the effect of synorhizobium meliloti inoculation on nutrient uptake and growth of sesame

in order to study the effect of synorhizobium meliloti on growth and nutrients uptake of sesame, a greenhouse test was carried out. the first isolates investigated in iaa and siderophore producing and their ability in solubilizing inorganic phosphates. the results showed that all of isolates were able to produce auxin with different among. the maximum amount of iaa production was 59.5 g ml-1 that was related to sr24 isolate. all isolates could solubilize tricalcium phosphate (ca3(po4)2) in sperber medium, and sr18 with 139 µg ml-1 had the highest ability to solubilize tricalcium phosphate. also sr3 and sr32 isolates produced the highest amont of siderophore. according to the results, five isolates that were better in iaa and siderophore producing and solubilizing inorganic phosphates were selected and used in a greenhouse test. this experiment was conducted base on completely randomized design with five treatment including four isolates of synorhizobium meliloti and one treatment without bacteria as control and four replications. the results indicated that inoculation of isolates enhanced sesame shoot dry weight compared to control and this increasing was significant for sr18, sr16 and sr3. application of most isolates also increased measured nutrients uptake in sesame shoot. however only isolate sr18 significantly increased the nutrients uptake including p, zn, cu and fe compared to control.