PHYLOGENETIC STUDY OF RALSTONIA SOLANACEARUM IN GEORGIA

Abstract

Ralstonia solanacearum is the causative agent of one of the most devastating plant diseases, known as bacterial wilt or brown rot. In the conducted study, it was observed that the majority of the isolates, specifically 19 out of 20, were classified within Phylotype II, Race 3, and Biovar II. This classification aligns with the global distribution patterns of R. solanacearum, suggesting a widespread adaptation of this phylogenetic group. The regions of Akhaltsikhe, Khulo, Kobuleti, and Akhalqalaqi were identified as the primary sources of these isolates, highlighting the significant prevalence of the pathogen in these areas. However, a singular isolate (KT47) was identified as Phylotype I, Race 1/Biovar III, marking a distinct genetic lineage and suggesting the presence of diverse evolutionary pathways within Georgia. The phylogenetic analysis revealed that the Georgian isolates of R. solanacearum exhibit a considerable degree of genetic diversity.  The clustering of the majority of isolates into a single phylogenetic group was noted, with a close relationship to strains from Indonesia indicating a common lineage. However, the distinct classification of one isolate into Phylotype I suggests the introduction of diverse strains into the Georgian agricultural ecosystem, possibly through international trade or other means of transmission.