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Abualghaith, Abdulaziz. "Carbon and nitrogen metabolisn in orchid-mycorrhiza associations." Thesis, University of Sheffield, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604555.
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Members of the Orchidales produce dust seeds so lacking in nutrient and carbon reserves that they are dependent upon appropriate fungal partners to supply the essential additional carbon and nutrients required for successful establishment in nature. These plants are thus initially mycoheterotrophic before they normally go on to develop green leaves and become autotrophic as adults. However, at least 210 species of orchid remain fully mycoheterotrophic into adulthood. The metabolic pathways involved in the nitrogen and carbon fluxes from fungus-to -plant in mycoheteratrophic are still poorly understood, but result in characteristic enrichment in 13C and 13N. In this thesis in vitro studies on agar are employed to investigate the effects of different N sources, with and without sugar or cellulose carbon sources on the heterotrophic growth of mycorrhizal orchid seedlings and metabolite pools in the plants and their fungal partners. It is hypothesised that glutamine, a central metabolite in assimilation of mineral by basidiomycete fungi, passes from fungus-to -plant as in traditional models of N assimilation by ectomycorrhizal plants. A range of nitrogen and carbon sources including isotopically labelled 14C and 13C-glucose together with 15N labelled N sources including nitrate, ammonium, ammonium nitrate, glutamine, glycine and arginine were supplied to orchid mycorrhizal fungi in pure culture and to mycorrhizal seedlings of Goodyera repens or Dactylorhiza fuchsii. In three compartment Petri dishes in which the seedlings were grown with their fungal partners colonising the two other compartments, simultaneous additions of DC and 15N tracers provided compelling evidence of fungal assimilatory pathways providing co-transport of C and N into heterotrophic seedlings of G. repens. Nitrate was a better N source than ammonium or amino acids for the plants, and metabolomic analysis showed strong up-regulation of relative abundance of glutamine in the fastest growing plants. The findings presented in this thesis provides strong circumstantial evidence that glutamine serves as a major combined N and C source transported from fungus-to-plant in heterotrophic orchid seedlings.
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Quirk, Joe. "Effects of evolutionary advances in plant-mycorrhiza associations on biological weathering." Thesis, University of Sheffield, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.555129.
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The evolution of Earth's first forests during the Devonian and expansion of angiosperrns at the expense of gymnosperms in the Cretaceous is thought to have accelerated the dissolution of continental Ca-Mg silicates. thereby enhancing long-term atmospheric CO2 draw-down and global climatic cooling. However, this paradigm of plant-driven atmospheric CO2 decline overlooks the role of eo-evolving arbuscular mycorrhizal (AM) soil fungi that have formed symbiotic partnerships with plants since the dawn of terrestrial plant life. and ectomycorrhizal (ECM) fungi whose evolutionary origins date from the Cretaceous. Both AM and ECM increase the mobilisation and uptake of elements from rocks and minerals. which they provide to their host plants in exchange for carbon energy. Although the involvement of later-evolving ECM in weathering is increasingly recognised, the role of AM has been overlooked or even prematurely dismissed. Here. evidence is presented of the effects of the co-evolutionary advances made by plants and mycorrhizal fungi on the weathering of silicates that in turn has been instrumental in modifying Earth's atmospheric CO2 over geological time. Whilst accounting for the functional type, leaf habit and mycorrhizal status of the hosts. this study addresses the missing mechanistic understanding of the impact that the major evolutionary advances from gymnosperm to anglosperm and AM to ECM have had on weathering processes over the last 400 Myr. Within this study. the relative importance of AM and ECM fungal-mineral interactions are examined using established trees in the field. as well as in fully controlled laboratory studies at ambient, sub- and super-ambient atmospheric CO2• The efficacy of mycorrhizal weathering is also assessed in comparison with that of plants which have evolved beyond the need for mycorrhizas in favour of alternative nutrient- acquisition strategies involving specialised roots. Finally. the effect of low atmospheric CO2 concentrations on drought-induced plant mortality is investigated as a mechanism attenuating silicate weathering by woody plants. potentially limiting atmospheric CO2 drawdown over the past 24 Myr. Three crucial gaps in our understanding of plant-mycorrhiza weathering are addressed: the ability of AM versus ECM fungi to colonise Ca-Mg silicate rocks such as basalt. their ability to physically alter minerals. and their capacity to chemically modify silicate rock. The results demonstrate that weathering beneath trees is fundamentally determined by co-evolutionary partnerships with mycorrhizal fungi. and provide critical lnsights of the geochemical consequences of the rise of the first forests in the Devonian and expansion of ECM gymnosperms and angiosperms at the expense of AM gymnosperms from the Cretaceous.
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Reiter, Noushka Hedy, and noushka reiter@dse vic gov au. "Borya mirabilis steps in the recovery of a critically endangered Australian native plant." RMIT University. Applied Sciences, 2009. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20090227.160625.
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Borya mirabilis is one of the world's most critically endangered plants. The research in this thesis has illuminated key aspects of: its reproductive biology; interspecies and intraspecies molecular relationships, mycorrhizal status, tissue culture potential and disease threats. Each of these aspects has fundamental management implications for the active management of B. mirabilis. Floral observations of B. mirabilis and related species affirmed the uniqueness of the Boryaceae amongst the Asparagales. B. mirabilis had an unusually high number of floral abnormalities compared with other species of Borya observed. B. mirabilis is fly-pollinated. Pollen of Borya species showed little difference in the characteristics of mature pollen between species, with viable pollen being prolate and unicolpate with a single colpa-style aperture and a unique patterning of the pila. The structural immaturity of B. mirabilis pollen correlated with evidence from pollen growth experiments, where B. mirabilis pollen had extremely low germination rates, with those grains that did germinate being slow to do so and with slow-growing pollen tubes compared to those of fertile Borya species. Examination of the ovules of B. mirabilis showed that morphologically they were viable compared to viable Borya species. The field population of B. mirabilis was crossed, with one seed produced (the first recorded seed for th is species). Cross-pollination using the pollen of the closely related B. constricta and B. sphaerocephala with B. mirabilis ovules proved unsuccessful. Examination of the chromosome number of B. mirabilis showed that it had approximately 66 chromosomes and is probably hexaploid, relative to the diploid number of 26 in B. constricta. This may explain its low fertility. Interspecies and intraspecies relationships of the Boryaceae and Borya mirabilis were investigated using sequences of chloroplast and nuclear DNA. The closest similarities to B. mirabilis were B. constricta and B. sphaerocephala. B. mirabilis may have emerged from alloploidy of these species in the past. Because of the consistent similarities of B. mirabilis and B. constricta chloroplast sequences, it is proposed that both shared a common ancestor with a chromosome number of 2n=22. A malfunction n meiosis may have resulted in ovules with 2n=44. The high similarity of the nuclear ribosomal ITS region DNA suggests that the nuclear DNA was derived from B. sphaerocephela. B. mirabilis may be an allopolyploid, from fertilisation of a diploid ovule of B. constricta with haploid pollen of B. sphaerocephala, resulting in a reproductively isolated polyploidy of low fertility. The wild population of B. mirabilis was determined to have a small amount of genetic variation. The genetic variation in the field population w as not fully reflected in the ex-situ population. An effective means of micro-propagation of B. nitida for use in B. mirabilis has been established, providing an effective means of mass production of the species. The research has determined: a suitable explant (shoot tips) for regeneration; an effective means of reducing contamination in tissue culture (PPM); what medium is required to micro-propagate the species (LMHM); an appropriate gelling agent (Phytagel); and a practical method for inducing roots on the shoots grown in tissue culture. B. mirabilis has been established as mycorrhizal. The predominant mycorrhizal association is a nodular arbuscular mycorrhiza, present in the form of coils in root nodules over wetter months and as spores in these nodules over dryer months. A significant increase in the health of the ex-situ population of B. mirabilis was recorded after addition of soil containing fine roots of the wild population. Of the plants associated with the wild population, Callitris rhomboidea had the most morphologically similar vesicular arbuscular mycorrhizal relationship. But molecular identification was not achieved due to recalcitrance of DNA in PCR attempts. Potential translocation sites for some of the ex-situ population of B. mirabilis were examined for Phytophthora infestation. Reid's Lookout and Mackey's Peak were infected with P. cinnamomi. Vegetation at Mackey's Peak displayed characteristic infection symptoms, resulted in isolates of P. cinnamomi from baiting and would directly receive runoff from both the walking track and the existing infested B .mirabilis site. At the Reid's Lookout site, both walking track and proposed translocation site were infested with P. cinnamomi, yet did not display the associated symptoms in the vegetation. The Pine Plantation translocation site was uninfected at the level of sampling undertaken. Its vegetation did not display any characteristic infection symptoms and was not isolated when soil samples were baited. It was therefore chosen for translocation and so far the plants are healthy and actively growing. This research has provided critical knowledge to aid the recovery team in its current and future endeavours to manage this species and bring it back from the brink of extinction.
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Kauppinen, M. (Miia). "Context dependent variation in associations between grasses and fungal symbionts." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216287.
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Abstract Most plants form symbiotic associations with various fungi in natural ecosystems. Traditionally, many of these associations are viewed as mutually beneficial, but recent studies show that symbiotic interactions can be complex and labile. I studied the variability of interactions between grasses and fungi, using root-associated fungi and foliar endophytes in grasses as study systems. First, I studied experimentally how root-associated fungi colonize their host grasses in different natural and artificial conditions. I then investigated experimentally how foliar endophytes affect their host grasses, and whether the endophyte contributes to the host’s adaptation to local and/or foreign habitats. Finally, I reviewed the current use of foliar endophytes in agriculture, with a particular focus on Europe, and critically considered their potential for practices beyond agriculture. I found root fungi to be common, but different types of root fungi had contrasting colonization patterns in natural environments. However, I found that grasses lose almost all of their root fungi in controlled and more favourable conditions, indicating that the associations are fairly loose and conditional to environmental context. My results also showed that foliar endophytes affected the host’s performance in varying ways, depending on plant origin and experimental country, indicating that the associations were context dependent and could represent conditional mutualism. I also found that endophytes contribute to plant adaptation only weakly, but that the grasses were clearly locally adapted to their sites of origin, especially in regard to reproduction. However, the grasses of subalpine origin performed well vegetatively also in Northern Finland, suggesting that they may have high adaptive potential under changing climates. The literary review showed that foliar endophytes are successfully used in agriculture, e.g. in the USA and New Zealand, and that they possess the potential for several practical applications. However, the intentional use of endophyte-enhanced grasses is non-existent in Europe, although many European grass cultivars have great potential for improvement via endophytes. Taken together, these results show that plant–fungal interactions are highly variable along sites, environmental contexts and origins of the symbiotum, making predictions for these interactions difficultTiivistelmä Luonnollisissa ekosysteemeissä melkein kaikilla kasveilla on symbionttisia sienikumppaneita. Perinteisesti monien näiden vuorovaikutusten on oletettu olevan molemmille hyödyllisiä, mutta viimeaikaiset tutkimukset osoittavat symbionttisten yhteyksien olevan vaihtelevia. Väitöskirjassani tutkin tätä heinien ja sienien välisten yhteyksien vaihtelevuutta, käyttäen heinissä esiintyviä juurisieniä ja lehtiendofyyttejä tutkimuskohteinani. Ensiksi tutkin kokeellisesti, kuinka juurisienet kolonisoivat heiniä erilaisissa luonnon- ja kasvihuoneolosuhteissa. Seuraavaksi tutkin kokeellisesti, kuinka lehtiendofyytit vaikuttivat heinien menestymiseen ja edesauttoivatko endofyytit heinien sopeutumista paikallisiin ja/tai vieraisiin elinympäristöihin. Viimeiseksi selvitin kirjallisuuskatsauksen avulla, kuinka lehtiendofyyttejä hyödynnetään maataloudessa ja arvioin endofyyttien potentiaalista käyttöarvoa maatalouden ulkopuolella, erityisesti keskittyen niiden hyödyntämiseen Euroopassa. Tutkimukseni osoitti, että heinien juurisienet ovat yleisiä, mutta niiden keskinäiset runsaussuhteet vaihtelivat luonnollisissa ympäristöissä. Kasvihuoneolosuhteissa heinät kuitenkin menettivät juurisienensä, viitaten siihen, että kyseinen yhteys on melko löyhä ja riippuvainen ympäristöstä. Tutkimukseni osoitti myös, että lehtiendofyytit vaikuttivat heinien menestykseen vaihtelevasti riippuen heinien alkuperästä sekä koemaasta, viitaten siihen, että nämä yhteydet ovat niin ikään olosuhteista riippuvaisia. Endofyytti vaikutti vain heikosti heinien sopeutumiseen, mutta heinät olivat selkeästi paikallisesti sopeutuneita niiden alkuperäisiin elinympäristöihin, erityisesti heinien lisääntymisen suhteen. Alppien heinät kuitenkin menestyivät vegetatiivisesti myös Pohjois-Lapissa, mikä viittaa siihen, että näillä heinillä saattaa olla korkea sopeutumispotentiaali muuttuvissa olosuhteissa. Kirjallisuuskatsaukseni osoitti, että lehtiendofyyttejä käytetään menestyksekkäästi mm. USA:n ja Uudessa-Seelannin maataloudessa. Euroopassa niiden käyttö on kuitenkin lähes olematonta, vaikka endofyyteillä voisi olla monia käyttömahdollisuuksia, sekä maataloudessa että ympäristön hoidossa. Kaiken kaikkiaan tutkimukseni osoittavat, että heinien ja sienten väliset vuorovaikutukset ovat hyvin vaihtelevia riippuen ympäristöstä ja heinien alkuperästä, minkä vuoksi näiden sienien vaikutuksia heiniin on vaikea ennustaa
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Grellier, Brigitte. "Approche biotechnologique des mycorhizes : culture in vitro et physiologie des associations ectomycorhiziennes." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37605677t.
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Tam, Chee-fai Paul. "Mycorrhizal associations in members of Hong Kong's fagaceae /." [Hong Kong : University of Hong Kong], 1993. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13465132.
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Misbahuzzaman, Khaled. "Mycorrhizal associations of Eucalyptus camaldulensis Dehnh." Thesis, University of Edinburgh, 1999. http://hdl.handle.net/1842/15403.
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The species Eucalyptus camaldulensis Dehnh. is of great importance in Mediterranean, sub-tropical and tropical countries for the production of domestic products, such as poles, posts timber and fuelwood. Some members of the genus Eucalyptus are reported to form both arbuscular- (AM) and ecto-mycorrhizas (EM). The main objectives of this study were to look at the host-symbiont interactions between E. Camaldulensis and AM and EM fungi, and interactions between the two mycorrhizal types. The initial aim of the project was to determine suitable experimental conditions for the formation of both types of mycorrhizas on E. camaldulensis seedlings. Two experiments, the first with AM fungi and the second with EM fungi, were set up successively using vermiculite-peat (VP) and sand-perlite (SP) as growth media, and 10 mg 1-1 and 30 mg l-1 phosphorus (P) Ingestad's nutrient solution in each case. Glomus intraradices Schenck and Smith. isolate UT 143-2 and Pisolithus tinctorius (Pers.) Coker and Crouch isolate PTE were used as the test AM and EM fungus respectively. Results showed that both AM and EM colonisation were very low (1-6%) but even so AM inoculation had a significantly depressive growth effect on seedlings of E. camaldulensis. In both experiments VP was found to be the best medium for both the growth of seedlings and the formation of mycorrhizas. A subsequent experiment using one nutrient concentration (5 mg 1-1 P) and three AM and six EM isolates with VP as the growth medium resulted in colonisation of up to 20% by two AM fungi (Glomus clarum Nicolson and Schenck. isolate BR148-1 and Gigaspora rosea Nicholson and Schenck isolate FL105-5) but none of the EM fungi used in that experiment formed any mycorrhizas. The fourth experiment using three AM inocula (including two from the previous experiment and one from a trap culture of Bangladeshi soil) and four nutrient regimes (Ingestad's 2.5,5.0,10 and 20 mg 1-1P) resulted in 30-50% colonisation; most colonisation was by G clarum BR148-1 and was greater at 10 mg 1-1P (>50%). AM colonisation again resulted in a negative growth response of E. camaldulensis seedlings. In a similar experiment using five isolates of P. tinctorius, only isolate K55 resulted in colonisation >15% most of which occurred at 2.5 mg 1-1 (>25%) while the other isolates resulted in <1% colonisation.
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Chan, Wing-kuen. "Studies of mycorrhizal associations of some trees grown in Hong Kong /." [Hong Kong : University of Hong Kong], 1991. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12971856.
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Mulowska, Z. "The effect of SOâ†2 on mycorrhizal associations." Thesis, Lancaster University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239846.
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Tam, Chee-fai Paul, and 譚志輝. "Mycorrhizal associations in members of Hong Kong's Fagaceae." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1993. http://hub.hku.hk/bib/B31233223.
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Winther, Jennifer. "Arbuscular mycorrhizal associations in mycoheterotrophic ferns and lycopods." Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3303816.
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Thesis (Ph.D.)--University of Colorado at Boulder, 2007.Source: Dissertation Abstracts International, Volume: 69-03, Section: B, page: 1407. Adviser: William E. Friedman. Includes supplementary digital materials.
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Chan, Wing-kuen, and 陳永娟. "Studies of mycorrhizal associations of some trees grown in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31232140.
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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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Cloete, Karen Jacqueline. "Physiological effects of indigenous arbuscular mycorrhizal associations on the sclerophyll Agathosma betulina (Berg.) Pillans." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/16600.
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Thesis (MSc)--University of Stellenbosch, 2005.ENGLISH ABSTRACT: The Mountain Fynbos biome, a division of the Cape Floristic Region (CFR), is home to round-leafed Buchu [Agathosma betulina (Berg.) Pillans], one of South Africa’s best-known endangered herbal medicinal plants. Agathosma betulina is renowned as a traditional additive to brandy or tea, which is used for the treatment of a myriad of ailments. In its natural habitat, A. betulina thrives on mountain slopes in acid and highly leached gravelly soils, with a low base saturation and low concentrations of organic matter. To adapt to such adverse conditions, these plants have formed mutualistic symbioses with arbuscular mycorrhizal (AM) fungi. In this study, the effect of indigenous AM taxa on the physiology of A. betulina is investigated. In addition, the AM taxa responsible for these physiological responses in the plant were identified using morphological and molecular techniques. Agathosma betulina was grown under glasshouse conditions in its native rhizosphere soil containing a mixed population of AM fungi. Control plants, grown in the absence of AM fungi, were included in the experimentation. In a time-course study, relative growth rate (RGR), phosphorus (P)-uptake, P utilization cost, and carbon (C)-economy of the AM symbiosis were calculated. The data showed that the initial stages of growth were characterized by a progressive increase in AM colonization. This resulted in an enhanced P-uptake in relation to non-AM plants once the symbiosis was established. Consequently, the lower P utilization cost in AM plants indicated that these plants were more efficient in acquiring P than non-AM plants. When colonization levels peaked, AM plants had consistently higher growth respiration. This indicated that the symbiosis was resulting in a C-cost to the host plant, characterized by a lower RGR in AM plants compared to non-AM plants. Arbuscular mycorrhizal colonization decreased with increasing plant age that coincided with a decline in P-uptake and growth respiration, along with increases in RGR to a level equal to non-AM plants. Consequently, the AM benefit was only observed during the initial stages of growth. In order to identify the AM fungi in planta, morphological and molecular techniques were employed, which indicated colonization by AM fungi belonging to the genera Acaulospora and Glomus. Phylogenetic analyses of a dataset containing aligned 5.8S ribosomal RNA gene sequences from all families within the Glomeromycota, including sequences obtained during the study, supported the above mentioned identification.
AFRIKAANSE OPSOMMING: Die Fynbos bergbioom, ‘n onderafdeling van die Kaapse Floristiese Streek, huisves rondeblaar Boegoe [Agathosma betulina (Berg.) Pillans], een van Suid Afrika se bekendste bedreigde medisinale plante. Agathosma betulina is bekend vir sy gebruik as tinktuur vir die behandeling van verskeie kwale. Die plant kom voor in bergagtige streke, in suur en mineraal-arm grond, met ‘n lae organiese inhoud. Gevolglik, om aan te pas by hierdie ongunstige kondisies, vorm die plante simbiotiese assosiasies met blaasagtige, struikvormige mikorrisa (BSM). In die huidige studie is die effek van hierdie BSM op die fisiologie van A. betulina ondersoek. Die identiteit van die BSM is ook gevolglik met morfologiese en molekulêre identifikasie tegnieke bepaal. Agathosma betulina plante is onder glashuis kondisies in hul natuurlike grond gekweek, wat ‘n natuurlike populasie van BSM bevat het. Kontroles is ook in die eksperiment ingesluit en hierdie stel plante is met geen BSM geïnokuleer nie. Gevolglik is die relatiewe groeitempo, fosfor opname, fosfor verbuikerskoste asook die koolstof ekonomie van die plante bereken. Die data het getoon dat die eerste groeifase gekarakteriseer is deur toenames in BSM kolonisasie vlakke. Dit het tot ‘n hoër fosfor opname in BSM geïnokuleerde plante gelei. Die laer fosfor verbuikerskoste gedurende hierdie fase het aangedui dat die plante wat geïnokuleer is met BSM oor beter meganismes beskik het om fosfor uit die grond te bekom. Toe BSM kolonisasie vlakke gepiek het, was groei respirasie hoër in BSM geïnokuleerde plante as in die kontroles. Dit het aangedui dat die BSM kolonisasie van plante tot hoër koolstof kostes vir hierdie plante gelei het, wat weerspieël is in die laer groeitempo van die BSM geïnokuleerde plante. Die BSM kolonisasie vlakke het gedaal met toenemende ouderdom van hul gasheer plante, wat gekarakteriseer is deur ‘n laer opname van fosfor en laer groei respirasie, tesame met ‘n toename in relatiewe groeitempo tot vlakke soortgelyk aan die van die kontrole plante. Die BSM voordele vir die plant is dus net gedurende die eerste groeifase waargeneem. Die BSM wat verantwoordelik is vir hierdie fisiologiese veranderinge is gevolglik geïdentifiseer met behulp van morfologiese en molekulêre tegnieke en dit is gevind dat BSM wat behoort tot die genera Acaulospora en Glomus binne hierdie plante voorkom. Filogenetiese analise gegrond op opgelynde 5.8S ribosomale RNA geen volgordes afkomstig van al die families binne Glomeromycota asook volgordes gevind in die studie, het die bogenoemde identifikasie gestaaf.
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Kennedy, Aaron H. "Phylogeny and Evolution of Mycorrhizal Associations in the Myco-heterotrophic Hexalectris Raf. (Orchidaceae : Epidendroideae)." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1232724178.
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Kabir, Md Zahangir. "Dynamics of mycorrhizal association in corn (Zea mays L.) : influence of tillage and manure." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0006/NQ30305.pdf.
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Louro, Rogério. "Terfezia diversity in southern Portugal and their mycorrhizal associations with Cistus L.: a study towards the viable production of desert truffles on acid soils." Doctoral thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/28085.
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Desert truffles are edible hypogenous ascocarps produced by Ascomycota (Pezizaceae) fungi characteristic of arid and semi-arid zones. Many of these desert truffle species are nowadays considered as valued Non-Wood Forest Products (NWFPs) endemic to the Mediterranean basin where their ascocarps, rich in proteins and poor in carbohydrates and lipids, constitute a potentially important food source for rural populations. They also represent a key component of the mycological flora on arid and semi-arid habitats, acting directly as symbiotic partners of diverse host plants, mainly Cistaceae, and indirectly as desertification and soil erosion prevention agents.
Terfezia (Tul. & Tul.) Tul. & Tul. is undoubtedly the best known and most diversified of all desert truffle genera, but its taxonomy is far from resolved. In addition, cultivation of desert truffles is not trivial and despite all research efforts in the last two decades, only two Terfezia species were to date successful cultivated both with perennial and annual Helianthemum species in basic soils. Research on how to cultivate Terfezia spp. with different plant hosts and over a broader array of soil types and pH values is still necessary to find most suitable “fungal symbiont – plant host” combinations for sustainable and efficient cultivation over a wider range of habitats.
With this in mind, this work aimed to: 1) expand the current knowledge on the diversity of genus Terfezia in southern Portugal; 2) study their putative mycorrhizal associations with Cistus spp.; and 3) develop methodologies to allow Cistus spp. to be used as host in desert truffle cultivation in acid soils.
Overall, the present research clearly demonstrates that Cistus spp. are indeed promising candidates for desert truffle cultivation and that different Terfezia-Cistus combinations can be used to enable desert truffle cultivation over a wide range of situations depending on the plantation purposes; DIVERSIDADE DO GÉNERO TERFEZIA NO SUL DE PORTUGAL E AS SUAS ASSOCIAÇÕES MICORRÍZICAS COM CISTUS L.: UM ESTUDO PARA VIABILIZAR A PRODUÇÃO DE TRUFAS DO DESERTO EM SOLOS ÁCIDOS
RESUMO:
O termo trufas do deserto descreve os ascocarpos hipógeos comestíveis, produzidos por fungos Ascomycota (Pezizaceae), característicos de zonas áridas e semiáridas. Estes são atualmente considerados como importantes produtos florestais não lenhosos, endémicos da bacia do Mediterrâneo, e constituem uma fonte de alimento, rica em proteínas e pobre em hidratos de carbono e lipídios, para as populações rurais. As trufas do deserto representam ainda um componente-chave da flora micológica em habitats áridos e semiáridos, atuando como parceiros simbióticos de diversas plantas hospedeiras, principalmente Cistaceae, e como agentes de prevenção contra a desertificação e erosão do solo.
Terfezia é indubitavelmente o género mais conhecido e diversificado de trufas do deserto, mas a sua taxonomia está longe de estar esclarecida. Também o seu cultivo não é trivial e, apesar de todos os esforços de pesquisa nas últimas duas décadas, apenas duas Terfezia foram, até o momento, cultivadas com sucesso, em solos básicos, com espécies perenes e anuais do género Helianthemum (Cistaceae). Falta ainda conhecer vários binómios “simbionte – planta hospedeira” que permitam o cultivo de Terfezia numa ampla variedade de solos e habitats.
Assim, os principais objetivos deste trabalho foram: 1) ampliar o conhecimento atual sobre a diversidade do género Terfezia no sul de Portugal, 2) estudar as suas potenciais associações micorrízicas com Cistus spp. e 3) desenvolver metodologias para permitir a sua aplicação no cultivo de trufas do deserto em solos ácidos.
No presente trabalho, é claramente demonstrado que Cistus spp. são candidatos promissores para o cultivo de trufas do deserto e que diferentes combinações de Terfezia-Cistus podem ser usadas para o cultivo de trufas do deserto numa ampla gama de situações, dependendo dos propósitos da plantação.
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Olsen, Margaret Anne. "How does dual-mycorrhizal association affect the ecological success of kanuka (Kunzea ericoides) across the South Island of New Zealand?" Thesis, University of Canterbury. School of Biological Sciences, 2015. http://hdl.handle.net/10092/10806.
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In this thesis I investigated the mutualism between Kunzea ericoides (kanuka) and two groups of soil fungi, ectomycorrhizae (ECM) and arbuscular mycorrhizae (AMF). Mycorrhizal mutualisms, which are considered globally ubiquitous, are poorly understood over changing abiotic gradients. A field survey of K. ericoides assessed how the relationship with the soil fungi varieties altered over a hydrologic gradient. Arbuscular mycorrhizal colonisation was significantly improved by increasing rainfall levels and amount of surrounding kanuka, and negatively affected by increasing altitude. Ectomycorrhizal colonisation was not significantly affected by any measured variables and remained relatively constant across all circumstances, suggesting that it is the preferred fungal mutualist for this tree species.
A glasshouse experiment was done to measure the effect of ECM inoculation on the growth and water usage of K. ericoides over varying moisture availability. The seedlings were planted in soil inoculated with both ECM and AMF (experimental) or AMF only (control) and then grown under varying levels of water stress. The experiment was replicated with two soil types, with soil from beneath adult manuka (Leptospermum scoparium) and soil from beneath adult kanuka (K. ericoides). ECM colonisation significantly increased as soil moisture decreased for both soil types. ECM inoculation also increased the root:shoot ratio, and drastically decreased water usage under drought conditions. There were some soil effects as the seedlings grown in manuka-soil achieving greater biomass than seedlings grown in kanuka-soil. This is possibly due to presence of pathogens or some type of legacy competition which the seedlings would experience growing near conspecifics.
Overall, K. ericoides formed a dominant mutualism with ectomycorrhizae. These two both thrive in dry environmental conditions and have a suite of complementing abilities which possibly allow K. ericoides to expand it range into these dry habitat types. The increased benefit of these mutualisms at the hydrologic range limit of the species supports the importance of biotic interaction mediating environmental stress. Understanding the effects and response of mycorrhizal mutualisms are especially significant considering current climate change issues in New Zealand and worldwide.
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Holland, Taylor Craig. "Vineyard soil communities and arbuscular mycorrhizal fungi associating with grapevine roots in response to irrigation frequency." Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/44234.
Full textAbstract:
Arbuscular mycorrhizal fungi form a root symbiosis with most plants and are known to benefit plants in a variety of ways. These organisms could be valuable in agricultural settings, leading to increased crop production and quality. For instance, the economically important Vitis vinifera is a highly mycorrhizal plant, dependent on the fungi for tolerating harsh growing conditions. Deficit irrigation is a viticultural practice that enables V. vinifera to be grown in arid climates where water resources are scarce, but how this management practice affects soil communities is not understood. There are three parts to this thesis. In the first experiment, I studied the abundance of different soil organisms to determine if irrigation frequency affects soil communities in general. The two frequencies of irrigation resulted in soil moisture levels that were either constant or fluctuated in a three-day cycle. I found that the biomass of fungi increased with fluctuating moisture, but in general the animal groups were most abundant in constantly moist soils. Secondly, I focused solely on the response of AM fungal communities. These did not respond to irrigation frequency. Instead, results of this experiment indicated there was an environmental effect as the fungal communities differed between the blocks. Both plant physiology and soil chemistry were identified as contributing to observed variation. Arbuscular colonization increased in the fluctuating soil moisture treatment compared with constant soil moisture, indicating a possible functional change in AM fungi due to irrigation frequency. In the final experiment I determined whether grapevines had distinct AM fungal communities compared to plants in co-occurring communities in the adjacent interrows. I found support for my prediction that the vinerow and interrow plant communities supported different AM fungal communities. Overall, this thesis indicates that management practices do affect soil communities, either in abundance, composition, or function. This could be due to changes in soil moisture, chemistry, or indirectly through changes in plant eco-physiology. It also provides
reasoning that more research is needed to enhance our understanding how AM fungal communities function in this agricultural setting.
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Asfaw, Zebene. "Tree species diversity, topsoil conditions and arbuscular mycorrhizal association in the Sidama traditional agroforestry land use, southern Ethiopia /." Uppsala : Dept. of Forest Management and Products, Swedish Univ. of Agricultural Sciences, 2003. http://epsilon.slu.se/s263-ab.html.
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McGreevy, Sonia. "Indigenous arbuscular mycorrhizal fungi of a tropical agroforestry system and their association with the intercrop, Zea mays L." Thesis, University of Edinburgh, 1996. http://hdl.handle.net/1842/11124.
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Zea mays L. is an important food crop and common intercrop species grown in semi-arid agroforestry systems in Kenya, East Africa. A preliminary field study showed that AMF spores occurred in particularly high number in this system compared with that reported for other less disturbed ecosystems. The same spore types occurred in tree and alley soil, however spore number and composition were variable, between host species, in fallow and cropped areas of the system and between wet and dry seasons. At the end of the dry season (February, 1991), fallow areas had significantly higher spore numbers than cropped areas of the system. Lower numbers of spores were found in soil in the dry season than in the wet season, when spore numbers were significantly higher in tree soil in the cropped area than in soil from other areas. The first experiment was established to determine the influence of host and fallowing on the effectiveness of AMF populations occurring in this system on mycorrhizal formation, growth and nutrition of plants. These results showed that plants inoculated with tree soil from the cropped area of the system had significantly higher mycorrhizal infection formation in roots, however this was not reflected in the growth and nutrient uptake of plants which were unaffected by AMF inoculation. The effects of soil type, soil volume and soil phosphorus were thought to have influenced the response of plants to inoculation in the previous experiment and so the influence of these factors on growth and nutrition of inoculated and uninoculated plants were investigated. Results from this experiment showed that plants had significantly different mycorrhizal infection in roots when grown in different soils. Mycorrhizal infection was higher in plants grown in smaller pots, decreasing significantly with incremental increases (1, 4 and 10 litre pots) in soil volume.
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Marques, Anderson Cesar Ramos. "FIXAÇÃO BIOLÓGICA DE NITROGÊNIO E MICORRÍZAÇÃO EM GRAMÍNEAS DOS CAMPOS SULINOS." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/4869.
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Empresa Brasileira de Pesquisa AgropecuáriaThe knowledge of the level of association that occurs between diazotrophic bacteria and fungi arbusculares mycorrhizae (AMF) in grassland ecosystems may be important for the understanding of the changes caused by the addition of fertilizers containing phosphorus (P) and nitrogen (N), in the production and botanical composition of natural pastures. The objective of this study was to evaluate. (a) the occurrence of three genera of diazotrophic bacterial in the root system under fertilization with N and P, and determine the contribution of N via BNF, and (b) evaluate the behavior of the association between AMF and native grasses. Four most abundant grasses in natural grasslands of the Southern Campos in Rio Grande do Sul , Axonopus affinis, Paspalum notatum, Andropogon lateralis and Aristida laevis were grown in pots of 5 kg, in a greenhouse, two studies being conducted (A e B ). In A, two treatments were applied: 50 mg kg-1 soil P and 100 mg kg-1 of soil N (NP) and a control, being evaluated, the number of diazotrophic bacteria of the genera Azotobacter, Azospirillum and Herbaspirillum, and the contribution of BNF was determined by the technique of natural 15N abundance. In B, the treatments consisted of applying 50 mg kg-1 soil P (P), application of 50 mg kg-1 soil P and 100 mg kg-1 of soil N (NP), and a control, in both treatments mycorrhizal colonization was determined. For A, A. laevis demonstrate to be more dependent on biological N fixation than the other species. The grass P. notatum compared with other species demonstrated to be more efficient to absorb available soil N. The dry matter accumulation in shoots of the native species was higher with the application of NP. In B the mycorrhizal colonization was similar between the control, P and NP to the roots of A. lateralis and A. laevis, thus presenting a greater dependence on the mycorrhizal association. Differently, in A. affinis and P. notatum, the mycorrhizal colonization was lower when subjected to fertilization with P and NP, thus presenting a lower dependence. It is concluded for A that fertilization with N and P reduces diazotrophic colonization, increasing the production of dry matter and N content of the tissue. A. laevis showed the highest contribution of biological nitrogen fixation, since P. notatum showed higher N accumulation in soil. In relation to B, A. laevis and A. lateralis have a higher dependence on the mycorrhizal than A. affinis and P. notatum.
O conhecimento do nível de associação que ocorre entre bactérias diazotróficas e fungos micorrízicos arbusculares (FMA) nos ecossistemas campestres, pode ser importante para a o entendimento das alterações provocadas pela adição de fertilizantes, contendo fósforo (P) e nitrogênio (N), na produção e na composição botânica das pastagens naturais. O objetivo do presente trabalho foi avaliar (a) a ocorrência de três gêneros de bactérias diazotróficas no sistema radicular sob fertilização com N e P, e determinar a contribuição de N via FBN, e (b) avaliar o comportamento da associação entre FMAs e gramíneas nativas. Foram utilizadas quatro gramíneas de maior abundância nas pastagens naturais dos Campos Sulinos no Rio Grande do Sul, Axonopus affinis, Paspalum notatum, Andropogon lateralis e Aristida laevis, cultivadas em casa de vegetação, sendo conduzidos dois estudos (A e B). Em A, foram aplicados dois tratamentos: 50 mg kg-1 de solo de P + 100 mg kg-1 de N solo (NP) e uma testemunha, sendo avaliados, o número de bactérias diazotróficas dos gêneros Azotobacter, Azospirillum e Herbaspirillum, e a contribuição da FBN através da técnica da abundância natural de 15N. Em B, os tratamentos consistiram na aplicação de 50 mg kg-1 de solo de P (P); aplicação de 50 mg kg-1 de solo de P + 100 mg kg-1 de N solo (NP), e uma testemunha, em ambos foi determinada a colonização micorrízica. A espécie A. laevis demonstrou ser mais dependente da fixação biológica de N que as demais espécies. A espécie P. notatum em comparação as demais espécies, demostrou ser mais hábil em absorver o N disponível no solo. A matéria seca acumulada da parte aérea das espécies nativas foi maior com a aplicação de NP. A colonização micorrízica foi semelhante entre a testemunha, P e NP para as raízes de A. lateralis e A. laevis, apresentando assim uma maior dependência da associação micorrízica. Diferentemente, nas espécies A. affinis e P. notatum, a colonização micorrízica foi menor quando submetidas a adubação com P e NP, apresentando assim uma menor dependência. Conclui-se assim, que a adubação com N e P reduz a colonização de bactérias diazotróficas, aumentando a produção de matéria seca e teor de N no tecido. A. laevis apresentou a maior contribuição da fixação biológica de nitrogênio, já P. notatum apresentou maior acúmulo de N do solo. As espécies A. laevis e A. lateralis apresentam maior dependência da micorrização que as espécies A. affinis e P. notatum.
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Cavender, Nicole D. "Genetic variation of Big Bluestem (Andropogon Gerardii) and its association with Arbuscular Mycorrhizal Fungi : implications for prairie restoration and reintroduction /." The Ohio State University, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486400446372186.
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Niu, Chih-hao. "Association of nitrogen-fixing bacteria with ectomycorrhizae in Douglas-fir /." 1987. http://hdl.handle.net/1957/11340.
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Li, Hoi-Tung, and 李鎧彤. "Study of hypogeous fungi and their mycorrhizal association with Pinaceae in Taiwan." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/733em2.
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碩士國立臺灣大學
森林環境暨資源學研究所
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Study of hypogeous fungi in Taiwan is scarce and insufficient, especially when comparing with epigeous mushrooms. The objective of this study is to investigate the association of hypogeous fungi with Pinaceae hosts, in both natural forest and plantation in Taiwan. Through morphological, molecular and phylogenetic analysis, sporocarp and mycorrhiza would be identified in order to study the diversity of hypogeous fungi in Taiwan. In June 2016 to May 2017, 9 locations with 6 endemic Pinaceae species were investigated. 4 new species, including Tuber piceanum Wong & Li sp. nov, Tuber xitouense Wong & Li sp. nov, Hydnotrya formosanum Wong & Li sp. nov and Elaphomyces verrucosispora Wong & Li sp. nov; and 3 Taiwan new discovery species, including Endogone flammicorona Trappe & Gerdem, Sclerogaster compactus (Tul. & C. Tul.) Sacc. and mycorrhiza of Cenococcum geophilum Fr. were found, in addition to an immature Hydnobolites cerebriformis Tul. & C. Tul. sporocarp, which possiblely be Taiwan new discovery species but unable to confirm without mature spore characteristics. Results show that hypogeous fungi in Taiwan are abundant and with high diversity, which worth input of more time and resources for further studies. Only one species of hypogeous fungi associated mycorrhiza was found in this study. Most mycorrhiza were found to be associated with epigeous mushrooms, despite their identical morphology with the hypogeous fungi associated mycorrhiza described in references. This confirm the difficulty and unreliability of identification of mycorrhizal fungi solely by mycorrhiza morphology, and review epigeous fungi comparatively more competitive in association with tree host. Comparing the hypogeous fungi diversity associating with different Pinaceae species, Picea has the highest diversity, with Tsuga and Pseudotsuga as the second and Keteleeria as the third, and no discovery for Abies and Pinus. Results also review the higher hypogeous fungi diversity in plantation than in natural forest. We believe that is caused by the high fungal diversity in soil community, resulting in fierce competition between mycorrhizal fungi in natural forest.
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Fathima, P. S. "Influence of various agrochemicals and inoculation techniques on va-mycorrhizal association in Mulberry." Thesis, 1997. http://hdl.handle.net/2009/1330.
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Carvalho, Pedro Daniel Santos de. "Studies of mycorrhizal associations in Cistaceae from a maritime pine forest: ecological and biotechnological approach." Master's thesis, 2016. http://hdl.handle.net/10316/32174.
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Dissertação de Mestrado em Biodiversidade e Biotecnologia Vegetal, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências da Universidade de Coimbra.Este trabalho foi desenvolvido em três capítulos com três diferentes, mas complementares, âmbitos de trabalho: crescimento fúngico, estudo de associações micorrízicas em campo e síntese de micorrizas. No primeiro capítulo descrevemos o estabelecimento de culturas de micélio de quatro fungos, duas espécies micorrízicas (Lactarius deliciosus e Tricholoma portentosum) e duas espécies saprófitas (Agaricus bisporus e Macrolepiota procera), e o seu crescimento em cinco meios (Potato dextrose agar (PDA), Malt extract agar number 2 (MEA), Murishage and Skoog medium (MS), Biotin-Aneurin-Folic acid medium (BAF) e Melin-Norkrans Modified medium (MNM)) a três temperaturas diferentes (4ºC, 24ºC e 30ºC). Os resultados mostram que L. deliciosus cresce melhor em MNM ou MS a 24ºC e que os melhores meios para manutenção de culturas a 4ºC são PDA ou MNM, T. portentosum apresenta melhor crescimento em MNM ou PDA a 24ºC e para manutenção os melhores meios são BAF ou MNM. Quanto aos saprófitas, A. bisporus mostra melhor crescimento em PDA ou BAF a 24ºC com os mesmos meios sendo os melhores para manutenção e para M. procera o melhor crescimento foi detetado em PDA a 30ºC e para manutenção os melhores meio são BAF ou MS. O estudo de associações micorrízicas foi realizado numa floresta de pinheiro bravo na costa Portuguesa, as espécies vegetais estudadas foram Halimium halimifolium, Acacia longifolia e Pinus pinaster. Foi possível identificar seis espécies fúngicas associadas com H. halimifolium, uma associada a A. longifolia e seis associadas a P. pinaster, uma espécie foi encontrada em todos os hospedeiros e três espécies partilhadas entre H. halimifolium e P. pinaster. No último capítulo, foi descrita uma nova metodologia para a síntese de micorrizas, usando o meio MS como substrato. A síntese foi testada entre duas espécies vegetais da família Cistaceae, Halimium halimifolium e Tuberaria lignosa, e três espécies fúngicas de importância económica, Lactarius deliciosus, Tricholoma equestre e Tricholoma portentosum. Apenas o ensaio de síntese entre Tuberaria lignosa e Tricholoma equestre não produziu ectomicorrízas, provavelmente devido a contaminações.
This work was developed in three chapters with three different, but complemental, work scopes: fungal growth, study of mycorrhizal associations and mycorrhizal synthesis. In the first chapter we described the establishment of mycelial cultures of four fungi, two mycorrhizal species (Lactarius deliciosus and Tricholoma portentosum) and two saprophytic species (Agaricus bisporus and Macrolepiota procera) and their growth behaviours in five media (Potato dextrose agar (PDA), Malt extract agar number 2 (MEA), Murishage and Skoog medium (MS), Biotin-Aneurin-Folic acid medium (BAF) and Melin-Norkrans Modified medium (MNM)) at three different temperatures (4ºC, 24ºC e 30ºC). Our results showed that L. deliciosus grows best in MNM or MS at 24ºC and that the best media for culture maintenance at 4ºC are PDA or MNM, T. portentosum showed the best growth in MNM or PDA at 24ºC, for maintenance the best media are BAF or MNM. For the saprophytes, A. bisporus had the best growth in PDA or BAF at 24ºC with the same media being the best for maintenance and for M. procera the best growth was in PDA at 30ºC and for maintenance the best media are BAF or MS. The study of mycorrhizal associations was performed in a maritime pine forest in the Portuguese coast, the plant species studied were Halimium halimifolium, Acacia longifolia e Pinus pinaster. We found six fungal species associated with H. halimifolium, one associated with A. longifolia and six associated with P. pinaster, one species was found associated with all hosts and three species shared between H. halimifolium e P. pinaster. In the last chapter, we describe a new methodology for mycorrhizal synthesis, using MS medium as substrate. The synthesis was tested between two Cistaceae, Halimium halimifolium and Tuberaria lignosa, and three fungal species of economic importance, Lactarius deliciosus, Tricholoma equestre and Tricholoma portentosum. Only the assay between Tuberaria lignosa and Tricholoma equestre didn’t produce ectomycorrhizas, probably due to contamination.
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Welsh, Catherine M. "Organic crop management can decrease labile soil P and promote mycorrhizal association of crops." 2007. http://hdl.handle.net/1993/312.
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A concern with organic farming is for the depletion of soil phosphorus. The objectives of this study were to determine which organic management systems deplete soil phosphorus and whether arbuscular mycorrhizal fungi (AMF) could assist crops in taking up phosphorus in these systems. The research site was a 14 year-old study at Glenlea, Manitoba, having 3 different 4-year rotations under organic and conventional management: forage-grain ± manure-compost, grain-only, and a restored tall grass prairie. The modified Hedley procedure revealed organic systems to have lower concentrations of labile phosphorus than conventional but recalcitrant fractions did not differ (P < 0.05). Nitrogen was limiting in the organic grain-only rotation; phosphorus in the organic forage-grain. Mycorrhizal colonization as arbuscules was higher in organic than conventional systems (P < 0.05). To prevent phosphorus limitation, we suggest high-export organic rotations be balanced with sufficient rates of manure-compost and AMF maintained to help with phosphorus absorption.May 2007
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Keane, Kevin D. "The separate and combined effects of ozone and acidic precipitation on paper birch seedlings (Betula papyrifera Marsh.) and their mycorrhizal associations /." 1987. https://scholarworks.umass.edu/theses/3400.
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"Association of chickpea with soil fungi: a comparison of cultivars." Thesis, 2014. http://hdl.handle.net/10388/ETD-2014-11-1848.
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Certain crop plants are susceptible to pathogens or unable to develop efficient microbial symbioses. These crops adversely impact soil biological quality with consequences on plant health and productivity of cropping systems. Chickpea is a rotational pulse crop with two types: kabuli and desi, and several cultivars. Cultivation of chickpea has inconsistent effects on soil microbial communities and subsequent wheat crops. I conducted field studies and used high throughput molecular analyses to explore the variations among chickpeas to identify cultivars developing fungal communities that are conducive to plant health and productivity. I also carried out greenhouse studies and used biochemical analyses to investigate the response of chickpea cultivars to arbuscular mycorrhizal (AM) fungi and non-AM fungal endophytes and identify the influence of root and root metabolites on the endophytic and pathogenic fungi. Cultivars and types of chickpeas and environmental conditions promoted different fungal communities in the root endosphere. Funneliformis and Claroideoglomus were the dominant AM fungal genera and Fusarium and Alternaria were the dominant non-AM fungal genera in the roots of chickpea. The roots of cultivars CDC Corrine, CDC Cory and CDC Anna hosted the most diverse fungal communities in contrast to CDC Alma and CDC Xena roots which hosted the least diverse communities. Plant response to AM and non-AM fungal endophytes varied with genotype and type of chickpea. The root symbiosis effectively promoted plant growth in CDC Cory, CDC Anna and CDC Frontier and stimulated nitrogen fixation in CDC Corrine. Cultivars of chickpea responded differently to dual inoculation of the AM and non-AM fungal endophytes. Co-inoculation with AM and non-AM fungal endophytes had additive effects on CDC Corrine, CDC Anna and CDC Cory but non-AM fungal endophytes reduced the positive effect of AM fungi in Amit and CDC Vanguard. Desi chickpea appeared to form more efficient symbioses with soil fungal resources than kabuli chickpea. Protein(s) up-regulated in the mycorrhizal roots of the desi chickpea CDC Anna suppressed the growth of the fungal endophytes Trichoderma harzianum and Geomyces vinaceus and of the pathogens Fusarium oxysporum and Rhizoctonia sp. The formation of AM symbiosis decreased the production of root bioactive metabolites soluble in 25% methanol. Some of the root metabolites stimulated the growth of Trichoderma harzianum and Geomyces vinaceus, and a few inhibited Rhizoctonia sp. and Fusarium oxysporum. A few metabolites with contrasting effects on the different fungal species were detected. The non-protein phytochemicals had selective effects on the endophytes and pathogens whereas the antifungal proteins of mycorrhizal roots were non-selective. Overall the study reveals a "genotype effect" of chickpea on the soil microbiota suggesting the possibility to improve the performance of this crop through the selection of genotypes improving the communities of root associated fungi, by associating and responding to beneficial fungi and repressing the pathogens.