Effects of Mycorrhizal Fungi and Salicylic Acid on Growth and Physiological Parameters of Basil (Ocimumbasilicum L.) UnderWater Deficit Conditions

Water deficit is one of the most important abiotic stresses which affects plant growth and yield. Application of the mycorrhizal fungi and plant hormones are fundamental for controlling of water deficit. For this purpose a factorial pot experiment based on completely randomized design with four replications was carried out. Experimental treatments included three levels of water deficit as 0.0, 40 and 70% of field capacity and inoculation of basil (Ocimum basilicum L.) plants with mycorrhizal fungi Glomus intraradices and Glomus fasciculatum and no inoculation and also foliar spraying of the plants with 100 and 200 mg L-1 concentrations of salicylic acid and control plants sprayed with water, in two stages after exposing of plants to drought stress. Results indicated that by increasing the water deficit severity, the vegetative growth parameters, relative water content, stomatal conductance and phosphorus uptake were reduced and the proline accumulation and potassium uptake were increased, while drought stress had no significant effect on root colonization by mycorrhizal fungi. Fungal inoculation and salicylic acid foliar spraying both significantly increased the vegetative growth parameters and relative water content of plants. Stomatal conductance and phosphorus and potassium uptake were increased by mycorrhizal fungi inoculation. Maximum phosphorus and potassium concentrations (0.466 and 3.14 percent) were obtained in plants inoculated with Glomus fasciculatum respectively. In general, results of this research revealed that mycorrhizal fungi inoculation and salicylic acid foliar spraying could play important roles in enhancing of growth and nutrient uptake in basil plants under water deficit conditions.