Whitaker Briana K, Christian Natalie, Chai Qing, Clay Keith
Department of Biology Indiana University Bloomington IN USA.
Department of Biology University of Louisville Louisville KY USA.
Ecol Evol. 2020 Nov 26;10(24):13895-13912. doi: 10.1002/ece3.6983. eCollection 2020 Dec.
Phylogenetic distance among host species represents a proxy for host traits that act as biotic filters to shape host-associated microbiome community structure. However, teasing apart potential biotic assembly mechanisms, such as host specificity or local species interactions, from abiotic factors, such as environmental specificity or dispersal barriers, in hyperdiverse, horizontally transmitted microbiomes remains a challenge. In this study, we tested whether host phylogenetic relatedness among 18 native Asteraceae plant species and spatial distance between replicated plots in a common garden affects foliar fungal endophyte (FFE) community structure. We found that FFE community structure varied significantly among host species, as well as host tribes, but not among host subfamilies. However, FFE community dissimilarity between host individuals was not significantly correlated with phylogenetic distance between host species. There was a significant effect of spatial distance among host individuals on FFE community dissimilarity within the common garden. The significant differences in FFE community structure among host species, but lack of a significant host phylogenetic effect, suggest functional differences among host species not accounted for by host phylogenetic distance, such as metabolic traits or phenology, may drive FFE community dissimilarity. Overall, our results indicate that host species identity and the spatial distance between plants can determine the similarity of their microbiomes, even across a single experimental field, but that host phylogeny is not closely tied to FFE community divergence in native Asteraceae.
宿主物种之间的系统发育距离代表了宿主性状的一个替代指标，这些性状作为生物过滤器塑造宿主相关微生物群落结构。然而，在高度多样化的、水平传播的微生物群落中，区分潜在的生物组装机制，如宿主特异性或局部物种相互作用，与非生物因素，如环境特异性或扩散障碍，仍然是一个挑战。在本研究中，我们测试了18种本土菊科植物物种之间的宿主系统发育相关性以及一个共同花园中重复样地之间的空间距离是否会影响叶部真菌内生菌（FFE）群落结构。我们发现，FFE群落结构在宿主物种之间以及宿主族之间有显著差异，但在宿主亚科之间没有差异。然而，宿主个体之间的FFE群落差异与宿主物种之间的系统发育距离没有显著相关性。宿主个体之间的空间距离对共同花园内的FFE群落差异有显著影响。宿主物种之间FFE群落结构存在显著差异，但缺乏显著的宿主系统发育效应，这表明宿主物种之间未被宿主系统发育距离所解释的功能差异，如代谢性状或物候，可能驱动FFE群落差异。总体而言，我们的结果表明，宿主物种身份和植物之间的空间距离可以决定它们微生物群落的相似性，即使是在单个实验田内，但宿主系统发育与本土菊科植物的FFE群落分化没有紧密联系。
