doiSerbia

Pectobacterium carotovorum subsp. carotovorum - the causal agent of broccoli soft rot in Serbia

Gašić Katarina (Institute for Plant Protection and Environment, Belgrade)
Gavrilović Veljko (Institute for Plant Protection and Environment, Belgrade)
Dolovac Nenad (Institute for Plant Protection and Environment, Belgrade)
Trkulja Nenad (Institute for Plant Protection and Environment, Belgrade)
Živković Svetlana (Institute for Plant Protection and Environment, Belgrade)
Ristić Danijela (Institute for Plant Protection and Environment, Belgrade)
Obradović Aleksa (Faculty of Agriculture, Belgrade)

Soft rot symptoms were observed on broccoli plants in several commercial fields in the western part of Serbia. Six strains of bacteria were isolated from diseased tissues and identified as Pectobacterium carotovorum subsp. carotovorum using conventional bacteriological and molecular methods. All strains were non-fluorescent, gram-negative, facultative anaerobes, oxidase-negative and catalase-positive, causing soft rot on potato and carrot slices and did not induce hypersensitive reaction on tobacco leaves. They grew in 5% NaCl and at 37°C, did not produce acid from α-methyl glucoside, sorbitol and maltose, nor reducing substances from sucrose, but utilized lactose and trehalose, and did not produce indole or lecithinase. The investigated strains showed characteristic growth on Logan’s medium and did not produce blue pigmented indigoidine on GYCA medium nor “fried egg” colonies on PDA. The identity of strains was confirmed by ITS-PCR and ITS-RFLP analyses and by sequence analysis of the 16S rRNA gene. In a pathogenicity assay, all strains caused tissue discoloration and soft rot development on inoculated broccoli head tissue fragments.

Keywords: broccoli, Pectobacterium carotovorum subsp. carotovorum, Soft rot, 16S rRNA gene, ITS-PCR-RFLP

Projekat Ministarstva nauke Republike Srbije, br. III46008: Development of integrated management of harmful organisms in plant production in order to overcome resistance and to improve food quality and safety i br. TR31018: Introduction of integrated managing and usage of modern principles in plant protection for the control of harmful organisms