Application of Pseudomonas Flourescens bacteria and two species of AM fungi on the deficit tolerance seedlings of Arizona cypress (Cupressus arizonica G)

Trees in the landscape always lost their vitality for various reasons, and decline or dieback are experiencing. One of the factors that can affect the decline of trees can be pointed to drought stress. This study was conducted to evaluate the effects of inoculation with mycorrhizal fungi (Rhizophagus intraradices and Funneliformis mosseae inoculated, and the combination of both species) and growth promoting bacteria; Pseudomonas Flourescens on growth responses of Cupressus arizonica in experiencing stress induced by a deficit of water as a factorial experiment based on completely randomized design, with 3 replications. In this study, the Interactions between fungi, bacteria and deficit irrigation on the concentration of phosphorus and iron, ion leakage, proline content and shoot dry weigh were significant. Under deficit irrigation most of the treatments such as colonization rate (by 39%), phosphorus (by 33%), potassium (by 16%) and iron (by 25%) cocentration, relative water content (by 25%), chlorophyll content (by 76%), height (by 29%), shoot dry weight (by 41%) and the Cupressus vitality (by 35%)  decreased; on the contrary, the percentage of electrolyt leakage (by 36%) and proline content (by 122%) increased. Morever, inoculation with mycorrhizal fungus increased the concentration of phosphorus and iron, relative water content, chlorophyll content, height, shoot dry weight and However reduced ion leakage and proline content and lead to improvement of plants growth and vitality. The presence of Pseudomonas alone did not have a significant role in improving the growth of plants under water stress conditions, but its interaction with mycorrhizal fungus showed positive effects. In general the results of this experiment showed that inoculation of cupressus plant with mycorrhizal fungus with the use of P. florescent bacteria can have a positive effect on the survival of this plant under water stress conditions.