Vesicular-Arbuscular Mycorrhizae (VAM) (Endotrophic)
Mycobiont - in order Glomales (Zygomycetes) - now raised to phylum Glomeromycota
most have no sexual stage
produce large lipid filled asexual spores in soil (are vesicles spores in root ?).
obligately biotrophic - can’t be grown in pure culture
VAM not usually essential but plants do much better with them (particularly in less fertile situations)
Plant nurseries need to find ways to ensure good infection with VAM - see pages 272-276