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Characterization of the oxidative system on Castanea sativa Mill. in association with the ectomycorrhizal fungi Pisolithus tinctorius and Amanita muscaria during the early stages of contact

Baptista, Paula; Martins, Anabela; Tavares, Rui Manuel; Lino-Neto, Teresa
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
57%
Mycorrhizae are symbiotic associations between soil borne fungi and the root system of higher plants having a beneficial role on plant growth. The fungus receives carbon from plant, while the plant increased nutrient uptake mediated via the fungus. In agroforestry systems, most of the mycorrhizae belong to ectomycorrhizal (ECM) group being the mechanisms controlling its development poorly defined. During arbuscular mycorrhizal (AM) establishment, some evidences suggest that a temporal and spatial activation of different defence mechanisms by plants are activated. The present work pretends to assess the influence of ECM inoculation on the activity of antioxidant enzymes from roots of Castanea sativa Mill., during the early stages of contact. The experimental work was carried out in an “in vitro” system, established between two symbiotic associations: Castanea sativa Mill. / Pisolithus tinctorius and Castanea sativa Mill. / Amanita muscaria. In these systems, plants were harvested at different times of fungi contact. The levels of H2O2 and the activity of oxidative stress enzymes, namely catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and ascorbate peroxidase (EC 1.11.1.11), were determined in roots. The results suggest that in the early stages of plant-ECM fungi interaction the oxidative metabolism could be involved...

Effect of the mycorrhizal symbiosis time in the antioxidant activity of fungi and Pinus pinaster roots, stems and leaves

Reis, Filipa S.; Ferreira, Isabel C.F.R.; Martins, Anabela
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
57.08%
The ectomycorrhizal (ECM) symbiosis that develops between the roots of host trees and the soil ECM fungi is an important factor towards the survival, health and growth of these trees, as it stimulates their water and nutrient uptake. Ectomycorrhizal colonization can result in the deposition of phenolic compounds in peripheral cortex cells and a similar answer can be recognized as one way of plant defense against pathogenic infections. The aim of the present work was the evaluation of antioxidant potential of the ectomycorrhizal fungi, Paxillus involutus and Pisolithus arhizus, in presence and absence of the symbiont – Pinus pinaster –, in response to the symbiotic association, under different contact periods (45 days and 48 h). Phenolic contents in mycelia, culture media and plant leaves, stems and roots were determined by Folin-Ciocalteu assay, and their antioxidant properties were evaluated by three in vitro assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and lipid peroxidation inhibition through B-carotene bleaching inhibition. Comparing the response of the symbionts to the host species, Pinus pinaster benefited most with the association, because it generally decreases the phenolics content and the antioxidant activity values in the presence of both ectomycorrhizal fungi along time. Pisolithus arhizus also decreased...

Signalling process during the early contact of ectomycorrhizal fungi Pisolithus tinctorius with Castanea sativa roots

Baptista, Paula; Martins, Anabela; Tavares, R. M.; Neto, T. Lino
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /12/2006 ENG
Relevância na Pesquisa
56.91%
Ectomycorrhizas (ECM) are symbiotic associations between roots of higher plants, mainly trees (e.g. Pinacea and Fagaceae), and soil fungi (asco- and basidiomycetes). The establishment of this symbiotic association requires a sequence of highly regulated and coordinated events, initiated by an exchange of specific signalling compounds between both partners. The triggering mechanisms and the progression of the colonization process are still not well understood. The present work focus on the signalling process occurring during the early contact of ectomycorrhizal fungi with Castanea sativa roots, using a model ECM fungus (Pisolithus tinctorius). Early contacts between symbionts were also observed by scanning electron microscopy. In previous work, we have evaluated the involvement of reactive oxygen species (ROS) during the first 48 h after P. tinctorius contact with C. sativa roots, in which three production peaks of H2O2 and two O2•- burst were detected. The effect of C. sativa root extracts in promoting ECM fungi growth was also evaluated by measuring the radial growth of P. tinctorius mycelium cultured in medium supplemented with crude extracts from C. sativa roots elicited with the same ECM fungi up to 48h. P. tinctorius growth is differentially stimulated in the presence of aqueous extracts from elicited C. sativa roots...

Study of competitive interactions between ectomycorrhizal and saprotrophic fungi and its effects on chestnut tree performance

Pereira, Eric; Tavares, R. M.; Neto, T. Lino; Baptista, Paula
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /10/2011 ENG
Relevância na Pesquisa
47.08%
European chestnut tree (Castanea sativa Mill.), as fruit and wood producers, have a great economic importance in Trás-os-Montes region (Northeast of Portugal). In this agro-ecosystem, the Hypholoma fasciculare and the Pisolithus tinctorius are the most commonest fungi among the saprophytic and mycorrhizal trophic groups, respectively. Although, interactions between ectomycorrhizal and saprotrophic fungi have been previously observed, their effects on plant growth and health are scarcely known. Therefore, the aim of the present work was to assess the effect of the interaction between P. tinctorius and H. fasciculare on growth, nutritional status and physiology of C. sativa seedlings. In pot experiments, C. sativa seedlings were inoculated with P. tinctorius and H. fasciculare individually or in combination. Plants inoculated with P. tinctorius showed a higher growth and an increased foliar-N, -P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tinctorius. However, when plants were inoculated with P. tinctorius and after 30 days with H. fasciculare the same parameter values were very close to those from plants only inoculated with P. tinctorius. These results are most probably due to the interaction between P. tinctorius and C. sativa roots and the ability of mycorrhizae formation before H. fasciculare application. Once formed...

Management of nursery practices for efficient ectomycorrhizal fungi application in the production of Quercus ilex

Oliveira, Rui S.; Franco, Albina R.; Vosátka, Miroslav; Castro, Paula M. L.
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
Publicado em //2010 ENG
Relevância na Pesquisa
56.91%
The application of ectomycorrhizal (ECM) fungi on forest nursery production is regarded as part of good management practice. However, before employing large scale inoculations in a nursery the interaction between ECM symbionts, growth substrate and fertilisation input should be studied to select the most suitable nursery practices for promoting plant growth and ECM colonisation. In this study, seedlings of Quercus ilex were inoculated with Paxillus involutus, Hebeloma mesophaeum or Cenococcum geophilum and grown in three different substrates commonly used in forest nurseries: peat-based compost, forest soil or composted pine bark. The effect of various fertilisation regimes was also studied. The choice of substrate had a significant effect on plant growth and ECM colonisation. The most appropriate combination of substrate and ECM fungus for Q. ilex growth and nutrition was peat and H. mesophaeum. Plants grown on a peat-based compost and inoculated with H. mesophaeum had a significantly greater biomass and leaf phosphorus concentration without fertilisation. Composted pine bark was found not to be suitable for growth or for mycorrhization. If the appropriate growth substrate is selected, it is possible to replace the use of chemical fertilisers by inoculation with selected ECM fungi. This results in a significant increase in plant development...

Reforestation of burned stands: the effect of ectomycorrhizal fungi on Pinus pinaster establishment

Sousa, Nadine R.; Franco, Albina R.; Ramos, Miguel A.; Oliveira, Rui S.; Castro, Paula M. L.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2011 ENG
Relevância na Pesquisa
67.18%
The area occupied by Pinus pinaster in Portugal is rapidly diminishing because of forest fires. Ectomycorrhizal fungi form obligate, mutually beneficial associations with P. pinaster which improve plant growth and resistance to adverse conditions. The aim of this work was to assess whether native ectomycorrhizal fungi could be a useful tool in the reforestation of burned areas. The work was conducted in a forest nursery greenhouse, where P. pinaster seedlings were inoculated with compatible ectomycorrhizal fungal isolates: Suillus bovinus, Pisolithus tinctorius, Rhizopogon roseolus, and a mixture of the three fungi, using burned and unburned forest soil as substrate. Inoculation significantly enhanced the growth of P. pinaster, with R. roseolus proving to be the most effective in burned soil, with an 8-fold increase in plant fresh weight. Overall, inoculation stimulated growth most in burned than in unburned soil. This study suggests that inoculation with selected ectomycorrhizal fungi in containerised nurseries can be an advantageous approach for the successful establishment of P. pinaster in burned soil. The obtained results point out to the interest of extending these studies into fire-impacted areas, using ectomycorrhizal fungi as a biological tool.

The interaction between ectomycorrhizal fungi and growth promoting bacteria in plant development from in-vitro to the field

Ramos, Miguel A.; Sousa, Nadine R.; Franco, Albina R.; Dundar, Gonul; Oliveira, Rui S.; Castro, Paula M. L.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em 05/06/2013 ENG
Relevância na Pesquisa
67.1%
There is currently an array of biotechnological tools which may positively influence plant development and establishment. Symbiosis with ectomycorrhizal fungi is known to improve plant health by increasing nutrient and water uptake and alleviating environmental stresses. Some rhizosphere bacteria are also proven to act as plant stimulating agents, health managers and growth promoters. The use of a combined inoculum using both microorganisms has great potential in forestry. Nevertheless, the interaction between fungi and bacteria is highly specific and bacteria are known not only to enhance fungal growth (mycorrhiza promoting bacteria), but also to strongly inhibit it. It is therefore important to evaluate the compatibility between ectomycorrhizal fungi and bacteria and to determine the impact of such combination in plant development when aiming at the use of optimized microbial inoculum for enhancing plant growth. In the present work we investigated the use of a dual inoculation system, consisting of a bacterial strain from the genus Mesorhizobium in combination with ectomycorrhizal fungi, from in-vitro tests to a nursery stage followed by transplantation to the field. Approximately 5000 seedlings were used in these experiments comprising Quercus suber...

Growth dynamic of dual culture systems comprising ectomycorrhizal fungi and mycorrhiza helper bacteria

Sousa, Nadine R.; Ramos, Miguel A.; Castro, Paula M. L.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
Relevância na Pesquisa
66.87%
Ectomycorrhizal fungi are ubiquitous root symbionts that associate with the majority of forest trees and often have a crucial role on plant survival and growth in impoverished soils. Within the vast community of soil microorganisms, the mycorrhiza helper bacteria (MHB) are recognizably one of the groups that most directly affect fungal growth and mycorrhiza establishment. Although their positive effect on the mycorrhizal partnership has been previously reported, the specificity of such association is high and the dynamics not yet fully understood. Many studies evaluated the impact of bacteria on fungal growth but the reciprocal has received little attention. The present study aimed to evaluate the growth dynamics of co-culturing fungi and bacteria, under both perspectives. Bacillus pumilus was chosen for its capability to promote the growth of Suillus granulatus in a dual culture system with a low nutrient medium. To assess the impact of fungal exudates on bacterial growth, different quantities of fungal culture medium were added to MMN medium containing a Bacillus pumilus inoculum and bacterial growth was monitored. To evaluate the influence of Bacillus pumilus on fungal growth, an experiment was setup where the bacterium was added at two different phases of fungal growth...

Combining ectomycorrhizal fungi and bacteria: a powerful tool to improve tree performance

Ramos, Miguel A.; Sousa, Nadine R.; Franco, Albina R.; Dundar, Gonul; Oliveira, Rui S.; Castro, Paula M. L.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em 06/12/2013 ENG
Relevância na Pesquisa
67.12%
Ectomycorrhizal fungi are ubiquitous to forest soils and the symbiosis between these microorganisms and plants roots is known to be essential for tree establishment and development, especially in areas of poor soil. Studies have also shown that some rhizosphere bacteria may act as plant stimulating agents and growth promoters. Additionally, bacteria and fungi strongly interact and therefore the analysis of the triangle plant-fungi-bacteria is a vital approach when aiming at the use of microbial inocula to enhance plant performance. To obtain a synergistic combination between microorganisms, a thorough selection is required since bacteria may strongly inhibit fungal growth, and vice versa, incurring in the risk of failed inoculum. In the present work we investigated the use of a dual inoculation system, consisting of a bacterial strain from the genus Mesorhizobium in combination with selected ectomycorrhizal fungi. In vitro tests were performed to assess the dynamic of co-culturing both microorganisms. The inoculum was applied at nursery stage and saplings were then transplanted into the field. Approximately 5000 seedlings were used in this experiment comprising the following species: Quercus suber, Quercus robur, Quercus rubra, Pinus pinaster and Pinus pinea. Seedlings were grown for 9 months in a commercial forest greenhouse and then transplanted to 4 locations in Portugal: Mindelo...

Succession dynamics of ectomycorrhizal fungi in inoculated Quercus rubra seedlings – a field study

Franco, Albina R.; Ramos, Miguel A.; Sousa, Nadine R.; Oliveira, Rui S.; Castro, Paula M. L.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em //2011 ENG
Relevância na Pesquisa
56.98%
Selected ectomycorrhizal (ECM) fungi may have a beneficial effect on the establishment of nursery grown seedlings and may influence their survival on the first years. By increasing seedling capacity to capture nutrients, ECM fungi often contribute to a successful plant establishment. We investigated the performance of pre-inoculated Quercus rubra seedlings on a reforestation site and monitored ECM fungal persistence and succession dynamics between selected ECM fungi and native fungal community. Nursery grown Q. rubra seedlings inoculated with a mixture of ECM fungi (Cenococcum geophilum, Hebeloma crustuliniforme, H. mesophaeum, H. velutipes, Paxillus involutus, Scleroderma citrinum) and non-inoculated control oak seedlings, were transplanted to Serra da Cabreira in Northern Portugal. Two years after planting, the subsistence of the inoculated ECM fungi was assessed using ITS-DGGE. Results demonstrated that inoculation with selected ECM fungi at nursery stage promoted the establishment and improved the growth performance of out planted oak seedlings. C. geophilum was significantly associated with inoculated saplings but other ECM fungi species were also found. Moreover, ECM fungal communities of inoculated and non-inoculated samples are significantly different. Further monitoring is required to increase knowledge on the persistence of ECM fungal communities and their succession dynamics.

Inoculation with ectomycorrhizal fungi affects Pinus pinaster performance under cadmium exposure

Sousa, Nadine R.; Ramos, Miguel A.; Marques, Ana P. G. C.; Castro, Paula M. L.
Fonte: Universidade Católica Portuguesa Publicador: Universidade Católica Portuguesa
Tipo: Conferência ou Objeto de Conferência
Publicado em //2014 ENG
Relevância na Pesquisa
66.87%
Afforestation of contaminated sites can represent a valuable approach to restore degraded ecosystems. Studies on the response of woody species to heavy metal contamination in soil are scarce compared to crop species. Cadmium is one of the most toxic heavy metals and its hazardous effects are well known. The aim of this work was to evaluate Pinus pinaster performance on Cd contaminated soil (15 and 30 mg Cd kg-1) and determine whether inoculation with two ectomycorrhizal fungi, Suillus bovinus and Rhizopogon roseolus influenced such response. Regarding non-inoculated seedlings, Cd exposure led to a lower shoot biomass and metal accumulation on the root system was proportional to its concentration in the soil. Inoculation with S. bovinus was the most favorable treatment for P. pinaster development by enhancing shoot development up to 1.3-fold in contaminated soil. Inoculation with R. roseolus increased Cd concentration in the shoots with no significant effect in any of the biometric traits studied. Metal accumulation on the shoots and roots of P. pinaster seedlings was significantly affected by the interaction between mycorrhizal inoculation and the Cd concentration to which the seedlings were exposed. Results from this study show that inoculation with selected ECM fungi can influence the performance of P. pinaster under Cd exposure and that this biotechnological tool could be of great value for plant establishment in contaminated sites.

Polymorphism in the internal transcribed spacer (ITS) of the ribosomal DNA of 26 isolates of ectomycorrhizal fungi

Gomes,Eliane A.; Kasuya,Maria Catarina M.; Barros,Everaldo G. de; Borges,Arnaldo C.; Araújo,Elza F.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 EN
Relevância na Pesquisa
66.96%
Inter- and intraspecific variation among 26 isolates of ectomycorrhizal fungi belonging to 8 genera and 19 species were evaluated by analysis of the internal transcribed sequence (ITS) of the rDNA region using restriction fragment length polymorphism (RFLP). The ITS region was first amplified by polymerase chain reaction (PCR) with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 560 and 750 base pairs (bp), were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the isolates. Cleavage of amplified fragments with the restriction enzymes Alu I, Hae III, Hinf I, and Hpa II revealed extensive polymorphism. All eight genera and most species presented specific restriction patterns. Species not identifiable by a specific pattern belonged to two genera: Rhizopogon (R. nigrescens, R. reaii, R. roseolus, R. rubescens and Rhizopogon sp.), and Laccaria (L. bicolor and L. amethystea). Our data confirm the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs.

Growth response of Pinus densiflora seedlings inoculated with three indigenous ectomycorrhizal fungi in combination

Dalong,M; Luhe,W; Guoting,Y; Liqiang,M; Chun,L
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2011 EN
Relevância na Pesquisa
67.02%
Pinus densiflora seedlings were inoculated with three indigenous ectomycorrhizal fungi (Cenococcum geophilum, Rhizopogon roseolus and Russula densifolia) in single-, two-, and three-species treatments. After 8 months, the colonization rates of each ectomycorrhizal species, seedling growth and the nutrition were assessed in each treatment. P. densiflora seedlings inoculated with different ECM species composition showed an increase in height and basal diameter and improved seedling root and shoot nutrition concentrations compared to control treatment. Generally, combined inoculation had a more positive influence on the seedlings than the single inoculation. The three-species inoculation presented the highest growth and basal diameter and concentration of most nutrients except potassium. In conclusion, the results provided strong evidence for benefits of combined inoculation with the indigenous ectomycorrhizal fungi on P. densiflora seedlings under controlled conditions.

Copper resistance of different ectomycorrhizal fungi such as Pisolithus microcarpus, Pisolithus sp., Scleroderma sp. and Suillus sp.

Silva,R.F.; Lupatini,M.; Trindade,L.; Antoniolli,Z.I.; Steffen,R.B.; Andreazza,R
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
56.82%
Environments contaminated with heavy metals negatively impact the living organisms. Ectomy­corrhizal fungi have shown important role in these impacted sites. Thus, this study aimed to evaluate the copper-resistance of ectomycorrhizal fungi isolates Pisolithus microcarpus - UFSC-Pt116; Pisolithus sp. - UFSC-PT24, Suillus sp. - UFSM RA 2.8 and Scleroderma sp. - UFSC-Sc124 to different copper doses in solid and liquid media. The copper doses tested were: 0.00, 0.25, 0.5, 0.75, 1.0 and 1.25 mmol L-1 in the solid medium and 0.00, 0.32, 0.64 and 0.96 mmol L-1 in the liquid medium. Copper was amended as copper sulphate in order to supplement the culture medium MNM at pH 4.8, with seven replicates to each fungus-dose combination. The fungal isolates were incubated for 30 days at 28 °C. UFSC-Pt116 showed high copper-resistance such as accessed by CL50 determinations (concentration to reduce 50% of the growth) as while as UFSC-PT24 displayed copper-resistance mechanism at 0.50 mmol L-1 in solid medium. The UFSC-PT24 and UFSC-Sc124 isolates have increased copper-resistance in liquid medium. The higher production of extracellular pigment was detected in UFSC-Pt116 cultures. The UFSC-Pt116 and UFSC-PT24 isolates showed higher resistance for copper and produced higher mycelium biomass than the other isolates. In this way...

Differential effect of purified spruce chitinases and beta-1,3-glucanases on the activity of elicitors from ectomycorrhizal fungi.

Salzer, P; Hübner, B; Sirrenberg, A; Hager, A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/1997 EN
Relevância na Pesquisa
46.96%
Two chitinases (EC 3.2.1.14) and two beta-1,3-glucanases (EC 3.2.1.39) were purified from the culture medium of spruce (Picea abines [L.] Karst.) cells to study their role in modifying elicitors, cell walls, growth, and hyphal morphology of ectomycorrhizal fungi. The 36-kD class I chitinase (isoelectric point [pl] 8.0) and the 28-kD chitinase (pl 8.7) decreased the activity of elicitor preparations from Hebeloma crustuliniforme (Bull. ex Fries.) Quél., Amanita muscaria (L.) Pers., and Suillus variegatus (Sw.: Fr.) O.K., as demonstrated by using the elicitor-induced extracellular alkalinization in spruce cells as a test system. In addition, chitinases released monomeric products from the walls of these ectomycorrhizal fungi. The beta-1,3-glucanases (35 kD, pl 3.7 and 3.9), in contrast, had little influence on the activity of the fungal elicitors and released only from walls of A. muscaria some polymeric products. Furthermore, chitinases alone and in combination with beta-1,3-glucanases had no effect on the growth and morphology of the hyphae. Thus, it is suggested that apoplastic chitinases in the root cortex destroy elicitors from the ectomycorrhizal fungi without damaging the fungus. By this mechanism the host plant could attenuate the elicitor signal and adjust its own defense reactions to a level allowing symbiotic interaction.

Availability of Ectomycorrhizal Fungi to Black Spruce above the Present Treeline in Eastern Labrador

Reithmeier, Laura; Kernaghan, Gavin
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 29/10/2013 EN
Relevância na Pesquisa
47.07%
Ectomycorrhizal fungi (ECMF) are an important biotic factor in the survival of conifer seedlings under stressful conditions and therefore have the potential to facilitate conifer establishment into alpine and tundra habitats. In order to assess patterns of ectomycorrhizal availability and community structure above treeline, we conducted soil bioassays in which Picea mariana (black spruce) seedlings were grown in field-collected soils under controlled conditions. Soils were collected from distinct alpine habitats, each dominated by a different ectomycorrhizal host shrub: Betula glandulosa, Arctostaphylos alpina or Salix herbacaea. Within each habitat, half of the soils collected contained roots of ectomycorrhizal shrubs (host+) and the other half were free of host plants (host−). Forest and glacial moraine soils were also included for comparison. Fungi forming ectomycorrhizae during the bioassays were identified by DNA sequencing. Our results indicate that ECMF capable of colonizing black spruce are widespread above the current tree line in Eastern Labrador and that the level of available inoculum has a significant influence on the growth of seedlings under controlled conditions. Many of the host− soils possessed appreciable levels of ectomycorrhizal inoculum...

Polymorphism in the internal transcribed spacer (ITS) of the ribosomal DNA of 26 isolates of ectomycorrhizal fungi.

GOMES, E.A.; KASUYA, M.C.M.; BARROS, E.G. de; BORGES, A.C.; ARAUJO, E.F.
Fonte: Genetics and Molecular Biology, Ribeirão Preto, v. 25, n. 4, p. 477-483, 2002. Publicador: Genetics and Molecular Biology, Ribeirão Preto, v. 25, n. 4, p. 477-483, 2002.
Tipo: Artigo em periódico indexado (ALICE)
EN
Relevância na Pesquisa
66.96%
Inter- and intraspecific variation among 26 isolates of ectomycorrhizal fungi belonging to 8 genera and 19 species were evaluated by analysis of the internal transcribed sequence (ITS) of the rDNA region using restriction fragment length polymorphism (RFLP). The ITS region was first amplified by polymerase chain reaction (PCR) with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 560 and 750 base pairs (bp), were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the isolates. Cleavage of amplified fragments with the restriction enzymes Alu I, Hae III, Hinf I, and Hpa II revealed extensive polymorphism. All eight genera and most species presented specific restriction patterns. Species not identifiable by a specific pattern belonged to two genera: Rhizopogon (R. nigrescens, R. reaii, R. roseolus, R. rubescens and Rhizopogon sp.), and Laccaria (L. bicolor and L. amethystea). Our data confirm the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs.; 2002

Efici?ncia de fungos ectomicorr?zicos no crescimento do eucalipto a partir de mudas clonais inoculadas; Efficiency of ectomycorrhizal fungi on the growth of eucalyptus from clonal seedlings inoculated

Costa, Lidiomar Soares da
Fonte: UFVJM Publicador: UFVJM
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
47.06%
ABSTRACT The inoculation of ectomycorrhizal fungi on seedlings can increase the sustainability of the commercial eucalypt plantations. This study evaluated the efficiency of inoculation in nursery clonal seedlings with mycelium of ectomycorrhizal impregnated in alginate gel on the growth of seedlings in the nursery and after planting in the field. First experiment was conducted in a randomized block in a factorial 2 x 5, with eucalyptus clones GG100 and GG680 inoculated with Pisolithus microcarpus, Hysterangium gardneri and Scleroderma areolatum and grown in a substrate with reduction of phosphorus fertilization and controls non-inoculated with (Controle) and without (Comercial) reduction of phosphorus fertilization in the nursery. In the second experiment, seedlings produced in the previous experiment were planted in the field to assess growth and colonization for one year. The seedling survival was not influenced by inoculation or by the reduction of phosphorus fertilization. At 120 days and in general for the two clones, height, diameter, dry weight of shoots, total dry matter and frequency of maximum grades for formation of clod of the roots of seedlings inoculated with P. microcarpus were greater than those of the Controle, and equals to the Comercial. The percentage of colonized tips roots were low for all fungi and not associated with the growth promotion. The inoculation or reduction of phosphorus fertilization only influenced the levels of Ca...

Promoção do crescimento e da nutrição de mudas clonais de Eucalyptus urophylla por fungos ectomicorrízicos em viveiro comercial.; Promotion of growing and nutrition of clonal Eucalyptus urophylla seedling by ectomycorrhizal fungi in commercial plant nursery.

Gandini, Andrezza Mara Martins
Fonte: Universidade Federal dos Vales do Jequitinhonha e Mucuri Publicador: Universidade Federal dos Vales do Jequitinhonha e Mucuri
Tipo: Dissertação de Mestrado
POR
Relevância na Pesquisa
46.97%
A utilização dos fungos ectomicorrízicos (FEM) em plantios comerciais de eucalipto melhora a adaptação das mudas no campo e permite um uso mais eficiente de fertilizantes. A eficiência de doses de inoculante de FEM em promover o crescimento, a absorção de nutrientes, a colonização ectomicorrízica e a qualidade de mudas clonais de Eucalyptus urophylla foi avaliada em condições de viveiro comercial. O experimento foi realizado em delineamento inteiramente casualizado em esquema fatorial 4 x 4, com quatro doses de inoculante composto de micélio vegetativo incluso em gel de alginato de cálcio (0, 5, 10 e 15 cápsulas) dos FEM Amanita muscaria isolado UFSC-Am161, Elaphomyces anthracinus (Cenococcum geophilum) isolado Amance, Pisolithus microcarpus isolado ITA-06 e Scleroderma areolatum isolado UFSC-Sc129, mais um controle não inoculado com 100 % da adubação de substrato, com quatro repetições. Os FEM, em geral, promoveram maior diâmetro do coleto, altura da parte aérea, massa seca da parte aérea, colonização ectomicorrízica, teores e conteúdos foliares de N, P e K nas mudas clonais de eucalipto. O melhor crescimento e colonização foram observados na maior dose de inoculante e os maiores teores e conteúdo de P...

Ectomycorrhizal Fungi Facilitate Competitive Interactions Between Tree Taxa: Host Preference, Seedling Recruitment, and Forest Succession

Williams, Gwendolyn Clare
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2014
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The mycorrhizal mutualism is one of the earliest and most influential of all terrestrial symbioses. As the primary method used by most plants to acquire nutrients from the soil, mycorrhizal fungi help to shape the structure and composition of many ecosystems. Ectomycorrhizal (EM) fungi play an especially significant role because most EM fungi prefer a limited number of host taxa, and EM plant species likewise associate with only a fraction of the available EM fungi. This host preference issue, combined with the high diversity of EM fungi in forest ecosystems, complicates interspecies competition both among fungi and among plants, because these plant and fungal communities interact.

Despite recent attempts at documenting mycorrhizal fungi in the context of ecological succession, many questions remain about the underlying causal relationships among EM fungi, soil conditions, and plant community assembly. The succession of mycorrhizal fungi often mirrors the succession of plants, and ectomycorrhizal (EM) community composition may affect the outcome of competition among trees during succession. In a pine-oak seral system, we tested the ability of Pinus taeda and Quercus alba seedlings to associate with EM fungi when planted under both conspecific and heterospecific adults. We found that EM communities under pine and oak canopy were distinct regardless of seedling identity...