Ectomycorrhizal fungi

The ectomycorrhizal fungi (ECM fungi) are both abundant and widespread in boreal forests. Host plant provides the assimilated carbon to the infecting ECM fungi. Many studies indicate that at most 10-30% of the assimilated carbon by the host plant photosynthesis may be used by the fungal partner for the production and sustenance of its external biomass (Smith and Read 1997). On the other hand, ECM fungi exude extracellular enzymes that are able to break down complex organic substances and consequently transmit the inorganic nutrients to their hosts. Such ECM activity results in greater plant growth under severe environmental conditions of the boreal forests (Read 1991; Chalot and Brun 1998). Tree seedlings infected with ECM can significantly improve their growth when compared with nonmycorrhizal seedlings.

Endemic populations of Abies religiosa (fir, oyamel) have great economic, ecological and social importance; in addition, they form different interactions with edaphic microorganisms, mainly with ectomycorrhizal fungi. Currently, isolated populations (i. e. fir) are threatened by deforestation, agricultural expansion and global warming; therefore, it is urgent to understand the ecological and evolutionary interactions with ectomycorrhizal fungi. The objective of the present research was to analyze the use of molecular ecology, taxonomy and biology of ectomycorrhizal
fungi to understand the role that these fungi play in A. religiosa trees in Mexico. Areas of research are presented as well as the main information gaps in the morphological/molecular characterization, taxonomy and evolution of the ectomycorrhizal symbiosis in A. religiosa. For the above, we collected information of 108 taxa of potentially ectomycorrhizal fungi obtained from different fir populations. The taxa with high potential to inoculate A. religiosa are Sebacina dimitica, Clavulina cf. cinerea, Membranomyces sp., Thelephoraceae, Russula spp., Ramaria spp., Lactarius spp. e Inocybe spp. Finally, we discuss issues that remain unresolved to determine their potential for use, management and conservation of A. religiosa in temperate areas of Mexico. This problem can be solved by combining molecular tools with the morphological and histological description of ectomycorrhizal morphotypes. In addition, methodologies are required to standardize results to come to more robust conclusions about mycorrhizal interactions.
Las poblaciones endémicas de Abies religiosa (abeto, oyamel) poseen gran importancia económica, ecológica y social; además, forman distintas interacciones con microorganismos edáficos, principalmente con hongos ectomicorrizógenos. Actualmente, las poblaciones aisladas (i. e. oyamel) están amenazadas por la deforestación, la expansión agrícola y el calentamiento global; por lo cual, es urgente entender las interacciones ecológicas y evolutivas con hongos ectomicorrizógenos. El objetivo de la presente investigación fue analizar el uso de la ecología, taxonomía y biología molecular de ectomicorrizas para comprender el papel que juegan estos hongos en árboles de A. religiosa en México. Se presentan áreas de oportunidad de investigación, así como los principales vacíos de información de la caracterización morfoanatómica/molecular, taxonomía y evolución de la simbiosis ectomicorrízica en bosques de A. religiosa. Para lo anterior, se reunió información de 108 taxones de hongos potencialmente ectomicorrizógenos, colectados en diferentes poblaciones de abetos. Los taxones con potencial alto para inocular A. religiosa son Sebacina dimitica, Clavulina cf. cinerea, Membranomyces sp., Thelephoraceae, Russula spp., Ramaria spp., Lactarius spp. e Inocybe spp. Finalmente, se discuten aspectos que faltan por resolver para determinar el potencial de uso, manejo, conservación y aprovechamiento de A. religiosa
en zonas templadas de México. Este problema puede resolverse combinando herramientas moleculares con la descripción morfológica e histológica de morfotipos ectomicorrizógenos. Adicionalmente, se requieren metodologías que permitan estandarizar resultados para llegar a conclusiones más sólidas sobre las interacciones micorrízicas.

The aim of the present work was to determine phylogenetic relationships among Astraeus species and to support macroscopic and microscopic characters of Astraeus with analysis of the ITS rDNA region. Collections of Astraeus basidiomes were made from different geographical areas in Thailand and compared with existing collections made worldwide.

Alsophila firma is a deciduous tree fern considered as an emblematic species of Mexican tropical montane cloud forest (TMCF). We studied spores diversity, structure and colonization by arbuscular mycorrhizal fungi (AMF) within the roots of the Alsophila firma in rainy and dry season.

We present a checklist of species in the Cortinariaceae (Agaricales) described from the Nothofagus forests of Argentina up to 2013. Names of the 247 species in Cortinarius, Dermocybe, Descolea, and Stephanopus have been revised and are accompanied by references and updated distributions.

Shorea balangeran is an important component of peat swamp forests in Southeast Asia and is an important source of timber. However, S. balangeran has been decreasing in number due to overexploitation. The objective of this study was to investigate the effect of inoculation of native ectomycorrhizal (ECM) fungi on growth of S. balangeran in degraded peat swamp forest. Spores of Boletus sp., Scleroderma sp., and Strobilomyces sp. were collected from natural peat swamp forest in Indonesia. Seedlings of S. balangeran were inoculated with or without (control) spores and grown in sterilized peat soil under nursery conditions for 6 months. Then, the seedlings were transplanted into a degraded peat swamp forest and grown for 40 months. ECM colonization was 59-67% under nursery conditions and increased shoot height and weight. Shoot height, stem diameter, and survival rates were higher in inoculated seedlings than in control 40 months after transplantation. The results suggest that inoculation of native ECM fungi onto native tree species is useful for reforestation of degraded peat swamp forests.

One sentence summary: Functional traits of host tree species and chemical soil parameters shape the spatial distribution of the ectomycorrhizal fungal community of a miombo forest. ABSTRACT Ectomycorrhizal fungi (EMF) are highly diversified and dominant in a number of forest ecosystems. Nevertheless, their scales of spatial distribution and the underlying ecological processes remain poorly understood. Although most EMF are considered to be generalists regarding host identity, a preference toward functional strategies of host trees has never been tested. Here, the EMF community was characterised by DNA sequencing in a 10-ha tropical dry season forest—referred to as miombo—an understudied ecosystem from a mycorrhizal perspective. We used 36 soil parameters and 21 host functional traits (FTs) as candidate explanatory variables in spatial constrained ordinations for explaining the EMF community assemblage. Results highlighted that the community variability was explained by host FTs related to the 'leaf economics spectrum' (adjusted R 2 = 11%; SLA, leaf area, foliar Mg content), and by soil parameters (adjusted R 2 = 17%), notably total forms of micronutrients or correlated available elements (Al, N, K, P). Both FTs and soil generated patterns in the community at scales ranging from 75 to 375 m. Our results indicate that soil is more important than previously thought for EMF in miombo woodlands, and show that FTs of host species can be better predictors of symbiont distribution than taxonomical identity.