Canker and dieback of is caused by .

Understanding the ecology of pathogens is important for disease management. Recently a devastating canker disease was found on red alder () planted as landscape trees. Bacteria were isolated from two groups of symptomatic trees located approximately 1 kilometer apart and one strain from each group was used to complete Koch's postulates.

Transmission and Management of Pathogenic and in Select Ornamentals.

Pathogenic and are phytobacteria that induce crown gall and leafy gall disease, respectively, resulting in undesirable growth abnormalities. When present in nurseries, plants infected by either bacterium are destroyed, resulting in substantial losses for growers, especially those producing plants valued for their ornamental attributes. There are many unanswered questions regarding pathogen transmission on tools used to take cuttings for propagation and whether products used for bacterial disease control are effective.

Whole Genome Sequencing-Based Tracing of a 2022 Introduction and Outbreak of pv. .

Globalization has made agricultural commodities more accessible, available, and affordable. However, their global movement increases the potential for invasion by pathogens and necessitates development and implementation of sensitive, rapid, and scalable surveillance methods. Here, we used 35 strains, isolated by multiple diagnostic laboratories, as a case study for using whole genome sequence data in a plant disease diagnostic setting.

Genomic Approaches to Plant-Pathogen Epidemiology and Diagnostics.

Diseases have a significant cost to agriculture. Findings from analyses of whole-genome sequences show great promise for informing strategies to mitigate risks from diseases caused by phytopathogens. Genomic approaches can be used to dramatically shorten response times to outbreaks and inform disease management in novel ways.

Unexpected conservation and global transmission of agrobacterial virulence plasmids.

The accelerated evolution and spread of pathogens are threats to host species. Agrobacteria require an oncogenic Ti or Ri plasmid to transfer genes into plants and cause disease. We developed a strategy to characterize virulence plasmids and applied it to analyze hundreds of strains collected between 1927 and 2017, on six continents and from more than 50 host species.

Response to comments on "Evolutionary transitions between beneficial and phytopathogenic challenge disease management".

Randall et al., 2018 and Vereecke, 2018 have raised concerns about a paper we published (Savory et al., 2017).

Evolutionary transitions between beneficial and phytopathogenic challenge disease management.

Understanding how bacteria affect plant health is crucial for developing sustainable crop production systems. We coupled ecological sampling and genome sequencing to characterize the population genetic history of and the distribution patterns of virulence plasmids in isolates from nurseries. Analysis of chromosome sequences shows that plants host multiple lineages of , and suggested that these bacteria are transmitted due to independent introductions, reservoir populations, and point source outbreaks.

Isothermal Amplification and Lateral-Flow Assay for Detecting Crown-Gall-Causing Agrobacterium spp.

Agrobacterium is a genus of soilborne gram-negative bacteria. Members carrying oncogenic plasmids can cause crown gall disease, which has significant economic costs, especially for the orchard and nursery industries. Early and rapid detection of pathogenic Agrobacterium spp.

Use of whole genome sequences to develop a molecular phylogenetic framework for Rhodococcus fascians and the Rhodococcus genus.

The accurate diagnosis of diseases caused by pathogenic bacteria requires a stable species classification. Rhodococcus fascians is the only documented member of its ill-defined genus that is capable of causing disease on a wide range of agriculturally important plants. Comparisons of genome sequences generated from isolates of Rhodococcus associated with diseased plants revealed a level of genetic diversity consistent with them representing multiple species.

Analysis of genome sequences from plant pathogenic Rhodococcus reveals genetic novelties in virulence loci.

Members of Gram-positive Actinobacteria cause economically important diseases to plants. Within the Rhodococcus genus, some members can cause growth deformities and persist as pathogens on a wide range of host plants. The current model predicts that phytopathogenic isolates require a cluster of three loci present on a linear plasmid, with the fas operon central to virulence.

A New Potyvirus sp. Infects Verbena Exhibiting Leaf Mottling Symptoms.

Verbena 'Taylortown Red' plants showed virus-like mottling symptoms. Virus purifications disclosed the presence of elongated and spherical particles, evidence of mixed virus infections, whereas double-stranded RNA analysis revealed the presence of several bands absent in healthy plants. After shotgun cloning, three viruses were identified in 'Taylortown Red': Broad bean wilt virus-1, Coleus vein necrosis virus, and a previously undescribed potyvirus.