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Bacterial leaf streak (BLS) of barley is caused by the Gram-negative bacterial pathogen Xanthomonas translucens (Sapkota et al. 2020). In 2021, we observed multiple hill plots with BLS symptomatic plants in a barley stripe rust nursery in Vancouver, BC, Canada. We collected 29 leaf samples showing typical BLS symptoms (e.g. necrotic lesions; Fig. S1) and stored at 4 oC until bacterial isolation. Samples were surface-sterilized in 10% NaOCl for 20 sec and rinsed twice. About 1 cm2 of leaf tissue containing BLS characteristic lesions was macerated in 200 μL sterile H2O on a petri dish, incubated for 15 min, and 10 μl of the homogenates was streaked onto Wilbrink's - Boric Acid - Cephalexin (WBC) agar medium. Plates were incubated at 28-30 oC for 48 hrs. Four single colonies were obtained: BC10-1-2a (USask BC10-2a), BC10-1-2b (USask BC10-2b), UBC026 and UBC028. Colonies were grown in WBC broth and gDNA was extracted using E.Z.N.A. Bacterial DNA Kit (Omega Bio-Tek) or DNeasy Plant Pro Kit® (Qiagen) following manufacturer protocols. Genus-level identification was achieved using 16S rRNA sequencing with 27F/1492R primers (Lane 1991) of UBC026 (1,399 bp; NCBI # OP327375) and UBC028 (1,415 bp; NCBI #OP327376). Complete 16S rRNA sequences (1,533bp) of BC10-2a and BC10-2b (1,533 bp) were extracted from the draft whole-genome sequences (WGS) generated in this study. The 16S rRNA sequence homology values of 99.0-100% were recorded between the 4 strains. BLAST analyses of the 16S rRNA sequences to GenBank entries exhibited 99.5-100% similarity values (100% coverage) with the pathotype strains of Xtt DSM 18974T (LT604072) and X. translucens pv. undulosa (Xtu) CFBP 2055 (CP074361). Whole genomes of BC10-2a (JANUQY01) and BC10-2b (JANUQZ01) were sequenced (150-bp; reads 33.1 million; mean coverage 2125x) using NovaSeq Illumina, assembled (Unicycler v0.4.8; Wick et al. 2017) and analyzed to identify the strains to the species-level (Tambong et al. 2021). WGS of strains USask BC10-2a and USask BC10-2b exhibited genome-based DNA-DNA hybridization (dDDH; Meier-Kolthoff et al. 2013) and BLAST-based average nucleotide identity (ANIb; Richter et al. 2015) of 100%. The two strains also showed dDDH and ANIb of 90.4% (species-leel cut-off of 70%) and 98.780% and 98.80% (cut-off of 96%), respectively, with Xtt DSM 18974T (LT604072). In contrast, the WGS of BC10-2a and BC10-2b exhibited only 78.2% dDDH homology values with Xtu CFBP 2055T, suggesting that the strains are genetically more similar to Xtt. The assignment of these strains to Xtt is corroborated by phylogenomic analysis (Fig. S2; Meier-Kolthoff and Göker 2019) that showed the two strains clustering together (100% bootstrap) with the type strain DSM 18974T. These data suggest that these strains are taxonomically members of Xtt. Identification was also confirmed to the genus-level by LAMP assay using published X. translucens primers (Langlois et al. 2017). Pathovar-level identification was confirmed using a cbsA and S8.pep multiplex PCR diagnostic assay (Roman-Reyna et al. 2022). Koch's postulates were verified by greenhouse inoculation via leaf infiltration of UBC026 and UBC028 on 21-day old barley plants (line HB522) using an inoculum of 108 CFU ml-1 followed by re-isolation of the bacteria on WBC. The inoculated plants showed typical BLS symptoms similar to those observed in the field (Fig. S1). Water-inoculated plants had no symptoms. To our knowledge, this is the first published report of BLS of barley in British Columbia.

Winterberries ( Ilex verticillata and hybrids) are deciduous species of holly whose branches bearing colorful fruit are cut in late Fall to be used for seasonal decorations. The annual wholesale value of the woody cuts is $1.5 million nationally (NASS, 2019). In June 2021, approximately 80% of the 45 Ilex verticillata 'Maryland Beauty' potted plants, which were maintained in a container yard at The Ohio State University research farm in Columbus, OH, presented leaves with irregular necrotic lesions surrounded by a chlorotic halo. No other symptoms were present on the plants. Bacterial streaming was observed from the lesions using a compound microscope and isolations were performed after surface disinfesting small sections of leaf tissue from the border of the lesions by soaking in 10% bleach for 30 sec, rinsing twice in sterile water, macerating in sterile water, and streaking the suspension on nutrient broth yeast extract agar. Creamy white, circular, smooth, and convex colonies were recovered after incubation at 28°C for 48 h. Bacterial identification of one representative isolate was initially pursued from single colonies of a purified culture using five discriminative phenotypic tests (i.e., LOPAT: "L", levan production; "O", oxidase activity; "P", pectinolytic activity; "A", arginine dehydrolase production; "T", tobacco hypersensitive reaction), which resulted in the L+ O- P- A- T+ profile consistent with the description of Pseudomonas syringae (Lelliott et al. 1996). Molecular identification was performed based on rpoD marker amplification and sequencing using primers PsrpoD FNP1/PsrpoDnprpcr1 (Parkison et al. 2011). NCBI GenBank BLASTn comparison of the rpoD sequence (GenBank Acc. No. OP221440) shared 99.12% identity to P. syringae pv. passiflorae (AB163366.1). Whole genome sequence analysis was conducted to strengthen the classification of the isolate species. To this extent, DNA was sequenced with an iSeq 100 Illumina benchtop sequencer using Illumina DNA Prep kit and iSeq 100 i1 Reagent v2 (Illumina, Inc, REF: 20060060 and 20031371). Illumina Local Run Manager software was used for base calling, demultiplexing, and trimming of the raw reads. Unicycler v0.5.0 was used for de novo assembly of the genome (Wick et al. 2017). The assembled genome size was 5.9 Mb with 959 contigs and 10× coverage (NCBI GenBank Biosample No. SAMN30281368; Acc. No. JANQCB010000000). Average nucleotide identity (ANI) analysis was performed on the server MiGA online (Rodriguez-R et al. 2018). Subgroup identification was inconclusive ( p >0.05), positioning this isolate between P. syringae pv. actinidiae (96.45% ANI) and pv. viburni (96.65% ANI) (Rodriguez-R & Konstantinidis, 2016). Both these pathovars cause leaf spots on woody plants such as kiwi and viburnum (Donati et al. 2020; Garibaldi et al. 2005). To confirm pathogenicity, three separate branches on each of two I. verticillata 'Maryland Beauty' potted plants were selected, and 5-7 individual young leaves (>2 weeks from emergence) on each branch were infiltrated with a bacterial suspension (10 8 CFU/mL) in sterile water (SW) using a needleless syringe by delivering 30-50 µL of suspension per infiltration point. One additional branch per plant was infiltrated with SW to serve as control. Plants were covered with a plastic bag for two days post-inoculation (DPI) and maintained in the laboratory at an average of 23°C. All inoculated leaves showed necrotic lesions two DPI while control leaves remained asymptomatic. To fulfill Koch's postulates, the bacterium was re-isolated from the symptomatic leaves six DPI and confirmed to be identical to the original isolate based on rpoD gene sequencing. To the best of our knowledge, this report signifies the first instance of P. syringae causing bacterial leaf spot on winterberry worldwide. Ornamental plant sales are based primarily on visual appeal; therefore, identification and monitoring of emerging pathogens is essential to ensure the health of the industry.

Ralstonia solanacearum phylotype II sequevar 1 ( Rs II-1, formerly race 3 biovar 2) causes tomato bacterial wilt, potato brown rot, and Southern wilt of geranium. Strains in Rs II-1 cause wilting in potato and tomato at cooler temperatures than tropical lowland R. solanacearum strains. Although periodically introduced, Rs II-1 has not established in the United States. This pathogen is of quarantine concern and listed as a Federal Select Agent. We report a rapidly sequenced (<2 days) draft genome of UW848, a Rs II-1 isolate introduced to the United States in geranium cuttings in spring 2020. UW848 belongs to the near-clonal cluster of Rs II-1 global pandemic strains.

In July 2018, a sample of lavender var. Grosso ( Lavandula × intermedia 'Grosso') from Miami County, OH was received by The Ohio State University Vegetable Pathology Laboratory in Wooster. Lavender plants were field-grown in sandy clay soil with plastic mulch under drip irrigation. Disease incidence ranged from 0 to 32% depending on variety. Leaves and stems showed dark necrotic lesions that varied from roughly circular (ca. 0.3 to 0.5 mm diameter) to large coalesced necrotic areas surrounded by a water-soaked halo. Bacterial streaming from lesions was observed microscopically. Leaf tissue pieces (~0.5 cm2) were surface sterilized in 70% ethanol for 30 seconds and rinsed in sterile deionized water. The tissue was sliced aseptically into smaller sections in 100 μl sterile water and the bacterial suspension was streaked on yeast dextrose calcium carbonate agar medium. Ten yellow Xanthomonas -like colonies were selected after 72 hours of incubation at 28ºC in the dark. Strains were gram negative, oxidase negative and caused hypersensitive reactions on Nicotiana benthamiana (L.). All strains were genotyped after whole-cell DNA extraction by BOX-PCR (Louws et al. 1999) and had the same banding profile. Four 8-wk-old lavender plants (Lavandula dentata and Lavandula × ginginsii 'Goodwin Creek Gray') were spray-inoculated with a 10 6 CFU/ml suspension of strain SM175-2018 in sterile water. Control plants were sprayed with sterile water. Plants were kept in plastic bags for the first 48 h at 28°C with a 14-h photoperiod. Water-soaked necrotic lesions appeared 14 days after inoculation with SM175-2018, whereas mock-inoculated plants did not show symptoms. Bacterial isolation from symptomatic leaf tissue was carried out as described above. The BOX-PCR profile of the re-isolated strain was identical to that of SM175-2018. Multilocus sequence analysis of the housekeeping genes fuyA , gyrB , and rpoD was performed (Accession numbers: MT764834 - MT764836). The resulting concatenated data set was used to perform a phylogenetic analysis using maximum likelihood criteria to evaluate relationships with closely related Xanthomonas spp. using published reference sequences (Young et al. 2008). SM175-2018 was assigned to the X. hortorum clade (Moriniere et al. 2020) with strong bootstrap support. The strain was subjected to whole genome analysis. Genomic DNA was extracted using a QIAGEN Genomic DNA buffer set with genomic-tip 100/G following manufacturer's protocol and sequenced using the iSeq-100 Illumina platform with the Nextera DNA Flex Library Prep protocol kit and Nextera DNA CD indexes. Average nucleotide identity (ANI) analysis was performed with the ANI-Matrix software Enveomics tool (Rodriguez-R and Konstantinidis 2016) using the sequenced genome (NCBI GenBank Biosample no. SAMN11831455) and those of other X. hortorum (Vauterin et al. 1995) bacteria (pvs. hederae , carotae , vitians ). SM175-2018 shared a 96% ANI with other X. hortorum strains. X. hortorum is associated with bacterial leaf spot of carrot (Scott and Dung, 2020) and also reported on ornamental plants (Mirik et al. 2010, Oliver et al. 2012, Roberts and Parkinson 2014, Klass et al. 2019), however additional research is needed to establish the host specificity of lavender strains. To our knowledge this is the first report of X. hortorum causing bacterial leaf spot of lavender in Ohio. The disease may negatively impact the yield and quality of flowers used in production of lavender oils and essences.

Xanthomonas translucens pv. translucens causes bacterial leaf streak and bacterial blight diseases of barley. This pathogen limits barley production globally but remains understudied, with limited genomic resources. To better understand the biology of this X. translucens subgroup, we sequenced the complete genome of the X. translucens pv. translucens strain UPB886.