Gi Yoon Shin
Postdoctoral Associate
University of California, Davis
Davis, California, United States
Caitilyn Allen
Professor Emeritus
Department of Plant Pathology, University of Wisconsin
Madison, Wisconsin, United States
Jessica Chitwood-Brown
Assistant Professor
Horticultural Sciences Department - Gulf Coast Research and Education Center, University of Florida
Wimauma, Florida, United States
Matthew Cope-Arguello
University of California, Davis
Davis, California, United States
Ronnie Dewberry
Department of Plant Pathology, University of Wisconsin-Madison
Madison, Wisconsin, United States
Jason Hong
USDA-ARS U.S. Horticultural Research Laboratory, Fort Pierce, FL
Fort Pierce, Florida, United States
Alejandra I. Huerta
Assistant Professor
North Carolina State University
Raleigh, North Carolina, United States
David Norman
Associate Professor
University of Florida
Apopka, Florida, United States
Jonathan E. Oliver, PhD
Associate Professor
University of Georgia
Tifton, Georgia, United States
Edward Sikora
Auburn University
Aubrun, Alabama, United States
Hehe Wang, PhD
Associate Professor
Clemson University
Blackville, SC, USA
Gary Vallad, PhD
Professor
University of Florida
Balm, Florida, United States
Ana Maria Bocsanczy
Research Scientist
University of Florida
Apopka, Florida, United States
Tiffany Lowe-Power (she/her/hers)
Asst Professor
Department of Plant Pathology, University of California
Davis, CA, USA
The Ralstonia solanacearum species complex (RSSC) is a group of pathogens globally distributed that cause devastating vascular wilts in a wide range of crops, resulting in significant agricultural and economic losses. These pathogens are phylogenetically classified into four phylotypes (I–IV) that originated on different continents. In the Southeast United States, two lineages, IIC-7 and IIA-38, have been historically associated with solanaceous crops and more recently with outbreaks of Ralstonia wilt in blueberry. Although these associations have been reported, the diversity and population structure of RSSC strains in the region remain poorly understood. To address this, we sequenced and conducted phylogenomic analyses of 70 RSSC strains recovered from various sources across the Southeast. Phylogenetic analyses based on the egl marker gene, and 49 conserved, universal genes revealed that most isolates belonged to phylotype IIC-7 (47/70) and IIA-38 (19/70), consistent with previous reports. A small number of isolates (4/70) clustered within the exotic phylotype I-13 lineage, one of several lineages implicated in recent outbreaks of Ralstonia wilt in blueberry. Our findings support the presence of established endemic lineages and the recent introduction of exotic strains into the U.S. population. As a next step, we aim to identify unique genomic regions of IIC-7 and IIA-38 lineages to develop targeted PCR assays. These assays will facilitate rapid detection, enhance surveillance of RSSC populations and support disease management efforts.