Characterization of Bacteria Isolated from the Saffron (Crocus sativus L.) Rhizosphere

One purpose of assessing the soil alive and active community is the identification of beneficial bacteria to use them as biological fertilizers, replacing or supplementing synthetic fertilizers. Such biofertilizers are predicted for the sustainability of agricultural production, especially for low input systems such as saffron fields. The aim of this work was to isolate and identify saffron rhizobacteria and to evaluate their possible effects on saffron growth. During 2013/14, some bacteria were isolated from the rhizosphere of the saffron plantations of different age in Gol village, Birjand, Iran. In total, 12 bacteria species were identified based on phenotypic traits and 16S rDNA sequences analysis. The strains were identified as B. subtilis, B. anthracis, B. cereus, B. megaterium, Bacillus sp., Paenibacillus, Pseudomonas fluorescens, P. putida, Escherichia coli, Pectobacterium sp. and Pantoea sp., with the dominant population belonging to the genus Bacillus. In the field study, inoculation of soil with these strains did not affect the leaf dry weight of the cultivated saffron, however, the strains of P. fluorescens increased the leaf area while P. fluorescens, Paenibacillus, Pectobacterium and B. megaterium increased the number of daughter corms and Azotobacter, B. cereus, B. subtilis and B. megaterium increased the corm weight. Our finding revealed that some bacteria present in the soil of perennial saffron plantations have a promising potential for developing as a plant growth promoting rhizobacteria.