Effect of ACC deaminase-producing bacteria and soil salinity on growth and nutritional indices of wheat

Plant growth promoting rhizobacteria with ACC deaminase activity can be applied for stimulating plant growth under tension situations. In the present study, bacterial isolates were isolated from wheat rhizosphere in three provinces of Zanjan, Kurdistan and Hamedan and then screened for ACC deaminase production and salinity tolerance. Six isolates out of 167 isolates were able to degrade ACC to alpha-keto-butyrate and ammonia and the K78 isolate was selected as superior isolate. A completely randomized design with factorial arrangement was carried out on wheat plant in a greenhouse experiment. Experimental factors include: five salinity levels (1.3, 8, 12, 14, and 16 dS.m-1), three bacterial inoculation levels (no inoculation (B0), inoculation with salinity-resistant isolate and ACC deaminase production capacity (B1), inoculation with salinity-resistant isolate without ACC deaminase production capacity (B2). The results showed that salinity had a significant and negative effects on growth and nutrient uptake and decreased shoot length. The K78 isolate increased shoot length (21.5 %) and potassium uptake (15 %) significantly compare to B0 treatment but had no significant effect on sodium uptake. Overall, it can be concluded that inoculation of K78 isolate can reduce the negative effects of salinity on growth indices and the nutritional conditions of wheat.