperature at 25℃is considered to be the most suitable for M. persicae.lt was suggested that the development and reproduction of M. persicae might be related to the temperature and tobacco infected cucumber mosaic virus. 3. Some enzymes in M. persicae on CMV-infected tobacco plants3.1 CarboxylesterasesCarboxylesterases (CarE) in M. persicae on CMV-infected tobacco plants (treatment) were determined, respectively, with those on the healthy plants (CK) as control. The study results showed that the specific activity of CarE on CMV-infected tobacco (0.3618μmol/(mg·min) was significantly higher than that on the healthy plants (0.1858μmol/(mg·min)), and meanwhile, there was a significant individual frequency distribution of CarE specific activities in M. persicae on CMV-infected and healthy plants.3.2 Acid phosphatases (ACP) and Alkaline phosphatases (ALP)The specific activities of ACP extracted from M. persicae on treatment and those on the CK were 101.6025±0.1582μmol / (mg·30min) and 143.7626±4.3368μmol/(mg·30min), and the specific activities of ALP on treatment and those on CK were 3.7356±0.0739μmol/(mg·30min) and 6.7240±0.133μmol/(mg·30min). Compared with the CK , the specific activities of ACP in treatment was 0.71-fold lower and the specific activities of ALP in treatment was 0.56-fold lower. The statistics analysis showed that the difference between treatment and CK for the same two enzyme specific activities were significant.3.3 GSTs,SOD and CATThe activities of GSTs of treatment was significantly lower than that of CK (P＜0.05), and the activities of SOD and CAT of treatment were significantly higher than those of CK. The affinities of GSTs from treatment to substrate reduced glutathione (GSH) and 1-chloro-2,4-dintrobenzene (CDNB) were both higher than those from CK.3.4 Acetylcholinesterase (AChE)The activity of AchE per insect in treatment was significantly higher than those of CK. There was significant difference between affinities (Km) of AChE toward ATChI from treatment and CK.4 Comparison of triacylglycerol and glucose concentrations in treatment and CK M. persicaeThe reserves of the triacylglycerol and glucose in treatment were highly significant than that in CK. The reserves of the triacylglycerol extracted from M. persicae on treatment and those on the CK were 145.5734±0.0574μg/head and 86.3034±2.7341μg/head. And the reserves of the glucose is 9.0814±0.5230μg/head of treatment and 6.6064±0.1344μg/head of CK.5 Laboratory observation on control of tobacco cucumber mosaic virus with four different medicament chemicalFor selecting more effective chemicalsto control CMV, the laboratory control effect experiments of Kangkai at dilution of 2000, Jiatai at dilution of 500, Haopu at dilution of 500, and Junkeduke at dilution of 800 were conducted. Spraying the chemicalsto on tobacco before inoculated the CMV to them, the suits showed that the control effects of Kangkai at adilution of 2000 was 71.54% , and that of Jiatai of 500 was 69.06%, Haopu of 500 was 65.29%, Junkeduke of 800 was 28.76%. The contro effects of Junkeduke were worse.
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