Pseudomonas syringae pv. syringae
bacterial canker, blast, holcus spot
Over sixty other names. See CABI.
Worldwide
Widespread
2025-11-06
bacterium
Thailand, China, Korea
Wide host range; over 200 different plant species. Important vegetable and agronomic crops are listed below.
PSDMSY
Pseudomonas syringae pv. syringae is a bacterial plant pathogen with an exceptionally broad host range, affecting fruits, vegetables, cereals, and ornamentals. It causes leaf spots, blight, and cankers, often entering through wounds or natural openings. The pathogen spreads through rain splash, contaminated tools, plant debris, and infected seed or planting material, and can survive on plant surfaces under cool, moist conditions that favor disease outbreaks.
11 Hosts
Allium cepa
onion
No
PSDMSY-2, CABI CPC, PSDMSY-25
Onion was previously not recognized as a host of Pseudomonas syringae pv. syringae, but recent findings identified it as a naturally infected host species. The bacterium was isolated from onion seeds, though transmission from seed to seedling was not confirmed.
2025-11-06 10:12:24
International Seed Federation Regulated Pest List Database. pestlist.worldseed.org Nyon, Switzerland
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Verma, L., Verma, A. K., & Nagar, A. (2025). Impact and Transmission Dynamics of Pseudomonas syringae pv. syringae isolated from Onion Crop grown in Alwar district of Rajasthan. Indian J. Applied & Pure Bio. Vol, 40(2), 1135-1139.
Brassica oleracea vars.
cabbage, cauliflower, broccoli, brussel sprouts
No
PSDMSY-3, CABI CPC, PSDMSY-26
No references found indicating that Brassica oleracea seed is a pathway.
2025-11-06 13:55:20
Richardson MJ, 1990. An Annotated List of Seed-borne Disease. International Seed Testing Association, Zurich, Switzerland
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Basavand, E., Khodaygan, P., Rahimian, H., Babaeizad, V., & Mirhosseini, H. A. (2021). Pseudomonas syringae pv. syringae as the new causal agent of cabbage leaf blight. Journal of Phytopathology, 169(4), 253-259.
Capsicum annuum
pepper
No
PSDMSY-2, PSDMSY-3, PSDMSY-10, PSDMSY-16, PSDMSY-33
Pepper is reported as a host of Pseudomonas syringae pv. syringae, and some sources speculate that seed may serve as a pathway. However, no scientific data support this claim, and no evidence confirms seed transmission in pepper.
2025-11-06 20:09:34
International Seed Federation Regulated Pest List Database. pestlist.worldseed.org Nyon, Switzerland
Richardson MJ, 1990. An Annotated List of Seed-borne Disease. International Seed Testing Association, Zurich, Switzerland
Mohan, S.K. and Schaad, N.W. 1987. An improved agar plating assay for detecting Pseudomonas syringae pv. syringae and P. s. pv. phaseolicola in contaminated bean seed. Phytopathology 77(10):1390-1395.
Buonarurio, R. and Scortichini, M. (1994). Pseudomonas syringae pv syringae on pepper seedlings in Italy. Plant Pathology, 43:216–219.
Ranjit S, Deblais L, Poelstra JW, Bhandari M, Rotondo F, Scaria J, Miller SA, Rajashekara G. In vitro, in planta, and comparative genomic analyses of Pseudomonas syringae pv. Syringae strains of pepper (Capsicum annuum var. annuum). Microbiol Spectr. 2024 Jun 4;12(6):e0006424.
Cucumis sativus
cucumber
No
PSDMSY-3, PSDMSY-17, CABI CPC
No evidence found indicating seed is a pathway. Cucumber has only been shown to be a host under experimental conditions, but no references found indicating natural infection.
2025-11-06 20:20:13
Richardson MJ, 1990. An Annotated List of Seed-borne Disease. International Seed Testing Association, Zurich, Switzerland
Slomnicka, R., Olczak-Woltman, H., Bartoszewski, G. and Niemirowicz-Szczytt, K. (2015). Genetic and pathogenic diversity of Pseudomonas syringae strains isolated from cucurbits. European Journal of Plant Pathology 141:1-14.
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Hordeum vulgare
barley
uncertain
PSDMSY-15, PSDMSY-18, CABI CPC, PSDMSY-38
Pseudomonas syringae pv. syringae has been detected on barley seeds and can cause kernel infection, but there is no confirmed evidence that seeds transmit the pathogen to seedlings under natural conditions.
Yes
Direct plating
This test was used for research purposes and has not been validated or standardized.
PSDMSY-15
2025-11-06 11:09:48
Mori, M., Sogou, K., and Inoue, Y., 2019. Development of a selective medium and antisera for Pseudomonas syringae pv. syringae from seeds of barley and wheat. Journal of General Plant Pathology, 85: 211-220.
Peters, RA and Timian, RG. 1981. A bacterial kernel blight caused by Pseudomonas syringae pv syringae. Phytopathology 81:1117 (abstr.)
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Fukuda T, Azegami K, Tabei H (1990) Histological studies on bacterial black node of barley and wheat caused by Pseudomonas syringae pv. japonica (in Japanese with English summary). Ann Phytopath Soc Jpn 56:252–256
Lactuca sativa
lettuce
Not a host
CABI CPC
No references found indicating lettuce seed is a host.
2025-11-06 20:21:07
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Oryza sativa
rice
uncertain
PSDMSY-6, PSDMSY-7
Pseudomonas syringae pv. syringae has been isolated from rice grains, but seed transmission has not been demonstrated under natural conditions. Infected seeds may lose viability, and no reports of this pathogen on rice in the US were found. This pathogen on rice is also referred to as P. oryzicola.
Yes
Visual examination
This method was used for research and has not been standardized or validated,
PSDMSY-6
2025-11-06 11:07:08
R. S. Zeigler and E. Alvarez. 1990. Characteristics of Pseudomonas spp. Causing Grain Discoloration and Sheath Rot of Rice, and Associated Pseudomonad Epiphytes. Plant Dis. 74: 917-922.
Ou, S.H., 1985. Rice Disease, Second Edition. Commonwealth Mycological Institiute, Great Britain
Phaseolus vulgaris
common bean
Yes
PSDMSY-2, PSDMSY-8, PSDMSY-9, PSDMSY-10, PSDMSY-11, PSDMSY-32
Seed as a pathway is well established and accepted.
Yes
Seed wash and agar plating
Seed wash agar plating is the standard method of the NSHS.
METHOD: Be 2.1 Agar Plate Assay
PSDMSY-10, NSHS USDA
Cultural, Chemical
Management includes using certified, disease-free seed, practicing crop rotation, and applying copper-based fungicides.
CABI CPC
2025-11-06 20:36:53
International Seed Federation Regulated Pest List Database. pestlist.worldseed.org Nyon, Switzerland
Rich JJ, Willis DK, 1997. Multiple loci of Pseudomonas syringae pv. syringae are involved in pathogenicity on bean: restoration of one lesion-deficient mutant requires two tRNA genes. Journal of Bacteriology 179:2247-2258
Legard, D.E. and Schwartz, H.F. 1987. Sources and management of Pseudomonas syringae pv. phaseolicola and Pseudomonas syringae pv. syringae epiphytes on dry beans in Colorado. Phytopathology 77(11):1503-1509
Mohan, S.K. and Schaad, N.W. 1987. An improved agar plating assay for detecting Pseudomonas syringae pv. syringae and P. s. pv. phaseolicola in contaminated bean seed. Phytopathology 77(10):1390-1395.
Hall R, 1991. Compendium of Bean Diseases. St Paul, Minnesota, USA: APS Press
Lindemann, J., Arny, D.C. and Upper, C.D., 1984. Epiphytic population of Pseudomonas syringae pv. syringae on snap bean and nonhost plants and the incidence of bacterial brown spot disease in relation to cropping patterns. Phytopathology, 74(11), pp.1329-1333
United Stated Department of Agriculture, Animal and Plant Health Protection Service National Seed Health System (USDA-APHIS NSHS) www.seedhealth.org
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Pisum sativum
pea
Yes
PSDMSY-3, PSDMSY-10, PSDMSY-20, CABI CPC, PSDMSY-28, PSDMSY-30, PSDMSY-31, PSDMSY-32
Pea seed is a pathway for Pseudomonas syringae pv. syringae. It has been detected in both naturally and artificially infected seeds, which can be deformed or discoloured, and is transmitted to seedlings. Transmission and disease development are strongly influenced by soil moisture under greenhouse and field conditions. The pathogen is one of the most important causes of pea losses, with yield reductions reported up to 94% in field pea.
Yes
LAMP, ELISA
A LAMP test can detect Pseudomonas syringae pv. pisi and pv. syringae. ELISA tests differentiate them, though it is not validated for pea seed.
PSDMSY-34, PSDMSY-35
Chemical, cultural
Management includes using disease-free seed, practicing crop rotation, avoiding wet soils, removing infected debris, and applying copper-based sprays where effective.
CABI CPC
2025-11-06 21:20:26
Richardson MJ, 1990. An Annotated List of Seed-borne Disease. International Seed Testing Association, Zurich, Switzerland
Mohan, S.K. and Schaad, N.W. 1987. An improved agar plating assay for detecting Pseudomonas syringae pv. syringae and P. s. pv. phaseolicola in contaminated bean seed. Phytopathology 77(10):1390-1395.
Jindal KK, Bhardwaj SS, 1989. Etiology of bacterial blight of pea caused by Pseudomonas syringae pv. syringae. Plant Disease Research, 4(2):165-166
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Martín-Sanz, A., De La Vega, M. P., Murillo, J., & Caminero, C. (2013). Strains of Pseudomonas syringae pv. syringae from pea are phylogenetically and pathogenically diverse. Phytopathology, 103(7), 673-681.
Chopra, R., Jindal, K.K. and Shyam, K.R., 1993. Detection of Pseudomonas syringae pv. syringae in pea seed. Indian Phytopathology, 46(1), pp.29-32.
Richardson, H.J. and Hollaway, G.J., 2011. Bacterial blight caused by Pseudomonas syringae pv. syringae shown to be an important disease of field pea in south eastern Australia. Australasian Plant Pathology, 40(3), pp.260-268.
Lindemann, J., Arny, D.C. and Upper, C.D., 1984. Epiphytic population of Pseudomonas syringae pv. syringae on snap bean and nonhost plants and the incidence of bacterial brown spot disease in relation to cropping patterns. Phytopathology, 74(11), pp.1329-1333
Kant, P., Fruzangohar, M., Mann, R., Rodoni, B., Hollaway, G. and Rosewarne, G., 2021. Development and Application of a Loop-Mediated Isothermal Amplification (LAMP) Assay for the Detection of Pseudomonas syringae Pathovars pisi and syringae. Agriculture, 11(9), p.875.
Popović, T., Ivanović, Ž., Trkulja, N., Milosavljević, A., & Ignjatov, M. (2015). First Report of Pseudomonas syringae pv. syringae on Pea ( Pisum sativum ) in Serbia. Plant Disease, 99(5), 724–724.
Triticum aestivum
wheat
uncertain
PSDMSY-5, PSDMSY-13, PSDMSY-14, PSDMSY-19, CABI CPC, PSDMSY-22, PSDMSY-23, PSDMSY-24, PSDMSY-36, PSDMSY-37, PSDMSY-38
Pseudomonas syringae pv. syringae causes leaf spots or blight under cool, wet conditions and may reduce germination and seedling vigor. The bacterium can survive in wheat on plant surfaces and in crop debris, and it has been detected on or in seeds. However, there is no confirmed evidence that wheat seed serves as a pathway for infection.
Yes
Seed wash and agar plating
Confirmation of pathogen with traditional biological tests and PCR included. This test has not been validated or standardized.
PSDMSY-19
biological
Resistant varieties are known.
2025-11-06 11:03:04
Wiese MV. 1991. Bacterial Leaf Blight, In, Compedium of Wheat Diseases, Eds. Wiese, M.V. APS Press, St. Paul, MN
Rashid AQMB, 1995. Detection of seed-borne Pseudomonas syringae pv. syringae in wheat. Plant Varieties & Seeds, 8:47-54
Otta JD, 1977. Occurrence and characteristics of isolates of Pseudomonas syringae on winter wheat. Phytopathology, 67:22-26
S. Asaad, D. C. Sands, and S. K. Mohan, 2017. CHAPTER 4: Detection of Pseudomonas syringae pv. syringae in Wheat Seeds. In, Detection of Plant-Pathogenic Bacteria in Seed and Other Planting Material, Second Edition Eds. M. Fatmi, R. R. Walcott, and N. W. Schaad. The American Phytopathological Society Press, St. Paul, MN
Crop Protection Compendium. Wallingford, UK: CAB International. www.cabi.org/cpc.
Afkhamifar, A., Moslemkhani, C., Hasanzadeh, N., & Razmi, J. (2023). Interactions of seed-borne bacterial pathogens Xanthomonas translucens and Pseudomonas syringae pv syringae on wheat. Journal of Plant Pathology, 105(3), 859-867.
Moukahel et al (2015) previously reported that in different cultivars of wheat, frequent Pseudomonas syringe strains with ice nucleation activity can be propagated with seeds and transmitted to daughter plants.
Kumari, S, A. R. Moukahel, A. Abo Bakr and M. Kassem. 2023. Detection and characterization of seed-borne bacterial leaf blight in wheat. Page 347. In: 12th International Congress of Plant Pathology, 20-25 August 2023, Lyon, France.
Yoshioka R, Uematsu H, Takikawa Y, Kajihara H, Inoue Y. 2020. PCR detection of Pseudomonas syringae pv. syringae, the causal agent of bacterial black node in barley and wheat, using newly designed primer sets. J Gen Plant Pathol 86:387–392.
Dutta B, Gitaitis R, Smith S, Langston JD (2014) Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.
Fukuda T, Azegami K, Tabei H (1990) Histological studies on bacterial black node of barley and wheat caused by Pseudomonas syringae pv. japonica (in Japanese with English summary). Ann Phytopath Soc Jpn 56:252–256
Zea mays
corn
No
PSDMSY-4, CABI CPC
No references found indicating corn seed is a pathway.
2025-11-06 21:30:53
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