Water relationships and agronomic indices of sunflower infection by microbial inoculants under saline condition

Salinity is one of the most important limiting factors for plant growth and crop production.Saline soils with having low activity in nutrient elements and high osmotic pressure in solution phasemake so much nutrition problems and physiological drought in plant. In this study, the effects ofarbuscular mycorrhiza fungi and plant growth promoting bacteria with ability to produce ACC deaminaseenzyme on water relationships and agronomic indices of sunflower cultivars were investigated. The salinesoil (EC = 7.6 dS m-1) used in this investigation was taken from Karaj region (Eshtehard) of Iran. In afactorial experimental design on the basis of randomized complete block samples, three levels ofarbuscular mycorrhizal inoculants (non inoculation, inoculation with Glomus etunicatum and Glomusintradices), four levels of inoculants (non inoculation, inoculation withPseudomonas fluorescens strains 4, 9 and 12) on two cultivars of sunflower (Euroflor and Master) withfour replications per treatment were applied. Results showed that all of the treatments significantly (P <0.05) increased relative water content (RWC) of two cultivars. Single inoculation of Pseudomonasfluorescens strains 12 and Glomus etunicatum and also co-inoculation of fungi with each one of thebacteria enhanced fresh and dry weight of tray in Euroflor cultivar, compared with the control treatment.In addition, all of the treatments except Pseudomonas fluorescens strains 4 and also Glomus intradicessignificantly (P < 0.05) increased dry weight of above ground part in Euroflor cultivar.