For the first time the transcriptional reprogramming of distinct root cortex cells during the arbuscular mycorrhizal (AM) symbiosis was investigated by combining Laser Capture Mirodissection and Affymetrix GeneChip® Medicago genome array hybridization. The establishment of cryosections facilitated the isolation of high quality RNA in sufficient amounts from three different cortical cell types. The transcript profiles of arbuscule-containing cells (arb cells), non-arbuscule-containing cells (nac cells) of Rhizophagus irregularis inoculated Medicago truncatula roots and cortex cells of non-inoculated roots (cor) were successfully explored. The data gave new insights in the symbiosis-related cellular reorganization processes and indicated that already nac cells seem to be prepared for the upcoming fungal colonization. The mycorrhizal- and phosphate-dependent transcription of a GRAS TF family member (MtGras8) was detected in arb cells and mycorrhizal roots. MtGRAS shares a high sequence similarity to a GRAS TF suggested to be involved in the fungal colonization processes (MtRAM1). The function of MtGras8 was unraveled upon RNA interference- (RNAi-) mediated gene silencing. An AM symbiosis-dependent expression of a RNAi construct (MtPt4pro::gras8-RNAi) revealed a successful gene silencing of MtGras8 leading to a reduced arbuscule abundance and a higher proportion of deformed arbuscules in root with reduced transcript levels. Accordingly, MtGras8 might control the arbuscule development and life-time. The targeting of MtGras8 by the phosphate-dependent regulated miRNA5204* was discovered previously (Devers et al., 2011). Since miRNA5204* is known to be affected by phosphate, the posttranscriptional regulation might represent a link between phosphate signaling and arbuscule development. In this work, the posttranscriptional regulation was confirmed by mis-expression of miRNA5204* in M. truncatula roots. The miRNA-mediated gene silencing affects the MtGras8 transcript abundance only in the first two weeks of the AM symbiosis and the mis-expression lines seem to mimic the phenotype of MtGras8-RNAi lines. Additionally, MtGRAS8 seems to form heterodimers with NSP2 and RAM1, which are known to be key regulators of the fungal colonization process (Hirsch et al., 2009; Gobbato et al., 2012). These data indicate that MtGras8 and miRNA5204* are linked to the sym pathway and regulate the arbuscule development in phosphate-dependent manner. / Die Leguminose Medicago truncatula (gehört zur Gattung des Schneckenklees) ist in der Lage sowohl eine Symbiose mit stickstofffixierenden Bakterien (Rhizobien), als auch mit Mykorrhiza-Pilzen einzugehen. Der Mykorrhiza-Pilz Rhizophagus irregularis dringt in die Wurzelrindenzellen ein und bildet Strukturen aus, die als Arbuskeln bezeichnet werden. Diese ermöglichen den Transfer von Nährstoffen, wie Phosphat in die Wurzelzellen. Die Pflanze liefert hingegen bis zu 20 % ihrer Photosyntheseprodukte an den Pilz. Da die Lebenszeit der Arbuskeln nur wenige Tage beträgt, können Wurzelrindenzellen mehrere Arbuskeln nacheinander beherbergen. Somit können neben arbuskelhaltigen, auch nicht-arbuskelhaltige Zellen in kolonisierten Wurzeln auftreten. Die nicht-arbuskelhaltigen Zellen beeinträchtigen die Sensitivität von Genregulationsanalysen, wenn die Genregulation während der Mykorrhiza-Symbiose anhand von ganzen kolonisierten Wurzeln untersucht wird. In dieser Arbeit konnte eine Zelltyp-spezifische Analyse der Genregulation von arbuskelhaltigen und nicht-arbuskelhaltigen Zellen durchgeführt, und eine Erhöhung der Sensitivität erreicht werden. Mittels Laser Capture Microdissection wurden Zellen aus Gefrierschnitten von Wurzeln isoliert. Aus den so gewonnen Zellen konnte RNA von ausreichender Qualität und Quantität extrahiert werden, um das Transkriptom der beiden Zelltypen mittels Mikroarrayhybridisierung zu untersuchen. Transkriptionsfaktoren (TFs) spielen wahrscheinlich eine Schlüsselrolle in der Umprogrammierung von Wurzelzellen während der Mykorrhiza-Symbiose. Daher wurde die Genregulation von TF-Genen in den zwei Zelltypen gezielt untersucht. Anhand von quantitativer RT-PCR und Promoter-Reporter-Fusionen wurde die differentielle Expression von mehreren TF-Transkripten in den verschiedenen Zelltypen bestätigt. Die Charakterisierung eines potentiellen GRAS TF (MtGRAS8) konnte eine stark Symbiose- und Phosphat-abhängige Induktion von Transkripten bestätigt werden. Mutanten mit verringerter MtGras8 Transkriptmenge wiesen eine verringerte Arbuskelzahl und deformierte Arbuskeln auf. MtGras8 scheint daher an der Arbuskelentwicklung beteiligt zu sein. Vorherige Experimente zeigten, dass MtGras8 Transkripte, von der Phosphat-regulierten MikroRNA5204* geschnitten werden (Devers et al., 2011). Dies konnte durch Überexpression der MikroRNA5204* in vivo bestätigt werden. Weiterhin konnten Protein-Protein-Interaktionen von MtGras8 mit bekannten GRAS TFs (NSP1, NSP2, RAM1) nachgewiesen und daraus eine Verbindung zu bekannten Symbiose-induzierten Signalkaskaden geschlossen werden. In dieser Arbeit wurde erstmals die Umprogrammierung von nicht-arbuskelhaltigen Zellen untersucht und neue Regulationselemente für die Kontrolle der Arbuskelentwicklung, wie MtGRAS8 und MikroRNA5204*, charakterisiert.

The study examined interactions between morogo plants, arbuscular mycorrhizal fungi (AMF) and Fusarium species. Morogo refers to traditional leafy vegetables that, together with maize porridge, are dominant staple foods in rural areas of the Limpopo Province such as the Dikgale Demographic Surveillance Site (DDSS). Morogo plants grow either as weeds (often among maize), occur naturally in the field or are cultivated as subsistence crops by rural communities. Botanical species of morogo plants consumed in the DDSS were determined. Colonisation of morogo plant roots by AMF and Fusarium species composition in the immediate soil environment were investigated in four of eight DDSS subsistence communities, Isolated AMF were shown to belong to the genera Acaulospora and Glomus. Twelve Fusarium species were isolated from soil among which Fusariurn verticilliodes and Fusarium proliferaturn occurred predominantly. Greenhouse pot trials were conducted to examine the effect of AMF on morogo plant growth (cowpea; Mgna unguiculata) and Fusarium proliferatum levels in soil, Interaction between plants and AMF, as well as tripartite interactions of cowpea plants, AMF and Fusarium proliferatum were investigated. Non-inoculated cowpea plants served as controls for the following inoculations of cowpea in pots: (i) Fusarium proliferatum; (ii) commercial AMF from Mycoroot (PTY) Ltd. (a mixture of selected indigenous Glomus spp referred to commercial AMF for the purpose of this study); (iii) indigenous AMF obtained from DDSS soil (referred to iocal AMF for the purpose of this study); (iv) commercial AMF plus Fusarium proliferatum; (v) local AMF plus Fusariurn proliferatum. Results showed reduced root colonization by local as well as commercial AMF when Fusarium proliferatum were present. Local AMF significantly enhanced cowpea growth while commercial AMF apparently reduced the level of Fusarium proliferatum in the rhizosphere and surrounding soil. Results suggest that AMF may have potential as biological growth enhancers and bioprotective agents against Fusarium proliferatum. / Thesis (M. Environmental Science (Water Science))--North-West University, Potchefstroom Campus, 2007.

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.

The occurrence in Scotland of arbuscular mycorrhizal fungi (AMF) infective on Alnus glutinosa and the effects on early growth of inoculation of seedlings with AMF and Frankia were investigated. AMF characteristic of G/omiw-like fungi were detected microscopically in A. glutinosa roots from mineral and loam but not from highly organic soils. Both GJomus- and Gigaspora-like fungi were detected only in roots from sandy soils. Glasshouse experiments showed that Glomus and Gigaspora species gave higher colonisation of roots, and were of higher compatibility with the host plant, than Acutelospora or Scutettospora species. Colonisation by AMF increased nodulation by Frankia and vice versa. Inoculation with AMF alone and dual inoculation with Gigaspora rosea and Frankia inhibited growth of young A. glutinosa seedlings. Initially after inoculation, AMF colonisation was poor allowing the host to meet the requirements of both developing symbioses. Mycorrhizal plants inoculated with Frankia 15 days after AMF inoculation, were under significant stress and this delayed the beneficial effects of AMF and Frankia symbiosis. Seedlings compensated for the cost of symbiosis by developing a larger, leafy shoot in a period of 25-30 days after AMF inoculation, with or with out, Frankia nodulation. A significant increase in root length and branching detected after inoculation with AMF and Frankia must impose additional energy requirements. However, the stimulation of lateral root branching that follows AMF colonisation may facilitate nutrient uptake, thus helping the plant to overcome the disadvantages of early retardation of shoot growth. Competition with adjacent plant species for below ground space may also be enhanced thus facilitating competition for growing space with other plant species. These factors may be part of a strategy that assists the survival of very young seedlings in the field. The data obtained suggest that delaying Frankia inoculation for 3-4 weeks after inoculation with selected AMF should improve the production in Scottish nurseries of robust, well nodulated and mycorrhizal seedlings.

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.

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.

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

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

Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-02-11Bitstream added on 2014-06-13T19:18:11Z : No. of bitstreams: 1 garcia_mrl_me_ilha.pdf: 144818 bytes, checksum: c7bfc6080d6e547db543086dc0ce6516 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / 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... . / 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).

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A salinizaÃÃo dos solos tem se constituÃdo um problema sÃrio para a agricultura, principalmente nas regiÃes Ãridas e semi-Ãridas em todo o mundo. O excesso de sais no solo afeta tanto as Ãreas irrigadas como as nÃo irrigadas, limitando, portanto o crescimento e a produtividade das culturas. O presente trabalho teve por objetivo avaliar os efeitos da inoculaÃÃo com fungo micorrÃzico arbuscular e da adubaÃÃo orgÃnica no desenvolvimento do sabià (Mimosa caesalpiniaefolia Benth), sob estresse salino. Portanto, foi instalado um experimento em casa de vegetaÃÃo do Departamento de CiÃncias do Solo da Universidade Federal do CearÃ, no Campus do Pici em Fortaleza. O delineamento experimental adotado foi o inteiramente casualizado, em esquema fatorial, 2 (presenÃa e ausÃncia de fungos micorrÃzicos arbusculares) X 2 (presenÃa e ausÃncia de composto orgÃnico) X 5 nÃveis de condutividade elÃtrica da Ãgua de irrigaÃÃo (0,7, 1,2, 2,2, 3,2 e 4,2 dS m1), com 4 repetiÃÃes. Ao final de 60 dias apÃs a germinaÃÃo das plantas foi coletado o experimento, onde determinou-se os fatores de crescimento, as variÃveis microbiolÃgicas, o pH do solo apÃs o cultivo, os teores minerais (N, P, K, Ca, Mg, Na, Cl) e as relaÃÃes Raiz/Parte AÃrea (R/PA) e SÃdio/PotÃssio (Na/K). A salinidade promoveu maior reduÃÃo na produÃÃo de matÃria seca das plantas nÃo micorrizadas e nÃo adubadas. A inoculaÃÃo com fungo micorrÃzico arbuscular aumentou a produÃÃo de matÃria seca das plantas de sabiÃ. As plantas adubadas com matÃria orgÃnica apresentaram maior desenvolvimento, quando comparadas com as plantas nÃo adubadas. As plantas micorrizadas apresentaram maiores conteÃdos de nutrientes, quando comparadas com as plantas nÃo micorrizadas. / Salt affected soils management is an important subject to be studied, especially when irrigated arid and semi-arid regions are considered, as soil salt excess may limit growth and plant productivity. The objective of this dissertation was to evaluate the effect of mycorrhizal arbuscular fungi (AMF) inoculation on growth of sabià plants (Mimosa caesalpiniaefolia Benth.), cultivated under salt stress in the presence or absence of organic compost. Thus, an experiment was conducted under green-house conditions to evaluate the potential of inoculated and fertilized plant establishment submitted to salt stress, in a complete randomized factorial design 2 (inoculated or non-inoculated plants) X 2 (fertilized or non-fertilized with organic compost) X 5 levels of irrigation water electrical conductivity (0.7, 1.2, 2.2, 3.2 and 4.2 dS mâ), with 4 replications. After 60 days from germination, plants were harvested and then and analyzed to evaluate growth factors, microbiological variables, soil pH, shoot-root and sodium/potassium ratios and mineral nutrient content (N, P. Ca, Mg, Na and Cl). Salinity decreased growth and plant biomass of non-mycorrhizal fertilized plants. Inoculation with AMF increased plant dry matter production when compared with non-inoculated plants under salt stress. When compared with non-fertilized plants, organic compost fertilization increased plant growth, Nutrient contents were always much higher in inoculated plants and in organic compost fertilized plants.