Investigation of drought tension tolerance in two wheat cultivars inoculated with plant growth promoting rhizobacteria (PGPR) under greenhouse conditions

This research was carried out in order to biomolecular investigate drought tension tolerance in two wheat cultivars inoculated with plant growth promoting rhizobacteria (PGPR) in the research greenhouse of Islamic Azad University, Karaj Branch in 2013-14 cropping year. The experiment design was in the split factorial arrangement based on a randomized complete blocks design with three replications. The main plot included two levels of desirable irrigation and drought tension (deficit irrigation in the pollination stage until the end of full maturity) and sub plots consisted the PGPR bacteria at four levels: 1) inoculation seed with Azotobacter chroococcum 2) inoculation seed with Azospirillum lipoferum 3) simultaneous use of both bacteria Azotobacter Azospirillum 4) non-application of bacteria (control) and two bread wheat cultivars consisted of Sirvan and Marvdasht. Experiment traits included the activity of superoxide dismutase antioxidant enzyme (SOD), the activity of biochemical biomarker Malondialdehyde (MDA) amount of chlorophyll a, b and a b. Results of the experiment showed that simple effect of irrigation, cultivar and bacteria treatments was significant on all the studied traits (01 / 0≥P). The activity of superoxide dismutase enzyme (SOD) in drought tension treatment was higher than full irrigation (normal). Sirwan and Marvdasht cultivars with 3.6 and 2.7 units per gram of protein, showed the higher and lower SOD enzyme activity, respectively. Sirvan cultivar compared to Marvdasht cultivar had less amount of biomarker MDA activity (27.424 milligram on gram fresh weight of tissue) and the higher content of chlorophyll a, b and a with 3.255, 1.578 and 4.811 (milligram on gram fresh weight of tissue), respectively.