ISOLATION AND IDENTIFICATION OF BACTERIA ASSOCIATED WITH ROTTEN POTATOES IN SELECTED COLD STORAGE OF COMILLA

Abstract

A study was conducted in order to assess the bacteria associated with post-harvest 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 during the period of November 2016 to August 2017. Four different bacteria (species) were isolated from the different rotten potato tubers following dilution plate method on NA medium. The isolated bacteria were Pectobacterium carotovorum,Ralstonia solanacearum, Pseudomonas spp. and Bacillus spp. Out of these four bacteria isolated, Pectobacterium and Ralstonia were more abundant. 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.