Host–parasite interactions in tan spot [Pyrenophora tritici-repentis] of wheat
Host–parasite interactions in tan spot [Pyrenophora tritici-repentis] of wheat
复制标题
小麦褐斑病[Pyrenophora tritici-repentis]中宿主与寄生虫的相互作用
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
L. Lamari
中科院分区：
文献类型：
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作者：
S. Strelkov;L. Lamari
小麦褐斑病是由子囊菌Prenophora tritici-epentis引起的一种重要的经济病害，在世界各地小麦主产区都有发生。虽然这种病原菌在80多年前就已知发生在牧草上，在小麦上偶尔发生，但在20世纪70年代初首次记录到大规模的褐斑病流行。发病率的增加与留茬有关，这是在土壤保持的背景下实施的一种做法。本文着重介绍了小麦-小麦疫霉相互作用研究的一些最新进展，并讨论了这些研究对我们理解寄主-寄生关系的意义。小黑麦小种至少产生三种寄主特有的毒素，对特定的寄主品系或品种有效。单一显性和独立遗传的基因控制宿主对这些毒素的反应，每种毒素对应一个基因。目前已从世界各地收集的病原菌中鉴定出8个小种，占所有毒力模式，预计来自3种毒素与寄主中的3个“易感”基因相匹配。对寄主和病原菌的遗传分析表明，小麦与小麦赤霉病的相互作用是一对一的关系。描述小麦褐斑病的模型似乎是经典的基因对基因模型的镜像，因为它是基于亲和性的。因此，有人提出，基因对基因的模型可以像以前预测的那样，扩展到涉及多种宿主特异性毒素的病理系统。文中还讨论了毒素产生与新小种进化的关系。
Tan spot of wheat, caused by the ascomycete Pyrenophora tritici-repentis, is an economically important disease in all the major wheat growing areas worldwide. Even though the pathogen was known to occur on grasses and episodically on wheat for more than eight decades, large-scale epidemics of tan spot were first recorded in the early 1970s. The increased incidence was associated with stubble retention, a practice implemented in the context of soil conservation. The present review highlights some of the recent developments that have occurred in studies of the wheat - P. tritici-repentis interaction and discusses the implications for our understanding of host-parasite relations in general. Races of P. tritici-repentis produce at least three host-specific toxins, effective on particular host lines or cultivars. Single dominant and independently inherited genes control host reaction to these toxins, with one gene for each toxin. Eight races of the pathogen have now been identified from collections made in several parts of the world, accounting for all virulence patterns expected from three toxins matching three "susceptibility" genes in the host. Genetic analyses of host and pathogen suggested that a one-to-one relationship existed in the wheat - P. tritici-repentis interaction. The model described for tan spot of wheat appears to be a mirror image of the classical gene-for-gene in that it is based on compatibility. Thus, it is proposed that the gene-for-gene model can be extended, as previously predicted by others, to pathosystems involving multiple host-specific toxins. The relationship between toxin production and the evolution of new races is also discussed.