Pectobacterium brasiliense as a Causative Agent for Soft Rot of Radish in Korea

Abstract

In October 2021, soft rot disease seriously affected radish crop in Dangjin, Chungcheongnam-do, Korea. The infected radishes were stunted and turned dark green, with yellowish leaf foliage. A slimy, wet, and decayed pith region was observed in the infected roots. The bacterial strain KNUB-03-21 was isolated from infected roots. The biochemical and morphological characteristics of the isolate were similar to those of Pectobacterium brasiliense. Phylogenetic analysis based on the sequences of the 16S rRNA region and the concatenated DNA polymerase III subunit tau (dnaX), leucine-tRNA ligase (leuS), and recombinase subunit A (recA) genes confirmed that the isolate is a novel strain of P. brasiliense. Artificial inoculation of radish with P. brasiliense KNUB-03-21 resulted in soft rot symptoms similar to those observed in infected radish in the field; subsequently, P. brasiliense KNUB-03-21 was reisolated and reidentified. To our knowledge, this is the first report of P. brasiliense as a causal pathogen of radish soft rot in Korea.

First Report of Pectobacterium aroidearum Causing Soft Rot on Zamioculcas zamiifolia

“…Recently, Pectobacterium spp. were mostly identified and confirmed using the combination of 16S rRNA gene se-quence analysis, multilocus sequence analysis (MLSA), and biochemical testing (Han et al, 2023;Park et al, 2022Park et al, , 2023aPark et al, , 2023b. In particular, the sequences of dnaX, leuS, and recA genes were successfully applied for phylogenetic analysis to revise the taxonomic status of several members of the genus Pectobacterium (Portier et al, 2019).…”