The cultivation of the ectomycorrhizal fungus Tuber melanosporum has considerably spread in recent years throughout the world. During the first years of truffle cultivation, weed control is a key practice to improve the establishment of host trees and the proliferation of the fungus in the soil. Glyphosate is nowadays the most commonly used herbicide in Spanish truffle orchards. We explored the effect of glyphosate on the proliferation of T. melanosporum mycorrhizae, on extraradical mycelium and on the inoculum potential of T. melanosporum spores in greenhouse experiments using Quercus ilex seedlings as host plants. No detrimental effect on the secondary infection of T. melanosporum was found after three sequential glyphosate applications in young seedlings during one vegetative period. Instead, a change in the distribution of fine roots and T. melanosporum mycorrhizae along soil depth was observed. On the other hand, results indicate that high application rates of glyphosate hinder the infectivity of T. melanosporum spore inoculum, without apparent impact on the host performance. Our results suggest that glyphosate has the potential to jeopardise the role of the soil spore bank as inoculum source for the colonisation of new roots, also raising the question of whether glyphosate could hinder the presumed role of spores in sexual mating.

近年来，外生菌根真菌Tuber melanosporum的种植已在世界范围内广泛传播。在松露种植的最初几年，杂草控制是改善寄主树的生长和土壤中真菌繁殖的关键做法。草甘膦是当今西班牙松露果园最常用的除草剂。我们在温室实验中以栎冬青幼苗为寄主植物，探讨了草甘膦对黑孢子菌菌根增殖、根外菌丝体以及黑孢子菌孢子接种潜力的影响。在一个生长期对幼苗连续施用 3 次草甘膦后，未发现对黑色孢子虫继发感染有不利影响。相反，观察到细根和T. melanosporum菌根沿土壤深度的分布发生变化。另一方面，结果表明，草甘膦的高施用量阻碍了黑孢子虫孢子接种物的感染性，但对宿主性能没有明显影响。我们的研究结果表明，草甘膦有可能损害土壤孢子库作为新根定殖的接种源的作用，同时也提出了草甘膦是否会阻碍孢子在有性交配中的假定作用的问题。