EVALUATION OF CULTURAL AND PATHOGENIC VARIABILITY,HOST RANGE SCREENING OF CLAVIBACTER MICHIGANENSISSUBSP MICHIGANENSIS AND ASSESSMENT OF METHODS OFINOCULATION FOR DISEASE INCEPTIONRUCHI TRIPATHI*, K. VISHUNAVAT AND RASHMI TEWARI1Abstract Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial wilt and canker diseases intomato. Studies on cultural and pathogenic variability of Cmm has been carried under greenhouse andlaboratory conditions using 10 isolates of Cmm, collected from different regions of Uttarakhand andHimachal Pradesh States of India. A susceptible tomato cultivar Arka Vikash was used to evaluate thepathogenic variability. All the isolates of Cmm exhibited differential reaction on host as regard to symptomexpression. Isolate Cmm 10 was observed to be the most virulent isolate which caused complete plant deathwithin 18th day of inoculation. During studies on cultural variability, the bacterial colonies of most of theisolates were initially small, (1-4 mm diameter), mucoid and concave with three different pigmentations viz.,yellow, pale-white and orange which became glistening with the increase in age. Among the differentinoculation methods used, stem inoculation method followed by the foliar spray was found to be the mosteffective method for quick spread of the pathogen within the plant. Out of the five host species, particularlyof solaneceous family (Capicum frutescens, Capsicum annum, Solanum tuberosum, Solanum nigrum), exceptChenopodium album when screened for host range of the pathogen, the bacterium exhibited the diseasedsymptoms only in bell pepper. |