WATER-STRESS AND MYCORRHIZAL ISOLATE EFFECTS ON GROWTH AND NUTRIENT ACQUISITION OF WHEAT

Arbuscular mycorrhizal (AM) colonized plants often have greater tolera nce to drought than nonmycorrhizal (nonAM) plants. Wheat(Triticum duru m Desf.), whose roots were colonized with Glomus mosseae (Gms) and G. monosporum (Gmn), were grown in a greenhouse to determine effects of w ater stress (WS) on shoot and root dry matter (DM), root length (RL), and shoot phosphorus (P), zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) concentrations and contents. Mycorrhizal colonization was hi gher in well-watered (nonWS) plants colonized with both AM isolates th an WS plants, and Gms had greater colonization than Gmn under both soi l moisture conditions. Shoot and root DM were higher in AM than in non AM plants irrespective of soil moisture, and Gms plants had higher sho ot but not root DM than Gmn plants grown under either soil moisture co ndition. Total RL of AM plants was greater than nonAM plants, but was consistently lower for plants grown with WS than with nonWS. The AM pl ants had similar shoot P and Mn concentrations as nonAM plants, but co ntents were higher in AM than in nonAM plants. The AM plants had highe r shoot Zn, Cu, and Fe concentrations and contents than nonAM plants. The Gms plants grown under nonWS generally had higher nutrient content s than Gmn plants, but nutrient contents were similar for both Gms and Gmn plants grown under WS. The results demonstrated a positive relati onship between enhanced growth and AM root colonization for plants gro wn under nonWS and WS.