Pest Risk Analysis For The Importation Sunfower And Research On The Rapid Detection Search On Phomopsis Helianthi

This paper analysis importation sunfower pest.Research on pathogen biological characteristics and rapid PCR detection methods for Phomopsis helianthi.To establish conventional and real-time PCR assays method for the bacteria.Virulence was tested in laboratory in order to provide theoretical basis to quarantine treatment for the bacteria.According to guide line for pest risk analysis constituted by FAO.Analysis the pest risk for the importation sunflower.Through risk assessment,screened out a list of seven quarantine pests,which4fungi,2virus and1weeds.That is Albugo tragopogi var. helianthi,Phomopsis helianthi,Phoma macdonaldi, Verti-cillium wilt, Sunflower ringspot virus,Tobacco ringspot virus and Orobanche spp..Excepting Phomopsis helianthi and Phoma macdonaldi,risk rating are both medium.Management measures through quarantine approval,seed treatment with pesticide and fungicide,ports of entry,quarantine and isolation to try to grow the risk of input sunflower further reduced to an acceptable level.Based on risk analysis results,select the phomopsis helianthi in-depth study.In order to establish the conventional biological detection method.The nutrition and culture condition of ecological adaptability for phomopsis helianthi has been studied.The fungus has been cultivated7days in different nutrition and cultu-re condition(including media,carbon sources,nitrogen source,temperature,acidity and alkalinity, light condi-tion),and measured its colonies diameter and observed the growth status.And software SPSS12.0was used for corresponding calculation processing and statistical analysis.The fungus could grow better on the PDA and CMA than modified Czapek and WA.It could fully utilize the yeast extract and potassium nitrate.It could grow within6～34℃,and23～26℃was its optimum temperature.The fungus could grow in pH4.0to pH11.0,and its optimal pH was pH5.0to pH10.0.Full light was beneficial to the mycelium growth of phomopsis helianthi.Using fungal universal primers ITS4/ITS5on the PCR amplification of the bacteria.The PCR products were cloned,restriction analysis and sequencing.Using4kinds of restriction enzymes areas of ITS amplify-ed products were digested with different restriction enzymes sites.Primers PHDF1/PHDF2,PHDF3/PHDF4and TaqMan probe PHDF5were designed based on the unique sequence of the strains by DNAMAN softw-are.Establish conventional PCR and real-time PCR assays method for detecting at first in china.The reacti-on system was optimized and detected.Thus,we can accurately distinguish Phomopsis helianthi bacteria fr-om other Phomopsis bacteria.In the aspect of disposal technology,the toxieity of8fungieides to the bacteria were tested in laborato-ry.The result show that70%thiophanate-methyl,%hexaconazoles,9%Hymexazol,on the virulence of the bacteria was significantly lower than the70%Propineb,20%Cupric acetate,75%chlorothalonil,30%Ethylicin and80%carbendazim.So the three fungieides can be used for effeetive control of these diseases.