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Publicaciones científicas más recientes (desde 2010)

Autores: Sanchez, S., (Autor de correspondencia); Martin-Santafe, M. ; Barriuso, J. ; et al.
ISSN 1125-4653  Vol. 102  Nº 2  2020  págs. 593 - 594
Autores: Queralt Azcona, Mikel; Walker, J. K. M.; de Miguel Velasco, Ana María; et al.
ISSN 0168-6496  Vol. 95  Nº 6  2019 
Some plants that associate with ectomycorrhizal (ECM) fungi are also able to simultaneously establish symbiosis with other types of partners. The presence of alternative partners that may provide similar benefits may affect ECM functioning. Here we compared potential leucine-aminopeptidase (LA) and acid phosphatase (AP) enzyme activity (involved in N and P cycling, respectively) in ECM fungi of three hosts planted under the same conditions but differing in the type of partners: Pinus (ECM fungi only), Eucalyptus (ECM and arbuscular mycorrhizal -AM- fungi) and Acacia (ECM, AM fungi and rhizobial bacteria). We found that the ECM community on Acacia and Eucalyptus had higher potential AP activity than the Pinus community. The ECM community in Acacia also showed increased potential LA activity compared to Pinus. Morphotypes present in more than one host showed higher potential AP and LA activity when colonizing Acacia than when colonizing another host. Our results suggest that competition with AM fungi and rhizobial bacteria could promote increased ECM activity in Eucalyptus and Acacia. Alternatively, other host-related differences such as ECM community composition could also play a role. We found evidence for ECM physiological plasticity when colonizing different hosts, which might be key for adaptation to future climate scenarios.
Autores: Parlade, J., (Autor de correspondencia); Queralt Azcona, Mikel; Pera, J.; et al.
ISSN 0378-1127  Vol. 449  2019  págs. 117456
Forest management aimed to maximize timber production might impact soil fungi, especially those symbiotically associated to tree roots. In this study, we analyse the temporal dynamics of soil fungi along five sampling years after tree removal in a managed Pinus sylvestris stand in northern Spain, where timber production is combined with regular mushroom harvesting. Two management methods were tested: total and partial clear-cutting leaving retention trees for seedling regeneration. Undisturbed, uncut plots were also included in the experiment as a control treatment. The whole fungal community (phylotypes and ecological guilds) were analysed by high-throughput Illumina MiSeq sequencing of fungal ITS1 amplicons. We hypothesized that (1) ectomycorrhizal fungal communities will decrease after both clear-cutting treatments with a concurrent increase in the abundance of saprotrophs, (2) the abundance and diversity of the ectomycorrhizal guild will be more preserved in partially clear-cut than in total clear-cut plots, and (3) the overall fungal diversity will decrease in the cut plots leading to major losses of ectomycorrhizal species. Our results show that soil fungal composition changed across the five years after clear-cutting by decreasing ectomycorrhizal fungi and increasing saprotrophs. However, these changes did not significantly affect fungal diversity and there were taxa-specific responses to tree harvest treatments.
Autores: Queralt Azcona, Mikel; Perladé, J.; Pera, J.; et al.
ISSN 0940-6360  Vol. 27  Nº 6  2017  págs. 565 - 576
Seasonal dynamics of black truffle (Tuber melanosporum) extraradical mycelium as well as the associated mycorrhizal community have been evaluated in a 16-year-old plantation with productive and non-productive trees. Mycelium biomass was seasonally quantified by real-time PCR over two consecutive years and the correlation with environmental variables explored. Extraradical mycelium biomass varied seasonally and between the two consecutive years, being correlated with the precipitation that occurred 1 month before sampling. In addition, productive trees had more mycelium in the brA >> l, area than non-productive trees did. The ectomycorrhizal community composition inside the burnt areas was seasonally evaluated during a year. Ten mycorrhizal morphotypes were detected; T. melanosporum was the most abundant in productive and non-productive trees. Black truffle mycorrhizas were more abundant (mycorrhizal tips per unit of soil volume) in productive trees, and no seasonal variation was observed. The occurrence of black truffle mycorrhizas was significantly and positively correlated with the biomass of extraradical mycelium. The mycorrhizal community within the brA >> l, areas was significantly different between productive and non-productive trees, and no variation was detected between seasons. The assessment of the fungal vegetative structures in a mature plantation is of paramount importance to develop trufficulture methods based on the knowledge of the biological cycle ...
Autores: Sánchez, S.; de Miguel Velasco, Ana María; Sáez, R.; et al.
ISSN 1699-6887  Vol. 112  Nº 1  2016  págs. 20 - 33
La trufa de verano (Tuber aestivum, incluyendo Tuber uncinatum) es una especie de un gran valor económico y social, que se produce de modo silvestre en toda Europa, norte de África y parte de Oriente medio. Los esfuerzos de cultivo de esta especie en la península ibérica han permanecido en un segundo plano debido a las condiciones adecuadas de ciertos terrenos para cultivar especies de mayor valor económico, como la trufa negra (Tuber melanosporum). Sin embargo, la trufa de verano es una alternativa viable y muy productiva para zonas de dudosa aptitud para T. melanosporum. En este trabajo, mediante revisión bibliográfica, se ponen de manifiesto los siguientes aspectos: la distribución y ecología de T. aestivum, la situación actual del cultivo, así como las perspectivas de futuro propias de esta especie en la península ibérica. En rasgos generales, se ha constatado su mayor amplitud ecológica y geográfica en relación a la trufa negra y se ha observado que es un cultivo incipiente pero en crecimiento. Sin embargo, se ha deducido que aún es necesario realizar un gran esfuerzo para dar a conocer este producto tanto a cultivadores como a consumidores potenciales en España así como divulgar aspectos técnicos sobre la gestión de su cultivo.
Autores: de Miguel Velasco, Ana María; Águeda, B.; Sáez, R.; et al.
ISSN 0940-6360  Vol. 26  Nº 3  2015  págs. 227 - 236
Truffles are edible hypogeous ascomycetes highly appreciated worldwide, especially the black truffle (Tuber melanosporum Vittad.). In recent decades, the cultivation of the black truffle has expanded across the Mediterranean climate regions in and outside its native range. Members of the Thelephoraceae (Thelephorales, Agaricomycetes, Basidiomycota) are commonly found in truffle plantations, but their co-occurrence with Tuber species and other members of the fungal community has been scarcely reported. Thelephoraceae is one of the most represented families of the ectomycorrhizal fungal community in boreal and Mediterranean forests. To reveal the diversity of these fungi in T. melanosporum-cultivated plantations, ten orchards located in the Navarra region (Northern Spain) were surveyed for 2 years. Morphological and molecular approaches were used to detect and identify the Thelephoraceae ectomycorrhizas present in those plantations. Ten different mycorrhizal types were detected and described. Four of them were morphologically identified as Tomentella galzinii, Quercirhiza cumulosa, Q. squamosa, and T39 Thelephoraceae type. Molecular analyses revealed 4¿6 operational taxonomic units (OTUs), depending on the nucleotide database used, but similarities remained under 95 % and no clear species assignments could be done. The results confirm the diversity and abundance of this fungal family in the ectomycorrhizal community of black truffle plantations, generally established in Mediterranean areas. The occurrence and relative abundance of Thelephoraceae ectomycorrhizas is discussed in relation to their possible influence on truffle production.
Autores: Queralt Azcona, Mikel; Moraza Zorrilla, María Lourdes; de Miguel Velasco, Ana María
ISSN 2171-5068  Vol. 23  Nº 2  2014  págs. 339 - 348
Aims of the study: The goals of this paper are to provide preliminary data on the composition of the mite community in truffle-producing soils (both wild and plantations); and to elucidate those species which may interact with the black truffle life cycle. Area of study: The study was carried out in two black truffle productive zones in Navarra (Spain), in four different plantations and five wild production areas. Material and Methods: Fauna was extracted using Berlese Tullgren funnels. Animals were separated into taxonomic groups, and mites were identified. To analyse the composition and community structure of the different habitats, parameters such as abundance, species richness, and Shanon Weiner diversity index (H¿) were calculated. Main results: A total of 305 mites were recognized, belonging to 58 species representing the three major taxonomic groups (Oribatida, Prostigmata, Mesostigmata). Research highlights: The results show a possible trend towards wild areas having greater diversity and species richness than plantations. Furthermore, community analysis shows differences in species compositions among different study areas, and oribatid mites always exhibit the highest relative abundance and species richness.
Autores: de Miguel Velasco, Ana María; Águeda, B.; Sánchez, S.; et al.
ISSN 0940-6360  Vol. 24  Nº 1 Suppl  2014  págs. 5 - 18
Since the first truffle plantations were established in France, Italy and other parts in the world, many studies have been carried out to improve their productivity and sustainability. Success of plantations is clearly related to the mycorrhizal status of the host trees over the years, from inoculated seedlings to truffle-producing trees. The experience gained in monitoring the ectomycorrhizal fungus status in cultivated truffle grounds has allowed us to develop an extensive catalogue of the ectomycorrhizal fungi present in truffle plantations. Herein, we summarize fungal community data from 85 references that represent different truffle studies in natural habitats and plantations. Approximately 25 % of the ectomycorrhizae reported in the 85 references are common to most of the studies. In general, more fungal species are detected in productive plantations than in the non-productive ones. Truffle plantations display a diverse ectomycorrhizal fungal community, in which species of the genus Tuber are well represented. Tuber rufum and some members of Boletales are typically restricted to productive truffle plots. On the other hand, Hebeloma, Laccaria and Russula species are mostly associated with unproductive plots. Ectomycorrhizae belonging to Thelephoraceae are frequently found in mature truffle orchards but do not seem to affect sporocarp production. Several biotic and abiotic factors affect the ectomycorrhizal fungus communities associated with truffle orchards. Among them are plantation age, host species and its growth, the surrounding environment (particularly the presence of other ectomycorrhizal hosts), and plantation management. Understanding the ectomycorrhizal fungal communities inhabiting different plantations may give us clues about the dynamics of the targeted truffles and the possibility of identifying mycorrhizal fungal species that are good indicators of successful truffle plantations.
Autores: Sánchez, S.; Ágreda, T.; Águeda, B.; et al.
ISSN 0940-6360  Vol. 24  Nº Supl. 1  2014  págs. 39 - 46
Owners of black truffle (Tuber melanosporum) plantations are concerned about the persistence of its mycorrhizas and mycelium in the soil, especially until the appearance of the "truffle burn" areas and the triggering of sporocarp production, at least 5-7 years after planting truffle-inoculated seedlings. During this period, the farmer does not know whether his management is promoting black truffle development. To study the presence and abundance of T. melanosporum ectomycorrhizas in plantations, two sampling methods, direct sampling of root tips and soil core collection, are compared by analyzing 48 evergreen oak trees (Quercus ilex) inoculated with truffle. Those trees are grouped by age (<6, 6-9, >9 years old) and presence or absence of truffle production. T. melanosporum was present in 46 out of the 48 studied trees, and its ectomycorrhizas appeared in 65 % of the ectomycorrhizal tips. Its abundance is significantly higher with productive trees and young trees. Direct sampling of root tips and soil core collection were equally effective in detecting this species, although soil core collection proved a better method to also evaluate ectomycorrhizal fungal diversity. To detect the presence of T. melanosporum in a given plantation, three samples suffice, with a single sample per random tree. Although the presence of mycorrhizas is not a sure sign of the future success of a black truffle plantation, its absence influences managers as to whether to continue culturing truffles in a plantation.
Autores: Sánchez, S.; Gómez, E.; Martín, M.; et al.
ISSN 1754-5048  Vol. 8  2014  págs. 59 - 65
Abstract: Sphaerosporella brunnea is a pioneer and opportunist ectomycorrhizal species, and the most common fungal competitor in nurseries producing plants mycorrhized with Tuber species. Our objective was to learn more about its life cycle as the first step to manage its presence in greenhouses. Conidiation and formation of resting spore-like structures were found to be triggered by aeration and to be highest on CMA medium. In pot experiments S. brunnea was able to form ectomycorrhizas and ascocarps rapidly, in 2 and 3 months respectively, if substratum moisture was high. Both mycelia and conidiospores were effective sources of inoculum for mycorrhization. This species seems to be homothallic as apothecia have been obtained after inoculations with single monospore isolates. Propagation by mitospores and homothallism are poorly documented in ECM fungi, therefore these results may be of fundamental interest beyond the question of greenhouse management.
Autores: Jaillard, B.; Barry-Etienne, D.; Colinas, C.; et al.
ISSN 2171-5068  Vol. 23  Nº 2  2014  págs. 364 - 377
Aim of study: The program "Typology of truffle stations in the Pyrenean Regions" aimed to define the ecological conditions and culture practices that favor Tuber melanosporum growth and fruiting in this area. Area of study: Navarra, Catalonia, Midi-Pyrenees and Languedoc-Roussillon. Material and methods: The program was based on the survey of 212 wild and cultivated truffle beds of evergreen oaks (Quercus ilex). The data collected in the field consisted of photographs, samples of soil, roots and mycorrhizae, and information on cultural practices followed by truffle growers. Main results: (i) truffle soils are alkaline, from neutral, dolomitic, to moderately or very calcareous soils; (ii) truffle soils are light, well-structured and stable to water immersion; (iii) mycelium that colonizes roots survives in suboptimal conditions, but it does not necessarily bear ascocarps. Finally our results suggest that T melanosporum is a relatively ubiquitous fungus able to grow, or at least to persist, in a wide range of physical and chemical soil conditions. We propose a probabilistic model of the environment favorable for fruiting, built around a two-dimensional graph with an axis for the chemical conditions, like soil alkalinity, and another axis for the physical conditions, like soil structure. Research highlights: Soil alkalinity and structure allow to built a convenient representation of the ecological capacity of a place to be good T melanosporum habitat, and thus of the probability for truffle growers to harvest truffles according to the environmental properties of their truffle orchards.
Autores: Oliach D.; Saez, M.; Genola, L.; et al.
ISSN 1245-5016  Vol. 82  2013  págs. 13
Autores: Parladé, J.; de la Varga, H.; de Miguel Velasco, Ana María; et al.
ISSN 0940-6360  Vol. 23  Nº 2  2013  págs. 99 - 106
Quantification of extraradical mycelium of black truffle (Tuber melanosporum) has been carried out in a natural truffle ground and in seven truffle orchards (around 20 years old) established in Tierra Estella and Valdorba sites, within the natural distribution area of the black truffles in Navarre (northern Spain). Specific primers and a TaqmanA (R) probe were designed to perform real-time PCR with DNA extracted from soil samples. Amplification of T. melanosporum DNA was obtained from 131 out of the 160 soil samples. The detection limit of the technique was 1.48 mu g mycelium/g of soil. The extraradical mycelium biomass detected in the soil from the natural truffle ground was significantly greater (up to ten times higher) than the mycelium biomass detected in any of the orchards. Soil from productive, nonirrigated orchards in the Tierra Estella site contained significantly more extraradical mycelium than the rest of orchards irrigated, productive of T. brumale, or nonproductive. The comparison of soil mycelium biomass in nonirrigated evergreen oak orchards in both sites showed significantly more mycelium biomass in the Tierra Estella site. This study is the first attempt to quantify extraradical mycelium of T. melanosporum in the soil using TaqmanA (R) probes. The obtained quantitative results are of special interest to evaluate the fungal response to cultural treatments and to monitor the dynamics of the extraradical mycelium of T. melanosporum in the soil.
Autores: Jaillard, B.; Barry-Etienne, D.; Colinas, C.; et al.
ISSN 1245-5016  Vol. 85  2013  págs. 16 - 21
Autores: González Armada, María Begoña; Cavero Remón, Rita Yolanda; de Miguel Velasco, Ana María; et al.
ISSN 1245-5016  Vol. 79  2012  págs. 8 - 10
Autores: González Armada, María Begoña; de Miguel Velasco, Ana María; Cavero Remón, Rita Yolanda
Revista: Biodiversity and Conservation
ISSN 0960-3115  Vol. 19  Nº 14  2010  págs. 3861 - 3891
The diversity below (ectomycorrhizae) and above (vascular flora) ground in brûlés of black truffle production areas have been studied together for the first time, both in plantations and in natural areas, as possible indicators of the microecology of these zones. Studies on the ectomycorrhizal community of mature plantations are scarce. However, monitoring the dynamics of such systems is important to understand the conditions that promote truffle fructification. In the study described here the most frequent ectomycorrhizae are Tuber melanosporum and Quercirrhiza quadratum. In the plantations, Q. quadratum is the most abundant morphotype and in the natural area it is Cenococcum geophilum. The development of truffle ecosystems involves the appearance of competitor species with wide networks of hyphae and rhizomorphs. On the other hand, there are few studies concerning the special composition of the vascular flora growing in brûlés. We identified 199 taxa, most of them Mediterranean or Eurosiberian xerophiles and therophytes. This is consistent with the ecology of truffle production areas (dry, sunny and stony). These plants are heavily influenced by the inhibiting substances produced by the truffle and, as a result, they suffer from inhibited growth and in some cases cannot complete their life cycle.
Autores: Águeda, B.; Fernández-Toirán, L.M.; de Miguel Velasco, Ana María; et al.
Revista: Forest Systems
ISSN 2171-5068  Vol. 19  Nº 1  2010  págs. 89 - 97
Autores: Parladé, J.; Águeda, B.; Fernández-Toirán, L.M.; et al.
Libro:  Root Engineering : basic and applied concepts
2014  págs. 171 - 191
Mycorrhizae are classic examples to explain the mutualistic interaction between two different organisms in nature: the roots of a vascular plant and a fungus. Both species establish a permanent relationship, they live together in symbiosis, and that differentiates the nature of mycorrhizae from other plant¿fungus interactions. Ectomycorrhizal associations increase the root exploration area in soil, boosting the potential for mineral nutrition, water availability, and mutual survival of plant and fungus. The diversity of ectomycorrhizal fungal communities in the roots of spermatophyte plants is impressively high and means a complex diversity of structures in the root system, including emanating hyphae and rhizomorphs, which enlarge its area of influence. The distribution of the ectomycorrhizae living in the root system in an ever-changing balance is conditioned by many factors. Some of them are related with the root morphology of the host tree and also with ectomycorrhizal morphology, but abiotic factors (such as soil properties) also play a role. Knowledge of the distribution and organization of ectomycorrhizal fungal communities in the rhizosphere is still in its infancy. The development of regional models of ectomycorrhizal sporocarp¿environment relationships and molecular tools and the study of anato-morphological structures are helping to increase levels of understanding.
Autores: de Miguel Velasco, Ana María; Reyna, A.M,
Libro:  Truficultura: Fundamentos y Técnicas
2012  págs. 73-104
Autores: Reyna, S.; Colinas, C.; de Miguel Velasco, Ana María; et al.
Libro:  Truficultura: Fundamentos y Técnicas
2012  págs. 303-356
Autores: Reyna, S.; de Miguel Velasco, Ana María
Libro:  Truficultura: Fundamentos y Técnicas
2012  págs. 105-150
Autores: de Miguel Velasco, Ana María
Libro:  La Mycosylviculture
2011  págs. 8-22
Autores: de Miguel Velasco, Ana María; Sáez, R.
Libro:  Atti 3º Congresso Internazionale di Spoleto sul Tartufo
2010  págs. 556-561
Autores: Sáez, R.; de Miguel Velasco, Ana María
Libro:  Les Nouvelles Techniques de Culture de la Truffe
2010  págs. 47 - 54
Autores: Águeda, B.; Fernández-Toirán, L.M.; de Miguel Velasco, Ana María; et al.
Libro:  Atti 3º Congresso Internazionale di Spoleto sul Tartufo
2010  págs. 371 - 382
Autores: Águeda, B.; Reinhard, A.; de Miguel Velasco, Ana María; et al.
Libro:  Atti 3º Congresso Internazionale di Spoleto sul Tartufo
2010  págs. 303 -307
Autores: González Armada, M.B.; de Miguel Velasco, Ana María; Cavero Remón, Rita Yolanda
Libro:  Atti 3º Congresso Internazionale di Spoleto sul Tartufo
2010  págs. 152 -162