Finnish Forest Research Institute-Metla, Jokiniemenkuja 1, Box 18, FI-01301 Vantaa, Finland.
Mycorrhiza. 2013 Jan;23(1):21-33. doi: 10.1007/s00572-012-0446-y. Epub 2012 May 30.
A greenhouse experiment was used to study the effects of host genotype on short root formation and ectomycorrhizal (ECM) fungal community structure in Norway spruce (Picea abies (L.) Karst.). Rooted cuttings representing 55 clones were inoculated with a mix of vegetative hyphae of five ECM fungal species (Laccaria sp., Amphinema byssoides, Piloderma sp., Cadophora finlandia, Paxillus involutus). After one growing season, the ECM fungal community structure was determined by amplifying the fungal internal transcribed spacer (ITS) of ribosomal DNA directly from ECM root tips. Restriction profiles of obtained amplicons were then compared to those of the inoculated strains. Spruce clones differed in their ECM fungal community composition; we found a statistically significant clone-specific effect on ECM fungal diversity and dominating fungal species. Nevertheless, the broad sense heritabilities of the levels of Laccaria sp., Piloderma sp. and A. byssoides colonisations as well as the ECM fungal community structure were low (H(2) = 0.04-0.11), owing to the high within-clone variation. As nitrogen concentration of needles correlated negatively with ECM fungal richness, our results imply that in the experimental conditions nutrient acquisition of young trees may benefit from colonisation with only one or two ECM fungal species. The heritability of short root density was moderate (H(2) = 0.41) and highest among all the measured shoot and root growth characteristics of Norway spruce cuttings. We suggest that the genetic component determining root growth and short root formation is significant for the performance of young trees in natural environments as these traits drive the formation of the below-ground symbiotic interactions.
采用温室试验研究了挪威云杉（Picea abies (L.) Karst.）宿主基因型对短根形成和外生菌根（ECM）真菌群落结构的影响。代表 55 个克隆的生根插条与五种 ECM 真菌物种（Laccaria sp.、Amphinema byssoides、Piloderma sp.、Cadophora finlandia、Paxillus involutus）的营养菌丝混合接种。经过一个生长季节，通过直接从 ECM 根尖扩增真菌核糖体 DNA 的内部转录间隔区（ITS）来确定 ECM 真菌群落结构。然后将获得的扩增子的限制图谱与接种菌株的图谱进行比较。云杉克隆在其 ECM 真菌群落组成上存在差异；我们发现 ECM 真菌多样性和优势真菌物种存在统计学上显著的克隆特异性效应。然而，Laccaria sp.、Piloderma sp. 和 A. byssoides 定植水平以及 ECM 真菌群落结构的广义遗传力较低（H(2) = 0.04-0.11），这是由于克隆内变异较大。由于针叶氮浓度与 ECM 真菌丰富度呈负相关，我们的结果表明，在实验条件下，幼树的养分获取可能受益于仅与一种或两种 ECM 真菌物种的定植。短根密度的遗传力中等（H(2) = 0.41），在挪威云杉插条所有测量的地上和地下生长特性中最高。我们认为，决定根系生长和短根形成的遗传成分对幼树在自然环境中的表现具有重要意义，因为这些特性驱动了地下共生相互作用的形成。
