|YIN, ZHONGWEI - Chinese Academy Of Agricultural Sciences|
|SHI, FACHAO - Chinese Academy Of Agricultural Sciences|
|JIANG, HONGMEI - Chinese Academy Of Agricultural Sciences|
|CHEN, SANFENG - Chinese Academy Of Agricultural Sciences|
|FAN, BINGQUAN - Chinese Academy Of Agricultural Sciences|
Submitted to: Canadian Journal of Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2015
Publication Date: 12/1/2015
Citation: Yin, Z., Shi, F., Jiang, H., Roberts, D.P., Chen, S., Fan, B. 2015. Phosphate solubilization and promotion of maize growth in a calcareous soil by penicillium oxalicum P4 and aspergillus niger P85. Canadian Journal of Microbiology. 61:913-923.
Interpretive Summary: Sustainable methods for the production of maize and other crops need to be developed. Use of chemical fertilizers in crop production can introduce damaging levels of phosphate into the environment. A potential solution is to develop phosphate-solubilizing microorganisms that help provide adequate quantities of phosphorus to plants in combination with reduced quantities of chemical fertilizer or no fertilizer. In this study, we showed that the beneficial fungus, Penicillium oxalicum P4, when applied as a seed treatment significantly improved maize plant growth and soil available phosphorus compared to the nontreated control. We also showed that this fungus is capable of solubilizing mineral phosphate in liquid culture. These experiments identify this fungus as an excellent candidate for development to be used in alternative strategies for fertility management of maize and other crops. This information will be useful to scientists devising alternative methods for fertility management in crop production.
Technical Abstract: Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere as the over-application of phosphatic fertilizers can adversely impact agricultural sustainability. Penicillium oxalicum P4 and Aspergillus niger P85 were isolated from a calcareous soil in China that had been exposed to excessive application of phosphatic fertilizer for decades. Each isolate excreted a number of organic acids into, acidified, and solubilized phosphorus in a synthetic broth containing insoluble tricalcium phosphate or rock phosphate. Isolate P4, applied as a seed treatment, increased maize fresh weight/plant and total phosphorus/plant when rock phosphate was added to the calcareous soil in greenhouse pot studies. Isolate P85 did not increase maize fresh weight/plant but did significantly increase total phosphorus/plant. Significant increases in eight, and four, organic acids were detected in soil in association with isolates P4, and P85, respectively, relative to the soil only control. Both isolates also significantly increased available phosphorus in soil in the presence and absence of added rock phosphate and effectively colonized the maize rhizosphere. Studies reported here indicate that isolate P4 is adapted to and capable of promoting maize growth in a calcareous soil. Plant-growth promotion by this isolate is likely due, at least in part, to increased phosphorus availability resulting from the excretion of organic acids into, and the resulting acidification of, this soil.