Liu Zhaohui, El-Basyoni Ibrahim, Kariyawasam Gayan, Zhang Guorong, Fritz Allan, Hansen Jana, Marais Francois, Friskop Andrew, Chao Shiaoman, Akhunov Eduard, Baenziger P Stephen
Department of Plant Pathology, North Dakota State University, Fargo 58102.
Department of Agronomy and Horticulture, University of Nebraska, Lincoln 68583.
Plant Dis. 2015 Oct;99(10):1333-1341. doi: 10.1094/PDIS-11-14-1131-RE. Epub 2015 Aug 20.
Tan spot and Stagonospora nodorum blotch (SNB), often occurring together, are two economically significant diseases of wheat in the Northern Great Plains of the United States. They are caused by the fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, both of which produce multiple necrotrophic effectors (NE) to cause disease. In this work, 120 hard red winter wheat (HRWW) cultivars or elite lines, mostly from the United States, were evaluated in the greenhouse for their reactions to the two diseases as well as NE produced by the two pathogens. One P. nodorum isolate (Sn4) and four Pyrenophora tritici-repentis isolates (Pti2, 331-9, DW5, and AR CrossB10) were used separately in the disease evaluations. NE sensitivity evaluation included ToxA, Ptr ToxB, SnTox1, and SnTox3. The numbers of lines that were rated highly resistant to individual isolates ranged from 11 (9%) to 30 (25%) but only six lines (5%) were highly resistant to all isolates, indicating limited sources of resistance to both diseases in the U.S. adapted HRWW germplasm. Sensitivity to ToxA was identified in 83 (69%) of the lines and significantly correlated with disease caused by Sn4 and Pti2, whereas sensitivity to other NE was present at much lower frequency and had no significant association with disease. As expected, association mapping located ToxA and SnTox3 sensitivity to chromosome arm 5BL and 5BS, respectively. A total of 24 potential quantitative trait loci was identified with -log (P value) > 3.0 on 12 chromosomes, some of which are novel. This work provides valuable information and tools for HRWW production and breeding in the Northern Great Plains.
黄斑病和颖枯病（SNB）常同时发生，是美国大平原北部两种具有经济重要性的小麦病害。它们分别由真菌小麦根腐离蠕孢和颖枯褐孢菌引起，这两种真菌都产生多种坏死营养型效应子（NE）来引发病害。在这项研究中，对120个硬红冬小麦（HRWW）品种或优良品系（大多来自美国）在温室中进行了评估，以研究它们对这两种病害以及两种病原菌产生的NE的反应。在病害评估中分别使用了一个颖枯褐孢菌分离株（Sn4）和四个小麦根腐离蠕孢分离株（Pti2、331 - 9、DW5和AR CrossB10）。NE敏感性评估包括ToxA、Ptr ToxB、SnTox1和SnTox3。对单个分离株表现为高抗的品系数目从11个（9%）到30个（25%）不等，但只有6个品系（5%）对所有分离株都高抗，这表明在美国适应的HRWW种质中，对这两种病害的抗性来源有限。83个（69%）品系被鉴定出对ToxA敏感，并且与由Sn4和Pti2引起的病害显著相关，而对其他NE的敏感性出现频率低得多，且与病害无显著关联。正如预期的那样，关联图谱定位发现ToxA和SnTox3敏感性分别位于5BL和5BS染色体臂上。在12条染色体上共鉴定出24个潜在的数量性状位点，其-log（P值）> 3.0，其中一些是新发现的。这项研究为美国大平原北部的HRWW生产和育种提供了有价值的信息和工具。
