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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 #426305
Research Project: Fungal Systematics and Diagnostic Resource Development for Safeguarding Plant Health

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Muscadine grape (Vitis rotundifolia) as a new host for the downy mildew Plasmopara ampelopsidis

Author
item DAVIS, WILLIAM - Non ARS Employee
item Salgado-Salazar, Catalina

Submitted to: Journal of Plant Diseases and Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2025
Publication Date: 12/29/2025
Citation: Davis, W., Salgado-Salazar, C. 2025. Muscadine grape (Vitis rotundifolia) as a new host for the downy mildew Plasmopara ampelopsidis. Journal of Plant Diseases and Protection. 133. Article 15. https://doi.org/10.1007/s41348-025-01208-9.
DOI: https://doi.org/10.1007/s41348-025-01208-9

Interpretive Summary: Downy mildews cause some of the most severe and destructive diseases of ornamental and wild plants, impacting both the environment and the commercial value of the ornamental industry. However there are many knowledge gaps concerning their identity. This study used DNA sequences and microscopy to describe the first observation of downy mildew disease on Muscadine grape in the U.S. The results of this study have important implications for muscadine grape production and disease management. The information from this study will be useful to plant pathologists, regulatory officials and others involved in the management of plant health in the grape and wine plant industry.

Technical Abstract: During a bioblitz at the Adkins Arboretum (Maryland, US.), a muscadine grape (Vitis rotundifolia) infected with downy mildew was observed and collected. Morphological analysis and a phylogenetic tree inferred from cox2 and 28S revealed the downy mildew was not Plasmopara viticola as expected but rather a strain of P. ampelopsidis, which previously has only been reported from Ampelopsis grandulosa var. brevipedunculata, Vitis vinifera, and a Vitis hybrids. Herein we describe the morphology of the collected downy mildew, present the molecular data confirming its identity, and report a new host for P. ampelopsidis.