title: Phosphate solubilization and promotion of maize growth by Penicillium oxalicum P4 and Aspergillus niger P85 in a calcareous soil.
abstract: Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere, as the overapplication 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 mass per plant when rock phosphate was added to the calcareous soil in greenhouse pot studies. Isolate P85 did not increase maize fresh mass per plant but did significantly increase total phosphorus per plant when rock phosphate was added. Significant increases in 7 and 4 organic acids were detected in soil in association with isolates P4 and P85, respectively, relative to the soil-only control. The quantity and (or) number of organic acids produced by these isolates increased when rock phosphate was added to the soil. Both isolates also significantly increased available phosphorus in soil in the presence 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.
authors.affiliation: a Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.|c State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100094, People's Republic of China.
authors.forename: Zhongwei
authors.initials: Z
authors.lastname: Yin
authors.affiliation: a Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
authors.forename: Fachao
authors.initials: F
authors.lastname: Shi
authors.affiliation: a Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Jiang
authors.affiliation: b Sustainable Agricultural Systems Laboratory, Henry A. Wallace Beltsville Agricultural Research Center, USDA-Agricultural Research Service, Beltsville, MD 20705-2350, USA.
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Roberts
authors.affiliation: c State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100094, People's Republic of China.
authors.forename: Sanfeng
authors.initials: S
authors.lastname: Chen
authors.affiliation: a Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, People's Republic of China.
authors.forename: Bingquan
authors.initials: B
authors.lastname: Fan
mesh_terms: D001234:Aspergillus niger / Q000378:metabolism*; D002681:China; D005308:Fertilizers / Q000032:analysis; D010407:Penicillium / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D012639:Seeds / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D003313:Zea mays / Q000254:growth & development* / Q000378:metabolism / Q000382:microbiology
chemical_list: D005308:Fertilizers; D010710:Phosphates; D012987:Soil
keywords: Aspergillus niger; Penicillium oxalicum; calcareous soil; champignon solubilisant le phosphate; phosphate-solubilizing fungi; plant growth promotion; sol calcaire; stimulation de la croissance végétale