Diversity of Bacterial Soft Rot-Causing Pectobacterium Species Affecting Cabbage in Serbia

• Published in: Microorganisms (Basel) Vol. 11; no. 2; p. 335
• Main Authors: Jelušić, Aleksandra, Mitrović, Petar, Marković, Sanja, Iličić, Renata, Milovanović, Predrag, Stanković, Slaviša, Popović Milovanović, Tatjana
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29.01.2023; MDPI
• Subjects: Agricultural production; Bacteria; bacterial soft rot; Brassica oleracea; cabbage; Discoloration; Drinking water; Exudation; Genes; Genetic diversity; Humidity; Hybrids; MLSA; Multilocus sequence typing; Odors; Pathogenicity; Pathogens; Pectobacterium; Pectobacterium spp; Phylogeny; Polymerase chain reaction; Potatoes; rep-PCR; Sequence analysis; Signs and symptoms; Soft rot; Species; Virulence; Serbia; rep-PCR; pathogenicity; cabbage; bacterial soft rot; virulence; Pectobacterium spp; MLSA
• ISSN: 2076-2607; 2076-2607
• DOI: 10.3390/microorganisms11020335

The aim of this work was to identify and characterize the pectolytic bacteria responsible for the emergence of bacterial soft rot on two summer cabbage hybrids (Cheers F1 and Hippo F1) grown in the Futog locality (Bačka, Vojvodina), known for the five-century-long tradition of cabbage cultivation in Serbia. Symptoms manifesting as soft lesions on outer head leaves were observed during August 2021, while the inner tissues were macerated, featuring cream to black discoloration. As the affected tissue decomposed, it exuded a specific odor. Disease incidence ranged from 15% to 25%. A total of 67 isolates producing pits on crystal violet pectate (CVP) medium were characterized for their phenotypic and genotypic features. The pathogenicity was confirmed on cabbage heads. Findings yielded by the repetitive element palindromic-polymerase chain reaction (rep-PCR) technique confirmed interspecies diversity between cabbage isolates, as well as intraspecies genetic diversity within the group of isolates. Based on multilocus sequence typing (MLST) using genes , , , and , five representative isolates were identified as (Cheers F1 and Hippo F1), while two were identified as (Hippo F1) and (Hippo F1), respectively, indicating the presence of diverse species even in combined infection in the same field. Among the obtained isolates, was the most prevalent species (62.69%), while and were less represented (contributing by 19.40% and 17.91%, respectively). Multilocus sequence analysis (MLSA) performed with concatenated sequences of four housekeeping genes ( , , , and ) and constructed a neighbor-joining phylogenetic tree enabled insight into the phylogenetic position of the Serbian cabbage isolates. Bacterium was found to be the most virulent species for cabbage, followed by , while all three species had comparable virulence with respect to potato. The results obtained in this work provide a better understanding of the spreading routes and abundance of different spp. in Serbia.