The Pyrenophora genus involves an extremely important group of fungal plant pathogens, causing some of the most devastating disease epidemics of cereal plants worldwide. Among them, tan spot caused by Pyrenophora tritici-repentis is one of the major constraints of wheat production in Argentina. Furthermore, Pyrenophora teres F. maculata is a new recently recorded pathogen infecting leaves of wheat plants causing the spot-type of net blotch, a leaf-spotting symptom easily confused with those caused by tan spot. Most of the wheat cultivars in Argentina have been reported as moderately susceptible to P. tritici-repentis under natural infections. Concerning P. teres F. maculata, no information is available about the currently used cultivars in Argentina. Thirty wheat cultivars currently widely used in Argentina were evaluated for their reaction to one isolate of P. tritici-repentis and two isolates of P. teres F. maculata. The type of lesions occurring on plants was a reliable indicator of susceptibility or resistance of cultivars to both pathogens with artificial inoculations under pot and field conditions. Several wheat genotypes showing susceptibility or resistance to the isolates of the two pathogens tested at seedling and adult plant stages were found. This is the first report of the reaction of Argentinian cultivars to the new pathogen P. teres F. maculata in wheat. We detected that Don Mario Algarrobo, Buck SY 110 and ACA Cedro could be used as source of resistance for both pathogens at seedling and adult stages. This information is useful to improve the resistance to the disease in breeding programs.

该核腔属涉及植物病原真菌引起的极其重要的群体，导致一些全球谷类植物的最具破坏性的疾病流行。其中，由Pyrenophora tritici-repentis引起的棕褐色斑是阿根廷小麦生产的主要制约因素之一。此外，Pyrenophora teres F. maculata是最近记录的一种感染小麦植物叶子的新病原体，导致斑点型网斑病，这种斑点症状很容易与棕褐色斑点引起的叶子斑点症状混淆。据报道，阿根廷的大多数小麦品种在自然感染下对小麦白粉病中度敏感。关于P. teres F. maculata，没有关于阿根廷目前使用的品种的信息。评估了目前在阿根廷广泛使用的 30 个小麦品种对一种P. tritici-repentis分离物和两种P. teres F. maculata分离物的反应。在盆栽和田间条件下进行人工接种，植物上发生的病变类型是栽培品种对两种病原体的易感性或抗性的可靠指标。发现了对在幼苗和成株阶段测试的两种病原体的分离物表现出易感性或抗性的几种小麦基因型。这是阿根廷品种对新病原体P. teres F. maculata反应的首次报告在小麦中。我们检测到 Don Mario Algarrobo、Buck SY 110 和 ACA Cedro 可作为两种病原体在幼苗和成虫阶段的抗性来源。该信息有助于提高育种计划中对该病的抵抗力。