Contribution of phosphate solubilizing activity to plants by Pseudomonas sp. having antifungal activity

摘要

The application of chemical fungicides has caused health hazards in animals and humans due to their residual toxicity. The objective of this research work is to find antagonistic bacteria having plant growth promoting activity for the control of some plant pathogenic fungi. Isolation of antagonistic bacteria from rhizosphere of rice, colonial and microscopic morphology and biochemical characterization were done. For antagonistic activity, dual culture and well diffusion method were employed. P-solubilizing activity was detected by plate screening and Vogel method. Isolated bacteria were assumed as Pseudomonas sp. according to its characteristic. This bacteria exhibited antagonistic activity against eight plant pathogenic fungi. The highest activity gave against fungi infected on green gram (26 mm) by dual culture method and against Fusarium sp. in giving 21 mm of inhibition zone by well diffusion method. 264.20 ppm and 235.77 ppm of soluble phosphate was detected by this isolate. Isolated bacteria exhibited antagonistic activity against eight plant pathogenic fungi by dual culture and well diffusion methods. Its activity was higher on PDA media than on nutrient media. In addition, isolated bacteria also possess P-solubilizing activity.