title: Profiling functions of ectomycorrhizal diversity and root structuring in seedlings of Norway spruce (Picea abies) with fast- and slow-growing phenotypes.
abstract: We studied the role of taxonomical and functional ectomycorrhizal (ECM) fungal diversity in root formation and nutrient uptake by Norway spruce (Picea abies) seedlings with fast- and slow-growing phenotypes. Seedlings were grown with an increasing ECM fungal diversity gradient from one to four species and sampled before aboveground growth differences between the two phenotypes were apparent. ECM fungal colonization patterns were determined and functional diversity was assayed via measurements of potential enzyme activities of eight exoenzymes probably involved in nutrient mobilization. Phenotypes did not vary in their receptiveness to different ECM fungal species. However, seedlings of slow-growing phenotypes had higher fine-root density and thus more condensed root systems than fast-growing seedlings, but the potential enzyme activities of ectomycorrhizas did not differ qualitatively or quantitatively. ECM species richness increased host nutrient acquisition potential by diversifying the exoenzyme palette. Needle nitrogen content correlated positively with high chitinase activity of ectomycorrhizas. Rather than fast- and slow-growing phenotypes exhibiting differing receptiveness to ECM fungi, our results suggest that distinctions in fine-root structuring and in the belowground growth strategy already apparent at early stages of seedling development may explain later growth differences between fast- and slow-growing families.
authors.affiliation: Finnish Forest Research Institute - Metla, PO Box 18, 01301 Vantaa, Finland.
authors.forename: Sannakajsa M
authors.initials: SM
authors.lastname: Velmala
authors.affiliation: Finnish Forest Research Institute - Metla, PO Box 18, 01301 Vantaa, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Rajala
authors.affiliation: Viikki Biocenter, Department of Food and Environmental Sciences, Faculty of Agriculture and Forestry, PO Box 56, 00014 University of Helsinki, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Heinonsalo
authors.affiliation: The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH, UK.|Institute of Biological and Environmental Sciences, University of Aberdeen, Cruickshank Building, St Machar Drive, Aberdeen AB24 3UU, UK.
authors.forename: Andy F S
authors.initials: AFS
authors.lastname: Taylor
authors.affiliation: Finnish Forest Research Institute - Metla, PO Box 18, 01301 Vantaa, Finland.
authors.forename: Taina
authors.initials: T
authors.lastname: Pennanen
mesh_terms: D044822:Biodiversity; D038821:Mycorrhizae / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D028222:Picea / Q000254:growth & development / Q000382:microbiology*; D018517:Plant Roots / Q000254:growth & development / Q000382:microbiology; D036226:Seedlings / Q000254:growth & development / Q000382:microbiology; D013997:Time Factors
chemical_list: D009584:Nitrogen
keywords: Norway spruce (Picea abies (L.) Karst); Piloderma sp.; Tylospora asterophora; Wilcoxina sp; ectomycorrhizal diversity; extracellular enzyme activities; fast- and slow-growing seedlings; fine roots