Interakcije v mikorizosferi določajo dinamiko ogljika v ekosistemu bukovih gozdov

Zaloga ogljika v gozdnih tleh je največji bazen terestičnih zalog organskega ogljika, njegova dinamika pa je vezana na talne, predvsem simbiontske organizme. Med najpomembnejše simbionte v gozdnih tleh, tako po vrstni kot funkcionalni pestrosti, sodijo ektomikorizne glive. V gozdnih ekosistemih v Sloveniji, v katerih prevladuje bukev, smo na osnovi morfoloških in molekularnih znakov identificirali večje število mikoriznih gliv in nekatere nove na kratko opisali. Na osnovi številčnosti posameznega tipa ektomikorize smo prvič izračunali prispevek tipa (vrste glive) ektomikorize k neposrednemu skladiščenju ogljika v ektomikorizi in v tleh v zgornjih plasteh tal (do globine 20 cm). Podatke o ogljiku, shranjenem v ektomikorizi, smo primerjali z modeliranimi količinami celotnega ogljika v gozdnih tleh, shematsko prikazali povezave in tokove ogljika ter pomen ektomikorize za dinamiko ogljika v gozdnih ekosistemih z bukvijo.Forest soils are the major stocks of organic carbon in terrestrial ecosystems.The dynamics of carbon in soil is closely related to soil (micro)organisms, predominantly symbiotic organisms. Key symbionts in forest soils regarding their taxonomic and functional diversity are ectomycorrhizal fungi. In the present study, we have analysed ectomycorrhizal community in beech dominated forest stands using morphological and molecular identification of ectomycorrhizae. Several new types were discovered and briefly described in soil samples taken in beech forest stands, down to 20 cm deep. Based on ectomycorrhizal type abundance, we have calculated the (static)content of total carbon in each of the type. Quantities of carbon stored in ectomycorrhizae were compared with modelled quantities of total carbon in forest soils. We summarise the role and importance of ectomycorrhizae for carbon dynamics in beech dominated forest ecosystems

Types of ectomycorrhizae on beech seedlings (Fagus sylvatica L.) in rhizotrons

Natural processes or human activities affect environmental conditions, as reflected in the structure of the communities and the level of ectomycorrhizalfungi. The aim of the study was to determine the potential impacts of several temperature regimes of air and soil (substrate) on the occurrence and species diversity of ectomycorrhizal fungi in symbiosis and in the substrate. For this purpose, we analyzed the occurrence of types of ectomycorrhizae on beech seedlings in rhizotrons exposed to four different environmental temperature conditions: 1) air 15-25°C, 2) air 15-25°C in combination with cooling of roots for 5°C, 3) elevated air temperature from 30-50°C, and 4) ambiental conditions (air temperature in Ljubljana). Types of ectomycorrhizae were identified with a combined approach of anatomical morphological characterisation and with analysis of molecular markers (ITS1-5.8S rDNA-ITS2 ribosomal region in rDNA). We identified a total of 6 types of ectomycorrhizae on 51 root tips on 40 beech seedlings. The diversity of ectomycorrhizal types was the highest in terms of near-optimal growth conditions of beech. Most similar as far as species diversity of ectomycorrhizal fungi are concerned were the experiments with air temperature of 15-25°C with or without cooling of the root system. The commonest ectomycorrhizal species was Hebeloma sacchariolens, which was also the most commonly seen species in fine roots of dead plants. Selected species of ectomycorrhizal fungi were further substantiated with DGGE method in all analyzed substrate samples

Mycorrhizal status of an ozone-sensitive poplar clone treated with the antiozonant ethylene diurea

The antiozonant ethylene diurea is proven to prevent growth reductions in forest trees induced by ozone. The community of mycorrhizal fungi could be useful indicator of environmental stress. In this study, response of mycorrhizal fungi and fine roots to a 4-year exposure to ambient ozone and treatment with antiozonant was investigated in ozone-sensitive poplar clone under field conditions. The community of ectomycorrhizal fungi and root length colonization with ectomycorrhizal, arbuscular mycorrhizal fungi, and root endophytic fungi was analyzed in antiozonant-treated poplar plants and in poplar plants irrigated with water. In general, plants protected by antiozonant showed higher total number of fine roots, number of ectomycorrhizal types, Shannon–Weaver diversity index, and Species richness index compared to the plants treated with water. The ectomycorrhizal community shifted from contact exploration type in the trees irrigated with water to short-distance exploration type in ethylene diurea-treated trees. Ozone protectant may beneficially affect the belowground community of mycorrhizal fungi colonizing roots of ozone-sensitive poplar clone

Two new species of Hydnum with ovoid basidiospores: H. ovoideisporum and H. vesterholtii

Two new species of Hydnum, characterized by slender Hydnum rufescens-like basidiomes and ovoid to broadly ellipsoid basidiospores, are described from the Iberian Peninsula based on morphological and ITS molecular data. Hydnum ovoideisporum is distinguished by pilei with deep orange tones and strong preference for calcareous soil. It is widespread in the Iberian-Mediterranean area. Hydnum vesterholtii is characterized by its ocher to light ocher pileus, and nearly all the collections were made in the Pyrenees. Both ovoid-spored species are monophyletic well supported groups in the maximum parsimony and Bayesian ITS phylogenies, while the remainder of the samples assigned to H. rufescens s.l. and having globose basidiospores split into six well supported clades. The need to typify the name Hydnum rufescens is discussed, and a provisional key is given for the European taxa of Hydnum.Peer Reviewe

Ectomycorrhizal fungi from southern Brazil - a literature-based review, their origin and potential hosts

A first list of ectomycorrhizal and putative ectomycorrhizal fungi from southern Brazil (the states of Rio Grande do Sul, Santa Catarina and Paraná), their potential hosts and origin is presented. The list is based on literature and authors observations. Ectomycorrhizal status and putative origin of listed species was assessed based on worldwide published data and, for some genera, deduced from taxonomic position of otherwise locally distributed species. A total of 144 species (including 18 doubtfull species) in 49 genera were recorded for this region, all accompanied with a brief distribution, habitat and substrate data. At least 30 collections were published only to the genus level and require further taxonomic review

Identification of types of ectomycorrhizae on seedlings in a beech provenance trial

Root systems and types of ectomycorrhizae (ECM) were analysed on three 7-year-old beech seedlings (Fagus sylvatica L.) of three provenances (Val di Sella, Idrija, Nizbor) from an international beech provenance trial and on a naturally regenerated 5-year-old beech seedling from the same site (Kamenski vrh by Novo mesto). All short roots were mycorrhizal. In the sampled 20,302 root tips 49 % were non-turgescent and unidentifiable ECM. Twenty-two different types of ECM were identified, out of which 11 were successfully determined either to the species or genus level. All ECM were described by morphological and anatomical characteristics, basidiomycetes also by molecularmethods. ECM that was not successfully determined either to the species or genus level formed a new cluster in the Slovenian mycorrhizal molecular database. Species richness and percentage of vital ECM roots were highest for the provenance from Idrija (Slovenia). The results indicate that there might be differences between provenances regarding the abundance of ECM,which should be further studied

Types of ectomycorrhizae on beech seedlings (Fagus sylvatica L.) in rhizotrons

Naravni procesi ali dejavnost človeka vplivajo na razmere v okolju, kar se zrcali v sestavi ektomikoriznih združb. V raziskavi smo želeli ugotavljati morebitne vplive več temperaturnih režimov zraka in tal (substrata) na pojavljanje in vrstno pestrost tipov ektomikorize na koreninskih vršičkih sadik bukve in v substratu. V ta namen smo analizirali pojavljanje tipov ektomikorize na sadikah bukve v rizotronih, izpostavljenih štirim temperaturnim razmeram v okolju: 1.) zrak 15-25 °C2.) zrak 15-25 °C v kombinaciji s hlajenim koreninskim sistemom za 5 °C3.) povišana temperatura zraka od 30-50 °C in 4.) zunanja (ambientalna) temperatura zraka v Ljubljani. Tipe ektomikorize smo identificirali s kombiniranim pristopom po anatomsko morfoloških znakih in z analizo molekularnih markerjev (ITS1-5.8S rDNK-ITS2 ribosomalna regija v rDNK). Na 51 koreninskih vršičkih 40 sadik smo identificirali 6 tipov ektomikorize. Pestrost ektomikoriznih tipov je bila največja pri razmerah blizu optimalnih za rast bukve. Po vrstni sestavi združbe ektomikoriznih gliv sta si najbolj podobna poskusa s temperaturo zraka15-25 °C z ali brez hlajenja koreninskega sistema. Najpogostejša ektomikorizna vrsta je bila Hebeloma sacchariolens, ki je bila tudi najpogosteje opažena vrsta na drobnih koreninah odmrlih sadik. Izbrane vrste ektomikoriznih gliv smo z metodo DGGE dokazali tudi v vseh analiziranih vzorcih substrata.Natural processes or human activities affect environmental conditions, as reflected in the structure of the communities and the level of ectomycorrhizalfungi. The aim of the study was to determine the potential impacts of several temperature regimes of air and soil (substrate) on the occurrence and species diversity of ectomycorrhizal fungi in symbiosis and in the substrate. For this purpose, we analyzed the occurrence of types of ectomycorrhizae on beech seedlings in rhizotrons exposed to four different environmental temperature conditions: 1) air 15-25°C, 2) air 15-25°C in combination with cooling of roots for 5°C, 3) elevated air temperature from 30-50°C, and 4) ambiental conditions (air temperature in Ljubljana). Types of ectomycorrhizae were identified with a combined approach of anatomical morphological characterisation and with analysis of molecular markers (ITS1-5.8S rDNA-ITS2 ribosomal region in rDNA). We identified a total of 6 types of ectomycorrhizae on 51 root tips on 40 beech seedlings. The diversity of ectomycorrhizal types was the highest in terms of near-optimal growth conditions of beech. Most similar as far as species diversity of ectomycorrhizal fungi are concerned were the experiments with air temperature of 15-25°C with or without cooling of the root system. The commonest ectomycorrhizal species was Hebeloma sacchariolens, which was also the most commonly seen species in fine roots of dead plants. Selected species of ectomycorrhizal fungi were further substantiated with DGGE method in all analyzed substrate samples