Propagule-Type Specificity in Arbuscular Mycorrhizal Fungal Communities in Early Growth of Allium tuberosum

Arbuscular mycorrhizal fungi (AMF) exhibit diverse strategies for colonization and survival, yet the extent to which different propagule types-roots, extraradical hyphae, and spores-contribute to these processes remains unclear. In a pot experiment using <i>Allium tuberosum</i> and soils from three field sites, we characterized AMF communities in root, hyphal, and spore fractions through 18S rRNA gene sequencing. A total of 427 OTUs were identified, with <i>Glomus</i> and <i>Paraglomus</i> dominating. Root fractions contained significantly more OTUs than hyphal fractions, suggesting strong specialization for intraradical colonization. Only a small subset of taxa occurred across all propagule types. Indicator species analysis revealed 21 OTUs with significant associations, mainly in root and hyphal fractions, while spore-specific taxa were rare. PERMANOVA revealed that both propagule type and soil type shaped the community structure, with propagule identity being the stronger factor. These results highlight propagule-type specialization as a key ecological trait in AMF and underscore the importance of examining multiple fungal compartments to fully capture AMF diversity and function.