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Dissertations / Theses on the topic 'Vesicular-arbuscular mycorrhizas'

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1

Facelli, Evelina. "The role of mycorrhizal symbiosis in plant intraspecific competition and population structure." Title page, Contents and Abstract only, 1998. http://hdl.handle.net/2440/37773.

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The overall objective of this project was to investigate the effects of the symbiotic association of plants with vesicular - arbuscular mycorrhizal fungi on the intensity of intraspecific competition and its consequences on population structure I performed four main glasshouse experiments using a non - cultivated species, Rhodanthe chlorocephala ssp rosea, or a cultivated species, Trifolium subterraneum. I grew the plants at different plant densities, under different levels of resources ( phosphorus and / or light ), in environments with homogeneous and / or patchy distribution of phosphorus ( P ). In pots with homogeneous distribution of P, the addition of P to R. chlorocephala and mycorrhizal infection in T. subterraneum increased plant biomass of single plants. However, these beneficial effects were reduced by increasing plant density. Shading of plants of T. subterraneum did not generally alter these effects. Mycorrhizal symbiosis and the addition of P always increased the intensity of plant intraspecific competition. In trays with patchy or homogeneous distribution of P, mycorrhizal infection and patchy distribution of P increased the total biomass and size inequality of populations of plants of T. subterraneum. Individual biomass was determined by the local soil P concentration in patchy environments and by mycorrhizal infection in low density treatments. Mycorrhizal infection, but not patchy P distribution, increased relative competition intensity. Asymmetric or symmetric distribution of resources between plants will change these size hierarchies. The distinction between these two types of distributions has lead to two different models explaining the interaction between competition and size inequality ( degree to which the biomass is concentrated within a small fraction of the population &# 40 Weiner and Thomas 1986 ) ) the resource depletion and resource pre - emption models ( Weiner and Thomas 1986, Weiner 1988b ). In the first model ( resource depletion ) competition reduces the relative growth rate of all the individuals by the same proportion, reduces variance of growth rates and reduces variation in sizes. Thus, in this model resource acquisition is proportional to plant size ( Weiner 1990 ). This model is also called symmetric or two - sided competition and applies when competition for nutrients predominates. It predicts that at high density, plants will be smaller but the population will have less inequality than at low density ( Weiner and Thomas 1986 ). In the second model ( resource pre - emption ), competition increases the variation in relative growth rates and increases variation in sizes. Large plants obtain a more than proportional share of the resources ( relative to sizes ) ( Weiner 1990 ) and this increases their competitive ability which results in a positive feedback on plant size. This phenomenon is also called snowball cumulation, asymmetric or one - sided competition and it was observed only when competition for light was predominant ( Wilson 1988a ). This second model predicts that at high density plant populations will have more inequality than at low density ( Weiner and Thomas 1986 ). Although these two models are generally accepted, alternative analyses and recent experiments show that the degree of asymmetry of the interaction depends on the spatial and temporal distribution of the resource, the spatial distribution of the individuals in the population, neighbourhood competition and the mobility of the resource ( Huston 1986 ; Miller and Weiner 1989, Weiner 1990, Bonan 1991 ). Weiner ( 1990 ) suggested that if nutrients are distributed homogeneously and the uptake is proportional to root size, the competitive interaction will be more symmetric, whereas if patches with more nutrients can be reached by large individuals, asymmetric competition will predominate. This hypothesis has not been tested yet. Turner and Rabinowitz ( 1983 ) found that populations with an initial random spatial distribution of individuals had an unexpected increase in size inequality. My results emphasise that the main effects of mycorrhizas at the individual level cannot be expected to be apparent at the population level, because of the influence of density - dependent processes. However, infected individuals with a strong response to the symbiosis would have an advantage in situations of competition. This scenario can explain the maintenance of the symbiotic ability even under conditions such as dense populations, where there is no obvious advantage of the symbiosis at the population level.
Thesis (Ph.D.)--Department of Soil and Water, 1998.
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2

Sanders, Ian Robert. "Seasonality, specificity and selectivity of vesicular-arbuscular mycorrhizas in grasslands." Thesis, University of York, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280447.

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3

Sukarno, Nampiah. "Effects of selected fungicides on vesicular-arbuscular mycorrhizal symbiosis." Title page, contents and summary only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phs948.pdf.

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4

Sancayaningsih, Retno Peni. "Studies of vesicular-arbuscular mycorrhiza in Wanagama I Forest Research Center, Yogyakarta, Indonesia." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30315.

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Three studies were conducted on VA mycorrhiza in Wanagama Forest Research Center, Yogyakarta, Indonesia. The first was on VA mycorrhizal status of four forest species (Acacia mangium, Acacia holosericea, Tectona grandis, and Swietenia macrophylla) plantations and nurseries of Acacia mangium and Tectona grandis. Samples from the field were only taken during the dry season, June 1988. These four six-year old forestry species were mycorrhizal. Nursery plants had higher VAM colonization than the plantation roots and both Acacia species have higher percent colonization than the other two species. Available phosphorus in calcareous soils is low and seems not to be a major contribution to the variation of VAM colonization. Potassium and sodium were more important in this case even though their role could not be determined in this study. The second study was conducted to determine VAM fungal species associated with the plant species. There were 16 different spore types belonging to the genera Glomus, (the most common found), Sclerocystis, Scutellispora, and probably Acaulospora. Type of inoculum and host compatibility were suggested as important factors in the success of pot culture study. The third study was carried out in a growth chamber to determine Acacia spp. response to single VAM fungal species and mixed species inoculum. Single species inoculum in both Acacia was observed to improve biomass and plant growth better than the mixed inoculum. Acacia mangium performed better with Glomus versiforme than did A. holosericea. Host compatibility, effectiveness of VAM spore inoculant, infectivity and environmental factors have major effects on plant growth responses. Study of tropical VAM requires further basic research, including taxonomy. Experimental procedures such as pot culture technique, type of inoculum, growth media and host plant specificity along with evaluation of appropriate soil chemical analysis also requirefurther elaboration. These types of studies are needed to understand the relationship between VAM and the environment and in the application studies in agriculture and forestry. This information is especially important in tropical countries, where little research results and limited resources, such as for fertilizers, are available.
Land and Food Systems, Faculty of
Graduate
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5

Sulistyowati, Emy. "Development of molecular probes to distinguish vesicular-arbuscular mycorrhizal fungi." Title page, Summary and Contents only, 1995. http://web4.library.adelaide.edu.au/theses/09A/09as949.pdf.

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Bibliography: leaves 71-79. Almost 80 percent of plant taxa develop vesicular-arbuscular mycorrhizae (VAM) which are symbiotic associations between plant roots and soil fungi. The fungi are biotropic-obligate symbionts. Identification of VAM fungi is currently based on spore characteristics. Molecular techniques provide tools for better and more accurate identification of species, as well as for the examination of genetic variability occuring between individual spores of a single species.
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6

McGonigle, T. P. "Vesicular-arbuscular mycorrhizas and plant performance in a semi-natural grassland." Thesis, University of York, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379456.

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7

Ike-Izundu, Nnenna Esther. "Interaction between arbuscular mycorrhizal fungi and soil microbial populations in the rhizosphere." Thesis, Rhodes University, 2008. http://hdl.handle.net/10962/d1004021.

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This study examined the rehabilitation potential of AM fungi with organic and inorganic fertilisers under pot and field trial conditions as well as their interaction with rhizospheric organisms and specific functional groups. In addition, the study highlighted the effects of land-use management on AM fungal populations in soil and the mycorrhizal status of some selected plants from one of the study sites. The study focussed on two sites that differ in operational activities and these included a mined area that was to be rehabilitated and a commercial farming site. A pot trial was conducted using an overburdened soil resulting from kaolin clay mining. Pots were seeded with Cynodon dactylon and treated with either Organic Tea or NPK (3:1:5) fertiliser, with or without AM fungal inoculum. The compatibility of these fertilisers with AM fungi was assessed by plant growth and percentage root colonisation. Maximum shoot height and plant biomass were observed at the 28th week with NPK (3:1:5) fertiliser supporting mycorrhizal colonisation by 80%. The result indicated the potential of AM fungi to be used in rehabilitation with minimal phosphate fertiliser. Similarly, a field trial was set-up using 17 x 17 m[superscript 2] plots in the mining site that were treated with the same organic and inorganic fertilisers as well as with AM fungal inoculum in different combinations. The interaction between AM fungi and soil microbial population was determined using culture dependent and culture independent techniques. The culture dependent technique involved the use of soil dilution and plating on general purpose and selective media. The result showed that there was no change in the total culturable bacterial number in the untreated and AM fungal treated plots, while a change in species composition was observed in the functional groups. Different functional groups identified included nitrogen fixing bacteria, pseudomonads, actinomycetes, phosphate solubilisers and the fungal counterparts. Gram-positive bacteria were observed as the predominant phenotypic type, while nitrogen fixers and actinomycetes were the predominant functional groups. Species identified from each functional group were Pseudomonas fulva, Bacillus megaterium, Streptomyces and actinomycetales bacteria. Meanwhile, fungi such as Ampelomyces, Fusarium, Penicillium, Aspergillus, Cephalosporium and Exserohilium were identified morphologically and molecularly. Furthermore, the mining site had a significantly higher bacterial number than the farming site thereby indicating the effects of land-use management on culturable bacterial numbers. The culture independent technique was carried out by cloning of the bacterial 16S rDNA and sequencing. Identified clones were Bradyrhizobium, Propionibacterium and Sporichthya. A cladogram constructed with the nucleotides sequences of identified functional species, clones and closely related nucleotide sequences from the Genbank indicated that nucleotide sequences differed in terms of the method used. The activity and establishment of the introduced AM fungal population was determined by spore enumeration, infectivity assay, percentage root colonisation and assessment of glomalin concentrations. The results indicated that the two land use types affected AM fungal populations. However, the establishment of AM fungi in the farming site was more successful than in the mining site as indicated by the higher infectivity pontential. Selected host plants, which were collected around the mine area, were observed to be mainly colonised by AM fungi and these were identified as Pentzia incana, Elytropappus rhinocerotis, Euphorbia meloformis, Selago corymbosa, Albuca canadensis and Helichrysum rosum. These plant species were able to thrive under harsh environmental conditions, thereby indicating their potential use as rehabilitation host plants. Generally, the findings of this study has provided an insight into the interaction between arbuscular mycorrhizal fungi and other soil microorganisms in two fields with differing land use management practices.
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8

Murphy, Phillip James. "Plant-fungal interactions during vesicular-arbuscular mycorrhiza development : a molecular approach." Title page, contents and abstract only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phm9778.pdf.

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Bibliography: leaves 153-185. Vesicular-arbuscular (VA) mycorrhiza formation is a complex process which is under the genetic control of both plant and fungus. This project aims to develop a model infection system in Hordeum vulgare L. (barley) suitable for molecular analysis; to identify host plant genes differentially expressed during the early stages of the infection process; and to screen a mutant barley population for phenotypes which form abnormal mycorrhizas.
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9

Curland, Rebecca D. "The effects of plant invasion on arbuscular mycorrhizal fungi : a review of how these community dynamics are studied /." Connect to online version, 2009. http://minds.wisconsin.edu/handle/1793/45114.

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10

Cooke, Margaret Anne. "Vesicular-arbuscular mycorrhizae and base cation fertilization in sugar maple (Acer saccharum marsh L.)." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39428.

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Under field conditions, vesicles were the most frequently observed mycorrhizal structures in sugar maple, while greenhouse grown seedlings formed more arbuscules. Seasonal fluctuations of vesicular-arbuscular mycorrhizae existed. Mycorrhizal associations formed within 30 days in the greenhouse. Arbuscules were usually formed from hyphal coils and occasionally from linear hyphae spreading from cell to cell. Degenerating arbuscules were not observed. The addition of basic cations increased the number of vesicles formed and decreased the overall infection rates and seedling growth. The uptake of calcium, magnesium, and nitrogen decreased, and potassium uptake increased as fertilization rates increased. Positive correlations existed between the incidence of arbuscules and plant growth and health and between the incidence of arbuscules and the uptake of calcium, magnesium, nitrogen and phosphorus, and with the uptake ratios and these elements with potassium. This suggests that vesicular-arbuscular mycorrhizae may in some way be regulating ionic balance in these seedlings.
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11

Morin, France 1963. "Vesicular-arbuscular mycorrhizal efficiency on apple rootstocks : effects of genotypes and herbicides." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68224.

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There has been little research into the compatibility of commonly utilized apple rootstocks and VA-fungal types, and even less research regarding the effects of herbicides used in orchards, on the VAM symbiosis of apple trees. Studies demonstrated that early inoculation of young apple plants, prior to transplanting, results in healthy and vigorous plants with better growth and nutrition than uninoculated plants. We studied the efficiency of VA-fungal species and isolates on young apple rootstocks, produced by in vitro propagation. Mycorrhizal inoculation promoted plant growth, dry mass production and leaf P concentration. Mycorrhizal efficiency was associated with larger external hyphal network but showed no relation with the internal colonization. Despite the high P-fertility of the soil used, growth enhancement due to mycorrhizal inoculation was attributed to an improved P nutrition.
In a second experiment, the effect of herbicides currently used in orchards was tested on the mycorrhizal symbiosis. Paraquat, simazine and dichlobenil were applied to soil with mycorrhizal and non-mycorrhizal apple plants. Mycorrhizae increased herbicide toxicity in apple, as demonstrated by the greatly increased plant mortality. While both paraquat and simazine decreased spore germination in vitro, none of the herbicide treatments affected root colonization in soil. Effects on the photosynthetic rate, measured after herbicide application, indicated a physiological interaction between mycorrhizal colonization and dichlobenil, involved in the toxic response of apple plants.
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12

Skinner, Amy. "Investigating the effect of Glomus etunicatum colonization on structure and phloem transport in roots of Eragrostis curvula (Umgeni)." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1003796.

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The symbiotic unit of an arbuscular mycorrhizal fungus and its host is able toachieve and maintain far higher inflow of nutrients than non-mycorrhizal roots. The colonization strategy of the mycobiont within the plant is intrinsic to the symbiosis with respect to both structural adaptations and nutrient exchange. An investigation into the effect of Glomus etunicatum colonization on the structure and phloem transport in Eragrostis curvula (Umgeni) allowed for greater insight into the dynamic of the symbiosis. The combined use of stains (such as Trypan Blue, Chlorazol Black, Safranin and Fast Green), and techniques, (such as freeze-microtome transverse sectioning and permanent slide preparations) contributed to a successful general observation of an intermediate colonization strategy using light microscopy methods. However, clarity into structural detail of mycorrhizal forms required electron microscopy studies. The SEM method used with freeze fracture was a relatively quick and simple method allowing for the observation of surface and internal features. The TEM method allowed for highresolution images providing insight into the variations in the apoplasmic compartmental form, and how this may relate to the function of the symbiosis with regard to fungal coils or arbuscules. The apoplasmic nature of mycorrhizas was substantiated and no symplasmic connections were found between symbionts. Fluorescence studies demonstrated that 5,6-carboxyfluorescein was transported through the phloem into the roots of E. curvula, but remained predominantly in the root phloem. Unloading only occurred in optimal nutrient exchange areas of meristimatic lateral or apical growth regions. It was not possible, using fluorescence techniques and related equipment available, to conclusively establish if there were symplasmic connections between the mycobiont and its host or if bidirectional transfer of nutrients occurred at the same interface.
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13

Snellgrove, Robert Charles. "Effects of vesicular-arbuscular mycorrhizas on the carbon and phosphorus physiology of Allium species." Thesis, Rothamsted Research, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376110.

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14

Ghomsheh, Habib Nadian. "Effects of soil compaction on growth and P uptake by Trifolium subterraneum colonised by VAM fungi /." Title page, Contents and Summary only, 1997. http://web4.library.adelaide.edu.au/theses/09ASOP/09asopg427.pdf.

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15

Van, den Bos Alexander Arthur. "How does agricultural management affect the structure and function of arbuscular mycorrhizal fungal communities?" Thesis, University of Aberdeen, 2015. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=228013.

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Arbuscular mycorrhizal (AM) fungi form an obligate symbiosis with many wild and cultivated plants. The plant may benefit from improved nutrient uptake (particularly phosphorus) and resistance to drought, pests and disease. Compared to more natural habitats, arable systems support reduced diversity of AM fungi, with community structure shifted in favour of ruderal types. Physical disturbance is an important driver of these differences and reduced tillage systems might facilitate greater utilisation of the AM symbiosis as part of more sustainable production systems. In this study, the structure of root-associated AM fungal communities in barley grown under a range of tillage regimes was characterised, using high-throughput molecular methodology. AM fungal community structure was significantly influenced by tillage intensity, with soils subject to high tillage burden richest in ruderal types. These findings were consistent in both winter and spring barley cultivars. Significant temporal changes in AM fungal community structure suggested an important role for plant growth stage in determining AM fungal community dynamics. Functional differences can occur between fungal species and different fungus-plant combinations, and in the second part of this study the functional consequences of changes in community structure due to tillage were tested in a model system using intact field-soil cores. There were clear differences in AM fungal community structure due to differential physical disturbance. Although no functional effects were observed, this may have been due to the inherent limitations of recreating field conditions in microcosm experiments. The results of this comprehensive assessment of fine-scale spatial variation in AM fungal community structure in an arable system identify tillage as an important driver of AM fungal community dynamics, and plant growth stage is also a key factor which has rarely been addressed. Elucidating the functional significance of these changes remains essential in order to justify future changes to arable management practices.
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Wang, Baoling 1965. "Low temperature and soil disturbance effects on winter survival and vigour in spring of arbuscular mycorrhiza fungus." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30764.

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Mycorrhiza is an association between a host plant and a soil fungus. Experiments were conducted to determine low temperature and soil disturbance effects on AM fungus winter survival and vigour in spring. The results showed that cool temperatures significantly reduced plant root growth and delayed AM formation. Glomus intraradices sporulation was highest at 23°C, while spore metabolic activity was significantly reduced with temperature below 10°C. Root length and colonization percentage decreased at 10°C. Mycorrhizal fungi increased 32P activity of leek leaves at a root zone temperature of 23°C 7 days after 32P injection, and at both 23°C and 15°C 14 days after injection. No difference was found at 0°C between mycorrhizal and non-mycorrhizal plants. Amounts of total and metabolically active spores and hyphae varied over sampling times. The infectivity of AM fungi was not affected by soil disturbance, but varied among the sampling times.
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Ubalijoro, Eliane. "Study of the arbuscular mycorrhizal fungus Glomus intraradices at the molecular level." Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=37852.

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Arbuscular mycorrhizal (AM) fungi have been living in association with land plants for at least 400 million years. Because they are obligate symbionts, the study of AM symbiosis has focused primarily on its plant host and progress in the molecular biology of AM fungi has been very slow. Using two different approaches, library screening and direct PCR-based assays, genetic information of AM fungi was compared across isolates and species. This allowed the study of novel DNA regions previously unexplored in AM fungi. The following species were investigated: Glomus intraradices, Glomus mosseae, Gigaspora margarita, Scutellospora calospora, Acaulospora scrobiculata and Entrophosphora colombiana. In the first approach, using in vitro grown G. intraradices, a DNA extraction protocol was developed for the construction of a partial genomic library. This library was screened for the presence of microsatellite-containing loci. PCR primers were designed based on five identified loci. Two of these loci were monomorphic for all isolates and species. The second approach used a combination of degenerate and specific primers for fungal chitin synthase genes to explore the variability of this gene family in AM fungi. A total of 21 AM sequences were isolated and sequenced, covering class I and II chitin synthases. RT-PCR with G. intraradices revealed differential expression of chitin synthases in spores and mycelium, as compared to mycorrhized roots. In addition, using primers designed from a highly conserved sequence for plant resistance genes, classical PCR and RT-PCR allowed the detection of a genomic sequence and its cDNA counterpart encoding a putative serine/lysine rich protein in G. intraradices. We have thus investigated genetic variability in AM fungi in functional genes as well as in repetitive DNA regions. Study of gene expression was also possible using in-vitro grown G. intraradices.
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Asif, Mohammad. "Comparative study of production, infectivity, and effectiveness of arbuscular mycorrhizal fungi produced by soil-based and soil-less techniques." Thesis, [Campbelltown, N.S.W. : The Author], 1997. http://handle.uws.edu.au:8081/1959.7/510.

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The present study was firstly aimed at producing the AM fungal inocula by using soil-based and soil-less culture techniques, including the in-vitro axenic technique, and secondly to assess the infectivity and effectiveness of the inocula so produced in glasshouse and field conditions. Indigenous AM fungi from 5 different sites of New South Wales were successfully propagated and multiplied using the pot-culture and atomizing disc aeroponic culture techniques, and their infectivity was measured using the MPN bioassay method. The coarse and fine sand mix was proven to be very effective for the production of AM fungal inocula. The findings indicated that aeroponic culture technique is far superior to that of conventional pot-culture technique, and could possibly substitute the most commonly used pot-culture technique of AM fungal inoculum production. The ultra-sonic nebulizer technology could possibly be an alternative to conventional aeroponic systems for producing AM fungal isolates in commercial quantities. The introduction of the sheared-root inoculum of Glomus intraradices, produced by the ultra-sonic nebulizer technique, into agricultural soils can substantially reduce the intake of P-fertilizers as much as 50% of the recommended level. The study also indicated that soil phosphorus is a critical factor in limiting mycorrhizal colonization, possibly limiting mycorrhizal responses.The research suggests that various commercially produced single or 'cocktail' inocula may work on mycorrhiza dependent plants in soils where the indigenous AM flora is either not abundant and/or efficient. Furthermore, ecophysiology of the same AM species have different effects on plant growth.
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Kasiamdari, Rina Sri. "Interactions between arbuscular mycorrhizal fungi and other root-infecting fungi." Title page, contents and abstract only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phk1887.pdf.

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Francis, R. "The biology of vesicular-arbuscular mycorrhizas with special reference to their role in nutrient transfer between plants." Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380957.

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Asif, Mohammad. "Comparative study of production, infectivity, and effectiveness of arbuscular mycorrhizal fungi produced by soil-based and soil-less techniques /." [Campbelltown, N.S.W. : The Author], 1997. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030716.094919/index.html.

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22

Workman, Rachael Elizabeth. "Effects of Arbuscular Mycorrhizal Fungal Infection and Common Mycelial Network Formation on Invasive Plant Competition." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2025.

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Understanding the biotic factors influencing invasive plant performance is essential for managing invaded land and preventing further exotic establishment and spread. I studied how competition between both conspecifics and native co-habitants and arbuscular mycorrhizal fungal (AMF) impacted the success of the invasive bunchgrass Brachypodium sylvaticumin early growth stages. I examined whether invasive plants performed and competed differently when grown in soil containing AMF from adjacent invaded and noninvaded ranges in order to determine the contribution of AMF to both monoculture stability and spread of the invasive to noninvaded territory. I also directly manipulated common mycelial network (CMN) formation by AMF to determine hyphal network contribution to competitive interactions. I found that invasive plants performed most poorly (as indicated by decreased chlorophyll content, size and shoot dry mass) in invaded range soil against conspecifics. This could be two-pronged evidence for existing biotic pressure on the invasives to expand into adjacent noninvaded ranges. I also found a negative effect of AMF colonization and invasive plant performance, potentially indicating deleterious plant-soil feedbacks which could help maintain plant biodiversity at a community level. CMN effects were found to be interactive with root competition and directly affected the performance and nutrient status of B. sylvaticum. Although no direct correlations between AMF colonization levels and competition were found, CMN presence contributed significantly to plant growth and nutrient status. Therefore AMF, through infection and CMN formation, may be able to influence invasive plant growth and spread in the field.
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Chen, Xunwen. "Expressions of transporters of arsenite and phosphate in rice (Oryza sativa L.) associated with arbuscular mycorrhizal fungi." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1464.

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Ndeinoma, Albertina. "Mycorrhiza re-establishment on post mined rehabilitated areas of the Brand se Baai Succulent Karoo vegetation /." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1133.

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Watson, Ray A. "The effect of VA endomycorrhizae on the growth of lettuce and pepper transplants." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=23949.

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Both lettuce and pepper crops are routinely grown as transplants in Quebec. Previous research has shown that both of these plants respond well to endomycorrhizae with a resulting improvement in plant growth and yield. Although many studies have been conducted on endomycorrhizal inoculation of transplants most were looking at the end result, i.e. yields, and did not focus on changes occurring at the transplant stage. This series of experiments was conducted to look at the effect of inoculation at the transplant stage. Lettuce (Lactuca sativa cv. Parris Island Cos) and pepper (Capsicum annuum cv. Hybrid Bell Boy) were inoculated with Glomus intraradix Schenck & Smith and Glomus versiforme (Karst.) Berch. Experiments involved testing the effect of different growing media, different container volumes and different light sources on the growth of endomycorrhizal lettuce and pepper transplants. In all experiments the amount of growth enhancement due to endomycorrhizal inoculation was low or negligible. Colonization rates were generally low, probably due to low light levels. Transplants grown in larger volume containers were generally larger than those grown in smaller containers. The transplants grown in the soil and compost based media were larger than those transplants grown in the artificial media. Growth of lettuce and pepper transplants was affected differently depending on the light source used. Some interactions between the light source and the endomycorrhizal treatments was observed.
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Wu, Fuyong. "Colonization and species diversity of arbuscular mycorrhizal fungi and their efffects on metal tolerance and metal accumulation in two metal hyperaccumulators, Pteris vittata L. and Sedum alfredii Hance." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/931.

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Gasch-Salava, Caley. "Comparison of vegetation, soil, and AM fungal activity in native and exotic annual brome dominated Wyoming rangeland." Laramie, Wyo. : University of Wyoming, 2008. http://proquest.umi.com/pqdweb?did=1594494571&sid=1&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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Gruhn, Christine Mae. "Effect of a heavy metal on ecto- and vesicular-arbuscular mycorrhizal fungi: the physiology, ultrastructure, and ecology of copper stress and tolerance." Diss., Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/54531.

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This work consists of an introduction, six chapters dealing with various aspects of the response of mycorrhizal fungi to copper, and a brief conclusion. The first chapter examines the enzyme tyrosinase in several ectomycorrhizal fungi and shows that its activity is altered in these fungi in response to copper. Polyamines are also examined in this chapter, and it is shown that their levels are altered in some ectomycorrhizal fungi due to copper stress but not in others. The second chapter uses transmission electron microscopy to demonstrate that copper is bound to the hyphae of ectomycorrhizal fungi grown on solid media, but the location of the binding varies between fungal species. In vitro copper tolerances of a number of ectomycorrhizal species are compared in this chapter and differences in tolerance are evident between species and between different isolates of the same species. In the third chapter, four ectomycorrhizal fungi and one nonmycorrhizal fungus are evaluated for their ability to improve the growth of Japanese Red Pine under conditions of copper stress. Improvement of pine seedling growth is not correlated with in vitro copper tolerance of the fungus, but is related to the degree of compatibility between host and fungus. Despite differences in in vitro tolerance between three isolates of the same species, there are no differences in the effect of the isolates on the tree host under conditions of copper stress. Ectomycorrhizal fungi were also inoculated in pairs on pine seedlings and the competitive abilities of the fungi are compared under stressed and nonstressed conditions. The fourth chapter discusses the results of inoculation of pine with a nonhost fungus which stimulates dichotomous branching of the root system. The compound responsible for the branching is demonstrated to be indole-3-acetic acid (IAA), a plant growth hormone. The final two chapters deal with endomycorrhizal fungi. In the first of the two, inoculation of onion with an endomycorrhizal fungus demonstrates that the fungus probably plays no direct role in the response of the plant to heavy metals, based on biomass production, nutrient uptake, and photosynthetic rate. The last chapter demonstrates that the vascular plants found on abandoned mines in Virginia and North Carolina are well colonized by endomycorrhizal fungi; thus, an absence of these fungi is not a reason for the limited natural recolonization of the mine spoils.
Ph. D.
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29

Mukasa-Mugerwa, Thomas Tendo. "The role of arbuscular mycorrhizal fungi in the biotransformation of coal and application in dump rehabilitation." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1004059.

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Fundamental processes underpinning the biotransformation of coal by fungal biocatalysts have been intensively investigated, however, limited large-scale industrial applications using such systems have been reported. The un-anticipated sporadic growth of Cynodon dactylon on the surface of un-rehabilitated discard coal dumps has been noted and this was found to be coupled with the breakdown of coal into a humic soil-like material in the top 1.5 metres of the dumps. Extensive fungal growth was observed to be associated with the Cynodon dactylon root system and examination of plant roots indicated the presence of mycorrhizal fungi. Analysis of the Cynodon dactylon plant roots around which coal biotransformation was occurring confirmed the presence of arbuscular mycorrhizal colonisation with the species Glomus clarum, Paraglomus occultum, Gigaspora gigantea and Glomus mosseae identified to be associated with the plants. Further molecular characterisation of non-mycorrhizal rhizospheric fungi showed the presence of fungal species with coal-degrading capabilities that most likely played a role in the coal biotransformation observed. The discard coal dump environment was simulated in pot and column studies and coal biotransformation was reproduced, with this process enhanced by the addition of mycorrhizal and non-mycorrhizal rhizospheric fungal inocula to the environment. Mycorrhizal and non-mycorrhizal species in the inoculum were re-isolated from the simulated environment fulfilling a number of Koch’s postulates and indicating a causal role in the biotransformation of coal. An inversion of conventional mycorrhizal colonisation was demonstrated in this system with reduction in extraradicular presence and an increase in intracellular colonisation compared to soil controls. A descriptive model was formulated suggesting a two-part fungal system involving organic carbon and nutrient exchange between the plant, mycorrhizal fungi and non-mycorrhizal coal-degrading rhizospheric fungi ultimately resulting in the biotransformation of coal. The biotransformation observed was comparable to reports of “rock-eating fungi”. Results suggest that the biological degradation of coal in situ with the production of a soil-like substrate could provide a feasible method of discard coal dump rehabilitation as well as provide a humic-rich substrate that can be utilised in further industrial applications.
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30

Abu-Zeyad, Raeda. "Occurrence of arbuscular mycorrhizae in castanospermum australe and their effect on growth and production of catanospermine (anti virus alkaloid) /." [Campbelltown, N.S.W. : The Author], 1997. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030708.090926/index.html.

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31

Filion, Martin. "The application of real-time PCR to investigate the effect of the arbuscular mycorrhizal fungus Glomus intraradices on the plant pathogen Fusarium solani f. sp. phaseoli /." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82870.

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The effect of the arbuscular mycorrhizal symbiosis at reducing the incidence of root diseases has received considerable attention. However, information on the role of mycorrhizae in reducing disease incidence of Fusarium root rot of beans (Phaseolus vulgaris), caused by the root pathogen Fusarium solani f. sp. phaseoli, is scarce. A study was undertaken to investigate how the arbuscular mycorrhizal fungus (AMF) Glomus intraradices affects disease development and population number of F. solani f. sp. phaseoli in the mycorhizosphere of bean plants growing in an experimental microcosm unit. This newly designed unit facilitated the spatial monitoring and quantification of both the symbiont and pathogen in different ecological soil regions of the mycorrhizosphere using compartmentation based on a physical segregation of roots, colonized or not by AMF (rhizosphere), AMF mycelium alone (mycosphere), or none (bulk soil). To study the interaction between both organisms, the experimental set-up consisted of a randomized complete block design using bean seedlings pre-colonized or not for 28 days by G. intraradices and infected or not for 6 days with F. solani f. sp. phaseoli. Monitoring of population number of the symbiont and the pathogen in bean plants and in the different mycorrhizosphere soil compartments was achieved with quantitative real-time PCR using specific molecular probes for each fungus, and with cultivation-dependant or morphological based methods. The results of this study indicated that non-mycorrhizal bean plants infected with the pathogen had typical root rot symptoms while infected plants that were pre-colonized by G. intraradices remained free of disease. The population number of F. solani f. sp. phaseoli was significantly reduced in the root system and in each of the mycorrhizosphere soil compartments of mycorrhizal infected plants. The mycorrhizosphere population of G. intraradices was not significantly modified, although the p
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32

Kosuta, Sonja A. "Movement of copper from in-ground root control fabrics." Thesis, McGill University, 1998. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=21582.

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Copper hydroxide-treated surfaces are commonly used to control roots in horticultural production systems, although the particulars of Cu movement from the treated surface are largely unknown. The rate and temporal pattern of Cu mobility from in-ground Cu-treated growing baskets, and the fate of this Cu, was studied. In a field experiment involving Acer platanoides, an alternative Cu formulation consisting of Cu metal powder was determined to move slightly more slowly from the basket fabric than Cu(OH)2 over the first season while providing adequate root control. Addition of Glomus intraradices inoculum to the basket system increased the mobility of Cu metal and had no effect on Cu(OH) 2. This suggests that VAM fungi can actively solubilize Cu metal. These results also confirm that the chemistry of the Cu, possibly in addition to the chemistry of the resin, determines Cu movement from the treated surface. The fate of Cu from in-ground baskets planted with Acer jinnala was elucidated in a second field experiment. After one field season, the majority of Cu initially on the basket fabric had been deposited in the soil both in- and outside the basket. While Cu recovered in leachate represented only a tiny fraction of basket Cu, the concentration of Cu in leachate exceeded acceptable limits in the majority of samples. This indicates that the use of Cu(OH) 2-treated baskets in the field may have a negative impact on groundwater quality.
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33

Joubert, Angelique. "Investigation on selected biotic and abiotic factors in the maintenance of the "fairy circles" (barren patches) of southern Africa." Diss., Electronic thesis, 2008. http://upetd.up.ac.za/thesis/available/etd-01172008-125625/.

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34

Sommerville, David W. "Phosphorus fertilization : effects on asparagus yield, and soil microbial parameters." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80876.

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Asparagus (Asparagus officinalis) is a perennial crop well suited to grow in Quebec. Despite high demand for this crop, asparagus production is declining because of asparagus root rot disease that is caused by Fusarium spp. Phosphorus is one of the most important nutrients for the production of healthy asparagus roots that may resist infection by Fusarium. The objective of this study was to determine the effects of phosphorus (P) applications on asparagus yield and soil microbial parameters. Plots receiving 0 to 200% of the P recommendation, based on the Centre de reference en agriculture et agroalimentaire du Quebec (CRAAQ) guidelines, did not differ significantly (p < 0.05) in first year yield or plant tissue concentrations. However, asparagus receiving no fertilizer had 2 to 3 times higher arbuscular mycorrhizal colonisation of roots than other treatments in May 2003. Fresh marketable yield was negatively correlated to Fusarium incidence (p = 0.0091 r = -0.51) suggesting that plants with higher yields are less susceptible to Fusarium symptoms and that producers should avoid over-harvesting low yielding plants to reduce Fusarium spread in the field. Soil microbial activity was not affected consistently by P fertilizers because of high variability in the field.
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Wilkinson, Melinda M. "Changes in growth and survival by three co-occurring grass species in response to mycorrhizae, fire, and drought." Thesis, University of Hawaii at Manoa, 2003. http://proquest.umi.com/pqdweb?index=0&did=765961171&SrchMode=2&sid=6&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1209417332&clientId=23440.

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36

Pezzente, Mauro. "Effects of urban environmental conditions on the symbiosis between vesicular-arbuscular mycorrhizal fungi and silver maple (Acer saccharinum L.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0002/MQ29764.pdf.

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37

Chan, Wai Fung. "The roles of arbuscular mycorrhizal fungi in arsenic uptake and tolerance of upland rice." HKBU Institutional Repository, 2011. http://repository.hkbu.edu.hk/etd_ra/1257.

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38

Leung, Ho Man Homan. "Interactions of arbuscular mycorrhizal fungi with an arsenic hyperaccumulator plant (pteris vittata) on the uptake of arsenic." HKBU Institutional Repository, 2008. http://repository.hkbu.edu.hk/etd_ra/945.

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39

Podrebarac, Frances Ann. "The Relative Nitrogen Fixation Rate and Colonization of Arbuscular Mycorrhizal Fungi of Iron Deficient Soybeans." Thesis, North Dakota State University, 2011. https://hdl.handle.net/10365/29600.

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Soybeans (Glycine max L. Merr.) are a symbiont of two beneficial associations: biological nitrogen fixation (BNF) with Bradyrhizobium japonicum, and arbuscular mycorrhizal fungi (AMF). Within the Northern Great Plains of the USA, iron deficiency chlorosis (IDC) of soybean is a yield-limiting factor. The effects of IDC on BNF and AMF are not well defined. This study was conducted to determine the effects of IDC on BNF and AMF. A laboratory study was performed to compare three methods of measuring ureide-N, a product of BNF in soybeans. Field studies in soybean were performed at three locations at eastern N011h Dakota. The experimental design was a factorial combination of three cultivars and three treatments. The three cultivars, in order of decreasing chlorosis susceptibility, were NuTech NT-0886, Roughrider Genetics RG 607, and Syngenta S01-C9 RR. The three treatments were control, Sorghum bicolor L. companion crop planted with the soybean seed, and FeEDDHA applied with the soybean seed. Chlorosis severity was the greatest and least for the NuTech and Syngenta cultivars, respectively. The FeEDDHA treatment decreased chlorosis severity. Ureide levels were abnormally high in plants severely stunted by JDC. The excess accumulation of ureides in IDC-stunted plants suggests that plant growth was reduced more than the rate of nitrogen fixation. The AMF population \vas at an adequate level at all locations and not affected by cultivar or treatment, in general. In the laboratory study, the Patterson et al. method had greater ureide concentrations due to the non-specific measuring of ammonium compounds compared to the Vogels and Van der Drift and Goos methods.
North Dakota Soybean Council
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40

Lee, Caitlin Elyse. "Assessment of Arbuscular Mycorrhizal Symbiosis on Invasion Success in Brachypodium sylvaticum." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/2108.

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The effects that mutualistic soil biota have on invasive species success is a growing topic of inquiry. Studies of the interactions between invasive plants and arbuscular mycorrhizal fungi (AMF) have shown changes in AMF community composition, reductions in AMF associations in invasive plants, and changes in native species fitness and competitive outcomes in invasive-shifted AMF communities. These findings support the degraded mutualist hypothesis, where invasive species alter the mutualist community composition, resulting in detrimental associations with the new mutualist community for native species. Here I present two studies that examine various aspects of the arbuscular mycorrhizal fungal (AMF) mutualism in the success of a newly invasive bunchgrass, Brachypodium sylvaticum. The first chapter is a field survey of AMF associations between a native bunchgrass, Elymus glaucus and B. sylvaticum in the invaded range. The second chapter presents a test of reduced mycorrhizal dependence between invasive and native-range populations of B. sylvaticum. For the field survey, AMF colonization and spore density of root and soil rhizosphere samples from B. sylvaticum and E. glaucus from the two regions of introduction of the B. sylvaticum invasion were measured. In this survey I found lower AMF colonization and spore density in B. sylvaticum compared to the native species in the invaded ranges. The reduction in AMF associations in B. sylvaticum was predicted to be due to the evolution of reduced mycorrhizal dependence in invasive populations compared to native populations of B. sylvaticum. I tested the prediction for reduced mycorrhizal dependence by measuring the fitness gains or losses with AMF inoculation compared to sterile conditions in both fertilized and unfertilized treatments for individuals of B. sylvaticum from each of the introduction sites in Oregon, USA and source populations from the native range in Europe. There were no differences in plant or AMF fitness between the invasive and native populations of B. sylvaticum. Under high nutrients the interaction between all B. sylvaticum plants and AMF was mutualistic. Under low nutrient treatments both B. sylvaticum and AMF had reduced fitness measures, suggesting a competitive interaction. Nutrient levels of inoculated unfertilized soils are similar to field conditions. It is likely that the reduction in AMF associations in B. sylvaticum observed in the field is due antagonistic interactions between AMF and B. sylvaticum.
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41

Li, Hui. "The role of arbuscular mycorrhizal fungi (AMF) on the tolerance and accumulation of arsenic in rice (Oryza sativa L.)." HKBU Institutional Repository, 2012. https://repository.hkbu.edu.hk/etd_ra/1409.

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42

Guillon, Christopher. "Systemic alteration of defense-related gene transcript levels in mycorrhizal bean plants infected with Rhizoctonia solani." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33767.

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A time course study was conducted to monitor disease development and expression of the defense-related genes phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), chalcone isomerase (CHI), and hydroxyproline-rich glycoprotein (HRGP) in bean (Phaseolus vulgaris L.) plants colonized by the arbuscular mycorrhizal (AM) fungus Glomus intraradices , and post-infected with the soil-borne pathogen Rhizoctonia solani. Pre-colonization of bean plants by the AM fungus did not significantly reduce the severity of rot symptoms. RNA blot analysis revealed a systemic increase in transcript levels of the four defense-related genes in response to R. solani infection. On the other hand, pre-colonization of bean plants with G. intraradices elicited no change in PAL, CHS and CHI transcripts, but an increase of HRGP transcripts in leaves was detected. A differential and systemic alteration in the expression of all four defense genes was observed in AM beans post-infected with R. solani. Depending on the time after infection with R. solani and the tissue examined, varying responses from stimulation, suppression, to no change in transcript levels were detected.
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43

Wen, Kui. "Down-regulation of defense gene transcripts of Rhizoctonia solani-infected bean seedlings in response to inoculation with non-pathogenic fungi." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=80895.

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In this study, we have demonstrated that inoculation of bean seeds with non-pathogenic binucleate Rhizoctonia (np-BNR) at sowing protected bean seedlings from infection of R. solani. Using quantitative real-time RT-PCR (QRT-PCR), transcript levels of defense genes encoding 1,3-beta-glucanase (GLUC), phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) in one-week old bean seedlings was monitored during np-BNR and R. solani interaction. The results revealed that protection effect of np-BNR correspond to a systemic suppression of these three defense genes' expression from significant higher level elicited by R. solani to the level of non-infected plants. This indicates that bio-protection by np-BNR isolates is not correlated to activation of these three defense genes' expression. Similar suppression was achieved for pre-colonization of bean seedlings with arbuscular mycorrhizal (AM) Glomus introradices on GLUC gene expression, although the AM fungus did not significantly reduce rot symptoms. Possible mechanisms implicated in down-regulation during plant-pathogen and np-BNR or AM interaction are discussed.
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Hu, Junli. "Risk assessment and mycorrhizal remediation of cadmium contamination in vegetable farms around the Pearl River Delta, China." HKBU Institutional Repository, 2013. http://repository.hkbu.edu.hk/etd_ra/1484.

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45

Abu-Zeyad, Raeda. "Occurrence of arbuscular mycorrhizae in castanospermum australe and their effect on growth and production of catanospermine (anti virus alkaloid)." Thesis, [Campbelltown, N.S.W. : The Author], 1997. http://handle.uws.edu.au:8081/1959.7/290.

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The present study was aimed to find out if there is any symbioses between C.australe roots and mycorrhizal fungi. This research also aimed to investigate the effect of Arbuscular mycorrhizal fungi on the growth of C.australe and the yield of alkaloid castanospermine. The rhizosphere soil and roots of C.australe from various sites in Sydney were collected. Roots were stained with vital and non-vital stains for assessment of mycorrhizal infection. The result indicated that AM fungi symbiotic associations with the roots of C.australe, producing arbuscules and vesicles in the root cortices. By wet sieving and decanting of rhizosphere soil, spores and sporocarps of AM fungi, were recovered. The spores mainly belonged to the genus Glomus. A correlation study was conducted to determine the relationship between the AM infection percentage in the roots and the Castanospermine amount in the leaves and seeds of the field grown trees. The results showed that there is a positive relationship between the castanospermine amount in the seeds and AM infection percentages in the roots. The effect of phosphorus on the yield of castanospermine was also investigated. The results indicated that phosphorus do enhance castanospermine at certain levels, but a further increase in phosphorus application resulted in reduced AM infection. It was found that AM has a great effect on the growth and production of C.australe and biosynthesis of castanospermine.
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46

Davidson, Kent. "Genetic studies of vesicular-arbuscular mycorrhizal fungi." Thesis, University of Bristol, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279742.

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47

Cheeke, Tanya Elizabeth Amy. "An Evaluation of the Nontarget Effects of Transgenic Bacillus thuringiensis Maize on Arbuscular Mycorrhizal Fungi in the Soil Ecosystem." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1027.

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My dissertation research examined the effect of the cultivation of insect-resistant Bacillus thuringiensis (Bt) maize on the soil environment with a goal of understanding how to obtain a balance between technological advancement and maintenance of a healthy soil ecosystem. Although Bt plants may help to reduce pesticide use, conferring benefits to farm workers and the environment, there are still unresolved questions about how the cultivation of Bt plants affects soil organisms. For this dissertation project, I used 14 different genotypes of Bt maize and non-Bt maize (Zea mays) to investigate the effects of transgenic Bt plants on the colonization ability, abundance, and diversity of symbiotic arbuscular mycorrhizal fungi (AMF) in the soil ecosystem over time. My greenhouse studies demonstrated that Bt maize plants exhibited reduced AMF colonization across multiple Bt genotypes and that effects were most pronounced when fertilizer levels were limited and spore density was high. In addition, I found that although differences in AMF colonization between Bt and non-Bt maize were difficult to detect in the field, spore density was reduced in Bt field plots after just one growing season. When I tested the effect of plot history on AMF and plant growth, I found that Bt and non-Bt maize plants had higher leaf chlorophyll content when grown in plots previously cultivated with the same maize line as the previous year, indicative of a positive feedback effect. I also examined potential mechanisms contributing to the reduced AMF colonization observed in Bt maize in greenhouse studies and determined that follow-up experiments should continue to investigate differences in root apoplastic invertase activity and root permeability in Bt and non-Bt maize. Future investigations would also benefit from examining potential differences in root exudate profiles and volatile organic compounds between Bt and non-Bt cultivars. Taken together, my dissertation results suggest that, while difficult to detect in the field, reductions in AMF colonization in Bt maize roots may be ecologically significant as they could lead to a decrease in the abundance of AMF propagules in the soil over time, potentially impacting soil structure and function in areas where Bt crop cultivation is high.
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48

Amijee, F. "Colonization of root systems by vesicular-arbuscular mycorrhizal fungi." Thesis, University of Leeds, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374170.

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49

Musandu, Amos Omonge Absalom. "Vesicular-arbuscular mycorrhiza and phosphorus availability in Kenyan soils." Thesis, Imperial College London, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.416441.

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50

Amerian, Mohammad Reza. "Effects of VA mycorrhizae and drought on the physiology of maize and bean grown singly and intercropped." Thesis, University of Newcastle Upon Tyne, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247833.

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