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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Phosphorus fertilization : effects on asparagus yield, and soil microbial parameters

Sommerville, David W. January 2004 (has links)
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.
202

The relationships between plant responses to arbuscular mycorrhizal fungi and phosphorus dynamics in the hyphae.

Shibata, Reiko January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Two experiments were conducted to find diversity in plant responses to arbuscular mycorrhizal (AM) fungi: positively and negatively/non-responsive combinations. Medic (Medicago truncatula L.) tomato (Solanum esculentum L.), leek (Allium porrum L.) and cucumber (Cucumis sativus L.) were inoculated with Glomus intraradices, Gigaspora margarita and Scutellospora calospora. It was found that soil differences critically affect plant responses to AM fungi. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283734 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007
203

The relationships between plant responses to arbuscular mycorrhizal fungi and phosphorus dynamics in the hyphae.

Shibata, Reiko January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / Two experiments were conducted to find diversity in plant responses to arbuscular mycorrhizal (AM) fungi: positively and negatively/non-responsive combinations. Medic (Medicago truncatula L.) tomato (Solanum esculentum L.), leek (Allium porrum L.) and cucumber (Cucumis sativus L.) were inoculated with Glomus intraradices, Gigaspora margarita and Scutellospora calospora. It was found that soil differences critically affect plant responses to AM fungi. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283734 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007
204

Importance des interactions entre plantes et mycorhizes dans le maintien de la productivité des écosystèmes pastoraux montagnards soumis à des forçages climatiques / Plant-fungus interactions in the alpine environment subjected to future climatic conditions

Wahl, Anne-Lena 13 June 2016 (has links)
Bien que les champignons mycorhiziens arbusculaires (AMF) soient présents des habitats collinaires aux habitats alpins, les recherches sur leur rôle dans l’écosystème montagnard sont encore incomplètes. Les objectifs de cette thèse sont d’analyser l’écologie et le fonctionnement des AMF ainsi que leur réponse au changement global dans les écosystèmes montagnards. Nous tentons de répondre aux questions de recherche suivantes : quels sont les effets de l’altitude sur les AMF indépendamment des effets des autres gradients et de la relation AMF-plante hôte ? Quelles relations de facilitation se développent dans les écosystèmes montagnards et quels bénéfices les plantes tirent-elles des AMF ?Avec l’augmentation d’un stress environnemental la symbiose AMF-plante doit théoriquement devenir plus mutualiste. Nous émettons l’hypothèse d’une modification du fonctionnement des interactions AMF-plante selon un gradient altitudinal dans les conditions environnementales actuelles, puis dans les conditions futures. Afin de vérifier ces hypothèses, une expérimentation in situ a été mise en place dans les Alpes Centrales d’Italie pour évaluer les variations des taux de mycorhization et leur abondance dans la communauté microbienne du sol, étudier la nature des relations entre plantes et mycorhizes ainsi que la productivité végétale le long d’un gradient altitudinal. De plus, les influences d’une augmentation de la température et d’une réduction des précipitations sont analysées séparément dans une chambre de croissance sous conditions contrôlées, ce qui permet de distinguer leurs effets respectifs sur la productivité des plantes et sur les interactions plantes – mycorhizes.Cette thèse montre que les AMF sont omniprésents dans les écosystèmes de montagne et qu’une diminution de leur abondance avec l'altitude dépend du contexte climatique global. D'autre part, la relation des AMF avec les plantes est fortement dépendante de la plante-hôte, ainsi que du contexte biotique et abiotique. Troisièmement, un changement des interactions AMF-plante avec l'altitude est suggéré par des indices indirects, mais est également très probablement dépendant de l'identité de la plante hôte. Cette thèse propose aussi une nouvelle orientation de recherche pour bien évaluer les hypothèses présentées. Il est nécessaire de réaliser des études sur le terrain où la présence des AMF est contrôlée et les interactions AMF-plante peuvent être évaluées. Afin de généraliser les résultats, ces expérimentations doivent être menées à différentes échelles spatiales et représenter différentes aires géographiques.Il est particulièrement important de comprendre et de qualifier ces processus en zone montagnarde pour prévoir leur évolution possible dans un contexte de changement global. Nos expérimentations montrent en effet que le réchauffement est un facteur important car il aggrave les conditions de sécheresse en basse altitude et entraine une baisse de la productivité des plantes. Nous démontrons que la présence de mycorhizes atténue l’impact du changement climatique sur la productivité des plantes mais que le niveau de cette atténuation varie selon les espèces de plantes.Les connaissances actuelles concernant les AMF en milieu montagnard sont peu développées sur les processus en jeu dans les interactions AMF-plantes. Grâce aux hypothèses présentées et à leur approche expérimentale cette thèse offre de nouvelles perspectives sur l’analyse de ces processus. / Even though arbuscular mycorrhizal fungi (AMF) are present from foothills to all alpine habitats, research on their role in mountain ecosystems remains incomplete. The main objective of this dissertation was to investigate interactions between AMF and plants along altitudinal gradients under both, natural conditions and simulated future climate change conditions.A novel framework is suggested for the functioning of the AMF-plant relationship along altitudinal gradients based on the stress gradient hypothesis. The first hypothesis expects the AMF-relationship to shift along the mutualism–parasitism continuum following changing environmental stress along the altitudinal gradient. The relationship might be most mutualistic at the subalpine zone. In a second hypothesis, this shift along the mutualism-parasitism continuum is predicted to be different under climate change conditions, and the most mutualistic expression of the AMF-plant relationship expected in the montane and alpine zone. Studies to validate the presented hypotheses will help to identify important mechanisms underlying plant-AMF interaction and with that the mediation of plant-plant interactions by AMF. In the scope of this thesis, the framework was addressed in field experiment as well as under controlled conditions in a climate chamber experiment.From a literature review and from a field experiment along a dry inner-alpine altitudinal gradient this thesis proposes the following conclusions: First, AMF are also ubiquitous in mountain ecosystems, but a decrease in their abundance with increasing altitude is dependent on the overall climatic context. Second, their relationship to plants is however strongly dependent on the host plant species as well as the biotic and abiotic context. Third, a shift of the AMF-relationship along with altitude is expected but will quite possibly also depend on the plant species identity. Fourth, to fully assess the suggested working hypotheses for AMF-plant interactions field studies must be conducted at different spatial scales and covering different mountain systems.It is particularly important to understand and investigate the drivers of AMF plant relationship in mountain ecosystems to be able to make sound predictions for AMF-plant interactions under future climate change conditions. The presented field and climate chamber experiments on climate change show that temperature is an important factor because it aggravates the conditions of drought in lowland and a threshold is surpassed. It becomes also clear that whether AMF mitigate climate change effects for plants or not is dependent on the plant species. Altogether this thesis contributes to current research questions in ecology, climate change mitigation and plant–soil interactions, because it addresses the role of AMF in mountain grassland ecosystem, investigates the effects of climate change and provides a new framework concerning the functioning of the AMF-plant relationship ranging from parasitism to mutualism.
205

Utilização de rizobactérias e micorrizas na produção de mudas de maracujá / Use of rhizobacterias and mycorrhizal in the production of passion fruit seedlings

Agra, Andre Gustavo Santos de Melo 11 May 2007 (has links)
Passion fruit is a tropical fruit seasoning used for the manufacture of juices pulps and ices cream, easy acceptance due to the characteristic of aroma and flavor, and of proven medicinal properties. In the search of plants of passion fruit high production, they leave of the principle of the necessity of the organic seasoning use and chemical, that finished for raising the production cost, transferred to test it mycorrhizal fungi arbuscular and for production of seedlings. The present work objectified to study the effect of the association of mycorrhizal symbiosis and promotional rhizobacterias of the growth for the production of changes of plants of passion fruit in the State of Alagoas. The present investigation was conducted on laboratory conditions (Laboratory of Microbiology) and green house of the Center of Agrarian Sciences of the UFAL. The experiment had duration of 90 days, the experimental was in a randomized complete designer delineation complete with inoculation (200 sporos/plant) of plants with mycorrhizal fungi associates and witness, associates and not, with rhizobacterias, seven repetitions each treatment. The analysis of the data with Scutellospora heterogama and for Glomus etunicatum had resulted in better leaf number and size of plants, and also when associates to Isolated the 15. For rhizobacterias, suspensions of bacteria from isolated out epiphytes and on epiphytes cultivated in half BD had been prepared (Potato), being the changes of plants of passion fruit kept 21 days in green house of production of changes, and after this period, had been evaluated cool substance of the roots, aerial and total part, beyond levels of N, P, K, Ca, Mg that had kept the levels balanced throughout the experiments. G. albida + I15, S. heterogama + I15 and G. etunicatum + I09 had also provided to improvement in leaf number and height of plants. The results suggest that the plants of passion fruit are not a species highly dependent of mycorrhizal fungi arbuscular. The results showed that use of isolated the 02, 09, 13, 15 had not effect in the production of seedlings of passion fruit, and that the FMA use can contribute for a significant improvement in the production of these seedlings. This research can to influence actions that aim at the production of seedlings with quality and in satisfactory number with the use of rhizobacteria and FMA. / Fundação de Amparo a Pesquisa do Estado de Alagoas / O maracujá (Passiflora edulis Sims f. flavicarpa) é uma fruta tropical bastante utilizada para a fabricação de sucos polpas e sorvetes, de fácil aceitação devido ao aroma e sabor característicos. O uso de fungos micorrízicos arbusculares e rizobactérias na produção de mudas podem contribuir para a diminuição dos custos de produção. Este trabalho objetivou estudar o efeito da associação simbiótica micorrízica e de rizobactérias na produção de mudas de maracujazeiro no Estado de Alagoas. O Trabalho foi conduzido no Laboratório de Microbiologia e casa-de-vegetação do Centro de Ciências Agrárias da UFAL. O experimento foi realizado em 90 dias, utilizando-se o delineamento experimental inteiramente casualizado com inoculação (200 esporos/planta) de plantas com fungos micorrízicos associadas e testemunha, associadas e não, com rizobactérias, com sete repetições cada tratamento. Para rizobactérias, foram preparadas suspensões a partir de isolados epífitos e endofíticos cultivados em meio BD (Batata-Dextrose), sendo as mudas de maracujazeiro mantidas por 21 dias em estufa e após esse período, foram avaliados matéria fresca das raízes, parte aérea e total, além de níveis dos elementos químicos N, P, K, Ca, Mg que mantiveram-se equilibrados ao longo dos experimentos. A análise dos dados com Scutellospora heterogama e com Glomus etunicatum resultaram em melhor número de folhas e tamanho de plantas, e também quando associados ao Isolado 15. Os fungos G. albida + I15, S. heterogama + I15 e G. etunicatum + I09 proporcionaram também melhoria em número de folhas e altura de plantas; o uso dos isolados 02, 09, 13, 15 quando de forma individual não influenciaram na produção de mudas de maracujá, o uso de FMA pode contribuir para uma melhoria significativa na produção destas mudas. Esta pesquisa pode influenciar ações que visem a produção de mudas com qualidade e em número satisfatório com o uso de rizobactérias e FMA.
206

Micorrização aumenta a tolerância de mudas de Jatropha Curcas L. à salinidade / Micorrization increases tolerance of Jatropha curcas L. seedlings to salinity

Oliveira, Dilliani Felipe Barros de 13 October 2016 (has links)
This study aimed to investigate the association of three species of arbuscular mycorrhizal (AM) fungi (Rhizophagus intraradices; Gigaspora albida and Claroideoglomus etunicatum) with J. curcas, and the effect this symbiosis in developing pre-mycorrhizal seedlings submitted to salt stress at home vegetation. Two experiments were conducted, the first to investigate the association of the fungus to the plant, in a completely randomized design with five treatments (control, isolated species and three inoculated together-MIX) and six repetitions. The second trial was completely randomized blocks in a factorial 4 x 2, with four levels of NaCl (2, 5, 8 and 10 dS / m), and presence or absence of mycorrhizae (MIX), which were evaluated mycorrhizal dependency (MD) and the development of seedlings in salinity soil. The three species of mycorrhizal fungi are associated with J. curcas both in isolation, as when inoculated together. The interaction between these factors showed that the control plants did not differ presence of mycorrhizae, whereas in the saline treatments, pre-mycorrhizal seedlings grew better than non-inoculated. The MD was higher in saline treatments and moderate stress (5 dS / m) provided the best results for this index. Salinity reduced the size of plants, photosynthetic performance, the photosynthetic pigment content, the amount of calcium, potassium, phosphorus and magnesium in the leaves and increased absorption of sodium and chlorine, lipid peroxidation, the activity of antioxidant enzymes and the concentration of proline. Pre-mycorrhizal plants had higher mass, height, stem diameter, number of leaves, leaf area, area ratio pillar, specific leaf area, reduced biomass allocation in leaves and larger, at root, increased root / shoot , higher photosynthetic rate and pigment content, lower activity of antioxidant enzymes, lipid peroxidation reduction, and increased proline content compared to plants not inoculated in the same saline conditions. In seedlings with AMF, high photosynthetic rate, coupled with the large amount of salts in the leaves, the significant increase in proline content and the absence of lipid peroxidation indicates a mechanism mitigating the effect of salinity associated with the presence of mycorrhizae. Therefore, J. curcas seedlings previously mycorrhizal are an alternative to the cultivation of the species under salt stress. / O objetivo deste estudo foi verificar a associação de três espécies de fungos micorrízicos arbusculates (FMAs) (Rhizophagus intraradices; Gigaspora albida e Claroideoglomus etunicatum) com Jatropha curcas L., e o efeito desta simbiose no desenvolvimento de mudas pré-micorrizadas, submetidas a estresse salino, em casa de vegetação. Foram realizados dois experimentos, sendo o primeiro para verificar a associação dos fungos à planta, em delineamento inteiramente casualizado, com cinco tratamentos (controle, espécies isoladas e as três inoculadas em conjunto-MIX) e seis repetições. O segundo experimento foi em blocos inteiramente casualizados, num esquema fatorial 4 x 2, com quatro níveis de NaCl (2, 5, 8 e 10 dS / m), e presença ou não de micorrizas (MIX), onde foram avaliados a dependência micorrízica (DM) e o desenvolvimento das mudas em solo salinizado. As três espécies de FMAs se associam a J. curcas tanto de forma isolada, como quando inoculadas em conjunto. A interação entre os fatores mostrou que plantas do tratamento controle não diferem quanto presença de micorrizas, enquanto que, nos tratamentos salinos, as mudas pré-micorrizadas se desenvolveram melhor que as não micorrizadas. A DM foi maior nos tratamentos salinos e o estresse moderado (5 dS / m) proporcionou o melhor resultado para este índice. A salinidade reduziu o tamanho das plantas, o desempenho fotossintético, o teor de pigmentos fotossintéticos, a quantidade de cálcio, potássio, fósforo e magnésio nas folhas, e aumentou a absorção de sódio e cloro, a peroxidação de lipídios, a atividade das enzimas antioxidantes e a concentração de prolina. As plantas pré-micorrizadas apresentaram maior massa, altura, diâmetro do coleto, número de folhas, área foliar, razão de área filar, área foliar específica, menor alocação de biomassa nas folhas e maior, na raiz, aumento da relação raiz/parte aérea, maior taxa fotossintética e teor de pigmentos, menor atividade de enzimas antioxidantes, redução da peroxidação lipídica e aumento no teor de prolina em relação às plantas não micorrizadas, nas mesmas condições salinas. Nas mudas com FMAs, a alta taxa fotossintética, associada a grande quantidade de sais nas folhas, ao aumento expressivo do teor de prolina e a ausência da peroxidação de lipídios indica que há um mecanismo mitigador do efeito da salinidade associado à presença de micorrizas. Portanto, mudas de J. curcas previamente micorrizadas são uma alternativa para o cultivo da espécie sob estresse salino.
207

Optimisation des performances d’inocula de champignons mycorhiziens dans le cadre d’une agriculture à faibles apports / Improving the mycorrhizal fungi inoculation performance under low input agriculture

Lies, Adrien 15 December 2016 (has links)
Les champignons endomycorhiziens arbusculaires (MA) forment des relations symbiotiques avec la majorité des espèces végétales terrestres. Leur rôle écologique dans la productivité et la stabilité des agrosystèmes sont connus depuis de nombreuses années. Plusieurs études ont montré que ces symbiotes augmentent la croissance végétale et la résistance des plantes aux stress biotiques et abiotiques. Malgré le potentiel avéré de la symbiose MA pour augmenter durablement la productivité des agrosystèmes dans le cadre d’une agriculture à faibles apports d’intrants, cette biotechnologie est encore sous exploitée. Ce constat résulte essentiellement de difficultés techniques pour produire en quantité un inoculum fongique de qualité et un manque de connaissance concernant les facteurs biologiques régulant la réceptivité des sols à l’inoculation des champignons MA. Les principaux objectifs de ces travaux sont d’optimiser les performances d’un inoculum MA. (1), en associant le champignon MA avec des bactéries PGPR ou MHB. Cette stratégie vise à promouvoir l’établissement et le fonctionnement de la symbiose MA. En effet, ces bactéries bénéfiques aux plantes peuvent augmenter la croissance végétale, directement en fournissant à la plante des composés bénéfique (phytohormone, etc), et indirectement en réduisant ou prévenant les effets délétères de phytopathogènes ou en augmentant l’établissement de la symbiose MA. (2), par la gestion des cultures, notamment par l’association céréales/légumineuses en culture intercalaire. Les légumineuses sont souvent dépendantes des associations symbiotiques avec les champignons MA, et ceux-ci peuvent participer dans la nutrition azotée et phosphatée de la plante. (3), par l’amendement en composé ou organique. Ces amendements peuvent être solubilisés et dégradés par des bactéries et ainsi promouvoir la nutrition végétale sans augmenter la disponibilité de P et N dans le sol. (4), en développant des inocula complexes associant bactéries bénéfiques, champignons MA et amendement, l’ensemble contenu dans un gel d’alginate. / Arbuscular Mycorrhizal fungi (AM) are ubiquitous microorganisms forming symbiotic relationships with the majority of terrestrial plant species. Their ecological functions in the productivity and stability of agroecosystems have been recognized for many years. Many studies have shown that these symbionts improved plant growth and plant resistance to biotic and abiotic stresses. Despite the proven potential of mycorrhizal symbiosis to sustainably improve the productivity of agroecosystems under low input agriculture, this biotechnology is still under exploited. This failure mainly results from technical difficulties to mass-produced fungal inoculum of high quality and a lack of knowledge about the biological factors regulating the soil receptivity of AM inoculation. The main objectives of our studies are to optimize the performance of an AM fungal inoculum. (1), by combining the AM fungus with Plant Growth Promoting Rhizobacteria, or Mycorrhizal Helper Bacteria. This strategy aims to promote the establishment and the functioning of the mycorrhizal symbiosis. Indeed, this plant beneficial bacteria may affect plant growth through two different pathways, directly by providing to the plant some beneficial compounds (i.e. phytohormones, etc), indirectly, by reducing or preventing the deleterious effects of phytopathogens or by improving the establishment of the mycorrhizal symbiosis. (2), by plant management with the association of cereal/leguminous in intercropping. Leguminous are often dependent of AM association and AM fungi may participate to promote N and P plant uptake. (3), by amendment of mineral or organic compounds. These amendments can be degraded slowly by bacteria and promote plant nutrition without increase P and N soil availability. (4), by development of complex inocula associating beneficial bacteria, AM fungi and amendment, based on the entrapment of these inocula in alginate gels
208

Fungos micorrízicos arbusculares no crescimento de mudas de pinhão manso (Jatropha curcas L.) / Arbuscular mycorrhizal fungi and growth of physic nut seedlings (Jatropha curcas L.)

Carvalho, André Mundstock Xavier de 25 February 2008 (has links)
Made available in DSpace on 2015-03-26T13:51:44Z (GMT). No. of bitstreams: 1 01 - capa_abstract.pdf: 243354 bytes, checksum: 16925925508f2aa300c66b038738c9bb (MD5) Previous issue date: 2008-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Physic nut is a shrub of the Euphorbiaceae family that can be used as raw material for the production of biodiesel. Its rusticity, tolerance to draught, and low nutritional demand, among other traits, may be related to the mycorrhizal dependency of this plant. Thus, the objective of this work was to evaluate the occurrence and the abundance of arbuscular mycorrhizal fungi (AMFs) in physic nut plantations and to evaluate the effect of soil P levels on the nutrition and growth of mycorrhizal physic nut seedlings. Soil and root samplings were done in a nursery and in seven plantation sites located in the municipalities of Viçosa and Canaã, Minas Gerais State, Brazil. The chemical characteristics of the soils in the plantation sites did not suppress mycorrhizal colonization, always higher than 70 %, although in some cases, significant negative correlations were observed between soil fertility and root colonization and spore numbers. Spore density varied from 8.5 to 47.4 spores per gram of dry soil. Nutrition and growth of mycorrhizal physic nut seedlings were evaluated in the greenhouse under different P levels. Seedling growth responded positively to phosphate fertilization and to mycorrhizal colonization. In general, AMF inoculation favored the total nutrient content and the leaf concentrations of N, P, K, Zn, and Fe. The inoculated plants showed mycorrhizal colonization percentages varying from 41 to 96 % and higher photosynthetic and transpiration rates than the non-inoculated control plants, even in the highest P level tested. The nutrient levels in the leaves indicated that the nature of the benefits brought about by AMF inoculation is due to a better plant nutrition. These results indicate that phosphate fertilization does not inhibit mycorrhizal colonization, even at 600 mg kg-1, suggesting that physic nut plants show a considerable level of dependency on the mycorrhizal association. / O pinhão manso é uma planta arbórea de pequeno porte da família das euforbiáceas, com grande potencial de uso como matéria-prima para produção de biocombustível. Possivelmente, características como rusticidade, tolerância à seca, baixa exigência nutricional, entre outras atribuídas à cultura, possam estar relacionadas ao nível de dependência micorrízica dessa espécie. Dessa forma, os objetivos deste trabalho foram avaliar a ocorrência e a abundância de fungos micorrízicos arbusculares (FMAs) em cultivos de pinhão manso e, avaliar o efeito de níveis de P no solo, na presença ou não de FMAs, sobre a nutrição e o crescimento do pinhão manso. Uma área de viveiro e sete áreas de cultivo de pinhão manso localizadas nos municípios de Viçosa e Canaã (MG) foram amostradas. As distintas características químicas dos solos sob estes cultivos, embora tenham em alguns casos apresentado correlações negativas significativas com a percentagem de colonização radicular ou com o número de esporos, não suprimiram a colonização micorrízica abaixo de 70 %. A densidade de esporos variou de 8,5 a 47,4 esporos por grama de solo seco. O efeito de níveis de P no solo, na presença ou não de FMAs, sobre a nutrição e o crescimento das plantas foi avaliado em casa de vegetação. O crescimento respondeu positivamente à adubação fosfatada e à colonização micorrízica. De um modo geral, a inoculação com FMAs favoreceu o acúmulo de nutrientes, influenciando também sobre os teores foliares de N, P, K, Zn e Fe. As plantas inoculadas apresentaram colonização micorrízica variando de 41 a 96 % e maiores taxas fotossintéticas e de transpiração que as plantas não inoculadas, mesmo nos níveis mais elevados de P no solo. Os teores foliares de nutrientes indicam que a natureza destes benefícios deve-se, em sua maior extensão, à melhor nutrição das folhas. Os resultados indicam que a adubação fosfatada não compromete a colonização micorrízica, mesmo em níveis de 600 mg kg-1, de solo, sugerindo que a planta apresenta considerável nível de dependência por essa associação.
209

Plantas de amendoim (Arachis hypogaea L.) submetidas à deficiência hídrica e a influência da associação com fungos micorrízicos arbusculares e extratos de algas marinhas / Peanut plants (Arachis hypogaea L.) submitted to water deficit and the influence of the association with arbuscular mycorrhic fungi and seaweeds extracts

Coscolin, Renata Bruna dos Santos [UNESP] 17 November 2016 (has links)
Submitted by Renata Bruna dos Santos Coscolin null (rbscoscolin@fca.unesp.br) on 2017-01-16T22:27:20Z No. of bitstreams: 1 definitivo tese 8_VF_Completa.pdf: 3379003 bytes, checksum: 659bf515460d03427a658914feaa471a (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-01-19T18:33:58Z (GMT) No. of bitstreams: 1 coscolim_rbs_dr_bot.pdf: 3379003 bytes, checksum: 659bf515460d03427a658914feaa471a (MD5) / Made available in DSpace on 2017-01-19T18:33:58Z (GMT). No. of bitstreams: 1 coscolim_rbs_dr_bot.pdf: 3379003 bytes, checksum: 659bf515460d03427a658914feaa471a (MD5) Previous issue date: 2016-11-17 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O amendoim é uma cultura de interesse econômico para o estado de São Paulo, principalmente para renovação de canaviais e pastagens na região oeste do estado. Nesta região, os crescentes custos de produção do amendoim acompanhados por baixo rendimento por área devido à suscetibilidade às variações climáticas são influências negativas e contribuem para desestimular a produção dessa cultura. Nesse âmbito, a associação com fungos micorrízicos arbusculares (FMAs) e suplementação com bioestimulante a base de extrato solúvel de algas (Ascophyllum nodosum) (ESA) podem promover melhorias no crescimento e desenvolvimento da planta, além de atenuarem os efeitos negativos provocados pela deficiência hídrica. As plantas foram cultivadas em estufa agrícola, com monitoramento das relações hídricas além do estudo de trocas gasosas, análise de crescimento, análises microbiológicas e de produção, bem como das respostas metabólicas das plantas em função dos tratamentos. A presente pesquisa valida os benefícios para a cultura do amendoim quando em associação com os FMAs e / ou com a suplementação com o ESA, pois além de incrementarem o crescimento e taxa de assimilação líquida de carbono nas plantas em condições hidratadas, mantiveram o status hídrico das plantas e proveram também o acionamento de enzimas do complexo antioxidativo nas plantas em condições de deficiência hídrica moderada e severa. / Water is essential element for plant development and its absence or deficiency induces physiological changes with severe consequences for productivity. Peanut is a culture of economic interest to the State of São Paulo especially in the western region. In this region, the increasing of production costs in peanuts is associate by low yield due to susceptibility to climate variations, such as dry seasons. They are negative influences and do not contribute to production in that crop. In this context, the association with arbuscular mycorrhizal fungi (AMF) and supplementation with biostimulant based on soluble algal extract (Ascophyllum nodosum) (ESA) can promote improvements in plant growth and development, as well as attenuate the negative effects caused by water deficiency. The plants grown in a greenhouse with monitoring of water relations in addition to the study of gas exchange parameters, growth analysis, microbiological analysis, production, and metabolic responses of plants in the treatments. The present study validates the benefits for peanut cultivation with fungus and/or seaweed extract supplementation. Plants under hydrated conditions had better performance in growth and carbon assimilation rate and under conditions of moderate and severe water deficiency.of, they maintained water status of the plants and also provided the activation of enzymes of the antioxidative complex. / CNPq: 141167/2014-9
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Quantificação do carbono da biomassa microbiana, do carbono do 'CO IND. 2' liberado e micorrização em função da calagem e do manejo do solo /

Garcia, Martha Regina Lucizano. January 2004 (has links)
Orientador: Ana Maria Rodrigues Cassiolato / Banca: Arnaldo Colozzi Filho / Banca: Luiz Malcolm Mano de Mello / Resumo: Vem sendo adotado no cerrado, cada vez mais, sistemas de manejos conservacionistas, como o plantio direto ou cultivo mínimo, que auxiliam na recuperação e na busca da sustentabilidade do agrossistema. Estes sistemas favorecem numerosos processos bioquímicos que ocorrem no solo devido à atividade microbiana, com efeitos sobre as propriedades físicas e químicas do solo e reflexos sobre o desenvolvimento das plantas, a produtividade agrícola e a qualidade do ambiente. Com isso, o objetivo deste trabalho foi quantificar o carbono da biomassa microbiana (CBM), o carbono do CO2 (C-CO2) liberado e a micorrização em função da calagem e do manejo do solo, em uma área de 20 anos de plantio direto, nas culturas de feijão (cultura de inverno) e milho (cultura de verão). O experimento foi conduzido na Fazenda de Ensino e Pesquisa da Faculdade de Engenharia, UNESP, Campus de Ilha Solteira, localizada no município de Selvíria-MS. O delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas, constituídas de 2 tratamentos (principais), 2 doses de calcário e 4 repetições cada. Os tratamentos foram: T1 - Plantio direto - calcário na superfície, sem incorporação; e T2 - Cultivo Mínimo - incorporação de calcário com o escarificador; e as doses de calcários foram: D1 - Testemunha (sem calcário) e D2 - 2000 kg ha-1 de calcário. O solo foi reclassificado como LATOSSOLO VERMELHO distrófico. Após amostragem (de 0 - 0,10 m de profundidade), o solo foi seco, peneirado (2 mm) e enviado para análise das características químicas. O CBM foi avaliado pelo método de fumigação-extração e a atividade respiratória foi verificada pela quantificação do C-CO2 liberado. Para as avaliações da porcentagem de segmentos de raízes colonizadas por fungos micorrízicos arbusculares as raízes foram clareadas, acidificadas, coloridas com azul de... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: There is a steady increase in the employment of conservation management systems such as no-tillage or minimum-tillage in the Brazilian 'cerrado', which help in the recovery and maintenance of the agrosystem sustainability. These systems benefits several biochemical processes that take place in the soil due to microbial activity, which impact its physical and chemical properties and reflect on the development of plants, agricultural yield and the environment quality. The objective of this research was to quantify the microbial biomas-C, the C-CO2 evaluated and the mycorrhization in relation to limestone application and soil management, in a site under no-tillage for 20 years. The experiment was deployed at the Teaching and Research Farm (Selvíria, Mato Grosso do Sul State, Brazil) of the College of Engineering of Ilha Solteira, UNESP. The experimental design was a split plot, with two managements (main) and two levels of limestone, with four replications each. Treatments were T1 - No-tillage: surface limestone application, with no incorporation and T2 - Minimum-tillage: limestone incorporation with chisel plowing, while limestone levels were D1 - control (no limestone) and D2 - 2,000 kg ha-1 limestone. The soil was reclassified as a red 'latossol' (oxisol). After sampling the soil was dried, sieved (2 mm mesh) and analyzed for its chemical properties. The microbial biomass-C was estimated by the fumigation-extraction method and respiratory activity was estimated by the quantification of the C-CO2 evaluated. Roots were clarified, acidified, stained with 0.05 trypan blue and preserved in lactoglycerol in order to estimate the percentage of root colonization by arbuscular mycorrhizal fungi. The assessment of mycorrhizal colonization was performed in 40 segments (one cm long), for each replication and treatment, under a... (Complete abstract, click electronic address below). / Mestre

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