MINERAL ACQUISITION BY MYCORRHIZAL MAIZE GROWN ON ACID AND ALKALINE SOIL

Arbuscular mycorrhizal (AM) fungi can enhance plant acquisition of min eral nutrients and function over relatively broad pH ranges. We have d etermined the effect of the AM fungi Glomus etunicatum WV579A (Ge), G. diaphanum WV579B (Gd), and G. intraradices WV894 (Gi) on the acquisit ion of minerals by maize (Zea mays L.) grown on acid (pH 4.2 and 4.6) and alkaline (pH 7.8 and 8.0) soils in a greenhouse. Shoot concentrati ons of P, Ca, Mg, K, Cu and Si were lower and Mn, Fe and Zn were highe r while the total shoot contents of N, P, S, Ca, Mg, K, Na, Cu, B and Si were lower and Mn, Fe and Zn were higher in plants grown on acid co mpared to alkaline soil. With few exceptions, mycorrhizal (AM) plants had higher mineral concentrations and contents than non-mycorrhizal (n onAM) plants. The three AM isolates were generally comparable for enha ncing acquisition of minerals in plants grown on acid soil, while Gi a nd Ge plants absorbed more minerals than Gd plants grown on alkaline s oil. Many of the enhanced mineral acquisition effects were greater tha n could be accounted for by increases in shoot biomass. Reduced acquis ition of P by Ge and Al by Gi plants grown on acid soil were noted. Th ese results provide evidence that Glomus isolates effectively enhance mineral acquisition over wide ranges of soil pH (similar to 3.5 pH uni ts), and that AM isolates varied extensively in enhancing or reducing mineral acquisition in maize. Published by Elsevier Science Ltd