حمیدرضا نوریزدان

This experiment to evaluate the effects fluorescent pseudomonads stimulating plant growth at different levels of salinity on barley yield was conducted in the greenhouse.In order to carry out this study, 25 strains of fluorescent Pseudomonads, isolated from barley and wheat rhizosphere, were assessed for plant growth-promoting traits including production of hydrogen cyanide, siderophore and growth hormone (IAA), the ability to solubilize inorganic phosphate and salt tolerance. Four strains which were superior to others based on growth-promoting properties and salt tolerance were selected for further study. To investigate the effect of fluorescent pseudomonads on yield and yield components of barley under different salinity levels, an experiment was performed under twice split plot design in three repetitions during 1394-95 in the research greenhouse at the Faculty of agriculture and natural resources, Persian Gulf University, Bushehr. Salinity stress was considered as a major factor in four levels (0, 50, 100 and 150 mm NaCl), barly cultivars (karon, zehak, sahra ,nimruz and jonob) as a first sub-plots and four strains of fluorescens pseudomonads ( B4-6? B2-10? B10 ? B2-11) along with a control (no bacteria) as the second factor were considered as a minor factor. At planting time, seeds were inoculated with suspension of selected Pseudomonas strains (108 CFU/ml). Saline treatments were applied gradually after four-leaf plant stage. Results of analysis of variance showed that the effects of salinity, variety and bacteria were significant for all traits. Effect of interaction of salinity × variety, salinity × bacteria, variety × bacteria, as well as the interaction of salinity × variety × bacteria were significant for all traits. The most significant positive correlation coefficient was observed between spike weight with number of spikes (r= 0/72), spike length with number of spikes (r= 0/62), one thousand- kernel weight with plant height (r= 0/62), plant height with