CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / In this work were studied diverse physiological mechanisms, as the osmotic adjustment, photosynthesis, including gas exchange and chlorophyll fluorescence parameters, as well the oxidative responses in physic nuts submitted to different abiotic stresses as: salinity, drought and high temperature. The first experiment aimed to study the effects of increase of the NaCl concentrations (0, 25, 50, 75 and 100 mM) in the ions accumulate (Na+, Cl- and K+) and some growth variables, as well evaluate the water state and the principals solutes (organic and inorganic) involved on the osmotic adjustment of physic nuts plants under this stressful condition. Physic nuts plants showed sensibility to salt stress, presenting a reduction by 50% in dry matter from by 47 mM of NaCl concentration during 15-d. This sensibility should be due the leaf Na+ and Cl- high accumulation, associated a strong reduction in the K+ concentration, induced by high Na+ content. On the other hand, physic nuts plants were able osmotic adjust to salinity due a severe decrease on the osmotic potential and increase of leaf water state, principally in the higher NaCl levels. Of the solutes studied, was observed that salt ions (Na+ and Cl-) contributed with the most of the osmotic adjustment, while that the K+ contribution was decreased strongly by NaCl. The glycinebetaine compared to proline was more important to the osmotic adjustment of physic nuts leaves, as in the absence as in presence of different NaCl levels in the nutrient solution. The second experiment evaluated the resistance of photosynthetic apparatus of physic nuts plants submitted to different time of exposure (7-d and 14-d of treatment and 3-d of recovery) to salt stress (100 mM of NaCl).The changes caused on photochemistry activity and leaf gas exchange were evaluate by Na+ and Cl- accumulation and decrease of K+/Na+ ratio in the leaves. After 7-d of treatment was observed a major action of osmotic effects. However, after 14-d of treatment, the ionic effects caused by Na+ and Cl- excessive accumulation and by K+/Na+ ratio strong reduction in the leaves, caused permanent damages on the photosynthesis of physic nuts plants due as the stomatal limitations as non-stomatal ones. The third experiment aimed to study the comparative effects between the salt stress (50 mM of NaCl) and water stress (induced for PEG 6000), both with osmotic potential of â0.22 MPa on the photosynthesis, water relations and growth of physic nuts plants. The water stress effects induced for PEG in the leaf growth, electrolyte leakage and leaf gas exchange were more deleterious than by NaCl ones. In the both stresses was observed decrease in the leaf CO2 assimilation due the stomatal and non-stomatal limitations. However, the chlorophyll fluorescence parameters did not affect. The fourth experiment aimed to evaluate the relative contribution of organic and inorganic solutes on the osmotic adjustment of leaves and roots physic nuts plants in different water restriction levels. Of the solutes studied, the K+ and soluble sugar were the most involved in the osmotic adjustment as in the leaves as in roots. Others solutes as, Na+, Cl-, total amino acids and glycibetaine, also presented a effective role in the reduction of osmotic potential in both organs. On the other hand, the leaf proline content, although has increased significantly, was not sufficient to promote an effective participation of this amino acid in the osmotic adjustment of physic nuts plants. The same experiment aimed to observe the isolated and combined effects of water stress and high temperature on the photosynthesis and evaluate the oxidative defenses system in physic nuts plants. The photosynthetic apparatus was more sensitive to water stress than heat ones, been that the combination of them caused deleterious effects yet large in this complex. Additionally, the oxidative damages also were more marked in the combined stress. In general, the data shown that physic nuts plants, although present ability to adjust osmotically to salinity and drought, have their photosynthetic apparatus very affected in this stressful conditions. Even as, the defense system against oxidative damages appears has not been efficient in plants exposure at the drought and heat isolated and combined stresses / In this work were studied diverse physiological mechanisms, as the osmotic adjustment, photosynthesis, including gas exchange and chlorophyll fluorescence parameters, as well the oxidative responses in physic nuts submitted to different abiotic stresses as: salinity, drought and high temperature. The first experiment aimed to study the effects of increase of the NaCl concentrations (0, 25, 50, 75 and 100 mM) in the ions accumulate (Na+, Cl- and K+) and some growth variables, as well evaluate the water state and the principals solutes (organic and inorganic) involved on the osmotic adjustment of physic nuts plants under this stressful condition. Physic nuts plants showed sensibility to salt stress, presenting a reduction by 50% in dry matter from by 47 mM of NaCl concentration during 15-d. This sensibility should be due the leaf Na+ and Cl- high accumulation, associated a strong reduction in the K+concentration, induced by high Na+ content. On the other hand, physic nuts plants were able osmotic adjust to salinity due a severe decrease on the osmotic potential and increase of leaf water state, principally in the higher NaCl levels. Of the solutes studied, was observed that salt ions (Na+ and Cl-) contributed with the most of the osmotic adjustment, while that the K+contribution was decreased strongly by NaCl. The glycinebetaine compared to proline was more important to the osmotic adjustment of physic nuts leaves, as in the absence as in presence of different NaCl levels in the nutrient solution. The second experiment evaluated the resistance of photosynthetic apparatus of physic nuts plants submitted to different time of exposure (7-d and 14-d of treatment and 3-d of recovery) to salt stress (100 mM of NaCl).The changes caused on photochemistry activity and leaf gas exchange were evaluate by Na+ and Cl- accumulation and decrease of K+/Na+ ratio in the leaves. After 7-d of treatment was observed a major action of osmotic effects. However, after 14-d of treatment, the ionic effects caused by Na+ and Cl- excessive accumulation and by K+/Na+ ratio strong reduction in the leaves, caused permanent damages on the photosynthesis of physic nuts plants due as the stomatal limitations as non-stomatal ones. The third experiment aimed to study the comparative effects between the salt stress (50 mM of NaCl) and water stress (induced for xv PEG 6000), both with osmotic potential of â0.22 MPa on the photosynthesis, water relations and growth of physic nuts plants. T e water stress effects induced for PEG in the leaf growth, electrolyte leakage and leaf gas exchange were more deleterious than by NaCl ones. In the both stresses was observed decrease in the leaf CO2 assimilation due the stomatal and nonstomatal limitations. However, the chlorophyll fluorescence parameters did not affect. The fourth experiment aimed to evaluate the relative contribution of organic and inorganic solutes on the osmotic adjustment of leaves and roots physic nuts plants in different water restriction levels. Of the solutes studied, the K+ and soluble sugar were the most involved in the osmotic adjustment as in the leaves as in roots. Others solutes as, Na+, Cl-, total amino acids and glycibetaine, also presented a effective role in the reduction of osmotic potential in both organs. On the other hand, the leaf proline content, although has increased significantly, was not sufficient to promote an effective participation of this amino acid in the osmotic adjustment of physic nuts plants. The same experiment aimed to observe the isolated and combined effects of water stress and high temperature on the photosynthesis and evaluate the oxidative defenses system in physic nuts plants. The photosynthetic apparatus was more sensitive to water stress than heat ones, been that the combination of them caused deleterious effects yet large in this complex. Additionally, the oxidative damages also were more marked in the combined stress. In general, the data shown that physic nuts plants, although present ability to adjust osmotically to salinity and drought, have their photosynthetic apparatus very affected in this stressful conditions. Even as, the defense system against oxidative damages appears has not been efficient in plants exposure at the drought and heat isolated and combined stresses

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-01-28T13:57:22Z No. of bitstreams: 2 Dissertação - Patrícia Pereira Ribeiro Keller - 2015.pdf: 8454284 bytes, checksum: d5e4ec0ee26ea90a9344aa5157836221 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-29T11:23:02Z (GMT) No. of bitstreams: 2 Dissertação - Patrícia Pereira Ribeiro Keller - 2015.pdf: 8454284 bytes, checksum: d5e4ec0ee26ea90a9344aa5157836221 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-29T11:23:02Z (GMT). No. of bitstreams: 2 Dissertação - Patrícia Pereira Ribeiro Keller - 2015.pdf: 8454284 bytes, checksum: d5e4ec0ee26ea90a9344aa5157836221 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-09-21 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The survey was developed with the objective of diagnosis of water stress in the catchment area of the hydrografic basin João Leite River, whereas seasonal aspects and the water regime (lotic system and still water system). Historic survey was conducted of the anthropogenic activities (industry, commerce, farmers, vegetable and mineral extraction) inserted into the catchment area of João Leite River. Following, he proceeded historical survey (2012 and 2013) of physico-chemical parameters (ambientte temperature, water temperature, turbidity, pH, nitrogen series, total phosphorus, dissolved oxygen - OD, biochemical demand of oxigênico - DBO, total dissolved solids - STD) and bacterial (Escherichia coli), resulting in the calculation of the Water Quality Index (IQA) in eleven (11) sampling points (Reservoir João Leite River, João Leite River, Bandeira Stream, Jenipapo Stream, Jurubatuba Stream, Rosa Stream, Descoberto Stream, Maria Paula Stream, Posse Stream, Mata Pasto Stream, Pedras Stream). It was found that five (5) sampling points highlighted by the lower IQA (Jurubatuba Stream - IQA 58.81; João Leite River - IQA 61.50; Bandeira Stream - IQA 63.41; Jenipapo Stream - IQA 65.22 ) or environmental significance in the Reservoir João Leite River - IQA 75.12 Subsequently, these five (5) points were monitored every two months in 2014 (3 collections in rainy season and 3 collections in dry season) analyzing 100 ( one hundred) parameters: 6 physical parameter (water temperature, transparency, quota, turbidity, apparent color and true), 89 chemical parameter (43 Organic 23 metals, caffeine, total solids, total nitrogen, pH, conductivity, STD, calcium, magnesium, chloride, nitrate, nitrite, ammonia, sulphate, total organic carbon, alkalinity, hardness, consumed oxygen, OD, DBO, chemical oxygen demand, surfactant, total iron and carbon dioxide) and 5 biological parameter (total coliforms, Escherichia coli, clorophyll- a, pheophytin and phytoplankton). The annual average of the data obtained showed the Water Quality Index 65.80 (good), Trophic State Index 52.93 (mesotrophic) and Community Index Phytoplankton 2.20 (good). Caffeine was quantified (0.315 mg L-1 to 1.512 mg L -1) at all sampling sites in the basin indicating contamination by domestic sewage. The present study demonstrated a resilient bowl with the presence of stress factors: micropollutants (demeton, atrazine, glyphosate, malathion, metolachlor, carbon tetrachloride, xylene, dichloromethane, dichloroethene, toluene), trace elements (As, Hg, Sb, Se, Cu , Fe, Al, Cr, Zn, In, Cd, Co, B, Mn, Li, Ag, Be, V, Ni, U, Ba, Pb), pathogenic organisms (Escherichia coli, Microcystis sp.) and first-order impacts (deforestation, presence of effluents and solid wastes) related to anthropogenic activities developed in the watershed region of João Leite River. / A pesquisa foi desenvolvida com objetivo de realizar o diagnóstico do estresse hídrico na bacia hidrográfica do Ribeirão João Leite, considerando aspectos sazonais e o regime hídrico (sistema lótico e sistema lêntico). Foi realizado levantamento histórico das atividades antrópicas (indústria, comércio, produtor rural, extração vegetal e mineral) inseridas na área da bacia hidrográfica do Ribeirão João Leite. Seguindo, procedeu-se levantamento histórico (2012 e 2013) de parâmetros físico-químicos (temperatura ambientte, temperatura da água, turbidez, pH, série nitrogenada, fósforo total, oxigênio dissolvido – OD, demanda bioquímica de oxigênico – DBO, sólidos totais dissolvidos – STD) e bacteriológico (Escherichia coli), resultando no cálculo do Índice de Qualidade da Água (IQA) em onze (11) pontos de amostragem (Barramento do Reservatório do Ribeirão João Leite, Ribeirão João Leite, Córrego Bandeira, Córrego Jenipapo, Córrego Jurubatuba, Córrego Rosa, Córrego Descoberto, Córrego Maria Paula, Córrego Posse, Córrego Mata Pasto, Córrego Pedras) . Verificou-se que cinco (5) pontos de amostragem destacaram-se pelo menor IQA (Córrego Jurubatuba – IQA 58,81; Ribeirão João Leite – IQA 61,50; Córrego Bandeira – IQA 63,41; Córrego Jenipapo – IQA 65,22) ou pela significância ambiental ( Barramento no Reservatório do Ribeirão João Leite – IQA 75,12. Posteriormente, estes cinco (5) pontos foram monitorados bimestralmente em 2014 (3 coletas em período de chuva e 3 coletas em período de seca) analisando 100 (cem) parâmetros: 6 físicos (temperatura da água; transparência; cota; turbidez; cor aparente e verdadeira); 89 químicos (43 orgânicos, 23 metais, cafeína, sólidos totais, nitrogênio total, pH, condutividade, STD, cálcio, magnésio, cloreto, nitrato, nitrito, amônia, sulfato, carbono orgânico total, alcalinidade, dureza, oxigênio consumido, OD, DBO, demanda química de oxigênio, surfactante, ferro total e gás carbônico) e 5 biológicos (coliformes totais, Escherichia coli, clorofila-a, feofitina e fitoplâncton). A média anual dos dados obtidos evidenciou Índice de Qualidade da Água 65,80 (bom), Índice do Estado Trófico 52,93 (mesotrófico) e Índice de Comunidade Fitoplanctônica 2,20 (bom). Foi quantificada cafeína (0,315 mg.L-1 a 1,512 mg.L-1) em todos os pontos amostrados indicando contaminação na bacia por efluentes domésticos. O presente estudo demonstrou uma bacia resiliente com presença de fatores estressantes: micropoluentes (demeton, atrazina, glifosato, malation, metolacloro, tetracloreto de carbono, xileno, diclorometano, dicloroeteno, tolueno), elementos traços (As, Hg, Sb, Se, Cu, Fe, Al, Cr, Zn, Na, Cd, Co, B, Mn, Li, Ag, Be, V, Ni, U, Ba, Pb), organismos patogênicos (Escherichia coli, Microcystis sp.) e impactos de primeira ordem (desmatamento, presença de efluentes e resíduos sólidos) relacionados às atividades antrópicas desenvolvidas na região da bacia hidrográfica do Ribeirão João Leite.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-08-18T19:35:56Z No. of bitstreams: 2 Dissertação - Flávio de Oliveira Rosa - 2014.pdf: 2072221 bytes, checksum: dd9c2aa9eb4e6bd9898133635dd43ba6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-19T13:11:08Z (GMT) No. of bitstreams: 2 Dissertação - Flávio de Oliveira Rosa - 2014.pdf: 2072221 bytes, checksum: dd9c2aa9eb4e6bd9898133635dd43ba6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-19T13:11:08Z (GMT). No. of bitstreams: 2 Dissertação - Flávio de Oliveira Rosa - 2014.pdf: 2072221 bytes, checksum: dd9c2aa9eb4e6bd9898133635dd43ba6 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014-07-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Due to the intensified devastation of native Brazilian Savanna biome (“Cerrado”) areas in recent decades, there is currently a major concern in preserving the remaining natural areas. In this view, the forest species cultivation purposes has emerged to meet the demand for wood. In the searching of forest species with good quality wood, easy adaptability and high commercial value, has been gaining space the african mahogany (Khaya ivorensis). Originally from west coast of Africa, is a specie that showed good adaptation to edaphoclimatic6 conditions of savanna besides being inserted in several other regions of Brazil. Although the recent implantation of the forest species in commercial plantations in Brazil, has been gaining visibility, but climate requirements is just a little known, beyond fluid and nutritional requirements of the crop. In this way, the aim of this study was to perform the brazilian edaphoclimatic zoning for african mahogany and evaluate the growth and development of this specie under savanna conditions of Goiás, as well. Firstly, edaphoclimatic zoning for the crop of african mahogany for different regions of Brazil was carried out using data temperature, rainfall and soil types, based on the origin region of species (west African coast).The field experiment was carried on Bonfinópolis, county of Goiás State. The plants were implanted is spacing of 5x5m. An irrigation system by conventional sprinkling3 was utilized to replace the lost water for evapotranspiration (ET-100%). 10 plants were evaluated, being 5 irrigated plants and 5 non-irrigated plants. The variables measured were: shaft4 height, number of leaves, stem diameter and leaf area. The experiment delimitation utilized was fully randomized (DIC), in a bi-factorial scheme 2x9 (A: irrigated and non-irrigated; D: times). The experiment in protected environment performed in EA-UFG, driving up of 18 plants in vases (20L.), with no fluid deficit, being the treatments formed by doses of N (0.0; 0.12; 0.24; 0.36; 0.48; 0.60g N plant1). These plants were evaluated for 5 months-period, with biweekly readings of: plant height, shaft height, number of leaves, number of leaflets, stem diameter and leaf area. The experimental drawing z was the DIC. From the zoning, it was realized that suitable areas to the cultivation of this species, cover most part of Brazil, extending though major part of regions Midwest of the country and thought coast of regions northeast and southeast. The suitable zones with restrictions comprise a large part of states of AM and AC, having more restrictions to south region of Brazil. Only a small strip neat the coast of SP state is considered unfit to the african mahogany plantation. The field experiment demonstrated that all evaluated variables obtained significant differences between the irrigated treatments and non-irrigated, as well, for the different times of evaluation. The irrigated plants showed higher growth than non-irrigated plants with daily rates for plant height and leaf extension of 0.706 cm and 80.354 cm2, respectively, the same variables for non-irrigated plants showed values of 0.508 cm and 63.104 cm2. The experiment in protected environment has found that nitrogen fertilization influenced the mean of leaf area wherein the dose of 0.48 and 0.60 g N-1 influenced better performance of the plants. Conclude that african mahogany can be cultivated in major areas of national territory. Irrigation is recommended on the period between May and September. Keywords: Khaya ivorensis, climate, soil, water stress, plant growth. / Devido à devastação de áreas nativas do bioma Cerrado intensificada nas últimas décadas, há atualmente uma grande preocupação em se preservar áreas naturais remanescentes. Em vista disto, o cultivo de espécies florestais para fins comerciais surgiu para suprir a demanda por madeira. Na busca por espécies florestais com boa qualidade de madeira, fácil adaptabilidade e elevado valor comercial, vem ganhando espaço o mogno africano (Khaya ivorensis). Natural da costa ocidental da África é uma espécie que mostrou boa adaptação às condições edafoclimáticas do Cerrado além de estar sendo inserida em várias outras regiões do Brasil. Esta espécie florestal embora recém implantada no Brasil em plantios comerciais, vem ganhando visibilidade, porém pouco se sabe com relação as exigências climáticas, hídricas e nutricionais desta cultura. Assim, o objetivo deste estudo foi de realizar o zoneamento edafoclimático brasileiro para o mogno africano, bem como, avaliar o crescimento e desenvolvimento desta espécie nas condições do Cerrado Goiano. Primeiramente foi realizado o zoneamento edafoclimático para a cultura do mogno africano para as diferentes regiões do Brasil, utilizando-se dados de temperatura, precipitação pluvial e tipos de solo, baseando-se na região de origem desta espécie (costa ocidental africana). O experimento em campo foi conduzido município de Bonfinópolis-GO. As plantas foram implantadas em espaçamento 5 x 5 m. Um sistema de irrigação por aspersão convencional foi utilizado para repor a água perdida por evapotranspiração (ET-100%). Avaliaram-se 10 plantas, sendo 5 plantas irrigadas e 5 plantas não irrigadas. As variáveis medidas foram: altura de planta, altura de fuste, número de folhas e de folíolos, diâmetro de caule e área foliar. O delineamento experimental utilizado foi o inteiramente casualizado (DIC), em esquema bifatorial 2x9 (A: irrigadas e não irrigadas; D: tempos). O experimento em ambiente protegido foi realizado na EA-UFG, conduzindo-se 18 plantas, em vasos (20 L), sem déficit hídrico, sendo os tratamentos formados por doses de N (0; 0,12; 0,24; 0,36; 0,48; 0,60 g N planta-1). Estas plantas foram avaliadas por um período de 5 meses, com leituras quinzenais de: altura de planta, altura de fuste, número de folhas e de folíolos, diâmetro de caule e área foliar. O desenho experimental foi o DIC. A partir do zoneamento verificou-se que as zonas aptas ao cultivo desta espécie abrangem a maior parte do Brasil, estendendo-se por boa parte das regiões Centro e Norte do país e pelo litoral das regiões nordeste e parte do sudeste , as zonas aptas com restrições compreendem grande parte dos estados do AM, AC, havendo maiores restrições na região sul do Brasil. Apenas uma pequena faixa próxima ao litoral do Estado de SP é considerada inapta ao plantio do mogno africano. O experimento em campo demonstrou que todas as variáveis avaliadas obtiveram diferenças significativas entre os tratamentos irrigados e não irrigados, bem como, para os diferentes tempos de avaliação. As plantas irrigadas apresentaram um maior crescimento que as plantas não irrigadas com taxas diárias para altura de planta e expansão foliar de 0,706 cm e 80,354 cm2, respectivamente, as mesmas variáveis para plantas não irrigadas apresentaram valores de 0,508 cm e 63,104 cm2. Já o experimento em ambiente protegido verificou-se que a adubação nitrogenada influenciou as médias de área foliar, em que as doses de 0,48 e 0,60 g N-1 influenciaram uma melhor performance das plantas. Conclui-se que o mogno africano pode ser cultivado em grande parte do território nacional, recomendando-se a utilização da irrigação nos períodos de maio a setembro.

No semiárido brasileiro, a vegetação predominante é a Caatinga, bioma ainda pouco explorado, que apresenta plantas e micro-organismos com alta resistência aos períodos de seca imposto pelo clima. Os micro-organismos associados às plantas deste bioma, são capazes de desenvolver mecanismos de proteção celular contra o estresse hídrico, assim como proteção vegetal contra a dessecação. O presente estudo buscou compreender as rizobactérias associadas a Mimosa artemisiana a fim de selecionar bactérias tolerantes à seca com características de promover o crescimento de plantas sob condições de estresse hídrico, diminuindo assim, os efeitos adversos impostos pela seca. As amostras de solo rizosférico foram coletadas ao longo da Caatinga, englobando os estados da BA e PE, totalizando quatro pontos de coleta. Com o uso de metodologias dependentes de cultivo, foi isolado bactérias com algumas características de promoção de crescimento de plantas diretos e/ou indiretos, como produção de AIA e fixação de nitrogênio. Além disso, linhagens capazes de crescer em meio com reduzida atividade de água e com mecanismos de proteção contra a dessecação, como, produção de EPS, biofilme, produção da ACC deaminase e indução de resistência sistêmica através das enzimas peroxidase e polifenoloxidase. Uma linhagem de Paenibacillus sp. e outra de Bacillus sp. foram capazes de promover o crescimento de soja sob condições de estresse hídrico, aumentando alguns parâmetros vegetais como, parte aérea e sistema radicular analisados. / In the Brazilian semi-arid region, the predominat vegetation is the Caatinga biome, still little explored, which features plants and micro-organisms with high resistance to drought periods imposed by the climate. Microorganisms associated with plants in this biome are able to develop mechanisms of cellular protection agains water stress, as well as vegetable protection agains desiccation. The presente study souught tounderstand the rhizobacteria associated with Mimosa artemisiana in order to select drought-tolerant bactéria with characteristics to promote the growth of plants under water stress conditions, thus reducing adverse effects imposed by drought. Rhizospheric soil samples were collectes along the Caatinga, encompassing the States of Bahia and Pernambuco, totaling four collection points. With the use of farming-dependet methodologies, was isolated bactéria with some features of promotion of growth of direct and/or indirect plants such as AIA production and nitrogen fixation. In addition, able to grow amid strains with reduced water activity and mechanisms of protection against desiccation, such as production of EPS, biofilm, production of ACC deaminase and induction of systemic resistance through peroxidase enzymes and polifenoloxidase. A strain of Paenibacillus sp. and Bacillus sp. were able to promote soybean gowth under water stress conditions, increasing some parameters like vegetables, shoot and root system.

Made available in DSpace on 2014-08-20T14:36:54Z (GMT). No. of bitstreams: 1 Dissertacao_Marilia_Alves_Brito_Pinto.pdf: 1469883 bytes, checksum: 0e148abbe007d166eb1aa6a2992757ac (MD5) Previous issue date: 2011-03-04 / With the incentive of biodiesel production in Brazil, the castor bean crop has gained importance in the agricultural scenario, mainly because its seeds have high oil content of good quality. Being considered drought resistant plant in most reports of the literature, this is a controversial aspect because under water deficit conditions low yield has been recorded. Therefore this study had the objective to evaluate the growth and development of the castor bean submitted to different soil water tensions. A greenhouse experiment was carried out with plants of the cultivar Al Guarany 2002. Plants were cultivated in pots with one tensiometer installed at the 0.15 m depth to monitor the water soil tension. The experimental design was completely randomized with three treatments and four replications: 1- water tension maintained at 0.01 MPa; 2 when the soil water tension reached 0.03 MPa, water was added to until returning 0.01 MPa; 3 when the soil water tension reached 0.06 MPa, water was added to until returning to 0.01 MPa. Between 30 and 105 days after plant emergence (DAE) plant transpiration, leaf area, plant height and stem diameter were biweekly evaluated. The time lapse to onset of flowering and height of insertion of the first raceme were evaluated. Physiological parameters such as leaf water potential, leaf firmness and stomatal resistance were measured at 105 DAE. Results show that increasing soil water tension decreased the transpiration and growth rates of the castor bean plant. The time to flowering and height of insertion of the first raceme were greater for plants submitted to lower soil water tension. The leaf water potential and leaf firmness decreased as the soil water tension decreased. As soil water tension increased the stomatal resistance increased mainly with the rise of the atmosphere evaporative demand. Keywords: transpiration, water stress, growth e development. / Com o incentivo à produção de biodiesel no Brasil, a cultura da mamona ganhou importância no cenário agrícola, visto que suas sementes tem alto teor de óleo de boa qualidade. Aliada a estas características está a resistência à seca, que envolve um aspecto controverso, pois o que se tem observado são baixas produtividades em condições de déficit hídrico. Em virtude disso, este trabalho teve como objetivo avaliar a resposta da cultura da mamona a diferentes tensões de água no solo, determinando o efeito das condições de déficit hídrico no crescimento e desenvolvimento da planta. Para tal, foi desenvolvido um experimento em ambiente protegido, com plantas de mamona da cultivar Al Guarany 2002. As plantas foram cultivadas em vasos nos quais foram instalados tensiômetros a 0,15 m de profundidade para monitoramento da tensão de água no solo. O delineamento experimental foi inteiramente casualizado, com três tratamentos e quatro repetições: 1 tensão mantida em 0,01 MPa; 2 quando a tensãochegava a 0,03 MPa as plantas eram irrigadas para retorna-la a 0,01 MPa; 3 quando a tensão chegava a 0,06 MPa as plantas eram irrigadas pararetorna-la a 0,01 MPa. No intervalo entre 30 e 105 dias após a emergência (DAE) foram avaliadas quinzenalmente a transpiração, a área foliar, a altura da planta e o diâmetro caulinar. Determinou-se ainda o tempo para início da floração e altura de inserção do primeiro racemo. Aos 105 DAE foram realizadas as avaliações dos parâmetros fisiológicos, potencial de água na folha, firmeza da folha e resistência estomática. Os resultados indicam que a mamona é sensível ao aumento da tensão de água no solo, sendo que em condições de maior tensão ela diminui a transpiração e o seu crescimento. O tempo para floração e a altura de inserção do primeiro racemo foram maiores nas plantas submetidas a menores tensões de água. O potencial de água na folha e a sua firmeza diminuiram com o aumento da tensão de água. O aumento da tensão de água no substrato aumentou a resistência estomática nas folhas da mamoneira, principalmente com o aumento da demanda evaporativa da atmosfera.

A cours du développement du fruit, son statut oxydatif évolue entraînant une évolution concomitante des activités enzymatiques antioxydantes et ceci en interaction avec des hormones impliquées dans le développement et la maturation du fruit. Ces enzymes antioxydantes sont la superoxyde dismutase (SOD) et la Catalase (CAT) mais également de celles du cycle d’Haliwell-Asada (ascorbate peroxydase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) et gluthation reductase (GR) impliquées également dans le recyclage de l’ascorbate. L’objectif de la thèse est de comprendre les interactions existant entre le stress oxydatif induit par les stress environnementaux au niveau des organes végétatifs et le recyclage de l’ascorbate dans les fruits de tomate (cv Micro-Tom).Dans une première partie nous montrons qu’un déficit hydrique contrôlé et rapide induit une diminution du potentiel hydrique foliaire (Ψh) sans aucun symptôme de stress photo-oxydatif détectable au niveau du PSII après 24h et sans que le statut hydrique du fruit ne soit affecté. Dans ces conditions, on observe toutefois une augmentation du H2O2 dans les fruits et une augmentation de l’activité des enzymes antioxydantes et de celles impliquées de recyclage de l’ascorbate. Par ailleurs, nous montrons une production de NO et de ABA en réponse au stress dans la plante. La localisation de NO a été réalisée par microscopie à fluorescence en utilisant la nouvelle sonde NO, la NO550 (mise au point pendant le doctorat).Afin de déterminer si NO est responsable de la mise en place de la réponse antioxydante du fruits en interaction avec l’ABA et H2O2, une approche pharmacologique a été réalisée. Les résultats montrent une augmentation des activités de ces enzymes en présence de ces trois molécules, avec une plus forte augmentation en présence de NO à chaque fois. Par ailleurs, nous montrons que l'ABA induit la synthèse de NO dans le fruit et non l’inverse. On peut conclure de cette analyse que l’ABA induit par le déficit hydrique est responsable de la synthèse de NO dans les fruits et ce signal va induire l’activation des enzymes antioxydantes en association avec H2O2.Finalement, une approche transcriptomique a été réalisée pour étudier d’une part les gènes induits par NO et les gènes induits par le déficit hydrique au travers du NO. Les résultats suggèrent quele NO est à la croisée de la réponse au stress biotique et abiotiques et pourrait être utilisé pour acclimater les plantes au stress biotiques. / Oxidative status alongside with antioxidant enzymes activities constantly evolve during fruit development. This evolution is closely related to hormones involved in fruit development and maturation. The antioxidant enzymes are superoxide dismutase (SOD) and Catalase (CAT) as well as those of Haliwell-Asada cycle (ascorbate peroxydase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and gluthation reductase (GR) which are also implicated in ascorbate recycling. The objective of this work is to decipher the interactions between oxidative stress induced by environmental stress in vegetative organs and ascorbate recycling in tomato fruits (cv Micro-Tom).Results obtained show that a rapid and controlled water deficit result in a fall in water potential (LΨw) whereas other water parameters remained unaffected and without any photo-oxidative symptoms detected in PS II after 24 hours. However we observed alongside an increase in H2O2 and of the activity of antioxidant enzymes as well as those involved in ascorbate recycling. Furthermore an increase in NO and ABA production was also detected in the plants in response to the stress. NO localisation was realised using fluorescence microscopy using the newly synthesised NO probe NO550 (developed during the thesis).We used a pharmacological approach in order to determine if NO is responsible of the set up of the antioxidant response together with ABA and H2O2. Results show an increase in the activity of the enzymes in contact with the three molecules with every time a greater increase with NO. Furthermore, we show that ABA induces NO production. Those results made us conclude that ABA production induced by the water deficit is responsible of NO synthesis in fruits and may have the action of a signal with activates antioxidant enzymes with the collaboration of H2O2.A microarray analysis was also conducted in order to study the genes induced by NO and the genes induced by water deficit through NO. Results suggest that NO is at the cross road of the response towards biotic and abiotic stress and might be a useful tool to acclimatize plant to stressful conditions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The chemical improvements provided by no-till have been restricted to the upper soil layers, limiting root development in the subsurface, and the efficient use of water, especially in years with drought. This study had the aim assesse: I- characterize the effects of the isolated use of gypsum or combined with lime on the soil chemical properties and crop grain yield in SPD; II- evaluate the effect of chemical improving layer rooting on the crop yield in SPD under induced water deficit. Four experiments were conducted in Oxisols dystrophic managed under continuous NT in Rio Grande do Sul State, with distinct chemical quality in rooting layer, from 2009 to 2014. The experimental design was randomized block with three replications. Two experiments were established in 2009 in Carazinho with treatments ranging 0.0 to 6.5 Mg ha-1 gypsum. In one experiment the plots were divided into two subplots without restriction and with 30% of the rainfall for the implementation of exclusion chamber. Two other experiments were implanted in São Miguel das Missões and Tupanciretã in 2011. In São Miguel das Missões used a randomized block design with split plots, the main plots with lime rates ranging from 0.0 to 5, 0 Mg ha-1, and the subplots composed by no lime treatment at a dose of 2.0 Mg ha-1. In Tupanciretã, the experiment was comprised of a 4x4 factorial design, with four levels of gypsum ranging from 0.0 to 6.0 Mg ha-1, and four liming levels ranging from 0.0 to 4.8 Mg ha-1. The soil samples were made in the stratified layer of 0.00 to 0.60 m. There was an increase in the Ca and S in the entire profile, and reduce the Al saturation and an increase in basis saturation and the saturation of Ca over time. In response to improving the quality of chemical rooting layer was found increased yield of soybean, corn and wheat. With crop rotation during the summer, the sample layers in which there was related to productivity stood at greater depth (0.25-0.40 m layer for the first experiment and 0.00 to 0.40 m for Experiment II). No crop rotation in summer the sample layers that were associated with productivity were located closer to the surface (layer from 0.00 to 0.10 m for Experiment III and 0.00 to 0.25 m for the experiment IV). An increase in base saturation and reduction in Al saturation throughout the EC with of isolated gypsum rates or combined to lime. The increase in the amount of grain produced per mm of rain, resulting from the application of gypsum, was higher when there was water estress during the critical period of crop. The chemical improvement of soil rooting layer provided by the addition of gypsum attenuated the soybean yield loss associated with water restriction. / As melhorias químicas proporcionadas pelo uso do sistema plantio direto têm se restringido às camadas superficiais do solo, limitando o desenvolvimento radicular em subsuperfície, e o uso eficiente da água, especialmente em anos com ocorrência de déficit hídrico. O presente estudo teve os seguintes objetivos: I- caracterizar os efeitos do uso isolado do gesso ou combinado com calcário sobre os atributos químicos do solo e a produtividade das culturas em SPD; II- avaliar o efeito da melhoria química da camada de enraizamento sobre a produtividade das culturas agrícolas em SPD sob condições de déficit hídrico induzido. Foram realizados quatro experimentos em Latossolos distróficos manejados sob SPD de longa duração no Rio Grande do Sul, com distinta qualidade química na camada de enraizamento, no período de 2009 a 2014. O delineamento experimental foi de blocos ao acaso com três repetições. Dois experimentos foram implantados em 2009 em Carazinho com tratamentos variando de 0,0 a 6,5 Mg ha-1 de gesso. Em um deles, as parcelas foram divididas em duas subparcelas sem e com restrição de 30% da precipitação pluvial pela implantação de câmaras de exclusão. Outros dois experimentos foram implantados em São Miguel das Missões e Tupanciretã em 2011. Em São Miguel das Missões utilizou-se um delineamento de blocos ao acaso com parcelas subdivididas, sendo as parcelas principais compostas por doses de gesso variando de 0,0 a 5,0 Mg ha-1, e as subparcelas compostas pelos tratamentos sem calcário na dose de 2,0 Mg ha-1. Em Tupanciretã, o experimento foi composto por um delineamento fatorial 4x4, com quatro doses de gesso variando de 0,0 a 6,0 Mg ha-1, e quatro doses de calcário variando de 0,0 a 4,8 Mg ha-1. As amostragens de solo foram feitas estratificadamente na camada de 0,00-0,60 m. Verificou-se incremento nos teores de Ca e S em todo o perfil, além de redução na saturação por Al e aumento na saturação por bases e na saturação por Ca ao longo do tempo. Em resposta a melhoria da qualidade química da camada de enraizamento foi verificado aumento da produtividade da soja, milho e trigo. Com a rotação de culturas durante o verão, as camadas amostrais em que houve relação com a produtividade situavam-se em maiores profundidade (camada de 0,25-0,40 m para o Experimento I e de 0,00-0,40 m para o Experimento II). Sem a rotação de culturas no verão as camadas amostrais que apresentaram relação com a produtividade situavam-se mais próximas da superfície (camada de 0,00-0,10 m para o Experimento III e de 0,00-0,25 m para o Experimento IV). Verificou-se aumento na saturação por bases e redução na Saturação por Al em toda a CE em função das doses de gesso isoladas ou combinadas ao calcário. O incremento na quantidade de grãos produzida por mm de chuva, decorrente da aplicação de gesso, foi maior quando houve déficit hídrico durante o período crítico das culturas. A melhoria química da camada de enraizamento do solo proporcionada pela adição de gesso em sistema plantio direto atenuou a perda de produtividade da soja associada à restrição hídrica.

Made available in DSpace on 2016-01-26T18:56:23Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 561254 bytes, checksum: 6fe1c6021f8ba849b15380f02e4a3762 (MD5) Previous issue date: 2012-02-06 / Water deficit is one of the main factors limiting agricultural production worldwide, affecting many physiological processes in plants. Based on this context, the study aimed to evaluate the interference of potassium fertilization on physiological responses of two soybean cultivars developed under water deficit, and assess the level of tolerance to water stress among cultivars. For this we tested the following hypotheses: 1) K supplementation in soybean plants grown under water deficiency can contribute to minimize the effects of water shortage on the physiology of the plant, 2) the difference in the level of tolerance to water stress between the cultivars depend directly from the application of K. The experiment was conducted in a greenhouse in 2x2x3 factorial design, ie, two soybean cultivars, water stress at 100% and 40% of the daily replacement of water compared to field capacity (CC), and three levels of supplementation with K which was held at planting. To test the assumptions above, we assessed the following parameters: leaf water potential index, chlorophyll content, membrane leakage, photosynthetic potential and biomass yield. Based on the results, we conclude that: Under conditions of water stress, the K fertilization did not interfere significantly in biomass and physiological parameters evaluated at work. Potassium supplementation promoted a better efficiency of physiological parameters in controlling water status in both cultivars, where the main variables were influenced by the nutrient to the stomatal conductance (gs), maximum rate of carboxylation of Rubisco (Vcmax) and maximum CO2 assimilation (Amax ). K supplementation improved the recovery of photosynthetic plants after rehydration, especially the cultivar Embrapa 48. With respect to the parameters of biomass in water status of control, the BR-16, potassium fertilization increased the production of total dry mass per plant and yield, as the cultivar Embrapa 48, only the latter parameter was influenced by biomass potassium. / A deficiência hídrica é um dos principais fatores limitantes da produção agrícola mundial, afetando diversos processos fisiológicos nas plantas. Com base neste contexto o trabalho o objetivo de avaliar a interferência da adubação potássica nas respostas fisiológicas de duas cultivares de soja desenvolvidas sob dois regimes hídricos. Foi testada a hipótese, de que a suplementação com K em plantas de soja cultivadas sob restrição hídrica poderia contribuir para minimizar os efeitos da falta de água sobre a fisiologia da planta. Para isso foram testadas as seguintes hipóteses: 1) a suplementação de K em plantas de soja cultivadas sob deficiência hídrica pode contribuir para minimizar os efeitos da falta de água sobre a fisiologia da planta; 2) a diferença no nível de tolerância à deficiência hídrica entre as cultivares avaliadas dependerá diretamente da aplicação de K. O experimento foi conduzido em casa de vegetação, em esquema fatorial 2x2x3, ou seja, duas cultivares de soja, deficiência hídrica com 100% e 40% da reposição diária de água em relação à capacidade de campo (CC), e três níveis de suplementação com K que foi realizada no plantio. Para testar as hipóteses consideradas anteriormente, foram avaliados os seguintes parâmetros: potencial de água foliar, índice de conteúdo de clorofila, extravasamento de membrana, potencial fotossintético e rendimento de biomassa. Com base nos resultados, é possível concluir que: Em condições de estresse hídrico, a adubação potássica não interferiu expressivamente nos parâmetros fisiológicos e de biomassa avaliados no trabalho. A suplementação com potássio promoveu uma melhor eficiência dos parâmetros fisiológicos em condição hídrica controle nas duas cultivares, onde as principais variáveis influenciadas pelo nutriente foram à condutância estomática (gs), taxa máxima de carboxilação da Rubisco (Vcmax) e assimilação máxima de CO2 (Amax). A suplementação com K melhorou a recuperação fotossintética das plantas após a reidratação, especialmente na cultivar Embrapa 48. Com relação aos parâmetros de biomassa, em condição hídrica controle, na cultivar BR-16, a adubação potássica aumentou a produção de massa seca total por planta e produção de grãos, já na cultivar Embrapa 48, só a massa se grãos foi influenciado pelo potássio.

Made available in DSpace on 2016-01-26T18:56:34Z (GMT). No. of bitstreams: 1 Dissertacao Marcia.pdf: 237755 bytes, checksum: cc3f62f324b3824c463dbc43ad5d87b2 (MD5) Previous issue date: 2007-10-19 / Stress could be defined as an external factor that could cause some disadvantageous influence over the plant. In tropical regions, crops suffer non biotic stress especially due to water deficit and high temperature. Cross tolerance allow the plants to be acclimated after a short exposition to a specific stress. The objective of this work was to verify the water stress tolerance during bean seed germination influenced by thermal shock induced cross tolerance. Seed of common bean cv IAPAR 81 were submitted to the imbibition in substrate paper with pure water at 20ºC for 24h. One third of the seeds were maintained in that temperature. One third were submitted to cold shock for 24h at 7ºC in the first assay and 13ºC in the second and the final part were submitted to heat shock for 24h at 38ºC and 33ºC as used for the cold shocks; in all experiments there was no change of substrate. Seeds submitted or not to shock were transferred to paper substrate simulating hydric potential of 0; -0.6; -0,9 and -1.2MPa, in the first experiment and 0;-0.3; -0.6; -0.9 and -1.2MPa in the second experiment using mannitol at: 0; 22.29; 44.58; 66.87 e 89.17 g.L-1. Treatments were evaluated by germination percentage, abnormal plants and dead seeds. Seedling evaluation was done with shoot, root and total dry matter and by relation of root/shoot. The best development, in water restriction in the early germination, was of that seeds that passed through a 7ºC or 33ºC during 24h, what allowed the affirmation that induced cross tolerance occurred and that could be induced in the beginning of the imbibition in bean seeds. / Estresse pode ser definido como um fator externo, que exerce influência desvantajosa sobre a planta. Em regiões tropicais, as culturas agrícolas sofrem estresse abiótico principalmente por períodos de deficiência de água e excesso de temperatura. A tolerância cruzada permite às plantas se aclimatarem a uma gama de diferentes estresses após exposição a um estresse específico. O objetivo deste trabalho foi avaliar a tolerância ao estresse hídrico durante a germinação das sementes de feijão sob influência da tolerância cruzada induzida por choque térmico. As sementes de feijão cultivar IAPAR 81 foram submetidas ao processo de embebição, em substrato papel-toalha umedecido com água pura sob temperatura de 20ºC por 24 horas. A seguir, parte foi mantida nessa temperatura e parte transferida para o choque frio por 24 horas a 7ºC no ensaio 1 e 13ºC no ensaio 2 e outra parte para o choque quente por 24 horas a 38oC no ensaio 1 e 33oC no ensaio 2, sem troca do substrato. Tanto as sementes que passaram pelo choque como as que não passaram (controle) foram transferidas para substrato papel simulando diferentes potenciais hídricos, 0; -0,6; -0,9 e -1,2MPa, no ensaio 1 e 0;-0,3; -0,6; -0,9 e 1,2MPa no ensaio 2, induzidos por manitol nas seguintes concentrações: 0; 22,29; 44,58; 66,87 e 89,17 g.L-1. Os tratamentos foram avaliados por meio da porcentagem de germinação, plântulas anormais e sementes mortas; avaliações do desenvolvimento como massa seca da parte aérea, massa seca de raiz, massa seca total e relação raiz/parte aérea. O melhor desempenho das sementes que passaram por choque, de 7oC por 24h ou de 33oC por 24h, à restrição hídrica no início do desenvolvimento, permite afirmar que ocorreu indução de tolerância cruzada e que esta pode ser induzida no início do processo de embebição em sementes de feijão.

Made available in DSpace on 2016-07-18T17:51:07Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 561254 bytes, checksum: 6fe1c6021f8ba849b15380f02e4a3762 (MD5) Previous issue date: 2012-02-06 / Water deficit is one of the main factors limiting agricultural production worldwide, affecting many physiological processes in plants. Based on this context, the study aimed to evaluate the interference of potassium fertilization on physiological responses of two soybean cultivars developed under water deficit, and assess the level of tolerance to water stress among cultivars. For this we tested the following hypotheses: 1) K supplementation in soybean plants grown under water deficiency can contribute to minimize the effects of water shortage on the physiology of the plant, 2) the difference in the level of tolerance to water stress between the cultivars depend directly from the application of K. The experiment was conducted in a greenhouse in 2x2x3 factorial design, ie, two soybean cultivars, water stress at 100% and 40% of the daily replacement of water compared to field capacity (CC), and three levels of supplementation with K which was held at planting. To test the assumptions above, we assessed the following parameters: leaf water potential index, chlorophyll content, membrane leakage, photosynthetic potential and biomass yield. Based on the results, we conclude that: Under conditions of water stress, the K fertilization did not interfere significantly in biomass and physiological parameters evaluated at work. Potassium supplementation promoted a better efficiency of physiological parameters in controlling water status in both cultivars, where the main variables were influenced by the nutrient to the stomatal conductance (gs), maximum rate of carboxylation of Rubisco (Vcmax) and maximum CO2 assimilation (Amax ). K supplementation improved the recovery of photosynthetic plants after rehydration, especially the cultivar Embrapa 48. With respect to the parameters of biomass in water status of control, the BR-16, potassium fertilization increased the production of total dry mass per plant and yield, as the cultivar Embrapa 48, only the latter parameter was influenced by biomass potassium. / A deficiência hídrica é um dos principais fatores limitantes da produção agrícola mundial, afetando diversos processos fisiológicos nas plantas. Com base neste contexto o trabalho o objetivo de avaliar a interferência da adubação potássica nas respostas fisiológicas de duas cultivares de soja desenvolvidas sob dois regimes hídricos. Foi testada a hipótese, de que a suplementação com K em plantas de soja cultivadas sob restrição hídrica poderia contribuir para minimizar os efeitos da falta de água sobre a fisiologia da planta. Para isso foram testadas as seguintes hipóteses: 1) a suplementação de K em plantas de soja cultivadas sob deficiência hídrica pode contribuir para minimizar os efeitos da falta de água sobre a fisiologia da planta; 2) a diferença no nível de tolerância à deficiência hídrica entre as cultivares avaliadas dependerá diretamente da aplicação de K. O experimento foi conduzido em casa de vegetação, em esquema fatorial 2x2x3, ou seja, duas cultivares de soja, deficiência hídrica com 100% e 40% da reposição diária de água em relação à capacidade de campo (CC), e três níveis de suplementação com K que foi realizada no plantio. Para testar as hipóteses consideradas anteriormente, foram avaliados os seguintes parâmetros: potencial de água foliar, índice de conteúdo de clorofila, extravasamento de membrana, potencial fotossintético e rendimento de biomassa. Com base nos resultados, é possível concluir que: Em condições de estresse hídrico, a adubação potássica não interferiu expressivamente nos parâmetros fisiológicos e de biomassa avaliados no trabalho. A suplementação com potássio promoveu uma melhor eficiência dos parâmetros fisiológicos em condição hídrica controle nas duas cultivares, onde as principais variáveis influenciadas pelo nutriente foram à condutância estomática (gs), taxa máxima de carboxilação da Rubisco (Vcmax) e assimilação máxima de CO2 (Amax). A suplementação com K melhorou a recuperação fotossintética das plantas após a reidratação, especialmente na cultivar Embrapa 48. Com relação aos parâmetros de biomassa, em condição hídrica controle, na cultivar BR-16, a adubação potássica aumentou a produção de massa seca total por planta e produção de grãos, já na cultivar Embrapa 48, só a massa se grãos foi influenciado pelo potássio.