Development of mycorrhizal infections from Endogone spores and infected root segments

TLDR: Germination, hyphal growth and root penetration from Endogone spores and from root-segments infected by Endog one, were studied on agar-coated glass slides buried in soil.

Abstract: Germination, hyphal growth and root penetration from Endogone spores and from root-segments infected by Endogone , were studied on agar-coated glass slides buried in soil. In most cases the spores germinated readily within 16 days, with or without the presence of onion roots. Germ tubes grew either through the old spore attachment or direct through the spore walls. Hyphae from spores were not attracted to the onion roots, until in very close proximity, when they formed fan-like structures of predominantly septate hyphae. Successful infections only occurred from aseptate hyphae, which developed later in the pre-infection fans. Hyphae from infected root-segments were always aseptate, and infected the roots without forming fan-like structures. The different infection patterns are probably due to different nutrient supply in resting spores and mycorrhizal root-segments.