Evaluation the effect of some selective PGPR,S strains on on wheat growth indices in salt stress condition

Abstract This study was done aiming to survey biological solutions in order to reduce salinity negative effects on wheat. Therefore it studied genus and combination of some species of bacteria on two tolerant and sensitive cultivars of wheat. So an experiment based on factorial test was done in completely randomized design with three repetition.Totally 72 treats for each cultivar in two separate phases (green house and laboratory) were done under saline and same condition.First factor: salinity in three levels: control (tap water) 0.00335, 6, 12 ds/m. (equivalent rates of NaCl and CaCl2 were used as salinity resources).Second factor: bacteria : 8 treats including : seed inoculation with 1: Azotobacter croccucom (AZ) (strain 5) 2: Azosperilium lipofrum (As) (strain OF) 3. Pseudomonas florescence (P3) (strain 169).Simple form (with one bacteria) and combination of two or all bacteria and seeds without inoculation as control ( totally 8 treats): 1- (Az) 2- (As) 3- (Ps) 4- (Az + As) 5: ( Az + Ps ) 6: ( As + Ps ) 7: ( Az + As + Ps) 8- without inoculation (control) were used.Statistical analysis of studied traits in germination test and green house showed that salinity stress leaded to seeds germination reduction and plant growth reduction in two cultivars. Salt concentration increment by effecting on physiological and biological parameters showed its preventing effects on plant growth. Bacterial tests had positive and significant effects on all studied traits. However traits with combination of some genus had more effect on increment of parameters comparing with one genus treat. Significant interaction between different salinity levels and bacteria was observed. It means that plant responses were different under saline condition with bacteria. Mean comparison results between two studied cultivars under different saline levels showed the difference of cultivars against salinity. (Being tolerant or sensitive). Keywords: wheat-salt stress-PGPR-Azosprilum-Azotobacter-Pseudomonas