Isolation And Screening Of Phosphate-Solubilizing Bacteria And Its Effect On Growth Of Potted Camphor Seedlings

Phosphorus is an important substance in plant growth and development.Phosphorus in soil is mainly insoluble phosphorus,which makes it difficult for plants to absorb and utilize.Phosphorus solubilizing microorganisms dissolve the insoluble phosphorus into soluble phosphorus mainly by transforming the phosphorus form in the soil,so as to improve the supply level of phosphorus to plant growth.Study the use of phosphate-solubilizing microorganisms in soil can not only improve the absorption and utilization of phosphorus in crops but also reduce the input of chemical phosphorus fertilizer.Soil samples were collected from the rice experimental field of Jiangxi Agricultural University,and three phosphorus releasing bacteria were preliminarily selected from mengjinna solid medium by dilution coating method.A phosphorus dissolving strain JP-3 with relatively high phosphorus dissolving ability and genetic stability was obtained by liquid phosphorus containing medium combined with colorimetry.Its phosphorus dissolving ability was 161.05 mg/L,and the increase rate of soluble phosphorus compared with the blank experiment was 401.24%.Through the morphological observation,physiological and biochemical detection,combined with16 sr DNA gene sequencing and comparison,the strain was preliminarily identified as Bacillus sp,and named as phosphorus solubilizing Bacillus sp.JP-3.The results showed that different nutrient elements and culture conditions had a great influence on the transformation and release of available phosphorus.When the initial p H value of Bacillus sp.JP-3 is 6.5,the concentration of carbon source selected glucose is 10 g/L,the concentration of nitrogen source selected ammonium sulfate is 1.5g/L and the concentration of sodium chloride is 0.30g/L,the maximum phosphorolysis capacity reaches 246.61 mg/L,which is 53.13% higher than that before optimization.At last,the growth-promoting effect of Bacillus sp.JP-3 on Camphor tree seedlings was studied.The results showed that vermiculite and phosphorus dissolving Bacillus sp.JP-3 were inoculated into potted soil,Compared with the control group,plant height increased by 17.02%,root length increased by 18.14%,stem length increased by22.85%,stem diameter increased by 23.39% and dry weight increased by 29.30%.Compared with the control group,total phosphorus content increased by 22.22%.It shows that Bacillus sp.JP-3 can significantly promote the growth and development of camphor seedlings.In short,this study aims to provide a scientific basis for the application of phosphorus solubilizing Bacillus sp.JP-3 in landscaping by carrying out the screening and identification of phosphorus solubilizing Bacillus sp.JP-3,the optimization of culture conditions and its impact on the growth and development of potted camphor seedlings.