First Report of Pectobacterium aroidearum Causing Soft Rot on Zamioculcas zamiifolia

Abstract

<i>Zamioculcas zamiifolia</i> is a popular indoor ornamental plant in Korea. In August 2021, a severe outbreak of soft rot disease affected <i>Z. zamiifolia</i> in Emseong, Chungcheongbuk-do, Korea. Infected plants displayed wilting, water-soaked lesions, stem collapse, and green-brown discoloration. The bacterial strain KNUB-05-21 was isolated from infected stems and identified as <i>Pectobacterium aroidearum</i> using 16S rRNA nucleotide sequencing and multilocus sequence analysis based on partial sequences of <i>dnaX, leuS</i>, and <i>recA</i> genes. Confirmation of its affiliation with <i>P. aroidearum</i> was also obtained through biochemical and morphological characterization. To confirm the pathogenicity of strain KNUB-05-21, its suspension was injected into <i>Z. zamiifolia</i> stems. Within a week, soft rot developed on the stems, exhibiting symptoms similar to those observed in field-infected plants. The reisolated strain was identical to those of <i>P. aroidearum</i>. Before this study, <i>P. aroidearum</i> was not reported as a causative pathogen of <i>Z. zamiifolia</i> soft rot in Korea.