GROWTH AND ROOT COLONIZATION OF MYCORRHIZAL MAIZE GROWN ON ACID AND ALKALINE SOIL

Arbuscular mycorrhizal fungi often have wide adaptability over many so il environments. We have determined the effects of the AM fungi Glomus etunicatum WV579A (Ge), G. diaphanum WV579B (Gd) and G. intraradices WV894 (Gi) on growth and root colonization of maize (Zea mays L.) grow n on two acid (pH 4.2 and 4.5) and two alkaline (pH 7.8 and 8.0) soils . Shoot and root dry matter (DM), leaf area (LA), and root length (RL) were higher for mycorrhizal (AM) than for nonmycorrhizal (nonAM) plan ts grown on all soils, and plants grown on alkaline soil had higher DM than plants grown on acid soil. Shoot and root DM followed a sequence of Ge > Gd greater than or equal to Gi > nonAM for plants grown on th e alkaline soil. The AM isolates enhanced DM of plants grown on acid s oil, and differences among isolates were minor. Differences between AM and nonAM plants for total LA and RL were greater than for DM. Specif ic LA values for AM plants were consistently higher than for nonAM pla nts, while specific RL values for AM plants were only slightly higher than nonAM plants. Roots with arbuscules or vesicles was nil to low fo r plants grown on acid soil and relatively high for plants grown on al kaline soil. Roots with hyphal infection varied with type of soil and AM isolate, and was considerably higher than arbuscules or vesicles fo r plants grown on acid soil. Root hyphal infection appeared to be more important than arbuscules for growth enhancement of plants on acid so il. The AM isolates used were effective in enhancing growth of plants on both acid and alkaline soils showing wide adaptability to broad soi l pH conditions. Published by Elsevier Science Ltd