Mahbou Somo Toukam Gabriel, Cellier Gilles, Wicker Emmanuel, Guilbaud Caroline, Kahane Rémi, Allen Caitilyn, Prior Philippe
Institut de Recherche Agronomique pour le développement, IRAD, Programme Légumineuses et Cultures Maraîchères, Yaoundé, BP 2067 Yaoundé, Cameroun.
CIRAD, UMRC53, Peuplement Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410, Saint-Pierre, La Réunion, France.
Plant Dis. 2009 Nov;93(11):1123-1130. doi: 10.1094/PDIS-93-11-1123.
In 2005, an extensive survey of bacterial wilt in Cameroon collected 110 strains of Ralstonia solanacearum from wilting tomato, potato, pepper, huckleberry (Solanum scabrum), sesame, and amaranth. The genetic diversity and phylogeny of selected strains from Cameroon were assessed by multiplex-polymerase chain reaction (PCR), race 3/biovar 2-specific PCR, and sequence analyses of the mutS and egl genes. These data were compared with those from 33 reference strains covering the known diversity within the R. solanacearum species complex. Strains isolated in Cameroon clustered into three of the four known phylotypes: I (Asian), II (American), and III (African). Lowland tomato strains belonged to phylotype I and were quite homogeneous. The strains belonging to phylotype II were genetically diverse, and partitioned into subclusters IIA and IIB (sequevar 1, race 3/biovar 2). Cameroon strains in the African phylotype III were distinct from reference strains from Zimbabwe or the Indian Ocean, highlighting the genetic diversity present within this phylotype. Strains from potatoes growing in the highlands of West Cameroon fell into both phylotypes II (race 3/biovar 2) and III. These phylotype II and III highland strains attacked both potato and tomato and could therefore pose an economic threat to potato and tomato crops throughout Central Africa. This is the first comprehensive report on the genetic diversity of R. solanacearum strains in Cameroon.
2005年，在喀麦隆开展的一项关于青枯病的广泛调查从萎蔫的番茄、马铃薯、辣椒、刺茄（Solanum scabrum）、芝麻和苋菜中收集了110株青枯雷尔氏菌（Ralstonia solanacearum）菌株。通过多重聚合酶链反应（PCR）、3号小种/生物变种2特异性PCR以及mutS和egl基因的序列分析，对喀麦隆选定菌株的遗传多样性和系统发育进行了评估。这些数据与来自33株参考菌株的数据进行了比较，这些参考菌株涵盖了青枯雷尔氏菌物种复合体已知的多样性。在喀麦隆分离出的菌株聚为已知四个菌系中的三个：菌系I（亚洲）、菌系II（美洲）和菌系III（非洲）。低地番茄菌株属于菌系I，且相当一致。属于菌系II的菌株遗传多样性高，并分为亚群IIA和IIB（序列变种1，3号小种/生物变种2）。非洲菌系III中的喀麦隆菌株与来自津巴布韦或印度洋的参考菌株不同，突出了该菌系内存在的遗传多样性。来自喀麦隆西部高地种植的马铃薯的菌株同时属于菌系II（3号小种/生物变种2）和菌系III。这些菌系II和III的高地菌株会侵袭马铃薯和番茄，因此可能对整个中非的马铃薯和番茄作物构成经济威胁。这是关于喀麦隆青枯雷尔氏菌菌株遗传多样性的第一份全面报告。
