Mycorrhizal associations of nursery grown Scots pine (Pinus sylvestris L.) seedlings in Poland

Abstract

-We investigated the species richness and composition of mycorrhizal fungi naturally colonizing one-and two-year-old Pinus sylvestris L. seedlings from four bare-root nurseries in Poland. We hypothesized that both edaphic factors and seedling age would affect ectomycorrhizal (ECM) community structure. We assessed the relative abundance of mycorrhizal morphotypes and distinguished ECM fungi present on root tips using RFLP (restriction fragment length polymorphism) of the ITS (internal transcribed spacer) of fungal rDNA. Most of the RFLP types were identified by comparing RFLP patterns with reference data obtained from regional sporocarps and isolates of ectendomycorrhizal species. Samples of unidentified RFLP types and representatives of suilloid RFLP patterns were sequenced and compared with available sequences. Overall, we identified 13 fungal species, with species richness varying from two to eight species among nurseries. The dominant species in each examined nursery were Wilcoxina mikolae and Thelephora terrestris. Suilloid fungi were also abundant in most of the nurseries. S. variegatus was the most frequent suilloid species among the nurseries. Seedling age affected the relative abundance of ECM species to some extent. Principal component analysis (PCA) revealed a lack of apparent correlations between the relative abundances of species and edaphic factors. Factors that may contribute to the maintenance of ECM community structure are discussed.forest nursery / mycorrhiza / ITS-RFLP / Scots pine Résumé -Associations mycorhiziennes des semis de pin sylvestre (Pinus sylvestris L.) en pépinière en Pologne. Nous avons étudié la richesse spécifique et la composition des champignons mycorhiziens colonisant naturellement des semis de Pinus sylvestris L. âgés de un et deux ans dans quatre pépinières de production de plants à racines nues en Pologne. Nous avons fait l'hypothèse que ensemble les facteurs édaphiques et l'âge des semis affecteraient la structure de la communauté ectomycorhizienne (ECM). Nous avons déterminé l'abondance relative des morphotypes mycorhiziens et distingué les champignons ECM présents dans les pointes racinaires en utilisant RFLP de ITS de l'ADNr fongique. La plupart des types RFLP ont été identifiés en comparant les modèles RFLP avec des données de référence obtenues de sporocarpes régionaux et isolés d'espèces ectoendomycorhiziennes. Des échantillons de types RFLP non identifiés et de modèles représentatifs de suilloides RFLP ont été séquencés et comparés avec les séquences disponibles. Globalement, nous avons identifié 13 espèces fongiques, avec une richesse spécifique variant de deux à huit espèces parmi les pépinières. Dans chaque pépinière étudiée, les espèces dominantes étaient Wilcoxina mikolae et Thelephora terrestris. Les champignons suilloides étaient aussi abondants dans la plupart des pépinières. S. variegatus était l'espèce suilloide la plus fréquente parmi les pépinières. L'âge des semis affecte dans une certaine mesure l'abondance relative des espèces ECM. Une analy...

Forest litter as the mulch improving growth and ectomycorrhizal diversity of bare-root Scots pine (Pinus sylvestris) seedlings

“…Similar sampling completeness is noted in many other studies as reported by Dickie (2007). All examined mycorrhizas are ubiquitous and the identity of EM fungi composing these morphotypes was established by molecular methods in bare-root forest nurseries in a previous study (Rudawska et al 2001, Iwanski et al 2006, Aučina et al 2007, Leski et al 2010. Our results indicate that the widespread W. mikolae mycorrhizae at the initial stages of seedling growth is better adapted to nursery conditions than other ECM fungal taxa, such as M. bicolor, C. geophilum, Atheliaceae sp., S. luteus, L. laccata, and unidentified Ascomycetes.…”

Diversity of ectomycorrhizal fungus assemblages on nursery grown European beech seedlings

“…In conclusion, as noted for beech and other forest tree species (Menkis et al 2005;Iwański et al 2006;Rudawska et al 2006;Leski et al 2008Leski et al , 2010Timonen and Kauppinen 2008), ECM fungal communities in forest bare-root nurseries are fairly diverse and the level of colonization of seedlings is very high. We therefore agree with the opinion of Southworth et al (2009) that artificial inoculation in general is not necessary in nursery practice.…”

“…We discovered 27 taxa of ECM fungi on 2-year-old beech seedlings from four bare-root nurseries. The number of recognized taxa was richer than for conifers (Scots pine, Norway spruce, and European larch) and small-leaved lime (Menkis et al 2005;Iwański et al 2006;Rudawska et al 2006;Leski et al 2008;Timonen and Kauppinen 2008), but comparable with pedunculate and sessile oak (Leski et al 2010) grown in nursery conditions. Taxa richness in individual nurseries ranged from 6 to 13, and is a characteristic feature of each nursery rather than a methodological bias causing underestimation.…”

“…Morphological typing of the ECM root tips was examined under a stereomicroscope at 10 to 60 times magnification. ECMs were separated into morphotypes based on macroscopic features (color of a mantle, type of ramification, and the presence of extramatrical hyphae, rhizomorphs, and cystidia) and referred to a database used in our Laboratory of Mycorrhizal Research, at the Institute of Dendrology (Iwański et al 2006;Rudawska et al 2006). The root system fragments with the same mycorrhizal morphotypes were placed in Eppendorf tubes in a cetyltrimethyl ammonium bromide buffer and kept at room temperature until processing for DNA isolation and amplification.…”

Influence de la méthode de fertilisation sur la mycorhization contrôlée de deux espèces de Pins méditerranéens

“…* Corresponding author: ana.rincon@ccma.csic.es Spontaneous mycorrhization of seedling commonly occurs in nursery although usually opportunistic fungi with low host specificity have been reported [11,16,19]. Inoculation with selected ectomycorrhizal fungi has been often signalled as a promising practise for improving the quality of nursery seedling stock [4,11,21].…”