The survival and development of inoculant ectomycorrhizal fungi on roots of outplanted Eucalyptus globulus Labill

• Published in: Plant and soil 1996-01, Vol.178 (2), p.247-253
• Main Authors: Thomson, B.D. (Division of Forestry CSIRO, Wembley, W.A. (Australia)), Hardy, G.E.J, Malajczuk, N, Grove, T.S
• Format: Article
• Language: English
• Subjects: Agricultural soils; Agronomy. Soil science and plant productions; Artificial regeneration. Forest nurseries. Planting; Biochemistry and biology; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; Economic plant physiology; EUCALYPTUS GLOBULUS; Forest soils; Forestry; Fundamental and applied biological sciences. Psychology; Fungi; Generalities; Microbial colonization; MYCORHIZE; MYCORRHIZAE; Mycorrhizas; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant roots; Plants; RACINE; RAICES; ROOTS; Seedlings; Soil fungi; Soil inoculation; Soil science; Sowing and planting; Symbiosis (nodules, symbiotic nitrogen fixation, mycorrhiza...)
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/bf00011590

The survival and development of two inoculant ectomycorrhizal fungi (Hebeloma westraliense Bough. Tom. and Mal. and Setchelliogaster sp. nov.) on roots of outplanted Eucalyptus globulus Labili, was examined at two expasture field sites in the south-west of Western Australia. Site 1 was a gravelly yellow duplex soil, and Site 2 was a yellow sandy earth. Plants were grown in steamed or unsteamed soil, in root bags designed as field containers for young growing trees. Three, 6 and 12 months after outplanting, plants were removed from these bags and assessed for dry weights of shoots and ectomycorrhizal colonization of roots. The inoculant ectomycorrhizal fungi (identified on the basis of the colour and morphology of their mycorrhizas) survived on roots of E. globulus for at least 12 months after outplanting at both field sites. At Site 1, however, colonization of new fine roots by the inoculant fungi was low (less than 20% of fine root length). Inoculation had no effect on the growth of E. globulus at this site. In contrast, at Site 2 the inoculant ectomycorrhizal fungi colonized up to 30-50% of new fine root length during the first 6 months after outplanting. There was a corresponding growth response to ectomycorrhizal inoculation at this site, with a close relationship (r² = 0.82**) between plant growth at 12 months and root colonization at 3 months. Plant growth at 12 months was related less closely with root colonization at 6 or 12 months. Root colonization by 'resident' ectomycorrhizal fungi increased with time at both field sites. At Site 2, this increase appeared to be at the expense of colonization by the inoculant fungi, which was reduced to less than 10% of fine root length at 12 months. Steaming the soil had little effect on colonization by the inoculant ectomycorrhizal fungi at either field site, but decreased colonization by the resident ectomycorrhizal fungi.