First report of Pectobacterium Carotovorum subsp. Carotovorum causing soft rot on white head cabbage in Turkey

Abstract

In October of 2016, soft rotted tissue on white head cabbage (Brassica oleraceaL. var.capitata subvar. Alba) were observed in commercial fields of Samsun province. Infected tissue was macerated in Bioreba extraction bags and extract was plated on Crystal Violet Pectate (CVP) medium. Cavity forming strains on CVP were facultative anaerobic with pectinolytic ability on potato tuber slices, grew at 37°C, produced acid from a-methyl glucoside, were negative for producing indole and reducing substances from sucrose. The sequence of 1400 bp of 16S rDNA gene (Weisburg et al., 1991) of strain BTC2 (GenBank accession No. MF314823) showed 99% identity to P. carotovorum subsp. carotovorumstrain ICMP 13550 (KY446059). Further confirmation of strain BTC2 was done with a 713 bp recA gene sequence (Waleron et al., 2002) (MF314822), which showed 99% similarity to P. carotovorum subsp. carotovorum strains in Genbank. Phylogenetic analysis based on 16S rDNA and recA sequences grouped our strain in the same cluster together with type strain ATCC 15713T and respective P. carotovorum subsp. carotovorum strains derived from GenBank. Pathogenicity was performed on cabbage plants (cv. Beyaz Bursa) by inoculation of 10 µl of suspension (108 cfu ml-1) using a syringe and hypodermic needle at the leaf axil. Inoculated plants were incubated in humid conditions at 28°C. Inky-black lesions and slimy decay developed within 72 h. To our knowledge,this is the first report of P. carotovorum subsp. carotovorum causing soft rot of white head cabbage in Turkey. © 2017, Edizioni ETS. All rights reserved.