ECTOMICORRIZAS EN Nothofagus alpina (P.et E.) Oerst y N. dombeyi (Mirb.) Oerst. DEL SUR DE CHILE

Mediante estudios de microscopía óptica se describe y caracteriza la simbiosis ectomicorrícica de Laccaria laccata (Scop) Berk + Nothofagus dombeyi (Mirb.) Oerst y Paxillus involutus (Batsch) Fr. + Nothofagus alpina (P. et E.) Oerst, en plántulas obtenidas de vivero el la Provincia de Valdivia, Sur de Chile. Se documenta la micorriza mediante ilustración del hábito y microfotografias del  manto fúngico, así como de secciones transversales y longitudinales, . La estructuramorfo-anatómica de las especies de hongos estudiadas, se compara con hospedantes de Europa. Se destaca la importancia de la asociación micorrícica, para futuros programas de reforestación en el Sur de Chile

Novel Root-Fungus Symbiosis in Ericaceae: Sheathed Ericoid Mycorrhiza Formed by a Hitherto Undescribed Basidiomycete with Affinities to Trechisporales

Ericaceae (the heath family) are widely distributed calcifuges inhabiting soils with inherently poor nutrient status. Ericaceae overcome nutrient limitation through symbiosis with ericoid mycorrhizal (ErM) fungi that mobilize nutrients complexed in recalcitrant organic matter. At present, recognized ErM fungi include a narrow taxonomic range within the Ascomycota, and the Sebacinales, basal Hymenomycetes with unclamped hyphae and imperforate parenthesomes. Here we describe a novel type of basidiomycetous ErM symbiosis, termed ‘sheathed ericoid mycorrhiza’, discovered in two habitats in mid-Norway as a co-dominant mycorrhizal symbiosis in Vaccinium spp. The basidiomycete forming sheathed ErM possesses clamped hyphae with perforate parenthesomes, produces 1- to 3-layer sheaths around terminal parts of hair roots and colonizes their rhizodermis intracellularly forming hyphal coils typical for ErM symbiosis. Two basidiomycetous isolates were obtained from sheathed ErM and molecular and phylogenetic tools were used to determine their identity; they were also examined for the ability to form sheathed ErM and lignocellulolytic potential. Surprisingly, ITS rDNA of both conspecific isolates failed to amplify with the most commonly used primer pairs, including ITS1 and ITS1F + ITS4. Phylogenetic analysis of nuclear LSU, SSU and 5.8S rDNA indicates that the basidiomycete occupies a long branch residing in the proximity of Trechisporales and Hymenochaetales, but lacks a clear sequence relationship (>90% similarity) to fungi currently placed in these orders. The basidiomycete formed the characteristic sheathed ErM symbiosis and enhanced growth of Vaccinium spp. in vitro, and degraded a recalcitrant aromatic substrate that was left unaltered by common ErM ascomycetes. Our findings provide coherent evidence that this hitherto undescribed basidiomycete forms a morphologically distinct ErM symbiosis that may occur at significant levels under natural conditions, yet remain undetected when subject to amplification by ‘universal’ primers. The lignocellulolytic assay suggests the basidiomycete may confer host adaptations distinct from those provisioned by the so far investigated ascomycetous ErM fungi

Biodiversity of Arbuscular Mycorrhizal Fungi in South America: A Review

Identification of species is crucial in understanding how diversity changes affect ecosystemic processes. Particularly, soil microbial are key factors of ecosystemic functioning .Among soil microbes, arbuscular mycorrhizal fungi (AMF, phylum Glomeromycota) are worldwide distributed and form symbiotic associations with almost 80% of the vascular plants of the earth, except for one species, Geosiphon pyriformis, which associates with the cyanobacteria Nostoc. AMF comprise around 300 morphologically defined or 350–1000 molecularly defined taxa. Since AMF associate with aboveground community, their occurrence and composition can influence ecosystemic processes either through affecting plant community composition and thus its processes rates, or soil microbial communities, which are directly involved in nutrient cycling. Soil microorganisms are considered a potentially suitable target for studying regional and local effects on diversity. The symbiosis with AMF not only increases nutrient uptake by the plant of mainly phosphorus (P) and nitrogen (N) in exchange for plant-assimilated carbon (C), but also improves the tolerance of plants to various biotic and abiotic stresses such as pathogens, salinity, and drought

"Quercirhiza squamosa" eine nichtidentifizierte Ektomykorrhiza an Quercus robur

Volume: 3Start Page: 137End Page: 14

SCREENING FOR LIGNOCELLULOLYTIC ENZYMES AND METAL TOLERANCE IN ISOLATES OF WOOD-ROT FUNGI FROM CHILE

Wood-rot fungi have been shown to be powerful agents in many biotechnological processes. However, there may be great inter- and intra-specific variability in their performance. Consequently, it is not only important to screen a broad range of species but also different isolates of the same species in order to obtain strains with specific biotechnological profiles. In this study, the presence of wood-rot fungi was monitored in Southern-Central Chile and the biotechnological potential of the isolates was analyzed by determining lignocellulolytic enzymes and tolerance to metal ions (Cu and Cd) in solid medium. Seventy-one strains were isolated from cultures of a total of 144 basidiomes collected from wood substrates and 59 species of 18 different genera were identified, of which four are first records for Chile: Antrodia xantha, Gloeophyllum abietinum, G. protractum and Stereum rameale. Cellulase and xylanase activity were detected in all strains and 20 strains showed significant ligninolytic activity. The great majority of the strains showed tolerance to 3mM Cu in solid medium, but were inhibited by 1mM Cd. In contrast, some strains of the white-rot fungi Ganoderma australe, Stereum hirsutum and Trametes versicolor presented high lignocellulolytic potential combined with metal tolerance. Possible applications of these strains in biodegradation or bioremediation processes are discussed.361186086

A comparative analysis of gaseous phase hydration properties of two lichenized fungi: Niebla tigrina (Follman) Rundel & Bowler from Atacama Desert and Umbilicaria antarctica Frey & I. M. Lamb from Robert Island, Southern Shetlands Archipelago, maritime Antarctica

Gaseous phase hydration properties for thalli of Niebla tigrina from Atacama Desert, and for Umbilicaria antarctica from Isla Robert, maritime Antarctica, were analyzed using H-1-NMR relaxometry, spectroscopy, and sorption isotherm analysis. The molecular dynamics of residual water was monitored to distinguish the sequential binding very tightly, tightly, and loosely bound water fractions. These two species differ in hydration kinetics faster for Desert N. tigrina [A(1) = 0.51(4); t(1) = 0.51(5) h, t(2) = 15.0(1.9) h; total 0.7 for p/p(0) = 100%], compared to Antarctic U. antarctica [A(1) = 0.082(6), t(1) = 2.4(2) h, t(2) = [26.9(2.7)] h, total 0.6 for p/p(0) = 100%] from humid polar area. The H-1-NMR measurements distinguish signal from tightly bound water, and two signals from loosely bound water, with different chemical shifts higher for U. antarctica than for N. tigrina. Both lichen species contain different amounts of water-soluble solid fraction. For U. antarctica, the saturation concentration of water soluble solid fraction, c(s) = 0.55(9), and the dissolution effect is detected at least up to Delta m/m(0) = 0.7, whereas for N. tigrina with the similar saturation concentration, c(s) = 053(4), this fraction is detected up to the threshold hydration level equal to Delta M/m(0) = 0.3 only