search for


First Report of Pseudomonas viridiflava Causing Leaf Spot of Cucumber in Korea
Res. Plant Dis. 2018;24:328-331
Published online December 31, 2018
© 2018 The Korean Society of Plant Pathology.

Yunhee Seo*, Mi-Jeong Park, Chang-Gi Back, and Jong-Han Park*

Horticultural and Herbal Crop Environment Division, National Institute of Horticultural and Herbal Science, Wanju 55365, Korea
*Y. Seo Tel: +82-10-4400-9823 Fax: +82-63-238-6352 E-mail:
J.-H. Park Tel: +82-63-238-6310 Fax: +82-63-238-6305 Email:
Received September 10, 2018; Revised October 15, 2018; Accepted October 16, 2018.
cc This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
A severe disease with leaf spots and necrotic symptoms was observed in cucumber (Cucumis sativus L.) seedlings in April 2018 at a nursery in Kimjae, Korea (35°47'09.8"N 127°2'24.3"E). The infected plants initially showed spots on water-soaked cotyledons which, at later stages, enlarged and spread to the leaves, which the lesions becoming dry and chlorotic. The symptomatic samples were collected from cucumber and the isolates were cultured on LB agar. The representative bacterial strain selected for identification showed fluorescent on King’s medium B, was potato rot-positive, levan and arginine dihydrolase-negative, oxidase-negative and tobacco hypersensitivity-positive in LOPAT group 2 as determined by LOPAT tests. A pathogenicity test was carried out on a 3-week-old cucumber. After 3 days of inoculation, leaf spots and necrotic symptoms appeared on the cucumber, similar to the originally infected plants. The infecting bacterial strain was identified as Pseudomonas viridiflava, by 16S rDNA sequence analysis. This is the first report of leaf spot diseases on cucumber caused by P. viridiflava.
Keywords : Cucumber disease, Cucumber leaf spot, Cucumis sativus L., Pseudomonas viridiflava

December 2018, 24 (4)