Geographic limits of a clonal population of wheat yellow rust in the Mediterranean region
Geographic limits of a clonal population of wheat yellow rust in the Mediterranean region
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DOI：
10.1111/j.1365-294x.2009.04267.x
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发表时间：
2009-10-01
影响因子：
4.9
通讯作者：
Enjalbert, J.
中科院分区：
文献类型：
--
作者：
Bahri, B.;Leconte, M.;Enjalbert, J.
大多数植物病原菌具有复杂的生活史，其中克隆繁殖可能阻碍种群实体的划分。通过对小麦条锈菌小种间遗传结构的研究，揭示了高克隆物种群体划分的困难。尽管PST的高扩散潜力，法国南部的分离株被证明是从欧洲西北部的人口不同。在地中海地区进行了一项为期2年的调查，以评估南方分离株的地理分布：使用15个简单序列重复标记对11个国家收集的453株分离株进行基因分型。分析子样品对23个抗性基因的毒力。在地中海西部地区的优势菌株进行了进一步研究，扩增片段长度多态性标记测试的地理子结构。这两个“个人”和“人口”为中心的多态性标记的分析揭示了两个南方特定的群体：一个占主导地位的群体，具有广泛的变异性和广泛的分布在西部和东部的地中海国家，在地中海西部的一个未成年人群体。遗传多样性的东西梯度表明基因流从中东随后的创始人效应和遗传分化，并证明了当地的生存西地中海人口。在突尼斯和阿尔及利亚的品种中观察到的高频率的抗性基因Yr 8可能有助于维持在法国观察到的北/南结构。除了迁移和局部适应之外，还应考虑克隆谱系多样化和替代的动态来定义强克隆物种的种群实体。
Most plant pathogens present complex life cycles, in which the clonal reproduction may impede the delimitation of population entities. By studying the genetic structure of the wheat yellow rust caused by Puccinia striiformis f.sp. tritici (PST), we highlighted difficulties impeding population delimitation in highly clonal species. Despite the high dispersal potential of PST, southern France isolates were shown to be divergent from a northwestern European population. A 2-year survey was performed in the Mediterranean region to assess the geographic distribution of southern isolates: 453 isolates collected in 11 countries were genotyped using 15 simple sequence repeat markers. A subsample was analysed for virulence against 23 resistance genes. The dominant strain in the western Mediterranean region was further studied with amplified fragment length polymorphism markers to test for a geographic substructure. Both 'individual'- and 'population' centred analyses of polymorphism markers revealed two south-specific groups: a predominant group, with a broad variability and a wide distribution in both western and eastern Mediterranean countries, and a minor group in the western Mediterranean. The east-west gradient of genetic diversity suggested gene flow from the Middle East with subsequent founder effects and genetic divergence, and demonstrated the local survival of a western Mediterranean population. The high frequency of the resistance gene Yr8 observed in cultivars from Tunisia and Algeria may contribute to maintain the north/south structure observed in France. In addition to migration and local adaptation, the dynamics of clonal lineage diversification and replacement should be considered to define population entities in strongly clonal species.