Characterization of Bacterial Isolates Associated with Postharvest Decay of Potato in Bangladesh

A study was conducted in order to assess the bacteria associated with postharvest decay of cold storage potato. Rotten potatoes were collected from cold storage of Homna upazilla under Comilla district of Bangladesh. The experiment was conducted in the MS Laboratory of Department of Plant Pathology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Bangladesh. Four different bacteria (species) were isolated from the different rotten potato tubers using standard bacteriological analysis or Standard dilution method. The isolated bacteria were Pectobacterium carotovorum, Ralstonia solanacearum, Pseudomonas spp. and Bacillus spp. Among the bacteria isolated and identified from rotten potatoes the highest frequency was found in Pectobacterium (46%) followed by Ralstonia (26%) and Pseudomonas (13.3%) and Bacillus (13.3%). Bacteria were identified based on morphological and biochemical tests. All the isolated bacteria showed positive results except Bacillus spp in potato soft rotting test. Pectobacterium, Ralstonia solanacearum and Pseudomonas spp. were pathogenic for storage potato while Bacillus spp. was possibly a secondary micro flora or saprophyte that manifested as contaminants.