DEVELOPMENT OF VESICULAR-ARBUSCULAR MYCORRHIZAE IN SUGAR MAPLE (ACER-SACCHARUM) AND EFFECTS OF BASE-CATION AMENDMENT ON VESICLE AND ARBUSCULE FORMATION

The development, condition, and incidence of vesicular-arbuscular mycorrhizae of Acer saccharum (sugar maple) seedlings grown in the greenhouse in natural sugar maple forest soil substrate were examined. The effects of the addition of a cation mixture containing calcium, magnesium, and potassium were also studied. The mycorrhizal structures observed were similar to those found in natural field conditions. Mycorrhizae developed intracellularly via hyphal coils, and arbuscules usually developed from these coils, forming arbusculate coils. This development is different from that observed in most annual crop plants. Vesicular-arbuscular mycorrhizal structures appeared within 30 days. The rate of mycorrhizal infection decreased, along with plant health, as the quantity of the added cations was increased, but the amendment did not affect the morphology of the infection. More vesicles were observed in the lowest level of application than in controls, suggesting a stress response and possible relationship between plant health and condition of the mycorrhizal association.