The nature of host–pathogen interactions between Pyrenophora teres f. teres and barley has been reported to be as well race-specific as race-non-specific with evidence that the definition of races is tenuous. Infection responses of 266 single-spore isolates of P. teres f. teres collected in Uruguay during regular surveys from 2005 to 2015 to 41 barley genotypes that had been determined on a 1–10 scale and thus allowed for qualitative and quantitative distinction in virulence and aggressiveness were subjected to cluster analysis. A total of four isolate clusters and seven barley clusters based on mean infection responses were determined. Infections reactions of the 266 isolates were continuous, and each isolate had a unique pathogenic spectrum. There were no effects of sampling year and location on the occurrence of similar isolates. Despite some very few and clear isolate-specific interactions, the interactions in this pathosystem can be described as predominately quantitative. For screening purposes, 1–2 isolates from the different clusters with broad aggressiveness to most or all of the respective barley genotype clusters will be the best choice.

产油假单胞菌之间宿主-病原体相互作用的性质。小圆和大麦已被报道种族特异性的种族-非特异性证据，证明种族的定义是脆弱的好。的266的单孢子分离感染应答P. TERES F。特雷斯从2005年至2015年的定期调查中，在乌拉圭收集了41种大麦基因型，这些基因型以1-10比例确定，因此可以对毒力和攻击性进行定性和定量区分，并进行聚类分析。基于平均感染反应确定了总共四个分离株簇和七个大麦簇。266个分离株的感染反应是连续的，每个分离株都有独特的致病谱。采样年份和地点对类似菌株的发生没有影响。尽管分离物之间的相互作用极少且清晰，但该病理系统中的相互作用可被描述为主要是定量的。出于筛选目的，