Effect of rhizobacteria treatments on nutrient content and organic and amino acid composition in raspberry plants

Abstract

Plant growth-promoting rhizobacteria (PGPR) have been found to be beneficial to plant growth, yield, crop quality, the environment, and sustainable agricultural production. Therefore, six bacterial strains were tested to determine their effects on raspberry’s nutrient content and organic and amino acid composition. The experiment was performed from 2015 to 2017. Two-year-old raspberry plants were inoculated with bacterial suspensions by a dipping method and were planted in 30-L pots. The mineral content and organic acid and amino acid composition of the leaf and root were compared in the Alcaligenes 637Ca, Staphylococcus MFDCa1 and MFDCa2, Agrobacterium A18, Pantoea FF1, and Bacillus M3 bacterial strains. Nitrogen (N) content of the leaf was 2.55% in the A18 treatment, while N content of the root was 1.61% in MFDCa2. The leaf ’s iron (Fe) content was highest in the M3 treatment with 91.76 mg kg –1 , while 637Ca gave the highest root’s Fe content with 107.80 mg kg –1 . The content of malonic acid (16.78 ng µL –1 ), malic acid (4.59 ng µL –1 ), citric acid (16.88 ng µL –1 ), and fumaric acid (4.94 ng µL –1 ) in leaves was higher in MFDCa2 than in the other treatments. In addition, 637Ca treatment had the highest root organic acid content in tartaric acid (5.94 ng µL –1 ), butyric acid (15.19 ng µL –1 ), and maleic acid (5.13 ng µL –1 ). FF1 treatment was more effective than the other treatments for increasing the leaf ’s amino acid content, while the 637Ca, MFDCa1 FF1, and M3 treatments were more effective in increasing the root’s amino acid content. As a result, it was determined that PGPR treatments play a significant role in mineral nutrient uptake and the organic acid and amino acid composition of the raspberry plant.