Radhika D. Patel
PhD Student and Teaching Assistant
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Gia Masny
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Drashti Shah
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Nrupali Patel
Assistant Teaching Professor
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
John Capik
Field Researcher
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Thomas Molnar
Associate Professor
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Donald Kobayashi
Professor
Rutgers, The State University of New Jersey
New Brunswick, New Jersey, United States
Bacterial blight (Xanthomonas arboricola pv. corylina) (Xac) is an emerging threat to hazelnut production worldwide. Symptoms characteristic of bacterial blight, including angular, reddish brown lesions on leaves, circular lesions on husks, and shallow lesions on nuts, have emerged in New Jersey, with increasing incidence and severity over the past decade. However, more destructive symptoms typical of the disease, such as stem lesions, girdling cankers, branch dieback, and seedling death, have been largely unobserved. To confirm the presence of Xac within the state, bacterial isolates from diseased hazelnut trees throughout New Jersey were analyzed using MLSA based on seven housekeeping genes. Phylogenetic analysis revealed that the isolates segregated into two major groups, with most New Jersey isolates clustering within a single clade related to Xac, while two isolates grouped with existing Xac strains obtained from the NCBI database. Whole genome sequencing of one isolate that clustered within each phylogenetic group revealed differences in effector repertoire, with the more common NJ Xac strain containing a smaller collection and one unique effector, xopAT, compared to both Xac isolated from the state and Xac genomes available on NCBI. The more common NJ Xac strain also had a smaller genome size of 4.9Mb, compared to the >5.0Mb size of all other Xac genomes. These differences in genome sequence, genome size, and effector repertoire may explain the differences in disease symptoms and severity observed in New Jersey when compared with strains worldwide.