| Five new diseases which are Saposhnikovia divaricata bacterial soft rot,bacterial leaf rot and Saposhnikovia divaricata stem blight were firstly reported for the world and Saposhnikovia divaricata leaf spot,powdery mildew,spot blight were firstly reported in Jilin Province,China.Sympotoms of the six diseases were described in detail,and biological characteristics and pestcides-screening indoor on some of pathogens were studied.Saposhnikovia clivaricata bacterial soft rot were foundon stalk near ground and root were mainly damaged by the pathogens,gradually extended to the entire root and internal softrot with mucus flow,infected plants departed easily.The strains were straight or curved rods,gram-negative,peritrichous flagella two or more,37℃growth positive,5%NaCl growth positive,sucrose reduction negative,malonic salt negative,potato rot positive,gelatin liquefaction negative.G+Cmol%-53.2%.According to the corresponding references the pathogen was identified as Pectobacterium carotovora subsp,carotovora(Jones 1901) Bergey et al.1923.Saposhnikovia divaricata bacterial leaf rot.The damaged leaves are necrosis,shrinkage and deformity.The strains gram-negative,polar flagellum one,41℃growth negative,oxidase negative,potato rot positive,arginine dihydrolase negative,levan negative,gelatin liquefaction positive,nitrate reduction negative,uslization of glucose,tartrate acid,sorbite for growth positive and acid from sucrose,trehalose,β-alanine and geraniol for growth negative,D(-)tartrate acid positive.G+Cmol%-58.3%.According to parts of《Bergey's Manual of Determinative Bacteriology》9th ed,the strains were identified as Pseudomonas viridiflava pv.saposhnikovia W.Xue pv.nov.Saposhnikovia divaricata septoria blight.Brown small spots appear on the leaf surface at early stage of disease,gradually formed round or nearly round,diameter of 2～5 mm,brown ring spot with light colorcenter and dark border,in which the small,dark pycnidium of fungus visible to the eye formed both sides of leaves,the pycnidium scattered or gregarious,Spherical or nearly spherical,connidia needle-shaped,blunt round at base,colorless and transparent,integrity or bend slightly.Slighty tipped top,oil ball observed,body and pathogenicity(18-) 20～45(-48)×1.5(-1.7)～2.5(-3.1)μm.According to the appearance of the disease, morphorlogy of the pathogen,the pathogens were identified as Septoria saposhnikoviae G.Z.Lu et J.K.Bai.Saposhnikovia divaricata powdery mildew.Powdery mildew was observed as small gray-white patches of mycelium on the both side of leaves,the whitish,powdery spot or areas eventually become spotted with minute blackdots,which are the cleistothecia or sexual frusting bodes of the fungus,infected leaves gradually become yellow and necrosis.Conidia nearly cylindrical,(20.4-) 25.3～36(-40.6)×(10.0-)12.5～16.2(-17.8)μm,ascocarp scattered or nearly gregariae,often dark brown,flat-sphere shape,the appendage 7(-8)～38(-48) nearly,double fork-shaped or irregular branches.Ascus 2～4(-6)nearly egg-shaped,ascospore(2-) 3～(6-)8, eggs to oval shape.According to the symptoms and morphology of the pathogens,the pathogens were identified as Erytsiphe heraclei DC.Saposhnikovia divaricata leaf blight.leaf spot with ring were the main symptoms of the disease,the spot has graynish-brown center with slightly depression and uplift dark-brown borders.Later in the growing season,pycnidia formed on the surface of leaves,scattered or gregarious,spherical or fiat spherical;conidia ellipse shaped,body(5-)7～9(-11)×2(-4)～3.5(-3.9)μm,long-fusiformed,single cell,colorless,the pathogens were identified as Phyllosticta apii Halsted.Saposhnikovia divaricata stem blight.Stem blight were the main sympotoms,which often obeseved at seedstalk and caused a heavy impact on seed yield,stem spot occurred on the lower of the seedstark flower buds at first,gradually spread around stem and eventually lead to die of seedstalk.Small black blots that are the pycnidium of the pathogen were observed on dead seedstalk.Pycnidium scattered or gregarious,spherical;conidia long spindle shaped,acuate on both ends,body(6.1-)6.5～10(-14)×2.5(-2.8)～(2.5-)3μm,single cell with two oil balss,colorless.Comparison with corresponding reference,the pathogen were identified as Phoma foeniculina Saccardo.Saposhnikovia divaricata bacterial soft rot,bacterial leaf rot and Saposhnikovia divaricata stem blight were not reported in the world,so Saposhnikovia divaricata were new record hosts of their pathogens. Saposhnikovia divaricata leaf spot was firstly reported in Jilin province,China.Pesticides were screeded for control of two fungical diseases with methods of inhabition zone and growth rate indoor,the lowest effective concentration and the diameter of inhabition zone of eight bactericides to bacterial soft rot and bacterial leaf rot were tested indoor.The results showed that the inhabtion rate of hymexazol and carbendazim were the highest to Phyllosticta apii Halsted and Phoma foeniculina Saccardo. So they were the preferred fungicides used for the field trial.Streptomycin sulfate was not only the best effective to inhabit the pathogen,but also the lowest effective concentration to inhabit pathogen,so streptomycin sulfate was the preferred bactericide to Pectobacterium carotovora subsp,carotovora and Pseudomonas viridiflava for field trial.
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