Holmes E A, Bennett R S, Spurgeon D W, Colyer P D, Davis R M
Department of Plant Pathology, University of California, Davis 95616.
Western Integrated Cropping Systems Research Unit, United States Department of Agriculture-Agricultural Research Service, Shafter, CA 93263.
Plant Dis. 2009 Dec;93(12):1298-1304. doi: 10.1094/PDIS-93-12-1298.
Sixty-one isolates of Fusarium oxysporum f. sp. vasinfectum were collected from cotton plants (Gossypium spp.) with symptoms of Fusarium wilt to determine the composition of races present in the southeastern United States. Analysis of partial sequences of the translation elongation factor gene revealed four novel genotypes, as well as the presence of races 3 and 8 for the first time in the United States outside of California. The majority of isolates (16 of 27) sampled from Arkansas were novel genotypes. A subset of isolates representing the novel genotypes was compared with previously described races using sequences from translation elongation factor, phosphate permase, and β-tubulin genes and their pathogenicity on a total of six Upland (Gossypium hirsutum) and Pima (G. barbadense) cotton cultivars. Two of the novel genotypes belonged to a clade containing races 1, 2, 4, 6, and 8 and two shared ancestry with race 3. All new genotypes were pathogenic to at least some of the cotton cultivars tested. The Pima cv. Phytogen 800 was relatively resistant to all genotypes of the pathogen. These results indicate that the population of F. oxysporum f. sp. vasinfectum in the southeastern United States is more diverse than previously recognized.
从患有枯萎病症状的棉花植株（棉属）中收集了61株尖孢镰刀菌萎蔫专化型菌株，以确定美国东南部存在的生理小种组成。对翻译延伸因子基因的部分序列分析揭示了四种新基因型，并且首次在美国加利福尼亚州以外的地区发现了生理小种3和8。从阿肯色州采集的大多数菌株（27株中的16株）为新基因型。使用翻译延伸因子、磷酸盐通透酶和β-微管蛋白基因的序列以及它们对总共六个陆地棉（陆地棉）和皮马棉（海岛棉）品种的致病性，将代表新基因型的一部分菌株与先前描述的生理小种进行了比较。其中两个新基因型属于一个包含生理小种1、2、4、6和8的进化枝，另外两个与生理小种3有共同的祖先。所有新基因型对至少一些测试的棉花品种具有致病性。皮马棉品种Phytogen 800对该病原菌的所有基因型相对抗性较强。这些结果表明，美国东南部的尖孢镰刀菌萎蔫专化型群体比以前认识到的更加多样化。
