Phenotypic and genetic properties of Ralstonia solanacearum strains, the causal agent of bacterial wilt of potato isolated from Kurdistan province

Phenotypic properties and genetic diversity of 24 strains of Ralstonia solanacearum causing bacterial wilt of potato plants isolated from various locations in Kurdistan province was investigated. According to physiological and biochemical properties, 19 and 5 of isolates were identified as R. solanacearum biovar 2 and 3, respectively. Identification of isolates was further confirmed by PCR using 759/760 primers specific to R. Solanasearum. Based on multiplex PCR, all strains identified as biovar 2 were belonging to phylotype II. In multiplex PCR, strains identified as biovar 3 produced R. solanacearum species-specific fragment but failed to produce expected phylotype-specific amplicon. Genetic diversity of selected strains was investigated by rep-PCR fingerprinting using REP, ERIC and BOX primers. UPGMA analysis of combined data obtained from rep-PCR fingerprint pattern using Dice,s coefficient revealed the strains could be separated into 5 groups at a similarity level of approximately 43%. There was no direct relationship between geographic locations of strains and grouping. Obtained results demonstrated the existence of a genetic diversity among R. solanacearum strains causing bacterial wilt disease of potato in Kurdistan province.