effect of application of pseudomonas fluorescents on yield and yield components of wheat under different soil salinity levels

abstract plant- growth promoting rhizobacteria enhance plant growth and yield directly and or indirectly. a factorial experiment was conducted in greenhouse to determine the efficacy of four strains of fluorescent pseudomonas on wheat yield and yield component under saline conditions. the experiment was carried out with the following treatments (non –inoculation control and inoculation with p.fluorescens strain153 p.fluorescens strain169 p.putida strain108 and p.putida strain 4) and four salinity levels (1,4,8 and 12 ds/m) in a completelyrandomized design .a combinationof (nacl+ cacl2 +mgcl2 with equal equivalent) dissolved in distilled water and added to soils to meet the desiredsalinity treatments .wheat seeds were inoculated whit strains before planting. during growing period, the pots were irrigated with distilled water to maintain soil moisture around 0.8 fc .before harvest, growth indices including: plantheight, number of tillers and heads and after harvest,dry weight of shoots and grain yield were determined .results showedthat with increasing salinity level ,grain yield,1000 weight ,number of grain per spick , plant height and biologic yield decreased significantly (p<0.05).inoculation with strains increased all mentioned indexes significantly(p<0.05) at all salinity levels. among the strains ,p.putida strain 108 exert greatest effect on yield and yield component of wheat .in compare to other strains ,the effect of p.putida strain 108 ongrain yield and 1000 weightwas significantbut on other indices was not significant .results of this research revealed that all investigated strains can be used as plant growth- promoting bacteria.