乌兰察布地区马铃薯疮痂病新型病原菌种类及致病性鉴定

Species and Pathogenicity Identification of Streptomyces Species Causing Potato Common Scab in Ulanqab Area

研究旨在对土壤中马铃薯病原菌分离鉴定,明确致病基因及致病能力。对开展抗疮痂病育种及综合防治具有重要意义。对采集的发病薯块,采用组织分离法和涂布稀释、通过16S r DNA测序进行种类鉴定并构建系统发育树,PCR鉴定致病基因,萝卜幼苗法、小薯片法和盆栽接种鉴定测试致病性。共分离鉴定致病性链霉菌4种,分别为Streptomyces scabies、Streptomyces thermocarboxydus、Streptomyces rubrogriseus、Streptomyces kanamyceticus。以上菌株分别接种希森3号进行致病性检测,测试结果表明,上述4种链霉菌均能引起块茎发病,且致病基因组合均为txtAB+/tomA+/nec1+;本研究共鉴定马铃薯疮痂病致病性链霉菌4种,除Streptomyces scabies外,Streptomyces thermocarboxydus、Streptomyces rubrogriseus、Streptomyces kanamyceticus 3种病原菌为马铃薯疮痂病新型致病菌。

This research aimed to isolate and identify potato common scab pathogens in soil,and clarify the pathogenic genes and pathogenicity.It is of great significance to carry out breeding and comprehensive prevention and control of scab disease.The collected diseased tubers were identified by tissue separation and coating dilution,and the phylogenetic tree was constructed by 16S rDNA measurement.The pathogenic genes were identified by PCR,and the pathogenicity was tested by radish seedling method,small potato chip method and pot inoculation.Four species of pathogenic Streptomyces were isolated and identified as Streptomyces scabies,Streptomyces thermocarboxydus,Streptomyces rubrogriseus and Streptomyces kanamyceticus.All strains were inoculated with‘Xisen 3’for pathogenicity test.The test results showed that four Streptomyces could cause tuber disease,and the pathogenic gene combination was txtAB+/tomA+/nec1+;in this study,a total of 4 pathogenic Streptomyces species were identified.Streptomyces thermocarboxydus,Streptomyces rubrogriseus and Streptomyces kanamyceticus were new pathogens of potato common scab.