Characterization and differentiation of soft rot causing Pectobacterium carotovorum of Indian origin

Abstract

Twenty different strains of Pectobacterium carotovorum (Pcc) were recovered from vegetable-growing fields of Vadodara, Gujarat (India) using a plant host enrichment approach during the years 2006–9. The isolated strains, based on differences in physiological and biochemical features, were classified into five different biovars, and then identified as Pectobacterium carotovorum (Pcc) by species-specific PCR and 16S rDNA sequences. Moreover, these Pcc strains were also differentiated based on virulence traits, plant cell wall degrading enzymes production and phylogenetic analysis of 16S rDNA sequence and Repetitive extragenic palindromic—PCR (rep-PCR). High genetic variability, independent of their pathogenicity, was revealed among these Pcc strains by rep-PCR typing using four different primer sets . Factors other than the plant host specificity seem to correlate with genetic variability of these economically important Pcc strains. Significantly, polyphasic characterization of the Pcc strains clearly reveals the heterogeneity among them. The present studies can be considered as useful epidemiological surveillance (or distribution) of soft rot causing Pcc in the semi arid region of India.