A new pathovar of Pseudomonas syringae, pathovar allii, isolated from onion plants exhibiting symptoms of blight

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• 作者：V. M. Moloto ; T. Goszczynska ; L. J. du Toit…
• 关键词：Phenotypic amplification ; Cluster core genome
• 刊名：European Journal of Plant Pathology
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：147
• 期：3
• 页码：591-603
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Plant Pathology; Plant Sciences; Ecology; Agriculture; Life Sciences, general;
• 出版者：Springer Netherlands
• ISSN：1573-8469
• 卷排序：147

文摘

Bacterial pathogens of onion (Allium cepa) plants and their undetected presence in seed can cause substantial losses to onion producers. In this study, 23 Pseudomonas syringae strains were isolated from five onion plants and 18 onion seeds. The symptoms on leaves and seed stalks were irregular lesions with necrotic centres and water soaked margins. The aim of the study was to characterize these P. syringae strains using Biolog GN III carbon source utilization, multilocus sequence typing (MLST) based on partial sequences of four housekeeping genes (cts, gapA, gyrB and rpoD), and to determine whether or not the strains were pathogenic on onion (cv. Granex 33), chive (Allium schoenoprasum cv. Grasiue), leek (Allium porrum cv. Giant Italian) and spring onion (Allium fistulosum cv. Salotte) plants. Both Biolog analysis and MLST analysis separated onion strains into two clusters, one supporting the existence of a new pathovar of P. syringae, and the other corresponding to P. syringae pv. porri. Pseudomonas syringae strains belonging to the new pathovar we pathogenic only on onion plants of the Allium spp. tested. The results of this study revealed that bacterial blight of onion in South Africa is caused by two pathovars of P. syringae sensu lato, namely, the newly described pathovar, allii, and P. syringae pv. porri. The symptoms caused by these two pathovars in the field were indistinguishable.