Fungal colonization of roots was characterized
by the presence of both OM and AM fungal structures,
whereas, rhizomes contained only OM fungal
structures. Cortical cells containing OM fungal
structures lacked AM fungal structures and
vice versa. Fungal penetration of the roots by AM
fungi occurred from ramifications of the hyphae
originating from the runner hyphae often preceded
by the formation of an appressorium on the root
surface. In contrast, OM fungal entry of roots was
through root hairs (Fig. 1b).