CORRELATION OF FUNGAL MORPHOLOGY AND DEVELOPMENT TO HOST GROWTH IN A GREEN ASH MYCORRHIZA

Abstract

The relationship between the growth of the host, and development and morphology of a vesicular‐arbuscular mycorrhizal fungus was. studied in green ash (Fraxinus pennsylvanica Marsh.). A yearly cycle with three phases is suggested. Phase I is a period of fast shoot growth, slow root growth, rapid colonization of the root system by the mycorrhizal fungus and greater numbers of fungal arbuscles than vesicles. Phase II is a period of fast root growth and a decline in the percentage of root length infected. Phase III is characterized by senescing leaves, infection percentages increasing to a static level, and greater numbers of vesicles than arbuscles. Mycorrhizal green ash seedlings generally had greater heights, weights and root collar diameters and lower root: shoot ratios than non‐mycorrhizal seedlings. Copyright © 1982, Wiley Blackwell. All rights reserved