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K. G. Savchenko L. M. Carris J. Demers D. S. Manamgoda L. A. Castlebury 《Plant pathology》2017,66(7):1139-1148
The causal agent of flag smut of wheat is currently subject to strict quarantine regulations in many countries and is believed to have a wide host range on wild and cultivated grasses. This fungus has been classified as both Urocystis agropyri and Urocystis tritici. Urocystis agropyri was first described from Elymus repens in Germany and U. tritici was first described from Triticum vulgare (=T. aestivum). In 1953, G. W. Fischer placed U. tritici and a large number of other Urocystis species in synonymy with U. agropyri. The present study is the first attempt to clarify the taxonomy and phylogeny of flag smut pathogens of grasses using molecular analyses. Three loci, the internal transcribed spacer (ITS) region of rDNA, the RNA polymerase II subunit 2 (RPB2), and translation elongation factor (TEF) protein‐coding regions were used for phylogenetic reconstruction to determine the species boundaries of 24 Urocystis specimens from triticoid hosts. Results indicate that there are several distinct lineages of flag smut pathogens, including the causal agent of flag smut of wheat, which is supported as a separate species, U. tritici. Sequences from specimens on E. repens, which are retained as U. agropyri, grouped in a clade distinct from those on wheat and rye. The closest relatives of U. tritici were found to be U. hispanica from Aegilops and Urocystis sp. from Thinopyrum junceiforme and Elymus trachycaulis. Recognition that U. tritici is genetically distinct from U. agropyri sensu stricto will impact regulatory policy and facilitate the development of diagnostic tests. 相似文献
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建设无疫小区是控制和消灭动物疫病的国际通行做法。2018年非洲猪瘟(African swine fever,ASF)传入我国,对我国养猪业的健康发展造成沉重打击。在尚无有效的治疗药物和疫苗的情况下,提高养殖场生物安全水平是防控ASF的关键,开展以生物安全管理体系构建、生物安全管理措施落实为核心的无疫小区建设,成为防控ASF的一条重要途径。本文重点介绍了无ASF小区建设的基本要求、生物安全体系建立要素和建设评估重点内容,总结了无ASF小区建设取得的成效,以期对我国ASF防控工作和无ASF小区建设提供参考。 相似文献