Screening Efficient Phosphate Solubilizing Strains Of Penicillium And Developing Complex Microorganism Agents With Phosphate Solubilizing And Plant Growth Promoting Ability

Phosphorus is not only one of the necessary nutrients for plant growth and development but also important components of plant's nucleic acid and a variety of enzymes,coenzymes,ATP.Plants mainly uptake the available phosphorus in the soil,but more than 95% of the phosphorus is invalid which is difficult to use.There are a lot solubilizing microorganisms in soil can transform insoluble phosphorus into soluble phosphorus.The study on screening the solubilizing Penicillium and combining it with growth-promoting bacteria strains to develop a complex agents with solubilizing and promoting effect,The specific results gained were summarized as following:Screening the Phosphate-solubilizing Penicillium from the saved Penicillium in the laboratory though the inorganic phosphate medium containing Ca₃?PO4?2 as sole phosphate source.In this assay the strains QM-13-2-1,QM-30-2-6,QM-12-1-1,QM-4-2-3,QM-12-3-3,QM-4-2-1,QM-4-1,QM-6,QM-7-1,QM-10,QM-11-3-2,QM-3-1,QM-9-1,QM-12-3-2demonstrated their capability of dissolving the Ca₃?PO4?2 in the culture medium.In order to obtain the strain with the highest phosphate-solubilizing,these Penicillium were individually inoculated into the liquid medium containing Ca₃?PO4?2 as sole phosphate source.According to processing the figures of soluble phosphorus and pH measured in different time sampling the inoculum showed that the content of soluble phosphorus rose first,then fell,and became stable in the end and the pH of the liquid medium decreased significantly until it became stable.Our result also showed,the content of the soluble phosphorus in the liquid medium would reach the peak at 96 hours,they were 1239.21mg/L?1386.93mg/L.Their respectively floor pH was 2.40?2.29.After identifying with morphological and cultural characteristics and ITSr DNA sequence analysis,we obtained these two strains were both Penicillium oxalicum.Greenhouse experiments on promoting and solubilizing effect of compound agents,the results showed that: Soil and microbial inoculum experiment,the wheat vaccinated H1-1 + B1+ 71-2 + QM-6,QM-10 + 71-2 had the highest total phosphorus in its group espectively13.66 mg / pots,15.43 mg / pots.Compared with the control total phosphorus content increased by 125.99%,57.82%,corresponding soil available phosphorus content was15.21 mg / pots,11.20 mg / pots.Wheat dealt with the mixed fertilizer combination agents QM-6 + H1-1 + B1 + 71-2,QM-10+ 71-2,had higher height and fresh weight,respectively 29.25%,14.87%,73.5%,96.37 %,the promoting effect was superior to other agents in the same group.In the matrix mixed with the soil pot experiment,after processed with QM-6 + B1,QM-10 + 71-2,the highest total phosphorus in its group was 25.41mg/pot,17.46 mg which was increased by 125.99%?57.82% compared with the control.The plant height compared with the control increased by 29.25%?14.87%,fresh weight increased by 73.5%?96.37%,so the promoting effect of wheat was better than the other treatment groups.Based on the pot experiments,the compound solubilizing agents QM-6 + H1-1 + B1 +71-2 and QM-10 + 71-2 had the better growth-promoting effect.