Affiliation: | Department of Soil and Water, University of Adelaide, Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia; Department of Environmental Biology, University of Adelaide, South Australia 5005, Australia; Centre for Plant Root Symbioses, University of Adelaide, Waite Campus, PMB 1, Glen Osmond, South Australia 5064, Australia; Author for correspondence (fax +61 8 8303 6511;e-mail;). |