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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Publications at this Location » Publication #433789
Research Project: Plant-associated Nematode Management and Systematics and USDA Nematode Collection Curation

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Pratylenchus pseudocoffeae Mizukubo, 1992 infecting dahlia (Dahlia hybrida) in the United States expands its known host and geographic ranges

Author
item CONSOLI, ERIDA - Pennsylvania State University
item BOGALE, MESFIN - The Ohio State University
item MONDAL, SANDIP - The Ohio State University
item RALSTON, TIMOTHY - The Ohio State University
item Habteweld, Alemayehu Wo
item HANDOO, ZAFAR - Retired ARS Employee
item WOLF, EMILY - Oak Ridge Institute For Science And Education (ORISE)
item Reis Vieira, Paulo
item HAND, FRANCESCA - The Ohio State University
item KANTOR, MIHAIL - Pennsylvania State University
item MAY, SARA - Pennsylvania State University
item LOPEZ-NICORA, HORACIO - The Ohio State University

Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/17/2026
Publication Date: 7/29/2026
Citation: Consoli, E., Bogale, M., Mondal, S., Ralston, T., Habteweld, A., Handoo, Z., Wolf, E., Reis Vieira, P.C., Hand, F., Kantor, M., May, S., Lopez-Nicora, H.D. 2026. Pratylenchus pseudocoffeae Mizukubo, 1992 infecting dahlia (Dahlia hybrida) in the United States expands its known host and geographic ranges. Journal of Nematology. 58(1):256-257. https://doi.org/10.2478/jofnem-2026-0019.
DOI: https://doi.org/10.2478/jofnem-2026-0019

Interpretive Summary: The United States floriculture industry is an economically valued at approximately USD 6.69 billion in 2023. Dahlia (Dahlia hybrida) has emerged as a high-value specialty crop driven by strong demand in both the cut-flower and tuber markets in the U.S. In this study, damaged dahlia tubers were examined and found to be affected by root lesion nematodes, which caused major losses on tuber production. The results show that dahlia is a newly identified host for this nematode (Pratylenchus pseudocoffeae), marking the first time this nematode has been reported in the Midwestern and Northeastern United States. This research will be used by plant pathologists and diagnosticians to monitor and detect this nematode for management and monitoring of its spread.

Technical Abstract: Pratylenchus pseudocoffeae is a migratory endoparasitic nematode with limited documented geographic distribution and host range. We studied nine tuber-derived P. pseudocoffeae populations recovered from symptomatic dahlia (Dahlia hybrida) tubers in Ohio and Pennsylvania and evaluated their pathogenicity. Nematodes were characterized using morphometric parameters, as well as phylogenetic analyses based on two ribosomal DNA loci (i.e., ITS and LSU regions). All populations were identified as P. pseudocoffeae, representing the first report of this species in Ohio and Pennsylvania, and the first report of dahlia as a natural host. Pathogenicity was measured by assessing plant growth response after inoculating dahlia cuttings with increasing nematode densities under greenhouse conditions. Inoculated plants exhibited significant reductions in root biomass (61–75%) relative to noninoculated controls. These results demonstrate that dahlia is a suitable host of P. pseudocoffeae, contribute to a better understanding of the distribution of this species in North America, and provide molecular diagnostic data to support accurate identification for future diagnostic and epidemiological studies.