Isolation of an endophytic plant growth promoting bacterium Pseudomonas sp strain gb3 (MTCC 9476) from Ginkgo biloba L., growing in temperate Himalaya

An endophytic bacterium has been isolated from cortical cells of Ginkgo biloba roots and evaluated for its plant growth promoting abilities. The bacterium developed mucoid khaki yellowish colonies on Tryptone Yeast extract agar plates in 48h at 25 degrees C and exhibited oval gram negative cells under microscope. The bacterium is psychrotrophic (temperature tolerance 4-35 degrees C, optimum 25 degrees C) in nature and based on phenotypic and genotypic characters it belongs to genus Pseudomonas. 16S rRNA analysis showed its maximum similarity (99%) with Pseudomonas sp. The bacterium showed antagonistic properties in plate assays, phosphate solubilization in suspension culture and growth promotion in plant based bioassays. The bacterium will be applicable in propagation of G. biloba L. under. temperate climatic conditions.