Effect of Arbuscular Mycorrhizae on Vegetative Growth and Phosphorous Uptake of Two Rootstocks Under Drought Stress of Sour Orange and Rough Lemon

Drought is one of the most restricting factor affecting plants growth and development in arid and semi-arid regions. Evaluation of plant yield under stress condition and the use of soil microorganisms to reduce stress damages is a new strategy for sustainable agriculture in these regions. The effect of an arbuscular mycorrhizal fungus and four irrigation interval (2, 4, 6 and 8 days) on the symbiotic root, and growth parameters (leaf number and area per pot, stem height and diameter, total dry weight) and concentration of P in shoots of two rootstocks (Sour orange and Rhough lemon) was studied through a factorial experiment based on a completely randomized design, with three replications in a greenhouse located in Jahrom. Evaluation of growth parameters (leaf number and area per pot, stem height and diameter, total dry weight) showed that these parameters were significantly reduced with increasing drought levels but mycorrhizal symbiosis decreased the adverse effects of drought on both rootstocks. Uptake of phosphorous was increased under stress in mycorrhizal plants. Drought stress reduced root colonization of both rootstocks for about 44.8%.