Egyptian Journal of Microbiology, 38(4): 323-336 (2003)
Rationalization of irrigation water of maize plants by inoculation with arbuscular mycorrhiza (AM) fungi.
S. M. S. B. El-Din, M. Attia
Agricultural Microbiology Department, National Research Centre, Cairo, Egypt.

The growth, nutrient status and conservation of irrigation water by maize inoculated with the arbuscular mycorrhizal (AM) fungi Glomus spp. was studied in a pot experiment using Delta clay loam soil. Maize (Zea mays) plants with and without the arbuscular mycorrhizal fungi Glomus spp. was acclimated by four drought cycles (10, 25, 50 and 75% water holding capacity (WHC)). All plants were then subjected to an additional drought followed by a 7-day irrigation recovery period. Soil moisture levels had a significant effect on mycorrhizal colonization. Root colonization significantly decreased with increasing soil water content. Mycorrhizal colonization was low for plants grown in soils maintained at moderate and high irrigation levels (50 and 75% WHC). Water regime and AM inoculation both had significant effects on plant growth and nutrient uptake. Generally, plant dry weight, N and P uptake was reduced by decreasing available soil water from 75 to 10% WHC. The increase in plant growth by AM inoculation under drought stress (10 to 25% WHC) was higher than that at high moisture levels (50 and 75% WHC). The mycorrhizal inoculation of maize plant at 25% WHC gave the same plant dry weight as uninoculated at 50 and 75% WHC. Water stress generally increased the concentration of N and P due to a concentration effect resulting from decreased growth in response to imposed water deficits. Mycorrhizal inoculation, also, increased P and N concentrations under water stress condition. It is suggested that the mycorrhizal colonization by AM fungi may improve the drought resistance of maize plants and conserve water used.

Mycorrhizal Fungi