EVIDENCE FOR HOST MYCORRHIZAL PREFERENCE IN NATIVE GRASSLAND SPECIES

Host-mycorrhizal preference was examined between native prairie grasses, Schizachyrium scoparium, Andropogon gerardii and Sporobolus heterolepis, and isolates of indigenous vesicular-arbuscular mycorrhizal fungal species, Glomus sp. (undescribed), G. geosporum and G. fasciculatum. For most grass-mycorrhizal combinations the percent of root length colonized either increased or remained unchanged with the increase in age of the plants. Glomus sp. was the most highly invasive mycorrhizal fungus, having the highest percent of root length colonized for all three grasses. The other fungal isolates exhibited preferential colonization of the three native grasses. The results demonstrate that the indigenous mycorrhizal fungal isolates tested showed a considerable amount of host preference.