Schematic drawing of the entry of Trichoderma harzianum into Solanum tuberosum var. ‘Bintje’ root. Trichoderma harzianum growth alongside and/or coil around the hyphae of the AM fungus Glomus sp. MUCL 41833 before penetration of hyphae and/or spores. The mycoparasitism of the ERM of the AM fungus led to IRM invasion via the appressoria. Intrahyphal growth of T. harzianum caused cytoplasm/protoplasm degradation, decreasing the ERM and IRM viability. Trichoderma harzianum perforated the septa to join the living section. Trichoderma harzianum exited the IRM to colonize the root in patches (i.e. peloton of hyphae).