Sharma Kalpana, Iruegas-Bocardo Fernanda, Abdurahman Abdulwahab, Alcalá-Briseño Ricardo I, Garrett Karen A, Goss Erica M, Ngundo George, Kreuze Jan, Atieno Elly, Munguti Florence
Consultative Group for International Agricultural Research (CGIAR) Research Program on Roots, Tubers and Bananas (RTB), Centro Internacional de la Papa, Nairobi, Kenya, Lima, Peru.
International Potato Center (CIP), Sub-Saharan Africa Regional Office, Nairobi, Kenya.
Phytopathology. 2022 Oct;112(10):2072-2083. doi: 10.1094/PHYTO-11-21-0455-R. Epub 2022 Sep 26.
Bacterial wilt, caused by the species complex (RSSC), is the most destructive potato disease in Kenya. Studies were conducted to (i) determine the molecular diversity of RSSC strains associated with bacterial wilt of potato in Kenya, (ii) generate an RSSC distribution map for epidemiological inference, and (iii) determine whether phylotype II sequevar 1 strains exhibit epidemic clonality. Surveys were conducted in 2018 and 2019, in which tubers from wilting potato plants and stem samples of potential alternative hosts were collected for pathogen isolation. The pathogen was phylotyped by multiplex PCR and 536 RSSC strains typed at a sequevar level. Two RSSC phylotypes were identified, phylotype II (98.4%, = 506 [sequevar 1 ( = 505) and sequevar 2 ( = 1)]) and phylotype I (1.6%, = 30 [sequevar 13 ( = 9) and a new sequevar ( = 21)]). The phylotype II sequevar 1 strains were haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. The TRST scheme identified 51 TRST profiles within the phylotype II sequevar 1 strains with a modest diversity index (HGDI = 0.87), confirming the epidemic clonality of RSSC phylotype II sequevar 1 strains in Kenya. A minimum spanning tree and mapping of the TRST profiles revealed that TRST27 '8-5-12-7-5' is the primary founder of the clonal complex of RSSC phylotype II sequevar 1 and is widely distributed via latently infected seed tubers. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
由Ralstonia solanacearum物种复合体（RSSC）引起的青枯病是肯尼亚最具破坏性的马铃薯病害。开展了多项研究，以（i）确定与肯尼亚马铃薯青枯病相关的RSSC菌株的分子多样性，（ii）生成用于流行病学推断的RSSC分布图，以及（iii）确定II型菌系序列变种1菌株是否表现出流行克隆性。在2018年和2019年进行了调查，从萎蔫马铃薯植株上采集块茎，并采集潜在替代寄主的茎样本用于病原菌分离。通过多重PCR对病原菌进行菌系分型，并在序列变种水平上对536个RSSC菌株进行分型。鉴定出两种RSSC菌系，II型菌系（98.4%，n = 506 [序列变种1（n = 505）和序列变种2（n = 1）]）和I型菌系（1.6%，n = 30 [序列变种13（n = 9）和一个新的序列变种（n = 21）]）。使用多位点串联重复序列分型（TRST）方案对II型菌系序列变种1菌株进行单倍型分型。TRST方案在II型菌系序列变种1菌株中鉴定出51个TRST谱型，多样性指数适中（HGDI = 0.87），证实了肯尼亚RSSC II型菌系序列变种1菌株的流行克隆性。最小生成树和TRST谱型图谱显示，TRST27 '8-5-12-7-5' 是RSSC II型菌系序列变种1克隆复合体的主要奠基者，并通过潜伏感染的种薯广泛传播。[公式：见正文] 版权所有© 2022作者。本文是一篇根据知识共享署名 - 非商业性使用 - 禁止演绎4.0国际许可协议分发的开放获取文章。
