Abstract
In this study we found that Penicillium spp. exhibiting P-solubilizing activity are common both on and in the roots of wheat plants grown in southern Australian agricultural soils. From 2,500 segments of washed and surface-disinfested root pieces, 608 and 223 fungi were isolated on a selective medium, respectively. All isolates were screened for P solubilization on solid medium containing hydroxyapatite (HA); 47 isolates (5.7%) solubilized HA and were identified as isolates of Penicillium or its teleomorphs. These isolates were evaluated for solubilization of Idaho rock phosphate (RP) in liquid culture. Penicillium bilaiae strain RS7B-SD1 was the most effective, mobilizing 101.7 mg P l−1 after 7 days. Other effective isolates included Penicillium simplicissimum (58.8 mg P l−1), five strains of Penicillium griseofulvum (56.1–47.6 mg P l−1), Talaromyces flavus (48.6 mg P l−1) and two unidentified Penicillium spp. (50.7 and 50 mg P l−1). A newly isolated strain of Penicillium radicum (KC1-SD1) mobilized 43.3 mg P l−1. RP solubilization, biomass production and solution pH for P. bilaiae RS7B-SD1, P. radicum FRR4718 or Penicillium sp. 1 KC6-W2 was determined over time. P. bilaiae RS7B-SD1 solubilized the greatest amount of RP (112.7 mg P l−1) and had the highest RP-solubilizing activity per unit of biomass produced (up to 603.2 μg P l−1 mg biomass−1 at 7 days growth). This study has identified new isolates of Penicillium fungi with high mineral phosphate solubilizing activity. These fungi are being investigated for the ability to increase crop production on strong P-retaining soils in Australia.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Asea PEA, Kucey RMN, Stewart JWB (1988) Inorganic phosphate solubilization by two Penicillium species in solution culture and soil. Soil Biol Biochem 20:459–464
Cunningham JE, Kuiack C (1992) Production of citric and oxalic acids and solubilization of calcium phosphate by Penicillium bilaii. Appl Environ Microbiol 58:1451–1458
Dewan MM, Sivasithamparam K (1988) Occurrence of species of Aspergillus and Penicillium in roots of wheat and ryegrass and their effect on root rot caused by Gaeumannomyces graminis var. tritici. Aust J Bot 36:701–710
Downey J, van Kessel C (1990) Dual inoculation of Pisum sativum with Rhizobium leguminosarumand Penicillium bilaji. Biol Fertil Soils 10:194–196
Gadd GM (1999) Fungal production of citric and oxalic acid: importance in metal speciation, physiology and biogeochemical processes. Adv Microb Physiol 41:47–92
Garrett SD (1970) Pathogenic root-infecting fungi. Cambridge University Press, London, p 294
Gerretsen FC (1948) The influence of microorganisms on the phosphate intake by the plant. Plant Soil 1:51–81
Gulden RH, Vessey JK (2000) Penicillium bilaii inoculation increases root-hair production in field pea. Can J Plant Sci 80:801–804
Harvey PR, Butterworth PJ, Hawke BG, Pankhurst CE (2000) Genetic variation among populations of Pythium irregularein southern Australia. Plant Pathol 49:619–627
Hocking AD, Whitelaw M, Harden TJ (1998) Penicillium radicum sp. nov. from the rhizosphere of Australian wheat. Mycol Res 102:801–806
Illmer P, Schinner F (1992) Solubilization of inorganic phosphates by microorganisms isolated from forest soils. Soil Biol Biochem 24:389–395
Illmer P, Barbato A, Schinner F (1995) Solubilization of hardly-soluble AlPO4 with P-solubilizing microorganisms. Soil Biol Biochem 27:265–270
Irving GCJ, McLaughlin MJ (1990) A rapid and simple field test for phosphorus in Olsen and Bray No. 1 extracts of soil. Commun Soil Sci Plant Anal 21:2245–2255
Kpomblekou AK, Tabatabai MA (1994) Effect of organic acids on release of phosphorus from phosphate rocks. Soil Sci 158:442–453
Kucey RMN (1983) Phosphate-solubilizing bacteria and fungi in various cultivated and virgin Alberta soils. Can J Soil Sci 63:671–678
Kucey RMN (1987) Increased phosphorus uptake by wheat and field beans inoculated with a phosphorus-solubilizing Penicillium bilaji strain and with vesicular-arbuscular mycorrhizal fungi. Appl Environ Microbiol 53:2699–2703
Kucey RMN, Leggett ME (1989) Increased yields and phosphorus uptake by Westar canola (Brassica napus L.) inoculated with a phosphate-solubilizing isolate of Penicillium bilaji. Can J Soil Sci 69:425–432
Kucey RMN, Janzen HH, Leggett ME (1989) Microbially mediated increases in plant-available phosphorus. Adv Agron 42:199–228
Marois JJ, Fravel DR, Papavizas GC (1984) Ability of Talaromyces flavus to occupy the rhizosphere and its interaction with Verticillium dahliae. Soil Biol Biochem 16:387–390
Nautiyal CS (1999) An efficient microbiological growth medium for screening phosphate solubilizing microorganisms. FEMS Microbiol Lett 170:265–270
Pitt JI (2000) A laboratory guide to common Penicillium species. Food Science Australia, North Ryde, NSW, p 197
Pitt JI, Hocking AD (1985) Fungi and food spoilage. CSIRO division of food processing, North Ryde, NSW, p 413
Ryan MH, Chilvers GA, Dumaresq DC (1994) Colonisation of wheat by VA-mycorrhizal fungi was found to be higher on a farm managed in an organic manner than on a conventional neighbour. Plant Soil 160:33–40
Sayer JA, Raggett SL, Gadd GM (1995) Solubilization of insoluble metal compounds by soil fungi: development of a screening method for solubilizing ability and metal tolerance. Mycol Res 99:987–993
Whipps J (1997) Developments in the biological control of soil-borne plant pathogens. Adv Bot Res 26:1–134
White TJ, Bruns T, Lee S, Taylor JW (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (eds) PCR protocols: a guide to methods and applications. Academic Press, San Diego, Calif., pp 315–322
Whitelaw MA (2000) Growth promotion of plants inoculated with phosphate-solubilizing fungi. Adv Agron 69:99–151
Whitelaw MA, Harden TJ, Bender GL (1997) Plant growth promotion of wheat inoculated with Penicillium radicum sp. nov. Aust J Soil Res 35:291–300
Whitelaw MA, Harden TJ, Helyar KR (1999) Phosphate solubilisation in solution culture by the soil fungus Penicillium radicum. Soil Biol Biochem 31:655–665
Acknowledgements
Dr Ailsa D Hocking, Food Science Australia, for Penicillium taxonomy. Bio-Care Technology, Somersby, NSW, Australia, for providing cultures of Penicillium radicum FRR4718. Dr Gupta Vadakattu (CSIRO) and Dr Stephen Barnett (SARDI) for helpful comments on this manuscript. This project is funded by the Grains Research & Development Corporation of Australia (project CS0223), and Bio-Care Technology, Australia.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wakelin, S.A., Warren, R.A., Harvey, P.R. et al. Phosphate solubilization by Penicillium spp. closely associated with wheat roots. Biol Fertil Soils 40, 36–43 (2004). https://doi.org/10.1007/s00374-004-0750-6
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00374-004-0750-6