Abstract

Arbuscular mycorrhizal fungi (AMF) are among the most important plant root symbiosis fungi enhancing plant P uptake. This research was conducted in Iran during 2006. The experimental design was a split factorial on the basis of completely randomized block design with four replicates. The control and AM species,  Glomus hoi were assigned to the main plots and the combination of P fertilizer including 0, 35 and 70 kg ha^-1 of triple super phosphate and the drought treatment including control (30 mm evaporation) and 60 mm evaporation from the evaporation pan were factorially assigned to the subplots. AM and P fertilizer significantly increased the root yield, root length, primary root dry weight and primary root length of coriander. Although the non-drought stress treatment significantly increased the root of coriander, the longest root length was achieved under the drought stress. It can be stated that AM is able to enhance the growth of coriander under drought stress through enhancing P uptake. This can have very important environmental impact through decreasing the amount of P fertilizer under control and drought stress conditions and also through enhancing the coriander resistance when subjected to the drought stress. Findings may interest farmers and agricultural researches to consider carefully on huge amount of soil phosphorus with interaction to water restriction as a challenge in environmental issues.    

Key words: AM fungi, drought stress, phosphorus, root growth, coriander.