SCREENING AND CHARACTERISATION OF SIDEROPHORE PRODUCING RHIZOBACTERIA FROM PADDY FIELD OF POONDI

ABSTRACT

To enhance the crop production and to manage plant diseases, many chemicals are being used. The use of such agrochemicals is hazardous to environment. To identify a viable alternate, biocontrol agent is necessary. Keeping this in point, the present investigation was undertaken to isolate PGPR bacteria from paddy rhizospheric soil. A total of 100 bacteria were isolated. On the basis of morphological, physiological and biochemical characterisation most of the isolates belong to Pseudomonas aeruginosa. The isolates were further screened for siderophores production by CAS method. In this 10 isolates showed positive results in siderophore production. The produced siderophore were further characterised based on their classi?cation such as hydroxylate, catecholate and carboxamate depending on the iron ligating group. In the present study, the effect of culture media components in the yield of siderophore was studied. Among the 10 isolates, 3 of were produced catecholate type of siderophore ef?ciently in succinate medium at neutral pH in low iron concentration. Potential siderophore producing isolates was further applied on Vigna radiata (Green gram). There was a signi?cant increase in the shoot and root length by roll towel method and Pot assay method: