Molecular identification and immunological characterization of plant growth promoting rhizobacteria of Camellia sinensis

Abstract

TWO rhizobacteria isolated from tea rhizosphere of Nagrakata and Hansqua tea estates were morphologically,
biochemically characterized and finally identified as Bacillus megaterium (TRS 7) and Serratia marcescens (TRS 1). The BLAST
query of 16S r DNA sequence of the isolates against GenBank database confirmed their identity. The sequences were deposited
in NCBI, GenBank database under the accession Nos. JX 312687.1 and JN 020963.1 for B.megaterium and S. marcescens
respectively. The identity of the isolates of S. megaterium (JX312687) and S. marcescens (JN 020963) were fiirther confirmed
by DGGE. Both the bacteria were able to produce lAA, volatiles, siderophores and solubilised phosphates in vitro but did not
produce HCN and B. megaterium was non- chitinase producing strain. Both the bacteria showed antagonism to Sclerotium
rolfsii. Effect of culture filtrate of B. megaterium and S. marcescens in inhibiting one of the root pathogen- S. rolfsii in terms of
inhibition of germination of sclerotia was noted. The bacterial sustainability in the soil was evaluated by ELISA, Western blot
and Dot blot using their PAbs. B. megaterium and S. marcescens could successfully survive and multiply in tea rhizosphere even
after three months of application.