Spatial and temporal dynamics of the extraradical phase of arbuscular mycorrhizal fungi.

摘要

The dynamics of AMF mycelium and spores were quantified in mesh-exclusion microcosms. In soil, the distance from the host root did not significantly affect the spatial dynamics of AMF biomass (hyphae or spores), with a distance of 12 cm from the host root being uniformly colonised within 1 month. Excision of the host shoot did not significantly affect sporulation and the numbers of spores remained the same for the next 12 weeks. The temporal dynamics of sporulation following excision of the host shoot was also determined in patches of organic fertiliser (farmyard manure, FYM) and field soil. Spore numbers were far higher in FYM than in patches of field soil. Following excision of the host shoot the number of spores dramatically decreased in both patches; however in FYM this was followed by a significant increase in spore numbers, suggesting a capability for non-symbiotic sporulation. This finding provides important insights into the nature of AMF sporulation in organic-rich patches and the consequent impacts for agronomic management.