Studies on endophytic Burkholderia sp. from sugarcane and its screening for plant growth promoting potential

The occurrence of Burkholderia genus as plant endophyte indigenous to locally cultivated sugarcane crop was studied. Totally 22 endophytic isolates were obtained from TB-T medium plates of which 10 were found to be putatively endophytic in sugarcane. The morphological, biochemical and MALDI-TOF MS analysis were done and 5 endophytic Burkholderia sp. isolates were identified. Among them, the isolate Burkholderia sp. ES4 shown maximum; diazotrophic activity (total nitrogen: 11.9 mg g -1 of malate; nitrogenase activity: 578.3 n mol C2H4 released h -1 mg -1 protein), mineral solubilization activity (10.2mm, 8.2mm and 3.2 mm solublization zone of P, ZnO and CaCO3 respectively; available phosphorous: 0.72mg ml -1 ), antagonistic activity (54.56 percent inhibition of Colletotrichum falcatum mycelium) and phytohormone production (IAA (16.09 g ml -1 ); GA (10.54 g ml -1 )), thereby revealing its plant growth promoting potential. The 16S r RNA gene sequence of the isolate Burkholderia sp. ES4 was sequenced and its phylogenetic analysis shown that the isolate forms a monophyletic subclade within the plant-beneficial-environment" (PBE) Burkholderia group. Thus a potent native plant endophytic strain, Burkholderia sp. ES4 that could be developed as biofertilizer inoculum for sugarcane crop, was obtained in this study.