Accurate species delimitation has a pivotal role in conservation biology, and it is especially important for threatened species where decisions have political and economic consequences. Finding and applying appropriate character sets and analytical tools to resolve interspecific relationships remains challenging in lichenized fungi. The main aim of our study was to re-assess the species boundaries between Usnea subfloridana and Usnea florida, which have been phylogenetically indistinguishable until now, but are different in reproductive mode and ecological preferences, using fungal-specific simple sequence repeats (SSR), i.e. microsatellite markers. Bayesian clustering analysis, discriminant analysis of principal components (DAPC), minimal spanning network (MSN), and principal component analysis (PCA) failed to separate U. florida and U. subfloridana populations. However, a low significant differentiation between the two taxa was observed across all populations according to AMOVA results. Also, analysis of shared haplotypes and statistical difference in clonal diversity (M) supported the present-day isolation between the apotheciate U. florida and predominantly sorediate U. subfloridana. Our results do not provide a clear support either for the separation of species in this pair or the synonymization of U. florida and U. subfloridana. We suggest that genome-wide data could help resolve the taxonomic question in this species pair.

中文翻译：

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基于微卫星数据的 Apotheciate Usnea florida 和 Sorediate U. subfloridana（Parmeliaceae，Ascomycota）之间的低遗传差异

准确的物种划界在保护生物学中具有关键作用，对于决策具有政治和经济后果的受威胁物种尤其重要。在地衣真菌中寻找和应用适当的字符集和分析工具来解决种间关系仍然具有挑战性。我们研究的主要目的是使用真菌特异性简单序列重复序列 (SSR) 重新评估 Usnea subfloridana 和 Usnea florida 之间的物种边界，这些边界迄今为止在系统发育上无法区分，但在繁殖模式和生态偏好上有所不同，即微卫星标记。贝叶斯聚类分析、主成分判别分析 (DAPC)、最小生成网络 (MSN) 和主成分分析 (PCA) 未能将 U. florida 和 U. 分开。亚佛罗里达种群。然而，根据 AMOVA 结果，在所有种群中观察到两个分类群之间的低显着差异。此外，对共享单倍型的分析和克隆多样性 (M) 的统计差异支持了 apotheciate U. florida 和主要 sorediate U. subfloridana 之间的当今隔离。我们的结果没有为这对物种的分离或 U. florida 和 U. subfloridana 的同义化提供明确的支持。我们建议全基因组数据可以帮助解决该物种对中的分类问题。对共享单倍型的分析和克隆多样性 (M) 的统计差异支持了 apotheciate U. florida 和主要 sorediate U. subfloridana 之间的当今隔离。我们的结果没有为这对物种的分离或 U. florida 和 U. subfloridana 的同义化提供明确的支持。我们建议全基因组数据可以帮助解决该物种对中的分类问题。对共享单倍型的分析和克隆多样性 (M) 的统计差异支持了 apotheciate U. florida 和主要 sorediate U. subfloridana 之间的当今隔离。我们的结果没有为这对物种的分离或 U. florida 和 U. subfloridana 的同义化提供明确的支持。我们建议全基因组数据可以帮助解决该物种对中的分类问题。