Clavibacter tessellarius causing bacterial mosaic of wheat establishes in the Old World

The genus Clavibacter (family Microbacteriaceae) includes gram‐positive actinobacterial species infecting diverse agricultural crops such as alfalfa, maize, pepper, potato, tomato and wheat. Clavibacter tessellarius, causing bacterial mosaic of wheat, was reported for the first time in 1976 in Nebra...

Full description

Saved in:
Bibliographic Details
Published in:Plant pathology 2024-08, Vol.73 (6), p.1363-1371
Main Authors: Nasiri, Mostafa, Faghihi, Mohammad Mehdi, Rahimian, Heshmat, Osdaghi, Ebrahim
Format: Article
Language:English
Subjects:
actinobacteria
Alfalfa
Bacteria
coryneform bacteria
DnaK protein
grasses
Multilocus sequence typing
Pathogenicity
Pathogens
Phylogeny
Plant bacterial diseases
Plant protection
Poaceae
Potatoes
quarantine pathogen
RpoB protein
Sequence analysis
Strains (organisms)
Tomatoes
Triticum aestivum
Wheat
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The genus Clavibacter (family Microbacteriaceae) includes gram‐positive actinobacterial species infecting diverse agricultural crops such as alfalfa, maize, pepper, potato, tomato and wheat. Clavibacter tessellarius, causing bacterial mosaic of wheat, was reported for the first time in 1976 in Nebraska (United States). Since then, the pathogen was thought to be restricted to North America (Canada and the United States). While bacterial strains suspected to be C. tessellarius have occasionally been isolated from wheat samples outside North America, occurrence of the pathogen in the Old World has not yet been confirmed by the plant protection authorities. In spring 2020 (January to May) dozens of wheat fields with young plants showing leaf chlorosis and mild mosaic symptoms were surveyed and sampled in southern Iran. Among 192 surveyed wheat fields, gram‐positive, orange‐pigmented actinobacterial strains were isolated from samples of 53 fields. Altogether, 61 bacterial strains were identified as C. tessellarius based on the phenotypic features, PCR‐based molecular tests and pathogenicity assays. Multilocus sequence analysis of five housekeeping genes (atpD, dnaK, gyrB, ppk and rpoB) using 10 representative strains from diverse geographic areas in southern Iran confirmed the phylogenetic status of the strains within C. tessellarius. Our data indicate that the bacterial mosaic pathogen occurs in four southern Iranian provinces including Bushehr, Fars, Kerman and Khuzestan. Thus, occurrence of C. tessellarius outside North America is confirmed. Potential risks associated with the emergence of the pathogen in the Old World, and the need for strict quarantine measures in the area, is further discussed. Using field surveys and samplings we confirmed widespread occurrence of the wheat pathogen Clavibacter tessellarius in southern Iran and establishment of the bacterium in the Old World.
ISSN:0032-0862
1365-3059
DOI:10.1111/ppa.13893