The graft cactus (<i>Gymnocalycium mihanovichii</i>) continues to be exported to more than 20 countries worldwide. In April 2021, typical bacterial symptoms of soft rot were observed in the graft cactus (cv. Yeonbit) in Goyang, Gyeonggi-do, Korea, resulting in economic losses in cactus production. The stems turned dark brown and the flowers were covered with black rot. The bacterial strain designated as KNUB-01-21 was isolated from infected stems and flowers. The results of the morphological and biochemical tests of the isolate were similar to those of <i>Pectobacterium brasiliense</i>. For molecular analysis, the 16S rRNA region and three housekeeping genes (<i>dnaX, leuS</i>, and <i>recA</i>) of the strain KNUB-01-21 were amplified. Based on the results of the molecular analysis and morphological and biochemical tests, KNUB-01-21 was identified as <i>P. brasiliense</i>. The pathogenicity of KNUB-01-21 on graft cactus was confirmed by an inoculation test. Artificial inoculation using <i>P. brasiliense</i> KNUB-01-21 produced soft rot symptoms on the grafted cactus, and the same bacterium was re-isolated and re-identified. This is the first report of <i>P. brasiliense</i> causing soft rot in graft cactus in Korea.

In September 2021, gray-to-brown discoloration and expanding water-soaked lesions were observed on the outer and inner layers and the core of kimchi cabbage (Brassica rapa subsp. pekinensis) in fields located in Samcheok, Gangwondo, Korea. A bacterial strain designated as KNUB-02-21 was isolated from infected cabbage samples. Phylogenetic analysis based on the sequences of the 16S rRNA region and the dnaX, leuS, and recA genes confirmed that the strain was affiliated with Pectobacterium versatile. Additionally, the biochemical and morphological profiles of the isolate were similar to those of P. versatile. Based on these results, the isolate was identified as a novel strain of P. versatile. Healthy kimchi cabbage slices developed soft rot upon inoculation with P. versatile KNUB-02-21 and exhibited symptoms similar to those observed in the diseased plants in fields. The re-isolated strains were similar to those of P. versatile. Prior to our study, P. versatile as the causative pathogen of kimchi cabbage soft rot had not been reported in Korea.

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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.