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Prendergast-Miller, Miranda T. "The role of ectomycorrhizal fungi in denitrification." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=56282.
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Tajuddin, Rosnida Binti. "Nutrient transport in ectomycorrhiza." Thesis, University of Aberdeen, 2013. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=210785.
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Ectomycorrhizal (ECM) fungi form mutualistic symbioses with trees in boreal and north temperate forests and have key roles in regulating biogeochemical cycles. The extensive mycelium produced by many ECM fungi enables resources to be transported over large distances. Some ECM fungi are considered to be specialists and have a restricted range of host plant species whilst others are considered generalists and can form mycorrhizas with a number of species. Little is currently known about the reasons why specialist and generalist mutualists have evolved and so this project aims to investigate the basis for these different strategies. The resource stoichiometry between plant and fungal partners was predicted to be a key factor: specialist fungi may be more efficient in obtaining nutrients from litter and transporting these rapidly to host plants and in return may receive larger amounts of plant photosynthate. Here, stable and radioisotopes were used to trace and quantify transfer of carbon and phosphorus, and fine-scale spatial-temporal analysis of amino acid transportation between host plants and fungi. The photon-counting scintillation imaging (PCSI) was used to show the amino acid was transported long-distance by ECM fungi intact and that the transportation was highly directional but the speed of transfer varies between species of ECM. The transportation of amino acid and phosphorus from generalist fungus to the host plant was rapid compared to the specialist fungus.
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Brearley, Francis Q. "The role of ectomycorrhizas in the regeneration of dipterocarp seedlings." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.422176.
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Izumi, Hironari. "The diversity of bacteria in ectomycorrhizas and other tissues of trees." Thesis, University of Aberdeen, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.424936.
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Diversity of bacteria inside the some ectomycorrhizas have been studied. To this end, isolation method using surface-sterilisation with chemical reagents was developed. The isolated bacteria from ectomycorrhizas of Suillus and Russula include Pseudomonas, Bacillus and Paenibacillus with other genera that have not been isolated from ectomycorrhizas. The isolated bacteria through cultivation include the genera of Pseudomonas, Bacillus and Acinetobacter while cultivation-independent methods detect significant amount of plant plastid-originated sequences. Cultivation-dependent and cultivation-independent methods including DNA and RNA based molecular methods were applied to investigate to study bacteria inside ectomycorrhizas colonised Corsican pine growing different nutrient status. These two methods gave rise to different bacterial species associated with ectomycorrhizas and, in particular, genus Pseudomonas was identified as metabolically active populations by RNA-based molecular methods. Possible functional roles of the bacteria associated with ectomycorrhizas were examined by detecting nitrogenase gene (nifH). While nif H DNA was detected in all the samples its expression was confirmed in only three samples collected from the nutrient deficient stand. NifH occurrence and their activity show that contribution of biological nitrogen fixation may not be significant in the field conditions studied here. The bacteria associated with ectomycorrhizas were studied in exotic environment by looking at pine plantations in south east Queensland, Australia. The study shows that there may be similar kind of bacteria in exotic pine plantations compared to pine forest in Scotland. Therefore it is possible that the bacteria may move around the globe by accompanying with the host plants although this is not fully appreciated yet.
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Saunders, Eleanor Margaret. "The effect of mineral nitrogen on ectomycorrhizas with special reference to nitrogen deposition." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299547.
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Moyersoen, Bernard. "Co-occurence of ectomycorrhizas and arbuscular mycorrhizas in tropical rainforests : extent and significance." Thesis, University of York, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387578.
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Burgess, Treena. "Changes in protein biosynthesis associated with the development of Pisolithus-Eucalyptus grandis ectomycorrhizas." Thesis, Burgess, Treena ORCID: 0000-0002-7962-219X (1995) Changes in protein biosynthesis associated with the development of Pisolithus-Eucalyptus grandis ectomycorrhizas. PhD thesis, Murdoch University, 1995. https://researchrepository.murdoch.edu.au/id/eprint/25142/.
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Ectomycorrhizas are formed as the outcome of a symbiotic association between the fine roots of the majority of temperate forest tree species and numerous species of higher order fungi. The development of an ectomycorrhizal structure involves the attraction of the fungal symbiont to the root surface, its recognition and attachment, the subsequent proliferation of the hyphre on the root surface and the formation of the Hartig net between root cells. Ectomycorrhizal formation is a complex and dynamic process during which the morphology, physiology and biochemistry of the individual symbionts alter, culminating in the formation of the symbiotic structure. These phenotypic changes are pre-empted by an alteration in gene expression and protein biosynthesis of both symbionts. However, whilst this is a recognised principle, the critical stages of control, at which compatibility, aggressiveness and specificity are determined, are unknown. These issue scan be approached by exploiting the natural variation that exists within a fungal population. This thesis focuses on Pisolithus-Eucalyptus ectomycorrhizas as a model system and exploits intraspecific variation in Pisolithus to investigate changes in protein biosynthesis during ectomycorrhizal formation. The Pisolithus-Eucalyptus symbiosis is well suited to such a study as both symbionts grow rapidly in vitro and ectomycorrhizas are produced within days.
The taxonomy of the genus Pisolithus is currently unclear. Thus, before selecting isolates for developmental studies it was necessary to classify available isolates. One hundred isolates of Pisolithus, predominantly collected within Australia, were assessed and found to vary greatly in basidiocarp and basidiospore morphology and culture characteristics. These isolates were also classified according to separation of soluble polypeptides using one dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (lD-SDS-PAGE). This technique resulted in groups that corresponded to host species and geographic location. Subsequently, 20 Pisolithus isolates, covering a range of hosts, basidiocarp types and geographic locations were compared on their ability to form mycorrhiza in vitro with Eucalyptus grandis and to stimulate seedling growth in vivo. There was a large variation between isolates in the rate of mycorrhizal development ranging from incompatible to very aggressive. In vivo observations of growth stimulation of E. grandis, under conditions of limiting phosphorus, were positively correlated to the extent of mycorrhizal development in vitro.
Isolates of differing aggressiveness were then selected to examine early changes in protein biosynthesis during ectomycorrhizal development. This study was facilitated by the development of a simple and reproducible in vitro system to rapidly produce eucalypt ectomycorrhizas. The seedlings germinated and grew in the presence of fungal exudates resulting in a two fold increase in the emergence of lateral root tips compared to seedlings germinated separately and challenged later. In addition, the lateral root tips of inoculated seedlings emerged closer to the primary root apex. The differentiation of ectomycorrhizas was followed by examining lateral tips basipetally along a single primary root.
Protein biosynthesis was examined over a time sequence (pre-contact to 8 days after contact) using 2D-PAGE of proteins labelled by in vivo incorporation of [35S] radiolabelled amino acids. For compatible isolates, ectomycorrhizal development was accompanied by an apparent loss of plant polypeptides, differential accumulation of some fungal polypeptides and the emergence of symbiosis-specific polypeptides. The accumulation of fungal polypeptides was more rapid than expected from the fungal biomass. Protein biosynthesis with the incompatible isolate was unaltered and roots sampled at 8 days had the same 2D-PAGE profile as an artificial mix of protein from non-inoculated seedlings and fungal hyphre. The rate of accumulation of fungal proteins was dependent upon the aggressiveness of the isolate.
In order to relate the changes in protein biosynthesis more closely to the developmental stage of the ectomycorrhizas, protein biosynthesis was related to primary root age by dividing the primary root into 10 mm segments. As the age of the primary root segment increased, so did the age of ectomycorrhizallateral tips which had emerged on that segment. The youngest segment of the primary root, which included the primary root apex, produced a biosynthesis profile very similar to that of non-inoculated roots. By contrast, the older segments of the primary root, produced a biosynthesis profile very similar to that of the free-living hyphre. Thus, the changes in protein biosynthesis along the primary root were similar to those observed during the time sequence except that abundant plant polypeptides were restricted to the youngest segment. It was concluded that, the domination of the fungal partner in the biosynthesis of developing ectomycorrhizas is probably a consequence of stimulated fungal growth and a corresponding decrease in plant meristematic activity.
In both experiments, the major changes in protein biosynthesis were observed in a group of acid polypeptides, of fungal origin, found between 29 and 37 kDa which constituted about 50% of protein biosynthesis in fully developed ectornycorrhizas. These polypeptides f1rst appeared at contact and increased during ectomycorrhizal formation. Fractionation of total soluble protein into cell wall, membrane, soluble cytoplasmic and secreted fractions, revealed that some of these acid polypeptides were bound to the cell membrane whilst others are associated with the cell wall or secreted into the external medium of free-living cultures. Some isomers which were stimulated in ectomycorrhizas were also present in free-living hyphre grown at high glucose levels, suggesting that the expression of these polypeptides could be constitutive in response to increased carbohydrate activity at the root surface. However, other isomers were more highly expressed in the ectomycorrhizas. These polypeptides are potentially involved in recognition, attachment and the formation of the extracellular matrix of the mantle. The role of this polypeptide group was less significant in mature ectomycorrhizas, further supporting their role in the formation of the symbiosis rather than in its functioning.
In conclusion, fungal protein biosynthesis is dominant during the early stages of ectomycorrhizal development. Secreted proteins, either bound to the cell wall or free, play an important role in determining success of symbiosis, and the rapid stimulation of these fungal proteins is indicative of a compatible association. To pinpoint the exact stage of induction of these proteins, individual inoculated tips ranging in development from pre-contact to maturity must be examined. This can be facilitated by the purification of specific proteins and the raising of antibodies to be used in immunolocalization or to probe for corresponding eDNA's.
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Mursidawati, Sofi. "Mycorrhizal association, propagation and conservation of the myco-heterotrophic orchid Rhizanthella gardneri." University of Western Australia. School of Earth and Geographical Sciences, 2004. http://theses.library.uwa.edu.au/adt-WU2004.0014.
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Many orchids require mycorrhizal symbioses with fungi for their development and survival. Rhizanthella gardneri the Western Australian underground orchid is associated with the companion plant Melaleuca uncinata and its ectomycorrhizal fungus symbiont. Much less is known about the habitat requirements of its sister species, R. slateri, which occurs in Eastern Australia. The absence of chlorophyll from Rhizanthella gardneri and R. slateri results in total dependency on associations with fungal symbionts. Many ecological and biological aspects of these fascinating orchids remained poorly known, including the identity of the fungal associates and the nature of their tripartite associations with Rhizanthella and Melaleuca. Extremely high specificity of these mycorrhizal relationships is likely to be the most important factor explaining the highly specific habitat requirements of underground orchids. The purpose of this study was to conduct further investigations of the role of the mycorrhizal associations of Australian underground orchids by identifying the fungi involved in these associations, optimising their growth in sterile culture and devising efficient means for synthesising their tripartite associations with R. gardneri and M. uncinata. In total, 16 isolates of fungi were successfully obtained from the two underground orchids and used in a series of experiments to understand both the nature of the fungi and their relationship with orchids. The identity of these fungi was established by using conventional morphological and molecular methods. Cultural and morphological studies revealed that all isolates from R. gardneri and R. slateri were binucleate rhizoctonias with affinities to members of the genus Ceratobasidium. However, the teleomorph state that was observed from the R. slateri symbiont during this study more closely resembled a Thanatephorus species. Further identification using ITS sequence comparisons confirmed that mycorrhizal fungi of Rhizanthella belonged to the Rhizoctonia alliance with relatives that include Thanatephorus, Ceratobasidium, or Rhizoctonia from other continents with over 90% similarity. Most of these related fungi are known as plant pathogens, but some were orchid mycorrhizal fungi. However, the isolates from the two underground orchids were most closely related to each other and formed a discrete group relative to other known members of the Rhizoctonia alliance. Sterile culture experiments determined culture media preferences for mycorrhizal fungi from Rhizanthella and other orchids. A fully defined sterile culture medium designed to more closely resemble Australian soil conditions was formulated. This new medium was compared to undefined media containing oats or yeast extract and recommendations for growth of these fungi are provided. The undefined media based on oats provided the best growth of most fungi, but the new Australian soil media was also effective at growing most orchid mycorrhizal fungi and this fully defined media was less prone to contamination and should provide more reproducible results. A comparison of three methods for inoculating M. uncinata with the underground orchid fungi resulted in the production and characterisation of ectomycorrhizal roots and hyphae formed by fungi isolated from R. gardneri and R. slateri. These underground orchid fungi could easily be distinguished from other mycorrhizal fungi (caused by airborne contamination) by the characteristic appearance of these roots and hyphae. A new system for growing and observing tripartite mycorrhizal associations was devised using pots with side viewing windows and the use of transparent seed packets to contain Rhizanthella seeds. This method allowed all the stages of seed germination to be observed in the glasshouse, culminating in the production of underground orchid rhizomes. Seed germination was only successful when seed was placed directly over active M. uncinata ectomycorrhizas confirmed to belong to the correct fungus by microscopic observations through the side of window pots. The importance of these new scientific discoveries concerning the biology and ecology of the underground orchids and their associated fungi for the recovery of these critically endangered orchids are discussed.
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Chuyong, George Bindeh. "Nutrient cycling in ectomycorrhizal legume-dominated forest in Korup National Park, Cameroon." Thesis, University of Stirling, 1994. http://hdl.handle.net/1893/2640.
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Patterns and rates of nutrient input to the forest floor in litterfall, throughfall and stemflow were investigated in plots of low and high abundance of ectomycorrhizal species. The aim of the study was to examine the comparative advantage of the ectomycorrhizal species in nutrient acquisition and cycling on nutrient-poor soils in Korup. Litterfall was similar in both forests with annual estimates of 9.00 and 8.33 t ha-1 yr-1 for LEM and HEM forests respectively. Litterfall distribution followed a mono-modal pattern, with peaks in the dry season in both forests and the HEM forest showing stronger seasonality. The concentrations N, K and Ca in total litterfall were higher in the LEM forest while those of P and Mg were higher in the HEM forest. The bulk of nutrients in total litterfall was in leaf litter with the reproductive fractions having the highest concentrations of nutrients. Ectomycorrhizal species showed lesser internal redistribution of nutrients than non-ectomycorrhizal species which resulted in their higher leaf litter concentrations of nutrients. Breakdown of litter was relatively faster in the LEM forest with an annual decomposition constant (KL) of 3.21 compared to 2.43 for the HEM forest. The reproductive fractions had relatively higher annual decomposition constants of 8.20 and 4.27 in the LEM and HEM forests respectively compared to the other fractions. The overall element mobility in decomposing leaf litter was similar in both forests and in the following order: Mg>K>Ca>P>N. Mineralization of N, P and K in the decomposing leaf litter was similar in both forests and higher in the HEM forest for Mg and Ca. Throughfall was 96.6% and 92.4%, and stemflow 1.5% and 2.2%, of gross rainfall in LEM and HEM forests respectively. Considerable amounts of Ca, Mg and P were brought to the forest canopy in gross rainfall (24-45% of total input through this route) with higher amounts of K and Ca leached from plant parts by the rainwater. The amounts of P, K and Ca in stemflow and throughfall were of the same magnitude in both forests with the enhancement of N slightly higher in the LEM forest and Mg in the HEM forest.
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Antunes, L?dia Alves. "Toler?ncia de isolados de Pisolithus sp. a cupinicidas." UFVJM, 2016. http://acervo.ufvjm.edu.br/jspui/handle/1/1321.
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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)
A imers?o de mudas de eucalipto em solu??es de cupinicidas antes do plantio pode influenciar o desempenho de programas de inocula??o com fungos ectomicorr?zicos (FEM) em viveiros comerciais, pois estes inseticidas podem interferir na simbiose. O objetivo deste trabalho foi avaliar a toler?ncia de isolados de Pisolithus sp. aos cupinicidas thiamethoxam, imidacloprid e fipronil. Discos de 5 mm de meio de cultura com mic?lio dos isolados D5, D17, D95, D216, D29, D10, D15, C9C, C16 e C13 de Pisolithus sp. foram pr?-imersos em solu??es com 3 g L-1 de thiamethoxam, 7,5 g L-1 imidacloprid e 7,5 g L-1 de fipronil. Ap?s este procedimento foram colocados para crescer por 10 dias em meio de cultura Melin-Norkrans modificado (MNM). Os cupinicidas foram avaliados em experimentos independentes. Em outra s?rie de experimentos, discos 5 mm dos isolados D5, D10 e D216 foram colocados para crescer por 20 dias em meio de cultura contendo 0 (controle), 0,4; 0,8 e 1,6 g L-1 de thiamethoxam, 3; 6 e 12 g L-1 de imidacloprid e 0 (controle); 3; 6 e 12 g L-1 de fipronil. O efeito dos cupinicidas sobre fungos ectomicorr?zicos foi dependente do isolado, do princ?pio ativo, do tempo de exposi??o e da concentra??o do cupinicida. Os isolados mais tolerantes a pr?-imers?o do mic?lio nos cupinicidas foram o C9C para o thiamethoxam, o D15 para o imidacloprid e o D10 para o fipronil. Os tr?s cupinicidas foram t?xicos aos isolados de Pisolithus sp. quando estes foram adicionados ao meio de cultura. Em geral, thiamethoxam foi o menos t?xico para os isolados de Pisolithus sp..
Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016.
The immersion eucalyptus seedlings in termiticides solutions before planting can influence the performance of inoculation programs with ectomycorrhizal fungi (EMF) in commercial nurseries, as these insecticides can interfere with symbiosis. Study aimed at assessing the tolerance of Pisolithus sp. isolates to the termiticides thiamethoxam, imidacloprid and fipronil. 5-mm-diameter circular sections of culture medium with the mycelial isolates D5, D17, D95, D216, D29, D10, D15, C9C, C16 and C13 Pisolithus sp. were pre-dipped in solutions with 3 g L-1 of thiamethoxam, 7.5 g L-1, 7.5 g L-1 imidacloprid and fipronil. Next were placed let grow for 10 days through the cultured on modified Melin-Norkrans (MNM) solid medium. The termiticides were through independent testing. In another series of experiments, 5-mm-diameter circular sections of culture medium with the mycelial isolates D5, D10 and D216 were placed let grow for 20 days in solid medium containing 0 (control) 0.4; 0.8 and 1.6 g L-1 thiamethoxam 3; 6; 12 g L-1 of imidacloprid and 0 (control); 3; 6; 12 g L-1 fipronil. The effect of termiticides on ectomycorrhizal fungi was dependent of isolated, of active ingredient, of exposure time and concentration of termiticide. The most tolerant isolates the pre-soaking the mycelium in termiticides were C9C for thiamethoxam, the D15 for imidacloprid and D10 for fipronil. The three termiticides were toxic to isolates Pisolithus sp. when they were added to the culture medium. In general, thiamethoxam was less toxic to isolates Pisolithus sp.
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Wyss, Lozano Hoyos Tania. "Pinus elliottii var. densa Seedling Performance Reflects Ectomycorrhizas, Soil Nutrient Availability and Root Competition." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/496.
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Ectomycorrhizas generally improve seedling mineral nutrition and growth, so I hypothesized that decline of the Florida native pine variety Pinus elliottii var. densa Little & Dorman is related to deficiency of appropriate ectomycorrhizal (ECM) fungi in the pine's native flatwoods. At Archbold Biological Station I examined how quickly ECM fungi colonize P. elliottii var. densa seedlings and I compared the effect of local absence versus presence of adult pines on ECM colonization and pine seedling performance. Under controlled greenhouse conditions, I investigated how a wide range of ECM colonization and spread of extraradical mycelium throughout a large volume of relatively infertile, flatwoods soil enhance the mineral nutrition and growth of pine seedlings. In a field bioassay, I transplanted two-month-old pine seedlings to three flatwoods sites with low (4 pines/400 square m), medium (9 pines/400 square m), and high (19 pines/400 square m) adult pine densities. I subsequently excavated seedlings every two weeks for four-and-a-half months and determined their ECM colonization, response to shade, and response to surrounding grass density. Across all sites, pine seedlings in high shade had a higher mean chlorophyll concentration and lower stem dry weight than in full sun. Competition with grass reduced seedling survival and stem dry weight. Initial colonization was rapid and not different among sites, with 5.4 % of roots colonized 15 days after transplant. Pine seedlings had midpoint means of 29.5 %, 18.1 % and 21.3 % ECM root tips in low, medium and high adult pine density sites, respectively, suggesting that pine seedlings establishing in flatwoods encounter sufficient ECM fungi to support their growth, regardless of adult pine density. In a field experiment, I determined in the presence versus absence of adult pines if pine seedlings had higher ECM colonization and consequent improved survival, mineral nutrition, and growth. Within and beyond pine stands, I transplanted seedlings into intact or drilled, hyphae in-growth pipes buried in the ground. I placed autoclaved or fresh ECM root inoculum in two sets of intact pipes, and autoclaved inoculum in drilled pipes into which mycorrhizal hyphae could extend from the surrounding vegetation. Seven-and-a-half months after transplant, ECM hyphae had penetrated the drilled pipes and colonized pine seedlings, but roots from the surrounding vegetation also penetrated pipes. Extraneous roots reduced the survival of seedlings both within and beyond pine stands, but extraneous roots reduced seedling growth only beyond pine stands. Because percentage ECM root tips was higher in the presence (53 %) than in the absence (38.8%) of adult pines, pine stands might benefit the competitive ability of seedlings by increased ECM colonization and possibly by common mycorrhizal networks connecting seedlings to adults. Because beneficial effects of ECM in the field were small, I also examined ECM effects on pine seedlings in a greenhouse experiment. I manipulated ECM fungus colonization and the volume of flatwoods soil to which extraradical mycelium had access. In a small volume of soil (220 mL), fresh ECM root inoculum promoted the mycorrhizal colonization of seedlings versus those receiving autoclaved roots, but seedling growth and uptake of Mg, Ca, and Zn was lower with fresh than with autoclaved root inoculum. Growth and mineral nutrient uptake likely was enhanced by a pulse of nutrients from autoclaved roots, but for inoculated plants may have been reduced because of nutrient retention by saprotrophic microorganisms degrading fresh ECM roots and because of mineral nutrient retention by ECM fungi. Ectomycorrhizal seedlings with extraradical mycelium access to a large soil volume had higher mean chlorophyll concentration than those in a small soil volume. Weekly disturbance of the extraradical mycelium, however, reduced foliar contents of Mn, K, P, N, and Zn by one-third to one-half, and reduced needle dry weight of seedlings by one-third, demonstrating the importance of extraradical mycelium accessing a large volume of soil when it is nutrient-poor. My research demonstrates that ECM fungi are widespread in flatwoods and rapidly colonize pine seedlings. ECM fungus inocula are greater in the presence than in the absence of adult pines, and ECM or seedlings' connections to a common mycorrhizal network improve seedlings' belowground competitive ability. ECM especially enhance seedling mineral nutrition and growth when undisturbed, extraradical mycelium extends throughout a large volume of soil. Populations of Pinus elliottii var. densa might best regenerate in flatwoods if seedlings recruit near adult pines and where there is little competition for light, water, and mineral nutrients.
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Sirajuddin, Ayesha Tasneem. "Impact of atmospheric nitrogen pollution on belowground mycorrhizal fungal community structure and composition in the San Bernardino Mountains." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=83&did=1874479991&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270233151&clientId=48051.
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Hasselquist, Niles Jacob. "Mycorrhizae, water, and a changing climate how do trees survive in a seasonally dry tropical forest? /." Diss., UC access only, 2009. http://proquest.umi.com/pqdweb?index=105&did=1871852251&SrchMode=1&sid=1&Fmt=7&retrieveGroup=0&VType=PQD&VInst=PROD&RQT=309&VName=PQD&TS=1270484435&clientId=48051.
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Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Includes bibliographical references (leaves ). Issued in print and online. Available via ProQuest Digital Dissertations.
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Siababa-Aggangan, Nelly. "Soil factors affecting the formation and function of Pisolithus-Eucalyptus urophylla ectomycorrhizas in acid soils in the Philippines." Thesis, Siababa-Aggangan, Nelly (1996) Soil factors affecting the formation and function of Pisolithus-Eucalyptus urophylla ectomycorrhizas in acid soils in the Philippines. PhD thesis, Murdoch University, 1996. https://researchrepository.murdoch.edu.au/id/eprint/51909/.
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With the present dwindling area of forest cover in the Philippines, the government is faced with reforestation of the vast marginal grasslands to meet the ever increasing demand for raw materials for the pulp and paper industries. Success in reforestation is low due to the inherent infertility status and acidic nature of Philippine soils. In addition, some reforestation sites have high concentrations of heavy metals such as chromium (Cr) and nickel (Ni) contributing to low survival and poor growth of trees in plantations. Eucalypts are favoured reforestation species because of their fast growth, multiple uses and adaptability to a wide range of sites. Survival of eucalypts in inhospitable sites may be due to their mycorrhizal associations. Mycorrhizas, symbiotic associations between plant roots and higher fungi, can increase tree growth in adverse sites mainly through increased nutrient uptake particularly phosphorus. Pisolithus is an ectomycorrhizal fungus that has been identified as a potential growth promoter for eucalypts in plantations in soils deficient in P and with acidic pH. Initial field trials in the Philipines have shown that Pisolithus can increase growth of pines and eucalypts and the technology has been adapted in some nurseries.
Formation of ectomycorrhizas and the survival of the symbiosis depend on three main components: the host plant, the soil and the fungus. This thesis investigates the effect of key soil factors (pH, soil microorganisms and heavy metals) that affect the formation of Pisolithus ectomycorrhizas on the roots of Eucalyptus urophylla S. T. Blake seedlings on acid soils in the Philippines. In chapters relating to soil pH (Chapter 2), soil microbes (Chapters 3 and 4) and field trials (Chapter 7), Pisolithus isolates collected from under eucalypts in Western Australia and in the Philippines were used while an isolate from under eucalypts growing in a nickel mining residue in New Caledonia was included in chapters relating to heavy metals (Chapters 5 and 6).
Experiments were conducted in the laboratory, glasshouse, nursery and in the Field in the Philippines as follows:
a). A glasshouse experiment was established to determine the effect of liming (with CaCO3) an acidic (pH 4.6, 0.005 M CaCl2) non-sterile sandy loam from Western Australia (Bodallin) on the formation of ectomycorrhizas by nine ectomycorrhizal fungi (seven Pisolithus spp., a Laccaria laccata and a Scleroderma cepa) on E. urophylla seedlings. Soil pH did not affect mycorrhizal formation by the different ectomycorrhizal fungi. However, percent mycorrhizal root tips colonized by the different ectomycorrhizal fungi varied greatly. A Pisolithus from Western Australia colonized more roots and promoted the highest dry weight at pH 4.6 than the other ectomycorrhizal fungi studied. Generally, Pisolithus spp. stimulated seedling growth more than L. laccata while S. cepa was ineffective at all pH levels.
b). A nursery experiment was conducted in the Philippines to examine the effect of soil microbes present in soils collected from three field sites (Pangasinan, Bukidnon and Surigao) in the Philippines on the formation of ectomycorrhizas by isolates of Pisolithus from Western Australia (H445) and from the Philippines (H615) on￡. urophylla seedlings. Soils were either fumigated with methyl bromide, reinfested (1% unfumigated soil added into 99% fumigated field soils, w/w) or unfumigated. The percentage of mycorrhizal root tips colonized by the Western Australian isolate was markedly affected by biological factors in unfumigated soil; highest infection was observed in reinfested soils while for the Philippine isolate it was highest in unfumigated soils. Seedlings transplanted into Bukidnon soil were affected by heavy metals resulting in very poor growth, toxicity symptoms and plant death.
A follow-up experiment on the effect of soil microbes on the formation of ectomycorrhizas by an Australian and a Philippine Pisolithus isolates was conducted in a glasshouse in Western Australia. Soils collected from Western Australia (Bodallin) and from two field sites in the Philippines (Pangasinan and Surigao) were either autoclaved or left non-sterile and were added (1% w/w) into pasteurized yellow sand. The Australian Pisolithus was more effective in colonizing root tips of E. urophylla with added nonsterile Pangasinan and Surigao soils and in promoting plant dry weight than the Philippine isolate. Percentage of root tips colonized by the two isolates in unamended pasteurized yellow sand was similar. However, the addition of sterile Bodaliin, Pangasinan and Surigao soils decreased the percentage of lateral root tips colonized by the Australian Pisolithus by 28%, 40% and 43%, respectively. Percentages of mycorrhizal root tips were higher with added non-sterile Pangasinan (55%) and Surigao (60%) soils than those of the Philippine isolate (45% in Pangasinan and 15% in Surigao). The addition of sterile or non-sterile Bodaliin soil decreased the percentage of root tips colonized by either isolates.
c). The effect of chromium and nickel cations on the rate of mycelial growth and dry weight of three isolates of Pisolithus and on the formation of ectomycorrhizas on E. urophylla were investigated in vitro. Nickel was more toxic to fungal growth and ectomycorrhiza formation than Cr. The fungi differed in their tolerance to the heavy metals and isolates from the Philippines and New Caledonia grew at higher Ni levels than the Australian isolate. Media concentrations of 50 mg Cr L-1 and 4 mg Ni L-1 reduced the percentage of root tips colonized by the fungi.
d). The effect of Ni on the formation of ectomycorrhizas by three isolates of Pisolithus on E. urophylla was studied in two separate experiments in a glasshouse. Nickel rates in one experiment were: 0, 1.5 and 3 mg Ni kg-1 pasteurized yellow sand while in the other experiment, Ni rates were: 0, 6, 12, 24 and 48 mg Ni kg-1 sand. The Pisolithus isolate collected from a Ni contaminated site in New Caledonia was more tolerant to Ni than the other two isolates. In both experiments, the New Caledonian isolate produced the highest percentage of mycorrhizal root tips (82% to 87%) and root colonization was not affected by the addition of 12 mg Ni kg-1 sand. Plant dry weight of seedlings inoculated with this isolate was not affected by the addition of 6 mg Ni kg-1 sand but it was reduced with the addition of 12 mg Ni kg-1. Inoculation with Pisolithus did not prevent the uptake of Ni into the shoots but Ni toxicity was minimized through a dilution effect brought about by the increase in plant biomass.
e). Field trials were established in three sites (Pangasinan, Luzon; Bukidnon and Surigao, Mindanao) in the Philippines to determine the effectiveness of isolates of Pisolithus from Western Australia and from the Philippines in promoting early growth (26 months) of E. urophylla trees. After 2 years, root infection levels in Pangasinan by the two isolates of Pisolithus were higher (30% and 36%, respectively) than in Bukidnon (15% and 5%) and in Surigao (5% and 2%). The Australian isolate generally promoted greater wood volume (37% at 26 months in Pangasinan and by 237% at 18 months in Surigao, relative to the uninoculated treatment) than the Philippine isolate (16% in Pangasinan and by 153% in Surigao). The two isolates promoted similar wood volume (63% and 69%) of trees 26 months after outplanting in Bukidnon.
Pending further research with a wider range of fungal isolates, it is concluded that the Australian Pisolithus isolate can be used to inoculate eucalypts for reforestation on problem soils in the Philippines similar to those in Pangasinan, Bukidnon and in Surigao. Pisolithus isolates collected from under eucalypts growing in heavy metal contaminated sites, including the New Caledonian isolate used in this study can be further tested in Bukidnon and other areas in the Philippines with soils of ultramafic origin. Future work should include: i) the introduction of a wider range of ectomycorrhizal fungi from Australia and comparison with endemic strains in a range of soils in order to identify those beneficial ectomycorrhizal fungi that can survive and persist for a long time in the field under a wide range of climatic conditions, ii) isolation and identification of soil microbes present in different soils which are beneficial to ectomycorrhizal symbiosis, iii) monitoring of responses of eucalypts to inoculation over a longer period in the field and iv) the development of markers for easier monitoring of persistence of introduced fungi in the field. Thus, the work described in this thesis will act as a firm foundation for the future development of eucalypt plantation forestry in the Philippines.
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Baldwin, Quentin F. "Effects of prescribed burning upon mycorrhizal fungal diversity inhabiting the roots of two and a half-year old black spruce (Picea mariana) : molecular characterization of ectomycorrhizal fungi via PCR/RFLP analysis /." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ42348.pdf.
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Castellano, Steven Michael. "Effect of Alliaria petiolata invasion on ectomycorrhizal colonization of Quercus rubra." Oxford, Ohio : Miami University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=miami1217280009.
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Taylor, Andrew F. S. "The structure and dynamics of a community of Ectomycorrhizas in a Sitka spruce plantation with special reference to Tylospora fibrillosa (Burt.) donk." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU088729.
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Root tip demography of a 43 year old Sitka spruce stand was determined over a two year period. A total of 35,300 root tips were examined. A total of 14 mycorrhizal and 4 non-mycorrhizal root tip types were recognised. One mycorrhizal type, formed by Tylospora fibrillosa, made up 67% of the root tips examined, the rest each made up less than 5% of the population. The level of infection was high, with c. 94% of the root tips infected with mycorrhizal fungi. There were marked short term fluctuations in the numbers and relative abundance of some of the types, as well as longer term, unidirectional increases in the dominant type and decreases in the numbers and relative abundance of non-mycorrhizal root tips. The effect of the addition of carbon and nitrogen was examined. Carbon addition had very little effect on the mycorrhizal population as a whole. Nitrogen, on the other hand, had a very marked effect on several of the root tip types. The relative abundance and the numbers of Tylospora fibrillosa mycorrhizas were both reduced by the addition of nitrogen, whereas the relative abundance and numbers of non-mycorrhizal tips increased. A large gradient of weight of organic matter and moisture existed on the site and this was shown to strongly influence the spatial distribution of the root tip types. Russula ochroleuca mycorrhizas were shown to have a positive association with organic matter and moisture. The occurrence of E-type mycorrhizas was negatively correlated with the accumulation of organic matter, which supports the idea that these mycorrhizas are primarily associated with mineral soil. Finally, the population structure of T.fibrillosa was examined using somatic incompatibility (SI) to determine the clone size of the fungus on the site. No SI was found between any of the isolates, even when collected 20m apart. This could mean that either T.fibrillosa does not exhibit SI or that the clone from which the isolates were collected was larger than 20m across.
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Gonzalez, Jhon Alexander Zambrano. "Acúmulo de ácido oxálico e cristais de cálcio em ectomicorrizas de eucalipto." Universidade Federal de Viçosa, 2007. http://locus.ufv.br/handle/123456789/5382.
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Previous issue date: 2007-04-04This work aimed at evaluating the role of the ectomycorrhizal fungi in the uptake and storage of calcium in Eucalyptus sp., grown for 2.5 years, in a mountainous area in the region of Viçosa, MG. Abundant accumulation of oxalate crystals as grains or druses was observed in 73.7 % of the ectomycorrhizas and fine lateral roots studied. The conspicuous presence of CaOx was observed in 56.2% of the ectomycorrhizae and in 17.5% of the nonmycorrhizal lateral fine roots, evidencing the role of the ectomycorrhizal association in the storage of calcium in the roots of Eucalyptus sp. The highest mycorrhizal colonization was observed in the Slope area that presented limited availability of nutrients and high Al saturation. Oxalic acid concentrations decreased in the following order, in mg Kg -1: leaves, 162.3 > ectomycorrhizas, 118.2 > non-mycorrhizal fine lateral roots, 116.0. Oxalic acid concentrations in the soil were higher in ectomycorhizospheric soil with 91.8 mg Kg-1, followed by the rhizospheric soil, with 67.2 mg Kg-1, and, finally, by the non-rhizospheric soil with 38 mg Kg-1. In the ectomycorrhizas collected in the Top area, the higher concentrations of oxalic acid and P, 173.3 mg Kg-1 and 6.35 mg Kg-1, respectively, probably resulted from nutrient solubilization by the ectomycorrhizal fungi associated with the host plants. The larger fraction of the litter layer corresponded to that showing the most advanced level of decomposition, being composed of dark fragments of leaves and branches in direct contact with the soil. Generally, nutrient content in the forest litter, in ka ha-1, decreased as follows: Ca (32.4) > Mg (5.4) > K (4.2) > P (1.7). Ca content in the litter and its low concentration in the soil shows the importance of the litter layer as a Ca reservoir for eucalypts. The highest concentrations and contents of P in the litter were verified in the Top position, however, the activity of acid phosphatases of ectomycorrhizas did not differ among the topographical positions evaluated. Fruit bodies of Laccaria, Pisolithus, Scleroderma, and of an unidentified fungus were observed in the area under study. The examination of the most decomposed litter layer and of the interface soil-litter showed an intense colonization by eucalypt roots, with eight distinct ectomycorrhizal morphotypes, hyphae, rhizomorphs, and basidiomes This work demonstrate that ectomycorrhizal fungi participate in the cycling of the eucalypt forest litter and in the storage of Ca when associated to eucalypt roots.
Este trabalho teve como objetivo determinar o papel dos fungos ectomicorrízicos na absorção e armazenamento de Ca por plantas de Eucalyptus sp., cultivado por 2,5 anos em área com topografia típica em meia laranja de vertente côncavo-convexa da região de Viçosa, MG. Em 73,7 % das ectomicorrizas e raízes observadas, observou-se abundante acúmulo de cristais de oxalato de cálcio (CaOx) nas células do córtex radicular, na forma de drusas e grânulos. A presença conspícua de CaOx foi observada em 56,2% das ectomicorrizas e em 17,5% das raízes laterais finas não-colonizadas, evidenciando o papel das micorrízas no acúmulo de cálcio em Eucalyptus sp. As maiores percentagens de colonização micorrízica foram observadas na área de Encosta, que apresenta limitada disponibilidade de nutrientes e alta saturação por Al. As concentrações de ácidos orgânicos foram quantificadas em diversas frações, a saber, em mg kg-1: folhas (162,3) > ectomicorrizas (118,2) > raízes laterais finas não-colonizadas (116). Os teores de ácido oxálico foram maiores no solo ectomicorrizosférico (91,8 mg kg-1), seguido pelo solo rizosférico (67,2 mg kg-1) e, finalmente, pelo não-rizosférico (38 mg kg-1). Nas ectomicorrizas da área Topo, os teores mais elevados (p<0,05) de ácido oxálico e P, 173,3 e 6,35 mg kg-1, respectivamente, possivelmente resultaram da solubilização de nutrientes pelos fungos ectomicorrízicos associados. A fração que mais contribuiu para a massa de serapilheira foi a em avançado grau de decomposição, sendo constituída de fragmentos de folhas e galhos escuros em contato com o solo. Em geral, a ordem de acúmulo de nutrientes na serapilheira correspondeu a, em kg ha-1: Ca (32,4) > Mg (5,4) > K (4,2) > P (1,7). O conteúdo de Ca na serapilheira e a baixa concentração do elemento no solo revelam a importância da manta orgânica como reservatório de Ca para o eucalipto. A maior concentração e conteúdo de P na serapilheira foram verificados na posição Topo, no entanto, a atividade das fosfatases ácidas nas ectomicorrizas não diferiu entre as amostras das posições topográficas avaliadas. Observaram-se basidiocarpos de Laccaria, Pisolithus, Scleroderma e de fungo ectomicorrízico não-identificado. A existência de densa camada de raízes de eucalipto na fração mais decomposta da serapilheira e na interface desta com o solo revelou intensa colonização da manta orgânica por raízes de eucalipto, com a presença de oito morfotipos distintos de ectomicorrizas, além de hifas, rizomorfos e basidiocarpos. O trabalho demonstra que os fungos ectomicorrízicos participam na ciclagem da serapilheira e no armazenamento de cálcio quando associados a raízes de eucalipto.
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Hodge, Angela. "Chitinolytic activity of ectomycorrhizal symbionts." Thesis, University of Aberdeen, 1994. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU068305.
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Chitinolytic activities from Pinus sylvestris L., Eucalyptus pilularis Sm. and a number of basidiomycete, ascomycete and oomycete fungi were characterised using a fluorogenic assay based on 4-methylumbelliferyl glycosides of N-acetylglucosamine oligosaccharides. Fungal extracellular chitinolytic activities were induced in the presence of chitin, and subject to catabolite repression by glucose, except those from Armillaria ostoyae Romagn. Activities were not repressed by ammonium phosphate. Addition of chitin to medium containing glucose and ammonium phosphate enhanced the growth of several fungi (e.g. Heterobasidion annosum (Fr.) Karst, Boletinus cavipes (Opat.) Kalch br., Paxillus involutus (Batsch) Fr. and Trichoderma harzianum Rifai) but repressed growth of the non-chitinous fungus, Phytophthora cinnamomi Rands. 14C dilution indicated that a change in carbon allocation within fungal mycelium occurred in the presence of chitin. Constitutive endochitinase activities from both plants and fungi were inhibited by the specific chitinase inhibitor allosamidin, but this was generally ineffective against exochitinase. Only exochitinase from P. involutus was inhibited sufficiently to allow determination of an IC50 value of 270 nM. A synthetic analogue of N-acetylglucosamine, (2-acetamido-2-deoxy-D-glucopyranosylidene) amino phenylcarbamate (PUGNAC), inhibited chitinolytic activities. The effect varied with species and substrate used, but was generally most marked against exochitinase. PUGNAC was used in challenge studies to distinguish between host and fungal endochitinase activities in sterile microcosms containing tree seedlings. Unchallenged P. sylvestris roots produced little N-acetylglucosaminidase activity. When challenged by the pathogen, H.annosum, root N-acetylglucosaminidase activity increased significantly. There was no response by either P. sylvestris or E. pilularis roots to challenge by the pathogen, P. cinnamomi, or the ectomycorrhizal fungus, Pisolithus tinctorius (Pers.) Coker & Couch.
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Rosling, Anna. "Responses of ectomycorrhizal fungi to mineral substrates /." Uppsala : Dept. of Forest Mycology and Pathology, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s296.pdf.
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Pereira, Maíra de Freitas. "Avaliação da expressão dos genes que codificam a proteína RAS e o fator de elongação EF1α em ectomicorrizas de Scleroderma laeve e Eucalyptus grandis." Universidade Federal de Viçosa, 2011. http://locus.ufv.br/handle/123456789/5339.
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Previous issue date: 2011-07-18Conselho Nacional de Desenvolvimento Científico e Tecnológico
The ectomycorrhizal association is a mutualistic interaction between plant roots and soil fungi that causes morphophysiological changes in the plant root system. The nutritional benefits result from the capacity of the fungus to increase the uptake of mineral nutrients by the host plant in exchange for photoassimilates. For the ectomycorrhizal association between Scleroderma laeve and Eucalyptus grandis, there is no information on which genes are decisive for the symbiosis and how they relate to the formation of ectomycorrhizas. Transcripts of the genes ras and ef1α were dentified as differentially expressed in many symbiotic associations and are related to signal transduction pathways and protein synthesis, respectively. Thus, the objectives of this work were to establish the ectomycorrhizal association between S. laeve and E. grandis in vitro, to isolate partial sequences of the genes ras and ef1α of S. laeve, and to evaluate the functional expression of these genes during ectomycorrhizal formation. Our works demonstrates the ectomycorrhizal association between S. laeve and E. grandis in vitro for the first time. The typical structures of ectomycorrhizas, such as the mantle and the Hartig net, were observed. At three days of contact between S. laeve and E. grandis roots the beginning of mantle formation could be observed. At 15 days, the mantle was completely formed, the epidermal cells were elongated, and the Hartig net formation was in progress. At 30 days, the ectomycorrhizas presented all the typical morphological structures fully developed. To evaluate gene expression during the association, partial sequences of ras and ef1α were isolated and the transcripts evaluated at the pre-symbiotic phase and at 3, 15 and 30 days after physical contact of the fungus with the plant roots. The transcripts of the gene ef1α were expressed at all evaluated times. Transcripts of ras were only detected in the ectomycorrhizas after three, 15, and 30 days of contact. These results are fundamental for a better understanding of the ectomycorrhizal association between S. laeve and E. grandis and suggest that ras-mediated signal transduction pathways may be functional during the establishment of the symbiosis between the fungus and the host roots.
A associação ectomicorrízica é uma interação mutualista entre raízes de plantas e fungos do solo, resultando em mudanças morfofisiológicas do sistema radicular das plantas. Os benefícios nutricionais advêm da capacidade do fungo em aumentar a absorção de nutrientes minerais pelas plantas, recebendo em troca os fotoassimilados. Na associação entre Scleroderma laeve e Eucalyptus grandis ainda não se tem informações de quais genes são decisivos e estão relacionados a este processo. Transcritos dos genes ras e ef1α foram identificados durante a formação da simbiose e sendo diferencialmente expressos na associação ectomicorrízica, e estão relacionados a vias de transdução de sinal e atuando na síntese protéica, respectivamente. Assim, os objetivos deste trabalho foram estabelecer a associação ectomicorrízica in vitro entre S. laeve e E. grandis, isolar sequências parciais dos genes ras e ef1α do fungo ectomicorrízico S. laeve, e avaliar a expressão funcional destes genes durante as fases de formação das ectomicorrizas. Este trabalho comprova a associação in vitro entre S. laeve e E. grandis, sendo registrada pela primeira vez. As estruturas típicas das ectomicorrizas, como a formação do manto fúngico e da rede de Hartig foram observadas. Nos tempos avaliados, em três dias de contato já havia a formação do manto fúngico. Aos 15 dias, o manto fúngico estava completamente formado, as células da epiderme alongadas e a rede de Hartig, em formação. Aos 30 dias, as ectomicorrizas apresentavam todas as estruturas típicas desenvolvidas. Para avaliar a expressão dos genes durante a associação, sequências parciais dos genes ras e ef1α foram isolados, e os transcritos destes genes foram avaliados na fase pré-simbiótica e aos três, 15 e 30 dias após o contato físico. Os transcritos do gene ef1α foram expressos durante todos os tempos avaliados. Os transcritos do gene ras foram detectados nas ectomicorrizas após três, 15 e 30 dias. Estes resultados são fundamentais para uma melhor compreensão da associação ectomicorrízica entre S. laeve e E. grandis e sugerem que as vias de transdução de sinais mediada por ras podem ser funcionais durante o estabelecimento da simbiose entre os fungos e as raízes de plantas.
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Wilkinson, Anna. "The significance of genetic diversity for ectomycorrhizal fungal productivity and CO₂ efflux." Thesis, University of Aberdeen, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.600050.
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Ectomycorrhizal (EM) fungi play key functional roles in forest ecosystems; they are fundamental to the health and nutrition of their plant partners and they cycle vast amounts of photosynthetically fixed carbon (C) through the soil. They also form diverse belowground communities, yet to date only a few studies have tested the effects of EM diversity on host plant responses, with belowground C flux effects remaining ignored. This thesis investigated how increasing species and genotypic richness affected the productivity and CO2 efflux of EM fungal mycelium grown in pure culture, and examined whether similar patterns between diversity and respiration were found in the field. Furthermore, the response of soil respiration to additions of increasingly diverse EM necromass was tested. Results from in vitro studies revealed that not only did productivity and respiration change significantly, but genotype richness also had strong effects on these processes. Biodiversity effects were driven by a combination of selection effects (dominance by a species) and complementarity effects (niche partitioning/complementary resource use). Furthermore, variation in productivity and CO2 efflux between individuals was large, and in some cases differences between genotypes was as great, if not greater, than between species. Strikingly, not only did the addition of EM fungal necromass to soil rapidly enhance respiration above that produced by unamended controls, but CO2 efflux also increased dramatically with increasing necromass richness. The relationship between species richness and soil CO2 efflux in the field was not as pronounced, although further work is needed to distinguish between sources of soil CO2 efflux variation in the field and to address confounding factors. This PhD thesis stresses the importance of diversity for soil C cycling in both living and decomposing EM fungi, and it supports calls to consider fine scale phylogenetic information about microbial communities when testing the effects of diversity on ecosystem processes.
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Das, Arpita [Verfasser], Uwe [Akademischer Betreuer] Nehls, Uwe [Gutachter] Nehls, and Barbara [Gutachter] Reinhold-Hurek. "Ectomycorrhiza Development : Investigation of Selected Ectomycorrhiza Induced Poplar Genes / Arpita Das ; Gutachter: Uwe Nehls, Barbara Reinhold-Hurek ; Betreuer: Uwe Nehls." Bremen : Staats- und Universitätsbibliothek Bremen, 2018. http://d-nb.info/1169299121/34.
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Husted, Lynn. "Low soil temperature and efficacy of ectomycorrhizal fungi." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30930.
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The influence of root-zone temperature on the efficacy of various ectomycorrhizal fungi, i.e., their ability: (1) to colonize roots in a nursery environment, (2) to persist and colonize new roots in the field and (3) to improve the growth, nutrition, and physiology of white spruce (Picea glauca (Moench) Voss) seedlings, was examined in controlled environment experiments using water baths to regulate root-zone temperature.
Eight-week-old non-mycorrhizal seedlings were inoculated with 13 different inocula (1 forest floor inoculum, 12 specific fungi), then transplanted into 6, 16, or 26°C peat:vermiculite mixes for 8 weeks. Maximum root colonization occurred at 16°C for most inocula. The 6°C mix strongly reduced mycorrhiza formation with only 8 of the 13 inocula forming any mycorrhizae during the 8-week test period. Primary infection from ectomycorrhizal propagules (spores and hyphal fragments) was reduced more than was secondary infection from established mycorrhizae; once established, all inocula colonized new roots in 6°C forest soil.
Fall-lifted cold-stored seedlings infected with 8 inocula (forest floor, 7 specific fungi) were planted into 6 and 12°C forest soil mixtures with or without indigenous ectomycorrhiza inoculum. Survival and colonization of new roots by inoculant fungi was good (> 50%) for the 12-week test duration despite the significant potential for infection by indigenous inoculum. High persistence appeared to be due to successful (>75%) root colonization by the inoculant fungi in the nursery production phase, to the relative weakness of ectomycorrhizal propagules (spores and hyphal fragments) compared with live ectomycorrhizal attachments, and to the favorable pattern of lateral root egress from the container plug after planting.
Colonization of new roots by established mycorrhizae showed an effect of soil temperature in the presence, but not the absence, of indigenous inoculum. Percent new root colonization by inoculant fungi was lower in the 12°C forest soil. Rapid extension of lateral roots in the 12°C soil increased the likelihood that short roots initiated near the tips of elongating roots would be infected by indigenous fungi. There was no evidence of active or passive interactive replacement between inoculant and indigenous fungi. However, Hebeloma crustuliniforme appeared to inhibit mycorrhizal formation by indigenous fungi; roots not infected by this fungus remained non-mycorrhizal. Application of slow-release fertilizer reduced new root colonization by E-strain but had no effect on colonization by H. crustuliniforme or indigenous forest floor fungi.
Non-inoculated seedlings (controls) and seedlings inoculated with 5 different inocula (forest floor, 4 specific fungi) were planted in 6 and 12°C forest soil for 3 weeks. Inoculation influenced the rate at which seedlings acclimated to the 6°C soil with respect to resistance to water flow and net photosynthetic rate, but had no effect on pre-dawn stomatal conductance. Differences among inoculation treatments were related to the size and nutritional status of seedlings at the time of transplanting. Seedlings infected with Laccaria bicolor or E-strain exhibited the least decrease in resistance to water flow due to the relatively small size (dry weight, short root number) of their root systems at the time of transplanting. Net photosynthetic rate and new foliage production correlated positively with shoot N and P (% dry weight) and the proportion of total seedling N and P contained in shoot tissues at the time of planting.
Non-inoculated seedlings (controls) and seedlings inoculated with forest floor or 5 specific fungi were planted in 6 and 12°C forest soil for 12 weeks. The presence of "any" mycorrhiza at the time of transplanting did not improve seedling growth under the experimental conditions (i.e., cool, acidic soils with an indigenous ectomycorrhizal fungal population). On average, mycorrhizal infection increased N and P uptake at 12°C but not at 6°C. Growth response to specific fungi was very variable with some fungi depressing seedlings growth (e.g., E-strain and H. crustuliniforme) and others strongly promoting it (forest floor inoculum, L. bicolour, Thelephora terrestris). Seedling response to the various inocula was not related to the degree of mycorrhizal infection at the time of planting nor to the source of inocula; but was associated with differences in the content and distribution of nutrients at the time of transplanting and differences in total nutrient uptake, root efficiency, nutrient-use efficiency and net photosynthetic rate after transplanting. Root efficiency was not proportional to the number of short roots per unit root or to the amount of external mycelium attached to the various mycorrhizae. Implications for applied forestry and research are discussed in the final chapter.Forestry, Faculty of
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Heller, Gregory. "Transcription analysis of Pinus sylvestris during ectomycorrhizal development /." Uppsala : Dept. of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200821.pdf.
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Nygren, Cajsa. "Functional diversity in nutrient acquisition by ectomycorrhizal fungi /." Uppsala : Dept. of Forest Mycology and Pathology, Swedish University of Agricultural Sciences, 2008. http://epsilon.slu.se/200854.pdf.
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Franco, Albina Cristina Ribeiro. "Ectomycorrhizal fungal community composition of Betula colonising Calluna moorland." Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2008. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=25222.
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Jonsson, Lena. "Community structure of ectomycorrhizal fungi in Swedish boreal forests /." Uppsala : Swedish Univ. of Agricultural Sciences (Sveriges lantbruksuniv.), 1998. http://epsilon.slu.se/avh/1998/91-576-5609-6.gif.
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Rasanayagam, Maretta Sharima. "Inhibitory effects of ectomycorrhizal fungi on other soil fungi." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332661.
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McLane, Kevin John. "Symbiosis of Ectomycorrhizae and Trees, an Agent-Based Model." Youngstown State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1620380794126532.
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Valentine, Lori Lisa. "The biodiversity of ectomycorrhizal fungi associated with Quercus garryana /." View full-text version online through Southern Oregon Digital Archives, 2002. http://soda.sou.edu/awdata/040226b1.pdf.
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Thesis (M.S.)--Southern Oregon University, 2002.Includes bibliographical references (leaves 37-43). Also available via Internet as PDF file through Southern Oregon Digital Archives: http://soda.sou.edu. Search Bioregion Collection.
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Howard, Kay. "The effect of the fungicide phosphite on ectomycorrhizal fungi." Thesis, Howard, Kay ORCID: 0000-0003-3977-1243 (2001) The effect of the fungicide phosphite on ectomycorrhizal fungi. PhD thesis, Murdoch University, 2001. https://researchrepository.murdoch.edu.au/id/eprint/3215/.
Full textAbstract:
In Western Australia, the fungicide phosphite is being applied to selected native plant communities in order to reduce the impact of the root and collar rot pathogen, Phytophthora cinnamomi. The effect of this fungicide on the growth and function of ectomycorrhizal (ECM) fungi and their mycorrhizas was unknown. Taking the hypothesis that phosphite has a deleterious effect on mycorrhizal fungi, this study explored potential detrimental effects of phosphite on early colonising ectomycorrhizal fungi.
Ten isolates of Scleroderma and Pisolithus from Western Australia, isolated from a range of host plants. These isolates were partnered with Agonis flexuosa, Melaleuca scabra, Eucalyptus globulus, E. sieberi and four clonal lines of E. marginata (jarrah) in vitro. The isolates that formed a mantle, Hartig net and epidermal cell elongation characteristic of a successful symbiosis, were chosen for further studies on two contrasting E. marginata clonal lines, that were resistant or susceptible to P. cinnamomi. Foliar drenching with phosphite induced different responses in the two clonal lines when they were non-mycorrhizal. Phosphite decreased root production in the resistant clone, and increased the number of plantlets that produced roots in the susceptible clonal line. Generally, 3 g phosphite/L reduced the host response to mycorrhizal infection, and mycorrhizas reduced root responses to phosphite compared to those seen in non-mycorrhizal plants.
To determine if phosphite could have a direct inhibitory effect on the hyphae of ECM fungi, three isolates of Laccaria, Scleroderma and Pisolithus were grown in pure culture, on media containing a range of phosphite and phosphate concentrations. The biomass of Laccaria generally decreased as phosphite concentration increased at low phosphate concentrations. As phosphate concentration increased, the biomass of each Laccaria isolate generally increased irrespective of phosphite concentration. In hyphae of the three isolates of Laccaria, the increasing concentrations of phosphate in the media resulted in significant accumulation of phosphate. In two isolates, external phosphite supply had no effect on phosphate uptake. Scleroderma and Pisolithus tolerated the same concentration of phosphite as phosphate, while Laccaria was more sensitive to phosphite. There was a significant difference in growth between Laccaria isolates, while there was less variation between isolates of Scleroderma and Pisolithus. Scleroderma was most sensitive with two isolates being killed by 40 mM and the third being killed by 100 mM phosphite, while 120 – 140 mM phosphite was fungicidal to Laccaria and Pisolithus isolates.
In the glasshouse, non-mycorrhizal seedlings of E. marginata, E. globulus and A. flexuosa were sprayed to run-off with 0 to 10 g phosphite/L, and then planted into soil naturally infested with early colonising mycorrhizal species. Phosphite had no effect on the percentage of roots infected with mycorrhizal fungi. In another experiment, E. globulus seedlings ectomycorrhizal with Scleroderma, Pisolithus and Descolea were treated with 0 to 10 g phosphite/L and infection of new roots by ectomycorrhizal fungi was assessed. At the recommended rate (5 g phosphite/L), phosphite had no effect on ectomycorrhizal formation, while at 10 g/L phosphite decreased infection by Descolea by 15%.
An in vitro study was undertaken on a clonal line of E. marginata to determine if the foliar application of 3 g phosphite/L had any effect on the ability of Scleroderma and Pisolithus spores to germinate and infect roots. There was no significant difference in the percentage of infected primary and lateral root tips in phosphite and control plants inoculated with Scleroderma or Pisolithus spores.
To determine if the soluble and cell wall bound peroxidases and phenolics involved in host defence responses are affected by phosphite treatment of the host, a series of interactions with E. marginata, ECM fungi and P. cinnamomi were examined. Phosphite significantly reduced P. cinnamomi lesion length in all mycorrhizal and non-mycorrhizal treatments and altered static peroxidase activity and phenolic concentrations in the roots of all non-mycorrhizal plants.
Phosphite did not induce changes in peroxidase activity or phenolic concentration in roots of the susceptible clone when in indirect contact with Pisolithus. However, there was a general increase in peroxidase activity and phenolic concentration in roots of the resistant clone in the presence of Pisolithus and P. cinnamomi. In contrast, phosphite decreased peroxidase activity in the susceptible clone in the presence of Scleroderma and had no effect on soluble or cell wall bound phenolics. Phosphite did not alter peroxidase activity or phenolic concentration in roots of the resistant clone challenged by P. cinnamomi in the presence of either Scleroderma or Pisolithus. In contrast, phosphite significantly increased peroxidase activity, and decreased soluble phenolic concentration in the roots of the susceptible clone in the presence of Pisolithus.
A glasshouse trial examined the effect of foliar applied phosphite (3 g/L) on P. cinnamomi infection of roots of mycorrhizal E. marginata plants. Laccaria, Scleroderma and Pisolithus mycorrhiza were established with seedlings and a P. cinnamomi susceptible clonal line of E. marginata prior to phosphite treatment. P. cinnamomi zoospores were inoculated to the root zone 10 days after phosphite application. P. cinnamomi was recovered from 84% and 52% of the untreated seedlings and clonal plants respectively, whether they were ectomycorrhizal or not. By contrast, in phosphite treated plants, P. cinnamomi was recovered in 10% of seedlings and 6% of clonal plants. There was no difference in P. cinnamomi recovery between mycorrhizal types in seedlings and clonal plants. More P. cinnamomi was recovered from mycorrhizal than non-mycorrhizal clonal plants. There was no correlation between the extent of mycorrhizal fungal colonisation and the percentage of P. cinnamomi infected roots in clonal plants or seedlings.
Overall conclusions
Although only a few ECM fungi and host species were examined in this study, it appears that phosphite, when used at the recommended rate (5 g/L), may not have a detrimental effect on ECM formation. The concentration of phosphite that is fungicidal to ECM fungi in vitro is generally in excess of levels that would be found in treated plant tissues. However, when the recommended rate was exceeded it was shown that phosphite significantly decreased infection by Descolea.
This study has shown that there is variation between genera of ECM fungi, host plants, type of plant (clonal material or seedlings) in response to phosphite. However, this study did not take into account differing phosphate concentrations and its effect on phosphite and mycorrhizal interactions, which would further increase these variations. This demonstrates that generalisations cannot be made on the effect of phosphite on ECM fungi and ECM plants.
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Leonardi, Pamela <1978>. "Studies on Tuber borchii ectomycorrhizal community, biology and genetics." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amsdottorato.unibo.it/8622/1/Leonardi%20Pamela%20Tesi.pdf.
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The work carried out during this PhD has allowed to increase the biological, reproductive and ecological knowledge of Tuber borchii. Moreover, it poses the basis for using the mycelial inoculation for the production of plants mycorrhized with Tuber spp. for truffle cultivation.
Initially the interaction of T. borchii with other fungal species in natural productive areas was studied, establishing that the threats to biodiversity of the genus Tuber spp. are mainly due to the fragmentation and loss of natural productive areas and the effect of climate changes. Subsequently, to test the possible effects of global warming on Tuber spp. development, in vitro study was carried out with the aim of testing the response of different strains of T. borchii at high temperatures.
A protocol for cryopreservation in liquid nitrogen has been developed to create a germplasm bank to preserve its genetic diversity.
Moreover a research was carried out to look for new compounds that could stimulate Tuber borchii mycelial fitness. Among these, nanoparticles gave the best results. In particular, NPs Fe-EPS (esopolysaccharide nanoparticles with iron oxide) had positive effects on the in vitro development of T. borchii, inducing a better quantitative and qualitative development of the T. borchii mycelium.
Least but not last in my PhD thesis i followed the experimental T. borchii truffle orchard located at Cadriano University farm. For the first time it was demonstrated that it is possible to obtain truffle productions with seedlings obtained with mycelial inoculation. This discovery opens up the possibility of using this method of mycorrhization, as an alternative to the costly sporal inoculation. In order to understand the dynamics of the inoculated strains in the truffle orchard the mating types of the strains used for inoculation and their distribution as mycorrhizas, fruiting bodies and extra-radical mycelium in soil was investigated.The work carried out during this PhD has allowed to increase the biological, reproductive and ecological knowledge of Tuber borchii. Moreover, it poses the basis for using the mycelial inoculation for the production of plants mycorrhized with Tuber spp. for truffle cultivation. Initially the interaction of T. borchii with other fungal species in natural productive areas was studied, establishing that the threats to biodiversity of the genus Tuber spp. are mainly due to the fragmentation and loss of natural productive areas and the effect of climate changes. Subsequently, to test the possible effects of global warming on Tuber spp. development, in vitro study was carried out with the aim of testing the response of different strains of T. borchii at high temperatures. A protocol for cryopreservation in liquid nitrogen has been developed to create a germplasm bank to preserve its genetic diversity. Moreover a research was carried out to look for new compounds that could stimulate Tuber borchii mycelial fitness. Among these, nanoparticles gave the best results. In particular, NPs Fe-EPS (esopolysaccharide nanoparticles with iron oxide) had positive effects on the in vitro development of T. borchii, inducing a better quantitative and qualitative development of the T. borchii mycelium. Least but not last in my PhD thesis i followed the experimental T. borchii truffle orchard located at Cadriano University farm. For the first time it was demonstrated that it is possible to obtain truffle productions with seedlings obtained with mycelial inoculation. This discovery opens up the possibility of using this method of mycorrhization, as an alternative to the costly sporal inoculation. In order to understand the dynamics of the inoculated strains in the truffle orchard the mating types of the strains used for inoculation and their distribution as mycorrhizas, fruiting bodies and extra-radical mycelium in soil was investigated.
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Poole, Elizabeth Jennifer. "Evaluation and localization of helper bacteria in ectomycorrhiza formation." Thesis, University of Sheffield, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322938.
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Tarkka, Mika. "Developmentally regulated proteins in Pinus sylvestris roots and ectomycorrhiza." Helsinki : University of Helsinki, 2001. http://ethesis.helsinki.fi/julkaisut/mat/bioti/vk/tarkka/.
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Trudell, Steven A. "Patterns of nitrogen and carbon stable isotope ratios in macrofungi, plants, and soils from two old-growth conifer forests, Olympic National Park, Washington, USA /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5572.
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Miller, Bradley W. "Long-term Effects of Fertilization on Phosphorus Biogeochemical Pools in Forest Soils." Diss., Virginia Tech, 2009. http://hdl.handle.net/10919/37386.
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Southern pines are typically limited by nitrogen (N) and phosphorus (P) availability in the soil environment. While the absolute quantities of P in forests soils may be large, the concentration of inorganic P in the soil solution is typically very small (&60; 0.01 mg L&178;-1). A onetime application of just 56 kg P ha&178;-1 can substantially increase growth of pine stands over a 20 year rotation (Pritchett and Comerford, 1982&59; Allen et al., 1990). Phosphorus fertilization of Pinus radiata in New Zealand has also shown long-term effects on labile P pools in the soil which improved stand growth during the subsequent rotations (Ballard, 1978&59; Gentle et al., 1986). Identifying and quantifying the biologically available P pools in the soil environment will help foresters in making site-specific P fertilizer prescriptions.
I examined soil phosphorus pools using the Hedley sequential fractionation procedure and Mehlich-3 soil tests in a long-term loblolly pine (Pinus taeda L.) fertilization trial from four sites in the Atlantic and Gulf Coastal Plains. After 22 years, fertilization effects were limited to the surface depths. Mehlich-3 extractable P was largest in the soil surface (0-10 cm) of the fertilized treatments plots. Hedley labile and moderately labile P pools were also largest in the soil surface and decreased with depth.
Results from the Hedley fractionation procedure suggested that the Virginia site has a large pool of organic P in the soil surface. Organic P pools can represent 20-90&37; of the total P present in most mineral soils increasing with the age of the soil (Condron et al., 2005). This increase in organic P pool suggests that biological cycling becomes more important as the stand develops (Wells and Jorgensen 1975). I used solution 31P nuclear magnetic resonance (NMR) spectroscopy to characterize organic P extracted with NaOH-EDTA in the surface of a Paleaquults from coastal Virginia. Total NaOH-EDTA extractable P was significantly larger in the fertilized treatment. Concentrations ranged from 0.1 mg P L&178;-1 in the control plots to 5.1 mg P L&178;-1 in fertilized plots. The surface soils in both treatments were dominated by inorganic orthophosphate. Monoester P compounds were the only organic P compounds detected and were present in very low quantities.
The significant increase of NaOH/EDTA extractable P in the soil surface of the VA site suggested there has been a beneficial long-term effect of fertilization similar to the observations from the Mehlich-3 soil test. Results from oxalate loading experiments on ligand exchangeable versus dissolvable P pools in the bulk soil suggested that the long-term effect of P fertilization increased oxalate dissolvable P pools.
Plants and microbes have evolved a variety of mechanisms to increase P uptake in low P soil environments. These mechanisms include changes in root morphology and architecture, preferential root growth into high P microsites, the secretion of low-molecular-mass organic acids (LMMOA), and uptake via symbiotic relationships (Fox and Comerford, 1992b&59; Raghothama, 1999&59; Hinsinger, 2001&59; Raghothama, 2005). Results from soil samples taken from the ectomycorrhizal rhizosphere found that loblolly pine mycorrhizal roots modified the soil environment, possibly making recalcitrant P more available. In addition, the long-term effect of fertilization was a 396&37; increase in biologically available P.
Fertilization increased loblolly pine volume growth by 57 m&185;3 ha and increased the P content in the litter layer by 118&37;. After the stand was harvested and replanted, mineralization of the litter layer may also increase soil P pools. Results from this long-term fertilization experiment in the Coastal Plain province of Virginia have demonstrated that there has been a significant increase in soil (33.6 kg P ha&178;-1) and biologically available P pools (3.0 kg P ha&178;-1).Ph. D.
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Wei, Jie. "Ectomycorrhizal diversity of Chinese pine (Pinus tabulaeformis) in North China." Diss., lmu, 2010. http://nbn-resolving.de/urn:nbn:de:bvb:19-115926.
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Phosri, Cherdchai. "Characterization and development of tropical gasteromycete fungi in ectomycorrhizal associations." Thesis, Liverpool John Moores University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402861.
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Shaw, Timothy M. "Modelling competition between ectomycorrhizal fungi for roots of pine seedlings." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303411.
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Gibson, Fiona. "Establishment of ectomycorrhizal fungi on roots of birch (Betula spp.)." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/14901.
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Barrento, Maria João Hortas. "Influence of soil parameters on ectomycorrhizal diversity in montado ecosystems." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5305.
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Mestrado em Engenharia Florestal e dos Recursos Florestais - Instituto Superior de AgronomiaThis study characterized the composition and the diversity of macrofungal communities associated with four plots of montado situated in Grândola Hills, Southern Portugal, and evaluated the influence of soil parameters on ectomycorrhizal fungal diversity and abundance. Phosphorus, potassium, total nitrogen, organic matter concentrations and soil pH were the parameters determined. Differences in soil chemical features were found between studied plots. A total of 132 species of macrofungi were found in the study area being Laccaria, Russula and Cortinarius the most abundant genera. Also dissimilarities on macrofungal communities, particularly, on abundance and diversity, were registered among plots. The influence of soil parameters on ectomycorrhizal diversity and abundance was studied in the plots with values of biological spectrum higher than one, and in particular for the most frequent species Laccaria laccata, Cortinarius trivialis, Russula amoenolens and Russula subfoetens. Results showed that ectomycorrhizal diversity is negatively correlated with the increasing of extractable phosphorus concentration, and the abundance of ectomycorrhizal species responds differently to soil chemical characteristics. The present study allows us to understanding the influence of some soil features on ectomycorrhizal fungal diversity and abundance. Finally, the effects of management practices on ectomycorrhizal fungal diversity in this Mediterranean ecosystem are discussed.
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Ali, Nahia A. "Spore germination and the pre-infection phase in ectomycorrhizal fungi." Thesis, University of Surrey, 1986. http://epubs.surrey.ac.uk/843799/.
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Spore germination of seven species of ectomycorrhizal fungi was studied under different conditions. Spores of most species tested did not germinate on laboratory media without stimulators. Various stimulators were tested and the greatest activation was that by Pseudomonas stutzeri which was obtained from fruitbodies of Hebeloma crustuliniforme and stimulated about 21% of spores of that fungus. Effects of plant roots on spore germination were studied in the laboratory and in soil. In mineral salts medium, spores of Paxillus involutus were stimulated by five of seven tree species and one of four non-tree species tested. Spores of Laccaria laccata and H. crustuliniforme were stimulated by birch and pine only, while those of lactarius turpis and Amanita fulva were only slightly stimulated by birch roots. Birch was more stimulatory and the highest germination (30%) was that of H. crustuliniforme at 0-1 mm from the root edge. In soil, spores of P. involutus only, of the seven species tested, were stimulated to germinate near roots of birch and spruce in steamed and untreated soils. Birch stimulated up to 96% of spores to germinate in untreated birch wood soil. Spruce had much less effect on germination in either steamed or untreated soil. The majority of germ tubes grew towards the roots. Exudate from roots of seedlings of birch previously grown in soil was active in stimulating germination of H. crustuliniforme, but not of the other six species tested. Activity of the root exudate was associated with the ninhydrin-positive fraction. The role of the basidiospores of the test fungi in initiating mycorrhizas in soil was also studied. Spores of P. involutus and L. laccata established mycorrhizas with birch, but not spruce or pine roots. Spores of the other five species tested did not establish mycorrhizas with any of the plant tested.
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Cripps, Cathy Lynn. "Ecological and taxonomic studies of ectomycorrhizal fungi associated with Aspen." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-160259/.
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Vishwanathan, Kishore [Verfasser]. "Defense remodelling by ectomycorrhizal fungi in non-hosts / Kishore Vishwanathan." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2020. http://d-nb.info/1215338651/34.
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Di, Marino Erika. "The ectomycorrhizal community structure in beech coppices of different age." Doctoral thesis, Università degli studi di Padova, 2008. http://hdl.handle.net/11577/3425219.
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The species composition of ectomycorrhizal (ECM) fungal communities can be strongly influenced by the sylvicultural practises, abiotic and biotic factors, which determine interactions among the species. In order to determine the influence of the coppicing on EM community, the shoot age, bedrock types, exposure, slope, humus features, soil conditions, sampling points locations were taken into account as the most representative and influencing factors in these soil ecological dynamics. In summer 2005, 2006 and 2007, in 7 [2-48-years-old] Beech [Fagus sylvatica (L.) Karst.] coppices located in the Province of Trento (northern Italy), a monitoring on the the root tipes was applied to compare these sites, and to give an additional instrument like a synthetic biological indicator for the traditional management strategies.
In the present study the results confirmed the ectomycorrhizal community structure investigated in 7 beech coppices of different age was typical with the occurrence of few abundant species and many others with significantly lower abundance. Cenococcum geophilum was the most frequently detected species in each site and in each sample date. Morphological, anatomical and molecular investigations revealed a total of 60 anatomotypes. Of these 35 were unknown on Fagus sylvatica up to now. The investigations on the community composition can be considered a great contribute to the biodiversity of the Beech forest, with four detailed species descriptions: Fagirhiza byssoporioides, Fagirhiza entolomoides, Fagirhiza stellata and Hygrophorus penarius. Additional investigations using also the stable isotopes were necessary to understand the parasitic attitude showed by this species in the years 2006-2007 in these coppices.
The investigation of the ECM community composition (species richness evenness, and dispertion, vitality and rate of mycorrhization) in relation to the shoot age and to the main ecological factors revealed the absence of a real reaction to the coppicing, and the major importance of the slope or other ecological conditions to understand the species distribution.
An aggregation of the species was releaved, but the species features didn't show a clear correlation with the ecological stands conditions, concerning the spatial distribution and the soil horizons.
The results suggest an hypothesis that the coppice treatment in Beech, didn't have a significant effect on the EM community structure since 2 until 48 years from coppicing. Considering the stability of the EM community as a bioindicator of the ecosystem resilience, it can be suppose that a rational coppicing treatment could be a sustainable human activity, compatible with the ecosystem dynamics with these environmental conditions. Two more EM descriptions were performed: Pseudotomentella humicola on Picea abies and Sistotrema muscicola on Castanea sativa.
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Di, Marino Erika. "The ectomycorrhizal community structure in beech coppices of different age." Diss., lmu, 2008. http://nbn-resolving.de/urn:nbn:de:bvb:19-97717.
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Quoreshi, Ali M. "Nutritional preconditioning and ectomycorrhizal formation of Picea mariana (Mill.) B.S.P. seedlings." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0023/NQ49890.pdf.
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Trusty, Paul Evan. "Impact of severe fire on ectomycorrhizal fungi of whitebark pine seedlings." Thesis, Montana State University, 2009. http://etd.lib.montana.edu/etd/2009/trusty/TrustyP0509.pdf.
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Whitebark pine (Pinus albicaulis) is a threatened keystone species in subalpine zones of Western North America critical to watersheds and maintenance of high elevation biodiversity. Pine nuts are an important food for wildlife including grizzly bears. Whitebark pine stands have experienced losses up to 90% due to white pine blister rust, mountain pine beetles and replacement due to fire suppression. Active management strategies include letting natural fires burn or applying prescribed fires to clear understory fir, stimulate seedling regeneration and provide openings for nutcrackers to plant seeds. However, post-fire plantings of rust-resistant seedlings have low survival rates. This study evaluated the impact of fire on the mycorrhizal fungi which are obligate mutualists with whitebark pine and to address management concerns. The 2001 Fridley fire burned a portion of a mature whitebark pine forest and a year later 20,000 seedlings were planted. After four years, natural and planted seedlings, on the burn and controls in the adjacent unburned forest were well colonized by mycorrhizal fungi (>90%) although a portion may be nursery E-strain. The severe burn reduced mycorrhizal diversity 27% on natural and planted seedlings and caused a significant shift in mycorrhizal species (determined by ITS sequencing, principal component analysis and multidimensional scaling). Seedlings in the burn (natural and planted) were dominated by Pseudotomentella nigra, Wilcoxina species and Amphinema byssoides while natural seedlings in unburned forest hosted mainly Cenococcum geophilum and Piloderma byssinum. Differences were minimal between planted and natural seedlings in the burn, but roots of planted pines retained the container shape. The functional significance of a species shift to seedling survival is not yet known. Seedlings in all treatments hosted suilloid fungi (Rhizopogon, Suillus) important in pine establishment. A greenhouse bioassay of burned and unburned soils using nursery seedlings did not reflect the full diversity found in the field study, but did reveal suilloid fungi indicating that bioassays can be used as a pre-planting assessment tool for this group. Despite high mycorrhization and availability of suilloids, seedling survival was low (22-42%) suggesting the timing/type of mycorrhization and/or other biotic/abiotic factors are a concern.
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Fransson, Petra M. A. "Responses of ectomycorrhizal fungi to changes in carbon and nutrient availability /." Uppsala : Swedish University of Agricultural Sciences (Sveriges lantbruksuniv.), 2001. http://epsilon.slu.se/s235.pdf.
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