The recovery of the soil ecosystem after severe disturbances, such as coal-mining activities, depends on both abiotic and biotic improvements. This study assessed the influence of arbuscular mycorrhizal (AM) fungal consortia on microbial community dynamics across two stages of soil recovery - 2 years (2Y) and 15 years (15Y) post-disturbance - using a secondary succession forest (SSR) as a reference. We analyzed bacterial community composition via 16 S rRNA gene amplicon sequencing and evaluated key soil quality indicators. While inoculation with AM fungal consortia had minimal effects on most soil parameters, significant differences were observed between recovery stages. The 15Y recovery site exhibited improved soil structure, microbial activity, and aggregate stability compared to the 2Y site, highlighting the importance of long-term restoration. However, potential overlap in ecological roles among native microorganisms likely mitigates the impact of AMF inoculation. These findings suggest that AM fungal consortia alone may not drive immediate improvements in soil quality but can contribute to microbial interactions and recovery processes over time. This study highlights the complexity of soil restoration and emphasizes the need for strategies that integrate plant cover with microbial community development to enhance long-term ecosystem stability. Further research should explore the specific roles of AM fungi and native soil microbes in promoting soil structure and accelerating recovery.

• Klíčová slova
• AM fungal consortia, Combined inoculation, Glomeromycota, Microbiome, Simplified community,
• MeSH
• Bacteria klasifikace   genetika   izolace a purifikace   MeSH
• ekosystém MeSH
• mikrobiota * MeSH
• mykorhiza * fyziologie   MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• těžba uhlí MeSH
• uhlí MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• půda MeSH
• uhlí MeSH

Differences in functioning among various genotypes of arbuscular mycorrhizal (AM) fungi can determine their fitness under specific environmental conditions, although knowledge of the underlying mechanisms still is very fragmented. Here we compared seven homokaryotic isolates (genotypes) of Rhizophagus irregularis, aiming to characterize the range of intraspecific variability with respect to hyphal exploration of organic nitrogen (N) resources, and N supply to plants. To this end we established two experiments (one in vitro and one in open pots) and used 15N-chitin as the isotopically labeled organic N source. In Experiment 1 (in vitro), mycelium of all AM fungal genotypes transferred a higher amount of 15N to the plants than the passive transfer of 15N measured in the non-mycorrhizal (NM) controls. Noticeably, certain genotypes (e.g., LPA9) showed higher extraradical mycelium biomass production but not necessarily greater 15N acquisition than the others. Experiment 2 (in pots) highlighted that some of the AM fungal genotypes (e.g., MA2, STSI) exhibited higher rates of targeted hyphal exploration of chitin-enriched zones, indicative of distinct N exploration patterns from the other genotypes. Importantly, there was a high congruence of hyphal exploration patterns between the two experiments (isolate STSI always showing highest efficiency of hyphal exploration and isolate L23/1 being consistently the lowest), despite very different (micro) environmental conditions in the two experiments. This study suggests possible strategies that AM fungal genotypes employ for efficient N acquisition, and how to measure them. Implications of such traits for local mycorrhizal community assembly still need to be understood.

• Klíčová slova
• Hyphosphere microbiome, Intraspecific differences, Mycorrhizal hyphal networks, Quantitative real-time PCR (qPCR), Soil nitrogen exploration, Stable isotopic labeling and tracing,
• MeSH
• chitin metabolismus   MeSH
• dusík metabolismus   MeSH
• genotyp * MeSH
• Glomeromycota fyziologie   genetika   MeSH
• houby MeSH
• hyfy * genetika   růst a vývoj   MeSH
• mykorhiza * fyziologie   genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chitin MeSH
• dusík MeSH