Cañizares M C, Gómez-Lama C, García-Pedrajas M D, Pérez-Artés E
Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora"-Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental La Mayora, 29750 Algarrobo-Costa, Málaga, Spain.
Department of Crop Protection, Instituto de Agricultura Sostenible-Consejo Superior de Investigaciones Científicas (IAS-CSIC), Alameda del Obispo s/n, Apdo 4084, 14004 Córdoba, Spain.
Plant Dis. 2015 Jun;99(6):780-787. doi: 10.1094/PDIS-07-14-0680-RE. Epub 2015 May 15.
Fusarium wilt, caused by Fusarium oxysporum f. sp. dianthi, is the most important disease of carnation worldwide. Knowing the diversity of the F. oxysporum f. sp. dianthi population present in a carnation growing area is a key component of preventing dramatic losses in production. Sequence analyses of partial β-tubulin, translation elongation factor 1α genes, and the full-length ribosomal DNA intergenic spacer (IGS) were conducted to resolve phylogenetic relationships in a wide collection of Spanish F. oxysporum f. sp. dianthi isolates, along with some representatives from Italy. We found that, among the three different gene regions, the IGS sequence was the best choice to resolve phylogenetic relationships among F. oxysporum f. sp. dianthi isolates. The phylogenetic tree generated with the complete IGS region was the only one showing a clear clustering of isolates according to the molecular group (virulence grouping) and the vegetative compatibility group. In order to develop a more practical tool based on a shorter DNA sequence to quickly analyze diversity in F. oxysporum f. sp. dianthi populations, we examined IGS nucleotide alignments and identified a region of approximately 300 bp that accumulates enough "informative" changes to resolve intraspecific relationships and determine pathogenic variants in F. oxysporum f. sp. dianthi. Moreover, the "condensed" alignment of this short IGS region showing only the informative positions revealed the existence of virulence group-discriminating positions. In addition to clarifying the phylogenetic relationships among F. oxysporum f. sp. dianthi isolates of the recently described race groups by using multigene genealogies, we have developed simple tools for the phylogenetic analyses of F. oxysporum f. sp. dianthi populations and the determination of the molecular group of uncharacterized F. oxysporum f. sp. dianthi isolates.
由尖孢镰刀菌石竹专化型（Fusarium oxysporum f. sp. dianthi）引起的枯萎病是全球石竹最重要的病害。了解石竹种植区中存在的尖孢镰刀菌石竹专化型群体的多样性是防止产量大幅损失的关键因素。对部分β-微管蛋白、翻译延伸因子1α基因以及全长核糖体DNA基因间隔区（IGS）进行序列分析，以解析来自西班牙的大量尖孢镰刀菌石竹专化型分离株以及一些来自意大利的代表菌株之间的系统发育关系。我们发现，在三个不同的基因区域中，IGS序列是解析尖孢镰刀菌石竹专化型分离株之间系统发育关系的最佳选择。用完整IGS区域构建的系统发育树是唯一根据分子组（毒力分组）和营养体亲和群显示分离株明显聚类的树。为了基于更短的DNA序列开发一种更实用的工具来快速分析尖孢镰刀菌石竹专化型群体的多样性，我们检查了IGS核苷酸比对，并确定了一个约300 bp的区域，该区域积累了足够的“信息性”变化以解析种内关系并确定尖孢镰刀菌石竹专化型中的致病变体。此外，这个短IGS区域仅显示信息性位置的“浓缩”比对揭示了毒力组区分位置的存在。除了通过多基因谱系阐明最近描述的种族组的尖孢镰刀菌石竹专化型分离株之间的系统发育关系外，我们还开发了用于尖孢镰刀菌石竹专化型群体系统发育分析和确定未鉴定的尖孢镰刀菌石竹专化型分离株分子组的简单工具。
