Species And Pathogenicity Identification Of Streptomyces Species Causing Potato Common Scab In Part Of Heilongjiang Province And Evaluation Of Cultivars For Scab Resistance

Common scab is one of serious diseases that affect potato market value in Heilongjiangprovince and even throughout China. Identification and characterization of the pathogens ofpotato common scab will contribute to breeding of resisting to common scab and development ofsuccessful control strategies.We sampled the tubers with typical scab lesions from8potatoplanted areas from2012to2013in Heilongjiang province, strains were isolated from thesetubers, and strains were detected pathogenic gene. the isolates with pathogenic gene were testedon radish seeding or potato.Species of isolates with pathogenic gene were identified by5pairs ofprimers on the basis of the differences of16S rRNA genes sequences or sequencing. Testing theresistance of potato cultivars to common scab by inculuming research in greenhouse. Mainresults were listed as follow:(1)There were Streptomyces. scabies、S. turgidiscabies and S. acidiscabies3specises at leastin Heilongjiang province, and S.scabies was dominat species. But S. turgidiscabies waspredominant species in Suihuan and Harbin.(2) There were four PAI genotypes(txtAB+/nec1+tomA+, txtAB+/nec1-/tomA+, txtAB+/nec1+tomA-and txtAB+/nec1-tomA-) in Heilongjiangprieince, pathogenic isolates are most complicated about the species and the genetypes of PAIfrom SuiHua and Suiling.(3) As inoculation was the isolate of HR15-1(S. aciscabies), KexinNo.18and Kexin No.13were medium susceptible, Dongnong303, Zhongshu No.5, KengshuNo.1, Zaodabai, Daxiyang, Helan No.15were very highly susceptible. Inoculation was StrainKS28-2(S. scabies), Kexin No.18and Kenshu No.1are medium susceptible, Youjin, KexinNo.13, Zhongshu No.5, Daxiyang, Helan No.15were very highly susceptible. Inoculation wasHR3-1(S. turgidiscabies), Kenshu No.1and Helan No.15were least susceptible cultivars, KexinNo18and Kexin No13were medium susceptible, Youjin and Zhongshu No.5were highlysuscdptible, Donong303, Zaodabai and Daxiyang were very highly susceptible.(4) There weredifferent virulence in S. aciscabies, S. scabies, S. turgidiscabies, S. turgidiscabies is weaker thanS. aciscabies and S. scabies.