細菌病はタマネギの球根品質と収量に大きな影響を与える Bacterial disease can significantly impact bulb quality and yield of onion
2022-05-09 テキサス A&M大学
Cross-section of onion bulb affected with the Pseudomonas uvaldensis sp. nov. bacterium. (Texas A&M AgriLife photo)
この研究は、テキサスA&Mアグリライフ研究・拡張センター(Uvalde)、フロリダ大学、南アフリカ共和国のプレトリア大学の科学者の共同研究です。研究結果は、International Journal of Systematic and Evolutionary Microbiologyに掲載されました。
<関連情報>
- https://agrilifetoday.tamu.edu/2022/05/09/novel-species-of-pathogenic-bacteria-of-onion-identified-in-texas/
- https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijsem.0.005311
タマネギ球根腐敗病菌 Pseudomonas uvaldensis sp. nov., a bacterial pathogen causing onion bulb rot
Manzeal Khanal, Sujan Timilsina, Bed Prakash Bhatta, Khumbuzile Bophela, Teresa Coutinho, Kimberly Cochran, Subas Malla
International Journal of Systematic and Evolutionary Microbiology Published: 20 April 2022
DOI:https://doi.org/10.1099/ijsem.0.005311
Abstract
A Gram-stain-negative, aerobic and non-spore-forming bacterial strain, designated 20TX0172T, was isolated from a rotting onion bulb in Texas, USA. The results of phylogenetic analysis based on the 16S rRNA sequence indicated that the novel strain represented a member of the genus Pseudomonas and had the greatest sequence similarities with Pseudomonas kilonensis 520-20T (99.3 %), Pseudomonas corrugata CFBP 2431T (99.2 %), and Pseudomonas viciae 11K1T (99.2 %) but the 16S rRNA phylogenetic tree displayed a monophyletic clade with Pseudomonas mediterranea CFBP 5447T. In the phylogenetic trees based on sequences of four housekeeping genes (gap1, gltA, gyrB and rpoD), the novel strain formed a separate branch, indicating that the strain was distinct phylogenetically from known species of the genus Pseudomonas . The genome-sequence-derived average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between the novel isolate and P. mediterranea DSM 16733T were 86.7 and 32.7 %, respectively. These values were below the accepted species cutoff threshold of 96 % ANI and 70 % dDDH, affirming that the strain represented a novel species. The genome size of the novel species was 5.98 Mbp with a DNA G+C content of 60.8 mol%. On the basis of phenotypic and genotypic characteristics, strain 20TX0172T represents a novel species of the genus Pseudomonas . The name Pseudomonas uvaldensis sp. nov. is proposed. The type strain is 20TX0172T (=NCIMB 15426T=CIP 112022T).
