Teratosphaeria pseudoeucalypti is a fungal pathogen that causes a severe leaf blight disease on Eucalyptus trees. While presumed to be native to Australia, T. pseudoeucalypti has become well established and an important constraint to forestry in South America. The aim of this study was to use microsatellite markers to investigate the genetic diversity of T. pseudoeucalypti outbreaks occurring in plantations in two distinct environments. In the New South Wales (NSW) plantation in Australia, a hybrid of two native Eucalyptus species was planted outside of its natural environment. In contrast, the plantations in Uruguay were of a non-native Eucalyptus species. Sixteen polymorphic microsatellite loci, identified in two genomes of T. pseudoeucalypti, were used to genotype 36 individuals from the NSW plantation and 21 were collected from across Uruguay. Genetic diversity in the NSW population was low (H_exp = 0.05), comprising five genotypes of which one occurred in > 80% of individuals. Despite high clonality and one MAT1-1 isolate among many MAT1-2 isolates, different genotypes co-occurred on a single tree and the hypothesis of recombination was not rejected. The diversity in the NSW plantation was consistent with that of an introduced pathogen, either from the surrounding native forests, or supporting earlier findings that T. pseudoeucalypti has only recently established in NSW. All isolates from Uruguay were clonal, harbouring the MAT1-1 idiomorph and a genotype distinct from those in Australia. This clonality suggests a single introduction of T. pseudoeucalypti into that country.

Teratosphaeria pseudoeucalypti是一种真菌病原体，可在桉树上引起严重的叶枯病。虽然被认为原产于澳大利亚，但T. pseudoeucalypti已成为南美洲林业的重要制约因素。本研究的目的是使用微卫星标记来调查在两种不同环境中种植园发生的假桉树爆发的遗传多样性。在澳大利亚的新南威尔士 (NSW) 种植园，在自然环境之外种植了两种本地桉树物种的杂交种。相比之下，乌拉圭的种植园是非本土桉树物种。在T. pseudoeucalypti 的两个基因组中鉴定出的 16 个多态性微卫星位点被用于对来自 NSW 种植园的 36 个个体进行基因分型，并从整个乌拉圭收集了 21 个。新南威尔士州人口的遗传多样性较低（H _exp  = 0.05），包括五种基因型，其中一种发生在 > 80% 的个体中。尽管在许多MAT1-2分离株中具有高克隆性和一个MAT1-1分离株，但不同的基因型在同一棵树上共存，重组的假设并未被拒绝。新南威尔士州人工林的多样性与引入病原体的多样性一致，无论是来自周围的原生森林，还是支持早期发现的T. pseudoeucalypti最近才在新南威尔士州成立。来自乌拉圭的所有分离株都是克隆性的，含有MAT1-1基因型和与澳大利亚不同的基因型。这种克隆性表明T. pseudoeucalypti被单一引入该国。