Pathogens Do Not Need Passports:Global Outbreaks and Collaborations on Clavibacter nebraskensis, causal agent of the Understudied Goss’s Wilt on Maize

Tuesday, August 5, 2025

4:15 PM - 4:30 PM HST

Location: Room 313 A

Presenting Author(s)

LF

Luis Fernando Flores-Lopez, M. Sc. (he/him/his)

M.Sc.
The Pennsylvania State University
State College, Pennsylvania, United States

Author(s)

AV

Anne Vidaver

Professor Emerita
University of Nebraska-Lincoln
Lincoln, Nebraska, United States
DK

Devanshi Khokhani, PhD (she/her/hers)

Assistant Professor
University of Minnesota
Saint Paul, MN, USA
OM

Oscar Morales-Galvan

Department Head and Professor
Universidad Autonoma Chapingo
Texcoco, Estado de México, Mexico
AH

Alejandra I. Huerta

Assistant Professor
North Carolina State University
Raleigh, North Carolina, United States
VR

Veronica Roman-Reyna

Assistant Professor
The Pennsylvania State University
University Park, Pennsylvania, United States

Abstract Text:
Clavibacter nebraskensis (Cn), the causal agent of Goss’s wilt and leaf blight, can infect maize, the second most important crop worldwide. Initially, Cn has been restricted to the U.S. and Canada. In 2024 and 2025, Cn was first reported in Mexico and South Africa, respectively. These reports highlight Cn's growing distribution and potential impact on global maize production. Investigations on the genomics, evolution, and epidemiology of Cn are necessary for developing and deploying disease management tactics. To this end, strains isolated from Mexico and the U.S. were sequenced using long- and short-read whole-genome sequencing technologies, including the first-ever reported strain from Nebraska in 1969. These strains were used to conduct comparative genomics and phenotypic characterization. Phylogenomic and population genetic analyses revealed that the strains exhibited a phylogeographic structure, where strains of Mexican origin formed a distinct yet closely related cluster to those of the U.S. Haplotype network analysis and phenotypic characterization indicated the genetic diversification may have originated in Mexico and may have followed the historical maize germplasm movement. However, to test this hypothesis, more strains are needed. Toward this effort, a real-time diagnostic workflow using Oxford Nanopore’s MinION sequencing was developed and implemented at Universidad Autonoma Chapingo in Mexico. This initiative, the first of many, demonstrates the importance of cross-border cooperation and the ease of portable pathogen detection to strengthen biosecurity.