Screening, Identification And Application Of Phosphate-Solubilizing And Potassium-Solubilizing Bacillus Isolated From Rhizosphere Of Some Plants In The Erdos Desert

Soil desertification has become the world's most serious environmental problems.In today's eco-efficiency advocate under the premise of improvement measures have become a hot research.In this paper,the research focuses on the use of Bacillus ability of dissolving phosphorus and potassium,and improving plant's nutrition environment or produce biological substances to stimulate plant growth,improving the survival rate of species.It provided the theory basis and the technical support for the soil desertification research.1.In this paper,95 Bacillus from rhizosphere of some plants in the Erdos desert were screened.41strains with ability of dissolving phosphorus were identified by means of phosphorus hole.Among them,26 strains have higher ability of dissolving phosphorus.Moreover,3 strains NTGB-Ⅱ-GM-2,NTBB-Ⅳ-GM-3,NTGB-Ⅲ-G-11 with higher capacity of dissolving phosphorus in broth assay were screened,the content of dissoluble phosphorous in the cultural solution together with what were absorbed by the 3 strains were 9.25 times,7.48 times and 7.2 times over the CK.The relationship between pH and phosphorus solubilization were also discussed and there were close relationship between the ability of phosphorus solubilization and pH.The relationship could be expressed in the formulas as Y=-4203.893X_PH+34426.346(n=15,0.05＞P=0.038＞0.01,r=0.54).Otherewise,research indicated that the results of the means of phosphorus hole were different from the results of rocking bottle in liquid medium.Maybe identifying their phosphate solubilizing capacity by rocking bottle in liquid medium was more reasonable.2.In this paper,95 Bacillus from rhizosphere of some plants in the Erdos desert were screened.15 strains with ability of dissolving potassium were identified by means of potassium hole.Among them,4 strains NTGB-Ⅲ-G-11,NTGB-Ⅱ-GM-8, NTBB-Ⅳ-GM-3,NTGB-Ⅲ-GM-4 with higher capacity of dissolving potassium were screened,the content of dissoluble potassium in the cultural solution together with what were absorbed by the 4 strains were 1.354 times,1.484 times,1.588 times and 1.677 times over the CK.Some strains like YCGB-Ⅱ-G-11,SLGB-Ⅱ-GM-7,SLGB-Ⅱ-GM-12, SLGB-Ⅱ-GM-8,SLGB-Ⅱ-GM-10,SLGB-Ⅱ-GM-14,SLGB-Ⅱ-GM-6 inoculated after a period of time,the fermented liquid water-soluble potassium content has dropped,lower than the CK,and then gradually increase,and then after the water-soluble potassium total stabilizing.This may be due to bacterial growth of consumption necessary potassium for the early time and lead the water-soluble potassium down,with Bacillus enhance the vitality of potassium,the release of potassium feldspar in the mineral-potassium and Water-soluble potassium content gradually increase.3.According to a pot experiment,the results of the 5 strains' applications were determined. The results showed that these strains have different effects on the plant height and the germination rate,with the exception of NTGB-Ⅲ-G-11,all the strains can promote plant growth,and enhance its germination rate.Based on the results of the analysis,we can see that these strains on the impact of soil nutrients were not significantly different.4.According to the result of pot experiment,the strain we need is NTGB-Ⅲ-GM-4,by the identification of molecular biology,the results show that NTGB-Ⅲ-GM-4 was clustered with Bacillus meqaterium.and the sequence identity was 99%.So NTGB-Ⅲ-GM-4 was identified to Bacillus meqaterium.The strain's effect on plant growth the germination rate is more ObviousThan other strains.However,the strain only has a function of dissolving potassium,no obvious dissolving phosphorus function.However,the dissolution of phosphorus dissolved insoluble phosphate capacity,mainly by the genetic characteristics of strains,and also its growing conditions and environment.Although the strains in laboratory conditions not clearly shown the ability of the dissolved phosphorus,But laboratory conditions and desert environment were very different,maybe the strain in the desert the actual effect of dissolving phosphorus is better than in the laboratory.Although the strain has effect on plant growth and germination rate,but through the soil nutrient analysis indicates that the strain on the improvement of soil nutrients is not satisfactory.