Evolutionary Relationships among the Fusarium oxysporum f. sp cubense Vegetative Compatibility Groups
Evolutionary Relationships among the Fusarium oxysporum f. sp cubense Vegetative Compatibility Groups
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DOI：
10.1128/aem.00370-09
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发表时间：
2009-07-15
影响因子：
4.4
通讯作者：
Viljoen, A.
中科院分区：
文献类型：
--
作者：
Fourie, Gerda;Steenkamp, E. T.;Viljoen, A.
香蕉枯萎sp. cubense，香蕉枯萎病的病原体，是维管枯萎病菌F.尖孢菌属研究了F. oxysporum F.通过对70株古巴镰刀菌（F. cubense）的两个核DNA和两个线粒体DNA区域进行测序，研究了古巴镰刀菌（F.尖孢镰刀菌分离物，包括代表20 VCG的F. oxysporum F. sp. cubense、其他特殊形式和非病原体。确定F. oxysporum F. sp. cubense进行有性重组，在相反交配型的分离物之间进行杂交。系统发育分析将F.尖孢菌（oxysporum）分为两个分支和八个谱系。F. oxysporum F. sp. cubense和F.尖孢镰刀菌VCG与小种的关系。oxysporum F. sp. cubense清楚地表明F. oxysporum F.古巴专化性病原菌在香蕉上引起疾病的能力已经多次独立地出现，并且对特定香蕉栽培品种引起疾病的能力也是多系性状。这些分析进一步表明，与宿主的协同进化和水平基因转移可能在病原体的进化历史中发挥了重要作用。所有研究的菌株窝藏两个交配型的自型之一，但从来没有两个，这表明异宗配合的交配系统应该有性生殖发生。虽然没有观察到有性结构，但F。oxysporum F. sp. cubense窝藏MAT-1和MAT-2分离物，这表明这些谱系具有可能比最初预期的更近的有性起源的潜力。
Fusarium oxysporum f. sp. cubense, the causal agent of fusarium wilt of banana (Musa spp.), is one of the most destructive strains of the vascular wilt fungus F. oxysporum. Genetic relatedness among and within vegetative compatibility groups (VCGs) of F. oxysporum f. sp. cubense was studied by sequencing two nuclear and two mitochondrial DNA regions in a collection of 70 F. oxysporum isolates that include representatives of 20 VCGs of F. oxysporum f. sp. cubense, other formae speciales, and nonpathogens. To determine the ability of F. oxysporum f. sp. cubense to sexually recombine, crosses were made between isolates of opposite mating types. Phylogenetic analysis separated the F. oxysporum isolates into two clades and eight lineages. Phylogenetic relationships between F. oxysporum f. sp. cubense and other formae speciales of F. oxysporum and the relationships among VCGs and races of F. oxysporum f. sp. cubense clearly showed that F. oxysporum f. sp. cubense's ability to cause disease on banana has emerged multiple times, independently, and that the ability to cause disease to a specific banana cultivar is also a polyphyletic trait. These analyses further suggest that both coevolution with the host and horizontal gene transfer may have played important roles in the evolutionary history of the pathogen. All examined isolates harbored one of the two mating-type idiomorphs, but never both, which suggests a heterothallic mating system should sexual reproduction occur. Although, no sexual structures were observed, some lineages of F. oxysporum f. sp. cubense harbored MAT-1 and MAT-2 isolates, suggesting a potential that these lineages have a sexual origin that might be more recent than initially anticipated.