University of Cocody-Abidjan, Côte d'Ivoire.
Phytopathology. 2012 Aug;102(8):733-40. doi: 10.1094/PHYTO-11-11-0300.
The genetic and phenotypic diversity of Côte d'Ivoire Ralstonia solanacearum strains was assessed on a 168-strain collection sampled on Solanaceae both in the southern lowlands and western highlands. Phylotypes I, II, and III were prevalent, though at unexpected frequencies. Phylotype I strains (87.5%) were genetically diverse and overrepresented in all agroecological areas, including highlands (AEZ III). Phylotype II strains (10.7%) only belonged to one tropical lowland-adapted broad host range lineage (IIA-35), whereas no highland-adapted potato brown rot (IIB-1) or Moko strains were detected. African phylotype III strains were rare (1.8%). They originated from a single Burkina Faso lineage (III-23) and were only found in lowlands. Three phylotype I strains were found harboring pRSC35, a plasmid identified in phylotype III strains in Cameroon. From pathogenicity tests performed on commercial varieties and tomato/eggplant/pepper references, the virulence diversity observed was high, with five pathoprofiles described. Eggplant accessions MM152 and EG203 and tomato HW7996 displayed the largest resistance spectrum and highest level. Two highly virulent phylotype I strains were able to bypass resistance of HW7996 and the eggplant reference AG91-25. Collectively, these points lead to the conclusion that the situation in Côte d'Ivoire is specific towards other African countries, and specifically from the Cameroon reference, and that within phylotype I can exist a high virulence diversity. This calls for similar studies in neighboring West African countries, linking R. solanacearum pathogen genetic diversity to strain virulence at the regional level, for the rationalization of regional resistance deployment strategies and future resistance durability studies.
对科特迪瓦 168 株罗尔斯通氏菌菌株的遗传和表型多样性进行了评估，这些菌株是在南部低地和西部高地的茄科植物上采集的。尽管频率出人意料，但 I、II 和 III 型是主要的流行型。I 型菌株（87.5%）遗传多样性丰富，在所有农业生态区均有代表性，包括高地（AEZ III）。II 型菌株（10.7%）仅属于一个热带低地适应的广泛宿主范围谱系（IIA-35），而未检测到适应高地的马铃薯褐腐病（IIB-1）或 Moko 菌株。非洲 III 型菌株很少见（1.8%）。它们源自布基纳法索的一个谱系（III-23），仅在低地发现。在对商业品种和番茄/茄子/辣椒参考品种进行的致病性测试中，观察到的毒力多样性很高，描述了五个致病谱。在喀麦隆的 III 型菌株中发现的质粒 pRSC35 存在于三种 I 型菌株中。茄子品种 MM152 和 EG203 以及番茄 HW7996 表现出最大的抗性谱和最高水平。两株高毒力的 I 型菌株能够绕过 HW7996 和茄子参考品种 AG91-25 的抗性。总的来说，这些结果表明科特迪瓦的情况与其他非洲国家特别是喀麦隆的参考情况不同，而且在 I 型中可能存在高毒力多样性。这就需要在邻国西非国家进行类似的研究，将罗尔斯通氏菌病原体的遗传多样性与区域水平的菌株毒力联系起来，为区域抗性部署策略的合理化和未来的抗性耐久性研究提供依据。
