Antibacterial Activity of Gnidia glauca (Fresen) Gilg. Phytochemical Extracts against Rice Bacterial Blight Pathogen Xanthomonas oryzae pv. oryzae

The present study was carried out to extract and screen the phytochemicals present in the aerial parts of Gnidia glauca (Fresen) Gilg. for their antibacterial activity against bacterial blight pathogen Xanthomonas oryzae pv. oryzae. Gram-negative bacterial species. Aerial parts of G. glauca were extracted for phytochemicals into water and organic solvents of different polarity such as petroleum ether, chloroform, ethyl acetate and methanol. The phytochemical screening of G. glauca extracts showed the presence of alkaloids, flavonoids, couma rins, terpenes, lignans, glycosides, saponins and steroids. Further the phytochemical extracts were evaluated for the antibacterial activity against Xanthomonas oryzae pv. oryzae by agar disk diffusion method. Bioactive extracts of leaf of G. glauca were found to be significantly effective against the X. oryzae at concentration of 10 mgmL -1 . Among these extracts leaf extracts were found to be most effective and showed bactericidal activities against X. oryzae with MIC ranged from 0.5 to 1 mgmL -1 . These solvent extracts of G. glauca which proved to be potentially effective can be used as natural alternative bioactive agents to control/manage bacterial blight disease caused by Xanthomonas bacteria not only in rice/paddy but also in other crop plants in an eco-friendly and economically feasible manner.