The Use Of Genetic Barcode Kits In Quarantine For Phytophthora Sp. And Tilletia Sp. And The Risk Analysis

As the key focus of the routine quarantine,Phytophthora sp.and Tilletia sp.have many important quarantine pathogenic fungus.Through the risk analysis,the purpose is realizing the fundamental state and the incoming risk of these fungus,clearing the risk rank,and proposing risk management practices,which could be provided reference for the inspection and quarantine work.Based on the risk analysis of Phytophthora sp.and Tilletia sp.,Phytophthora sp.was considered having 7 high-risk species,including:P.cambivora,P.erythroseptica,P.sojae,P.syringae,P.hibernalis,P.medicaginis,P.ramorum;Tilletia sp.was considered having 3 high-risk species,including:T.indica,T.controversa,T.walkeri.At present,T.walkeri has not been included in the list of harmful organisms which not be allowed to enter.After extensive collection of related documents and data,comprehensive analysis reveals that the possibilities of entering,colonizing,dissemination for T.walkeri is high,and causing severe economic harm.This article suggests to increase it as the entry plant quarantine pest.The existence of approximate kind increases the difficulty of the inspection and quarantine work.Genetic barcode kits has the advantages of simple operation and reliable results,and doesn't rely on the experience technical of quarantine personnel.It is important to research the genetic barcode testing technology for Phytophthora sp.and Tilletia sp.In this study,we developed two genetic barcode kits for Phytophthora sp.and Tilletia sp.(Phytophthora genetic barcode testing web site,http://58.211.92.14:8080/myap;Plant quarantine organisms identification system,http://58.211.92.14/sysinspect/kj.aspx),in oder to identify pathogenic fungus of Phytophthora sp.and Tilletia sp.quickly and accurately.In the actual work,effectively solve the difficulty of identification at the species level.Genetic barcode kits are presented in the form of the web site,it's very convenient for users.The genetic barcode kit of Phytophthora sp.involves four gene segments,including ITS?28S?60S?COX2,and having the primer?reaction system and condition for PCR amplification.Through the analysis software which is developed by ourselves,finding out 238 specific nucleotide sites,including 86 sites in ITS in relation to 8 species,42 sites in 60S in relation to 13 species,44 sites in 28S in relation to 12 species,66 sites in COX2 in relation to 13 species.Except P.drechsleri,other species all have specific nucleotide sites,reaching the basic realization of the identification at the species level for Phytophthora sp.Because lack of gene sequence,the genetic barcode kit of Tilletia sp.only use the gene segment of ITS.Through the analysis software,finding out 67 specific nucleotide sites,in relation to 6 species.Through the genetic barcode kits,only can realize the identification of several species.With the continuous development of the research,we can try to find more nucleotide sites on other gene segments,improving the genetic barcode kit of Tilletia sp.further.