Abstract
We studied the role of taxonomical and functional ectomycorrhizal (ECM) fungal diversityin root formation and nutrient uptake by Norway spruce (Picea abies) seedlings with fast- andslow-growing phenotypes.
Seedlings were grown with an increasing ECM fungal diversity gradient from one to fourspecies and sampled before aboveground growth differences between the two phenotypeswere apparent. ECM fungal colonization patterns were determined and functional diversitywas assayed via measurements of potential enzyme activities of eight exoenzymes probablyinvolved 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 condensedroot systems than fast-growing seedlings, but the potential enzyme activities of ectomycor-rhizas did not differ qualitatively or quantitatively. ECM species richness increased host nutri-ent acquisition potential by diversifying the exoenzyme palette. Needle nitrogen contentcorrelated positively with high chitinase activity of ectomycorrhizas.
Rather than fast- and slow-growing phenotypes exhibiting differing receptiveness to ECMfungi, our results suggest that distinctions in fine-root structuring and in the belowgroundgrowth strategy already apparent at early stages of seedling development may explain latergrowth differences between fast- and slow-growing families.
Seedlings were grown with an increasing ECM fungal diversity gradient from one to fourspecies and sampled before aboveground growth differences between the two phenotypeswere apparent. ECM fungal colonization patterns were determined and functional diversitywas assayed via measurements of potential enzyme activities of eight exoenzymes probablyinvolved 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 condensedroot systems than fast-growing seedlings, but the potential enzyme activities of ectomycor-rhizas did not differ qualitatively or quantitatively. ECM species richness increased host nutri-ent acquisition potential by diversifying the exoenzyme palette. Needle nitrogen contentcorrelated positively with high chitinase activity of ectomycorrhizas.
Rather than fast- and slow-growing phenotypes exhibiting differing receptiveness to ECMfungi, our results suggest that distinctions in fine-root structuring and in the belowgroundgrowth strategy already apparent at early stages of seedling development may explain latergrowth differences between fast- and slow-growing families.
| Original language | English |
|---|---|
| Pages (from-to) | 610-622 |
| Number of pages | 13 |
| Journal | New Phytologist |
| Volume | 201 |
| Issue number | 2 |
| Early online date | 14 Oct 2013 |
| DOIs | |
| Publication status | Published - Jan 2014 |
Bibliographical note
This work was funded by the Academy of Finland project number 128229. We are grateful for the work of Marja-Leena Napola, Satu Peltola, the staff of Haapastensyrjä nursery, Arja Tervahauta, Minna Oksanen, Matias Häyrynen, Vesa Hautala, Ritva Vanhanen, Adriana Villaverde Monar, Laura Hänninen and Tatu Uutela. We thank Dr Audrius Menkis for providing us with the Wilcoxina sp. isolate. We are thankful to three anonymous referees for their suggestions which greatly improved the manuscript.Keywords
- ectomycorrhizal diversity
- extracellular enzyme activities
- fast- and slow-growing seedlings
- fine roots
- Norway spruce (Picea abies (L.) Karst)
- Piloderma sp.
- Tylospora asterophora
- Wilcoxina sp