ICOM1 Abstract

category: 3 Mycorrhizae in Stressed Ecosystems (Monday) CLARK, R. B. & S. K. ZETO. Appalachian Soil & Water Conservation Research Laboratory, U.S. Department of Agriculture, Agricultural Research Service, P.O. Box 867, Beckley, WV 25802USA. - Mineral acquisition by mycorrhizal maize grown on acid and alkaline soil Arbuscular mycorrhizal (AM) fungi can enhance plant acquisition of mineral nutrients and function over relatively broad pH ranges. This study was conducted to determine the effect of the AM fungi Glomus etunicatum WV579A (Ge), G. diaphanum WV579B (Gd), and G. intraradices WV894 (Gi) for acquisition of minerals in 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 concentra-tions of P, Ca, Mg, K, Cu and Si were lower and Mn, Fe and Zn were higher while 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 compared to alkaline soil. With few exceptions, mycorrhizal (AM) plants had higher mineral concentrations and contents than non-mycor- rhizal (nonAM) plants. The AM isolates were generally comparable for enhancing acquisition of elements in plants grown on acid soil, while Gi and Ge plants absorbed more nutrients than Gd plants grown on alkaline soil. Many of the enhanced mineral acquisition effects were greater than could be accounted for by increases in shoot biomass. Reduced acquisition of P by Ge and Al by Gi plants grown on acid soil were noted. These results provide evidence that Glomus isolates can be effective in enhancing mineral acquisition over wide ranges of soil pH (_3.5 pH units), and that AM isolates varied extensively in enhancing or reducing mineral acquisition in maize.