Isolating Plant Growth-promoting Rhizobacteria From Wheat In Tianjin And Its Effect On Fostering Fertility

29 different Bacillus bacterium were isolated from wheat rhizosphere nearb Tianjin Polytechnic University and Wuqing Destrict. The experiments in pot culture are conducted to isolate Plant Growth-promoting Rhizobacterium(PGPR). Then these growth-promoting bacterium were priliminary identified by bacterial morphology and physiological and biochemical tests. Last, a series of pot experiment to study the effect on fostering soil fertility. The study conclusions make the basic data eference for production and application of the PGPR.2 strains of bacteria named B21 and B81 showed significant plant promoting effect on wheat germination, seedling height, fresh weight above ground and root fresh weight compared with the control test in the pot test.Morphological,physiological and biochemical teste were used.Gram staining, spore staining and capsule staining results showed that: 2 strains of bacteria were free capsule G+ Bacillus,forming spore at aerobic enbironment.According to further physiological and biochemical test, B21 was identified as Bacillus coagulans, B81 as Bacillus megaterium.With B21, B81 strain soaking wheat, pot experiments of natural soil carried out to compare the soil pH, organic matter, available nutrients with the control test.The comparative analysis shows that: B21 and B81 soil pH was 7.65 and 7.67, reduced soil alkalinity; B21 and B81 treatment soil organic matter content was 6.20g/kg and 7.05g / kg, respectively, increased by 1.5% and 15.3%; B21 and B81 treatment efficient nitrogen reach 58.27mg/kg and 70.00mg/kg, respectively,increased by 1.9% and 22.4%; B21 and B81 treatment soil available K content was 63.40mg/kg, 67.96mg/kg, increased by 3.6%, 11.1%;B81 treatment soil available phosphorus content were 33.10mg/kg, increased 18.2% .B21, B81 able to adjust soil pH, increased organic matter, available nitrogen, available phosphorus and available potassium contents. Thus,they play a great role on increasing soil nutrients, improving soil fertility levels and fostering soil fertility. B81 strains showed better regulation and Improvement effect than B21 strains in various indicators.