Study On Rapid Detection Of Two Kinds Of Quarantine Pests Of Sugar Beet And Chemical Control Of Downy Mildew In Xinjiang

Sugar beet downy mildew(Peronospora schachtii) and sugar beet cyst nematode(Heterodera schachtii) are two kinds of pathogens which can cause devastating diseases to sugar beet. They were listed as entry plant quarantine pests by the government of our country in 2007. So far, studies about downy mildew and cyst nematode of sugar beet were reported less, and studies about molecular detection methods of both were reported less too. Meanwhile, studies about the controlling experiment in the filed was relative simple. These study was about the rapid detection technology of sugar beet downy mildew and sugar beet cyst nematode and pesticide control of sugar beet downy mildew. In this study, we established rapid molecular detection methods of downy mildew and cyst nematode of sugar beet and screened the efficient treatment, pesticide and its' dosage which had a better control against sugar beet downy mildew in the field.The results were as follows:(1) A study was carried out which was about molecular detection technology of sugar beet downy mildew and a rapid detection method of sugar beet downy mildew was established. 1) A conventional PCR detection method: According to AS-PCR, this study used universal primers(P-cox2F/P-cox2R) to amplify the target fragments of mt-DNA cox2 gene of sugar beet downy mildew pathogen. Then the specific primers BSP-F/BSP-R were designed which were highly specificity through other 6 kinds of control samples and the minimum detectable concentration of plasmid of sugar beet downy mildew pathogen was10 pg/?L. 2) A TaqMan real-time PCR detection method: According to ASPAA-PCR, this study used universal primers(P-cox2F/P-cox2R) to amplify the target fragments of mt-DNA cox2 gene of sugar beet downy mildew pathogen. Then TaqMan MGB probe BETEV-probe and primers BETEV-F/BETEV-R were designed which were highly specificity through detecting other 6 kinds of control samples and the minimum detectable concentration of plasmid DNA of sugar beet downy mildew was 10 fg/?L, and the optimal concentration was 800 nM/400 nM(primer/probe).(2) A study was started which was about molecular detection technology of sugar beet cyst nematode and a real-time PCR detection method of sugar beet cyst nematode was established. The sequence of 28 S rRNA gene of sugar beet cyst nematode was amplified with universal primers D2A/D3 B. TaqMan probe HS-28s-Probe and primers HS-28s-F/HS-28s-R was designed which were highly specificity through detecting other control samples and the minimum detectable concentration of sugar beet cyst nematode DNA was 100 fg/?L.(3) A chemical experiment was carried out including foliar spray, seed dressing and seed fumigations,in which the result of foliar spray had a better control against sugar beet downy mildew and the optimal pesticide was 50% dimethomorph WP at 40 g/667 m2. The results were as followed: 1) The control effect of foliar spray treatments: 50% dimethomorph WP at 40 g/667 m2 had the best control effect which was92.17%; 66.8% propineb WP at 1500 times dilution had the worst control effect which was 66.15%. 2) The control effect of seed dressing treatments: 35% metalaxyl-M emulsion at 0.60% dosage had the best control effect which was 67.19%; 95% fenaminosulf WP at 0.20% dosage had the worst control effect which was 42.2%. 3) The control effect of seed fumigation treatments: 99% vikane at 40 g/m3 had the best control effect which was 58.48%; 56% aluminium phosphide had the worst control effect which was37.37%.