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.
Abstract:
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.