Molecular identification of Azotobacter isolated from the rhizosphere of Karunvariety of barley in desert and its comparison with standard Azotobacter andinvestigation of some of the vegetation indicators after inoculation

Abstract

This study was conducted in acompletely randomized block design with three replications using three concentrations of 107, 105, and 103cfu/ml of Azotobacter isolated from the rhizosphere of Karun varieties of barley (Az. salentris) and standard Az.chrococom along with control (zero concentration of bacteria). The aim of this study was to study the reactions of barley plantin response to inoculation by mentioned bacteria in the form of infected separate inoculation and non-inoculated seeds as a control. For isolation the number of mentioned bacteria, Karun variety of barley in desert was cultivated in the mannitol broth environment, and macroscopic and microscopic characteristics of bacterial colonies were evaluated. Finally, using gene 16Sr DNA, isolated variety was identified molecularly. At the end of plant growth, important traits such as percent of germination, total protein level, and activity of antioxidant enzymes of catalase and peroxide were measured from the desired plant and they were analyzed statistically. After 18 days, results showed that the concentration of 107, 105, 103cfu / ml of Azotobacter isolated from the rhizosphereKarun variety of barley plant in the desert (Az. salentris) increased the activity of antioxidant enzymes, total protein, and percentage of germination compared with control. In addition, different concentrations of Azotobacter isolated from the rhizosphere of barley plant (Az. salentris) showed higher and significant impact on catalase activity, total protein level, and percentage of Karun variety of barley germination compared with standard Az.chrococom.