Biologia Vegetal

URI Permanente desta comunidade

http://repositorio.ufes.br/handle/10/17503

Programa de Pós-Graduação em Biologia Vegetal

Centro: CCHN
Telefone: (27) 4009 2588
URL do programa: http://www.biologiavegetal.ufes.br/

Navegar

Agora exibindo 1 - 11 de 11

Atividade fotoquímica em folhas do mamoeiro Carica papaya L. durante o período reprodutivo e caracterização da ontogenia dos frutos
(Universidade Federal do Espírito Santo, 2007-12-14) Santos, Ketney Tonetto dos; Oliveira Júnior, Luis Fernando Ganassali de; Silva, Diolina Moura; Schneider, Edgar; Aguilar, Marco Antonio Galeas
In this work the photochemistry activity in leaves of plants of the papaya tree Carica papaya L. cv. Golden was evaluated fotnightly in a commercial plantation. The measures had beginning in the anthesis and concluded after the first crop (January for junho/2007). The kinetics of the emission of the fast fluorescence of the chlorophyll was she obtained with aid of a portable fluorometer (Handy-PEA, Hansatech, UK) using leaves previously adapted to the darkness. The results showed that the alterations happened in the apparel photosynthetic were more severe in the month where there was an abrupt fall in the precipitation. Low values of the initial fluorescence (F0), maximum fluorescence (FM) and of the revenue quantum potential maximum of the PS II (FV/FM) they indicated the occurrence of chronic photoinhibition in this period. For they be still scarce the studies on the chemical and biochemical changes that happen starting from the ontogeny of the fruits of the papaya tree, in this work it was also evaluated some physical changes, chemistries and biochemistries in the fruits of this the anthesis to the matureness. The activity of pectinametylesterase (PME), enzyme that prepares the substratum so that the other enzymes pectinolíticas acts in the process of matureness of these fruits, it increased starting from 120 DPA in the same way that the index of SS. On this same occasion it happened a decrease of the pH of the cellular juice and of the titratable acidity (ATTN) contained in the pulp of the fruits. These results confirm the participation of the PME, the presence of the acids organic and the beginning of the degradation of the it seems cellular before even of the crop.
Crescimento, teores e acúmulo de nutrientes em plantas de milho fertirrigadas com água residuária do beneficiamento de frutos de café
(Universidade Federal do Espírito Santo, 2013-11-06) Raposo Filho, Frederico Lopes; Costa, Aureliano Nogueira da; Costa, Adelaide de Fátima Santana da; Aguilar, Marco Antonio Galeas
The coffee production always held a prominent place in the national economy, due to its importance in the economic and social community, looking for a distinct market with new technologies to improve the beverage quality. The activities of washing and pulping coffee, necessary to reduce drying costs and improve the quality of beverage, generates a large amount of solid and liquid waste which has a notable rates of organic and inorganic material. The residual water from processing coffee activity (RWC) has been generated every year in a large volume in Espírito Santo and the presence of nutrients indicates the viability to its reuse in fertigation of crops. The aim of this study was to evaluate the effect of different doses of residual water of coffee on growth, absorption, interaction of nutrients and the nutritional condition of corn (Zea mays L.). In this context, the experiment was conduct in a greenhouse applying the completely randomized design, where seven RWC doses were applied with three repetitions in experimental unities composed by vases with 2 dm³ of soil. The dosages had the following concentrations: 0.00, 15.17, 30.35, 45.52, 60.70, 75.87 and 91.05 liters of ARC per m² of soil. The seeding were performed using five seeds of BR 206 hybrid corn per vase and after five days were made the thinning, maintaining only three plants per vase. On the 30th day after germination, the following measurements were determined: stem diameter (SD), leaf area (LA), shoot dry matter (SDM), root dry matter (RDM), shoot/root ratio (SDM/RDM), root mass ratio (root dry weight / total dry matter) and leaf area ratio (leaf area / total dry matter). Aerial part of plants was used to established the levels of macronutrients (N, P, K, Ca, Mg and S). The data were subjected to analysis of variance and the doses of RWC were adjusted in regression models. For dependent variables was calculated the Pearson linear correlation coefficient. The application of ARC served as a fertilization input to corn crop, increasing most of the growth variables and N, K and S levels. However, it caused a decrease in shoot Ca, Mg and P levels, indicating that high dosages promote a disturb in nutrient relations.
Efeitos da adubação foliar com silício na resistência do cacaueiro (Theobroma cacao L.) à vassoura-de-bruxa (Moniliophthora perniciosa (Stahel) Aime & Phillips-Mora)
(Universidade Federal do Espírito Santo, 2014-02-26) Fantinato, Dayana Effgen; Aguilar, Marco Antonio Galeas; Milanez, Camilla Rozindo Dias; Corte, Viviana Borges; Aquije, Glória Maria de Farias Viegas
The economic interest of cocoa (Theobroma cacao) isbecause, mainly, of using itsseeds to produce cocoa butter and chocolate. However, this business has encountered a crisis caused, mainly, by witches’ broom, caused by the fungal Moniliophthora perniciosa, that could induce losses of until 90% of the production,beenconsidered one of the most destructive disease of cocoa. One management alternative of diseases that has been used it’sthe inducedresistance, that could be obtained by treatments using products with silicon. Therefore, we verified the efficiency of different dose of silicon in protection against the disease witches’ broom in the clonal Catongo of cocoa inoculated with M.perniciosaby analysis of morpho-physiological and biochemical characteristics. The experimental design wasinrandomized blocks (DBC), with four replications in a factorial 2 x 4, consistingof two factors of inoculation (inoculated and non-inoculated) and four dosesof silicon (0 mg mL-1 ; 0,5 mg mL-1; 1,0 mg mL-1e 2,0 mg mL-1)with the product AgriSil (98% ofSiO2), resulting in 32 plots with 10 plants each,totaling 320 plants. The results obtained were submitted to analysis of variance and regression. Evaluations about enzyme analysis, gas exchange, foliar silicon content and stomatal density were conducted.Inoculated plants presentedincreased of photosynthesis and of chitinase and polyphenoloxidase activities with application of growing dosesof Si. Already stomatal density showed maxim in the dose 0,79 mg/mL of Si, while the foliar silicon content was obtained in the dose 0,7 mg/mL of Si. The results suggestthat growing doses of silicon demonstrated beneficial to ease the effects caused by M. perniciosain cocoa seedlings
Efeitos da luminosidade na germinação e no desenvolvimento de arbóreas nativas de Mata Atlântica
(Universidade Federal do Espírito Santo, 2011-02-25) Paradizo, Inayá Castiglioni; Aguilar, Marco Antonio Galeas; Cuzzuol, Geraldo Rogério Faustini; Silva, Diolina Moura; Mecier, Helenice
We call germination the period of the life’s circle that is relationed with plants distribution. The radiation for the plant is not only one source of energy, but is an incentive governing the development and also can be a stressful factor. To comprehend all stages of a vegetal community, as the survival and regeneration of the habitat, a lot of studies about the eco-physiology of germination and the effects of luminosity radiation are important. In this context, the objective of this study was: Chapter 1: a) Determinate the great conditions of the germination of Angico, P. dubium, and Braúna, M. brauna, in relation between luminosity intensity(light, dark and photoperiod), temperature (20,25,30,35 and 40ºC) and rupture of dormancy with mechanic scarification; b) Quantify the production of nitric oxide and ethylene during the germination of the species described as a result of the luminosity intensity struck : dark, low light (50 photons), media light (250 photons) and high light (1200 photons); c) Contrast the nitric oxide production with the percentage of germination of Angico, adding one “kidnapper” of nitrogen (c- PTIO) to the water available to the seed, and adding one donator of nitrogen (SNP). Chapter 2: a) Verify the photossyntetisis pigment’s quantity made in sun plants and shadow plants of Peroba and Jequitibá; b) Analysis of fluorescence of chlorophyll in the different species and treatments; c) Quantify the carbohydrates made in the xylem walls and of bark; d) Carry out the growing analysis in the species in the initial time and after 60 days of treatment; e) Visualize the anatomic and histochemical differences between the species in a direct sunray and in the shadow. It was determinate the great conditions of germination, percentage of germination, IVG, TMG and VMG. The angico, P. dubium, has the best coefficient of germination in light, temperature between 25 and 30ºC, with its seeds scarificated. The production of No for the specie is highest in the dark, being this factor stressful for the seeds. Although, in high luminosity intensity, even the percentage of germination being lower, the production of ethylene offered the germination of some seeds. The function of nitrogen in the sinalization of the germination is confirmed with the treatments of c-PTIO and c- PTIO + SNP. The interation between No and ethylene is antagonist for the germination of the seeds, being made a high quantity of NO in the first 24 hours, after is made the ethylene, breaking the production of NO. For Braúna, the specie has germinative comportament only in the dark with 30º C of temperature. In spite of angico, braúna make for quantity of NO when they are in great conditions, being the production lower when the seeds are in stressful of light. C. legalis, jequitibá, can be considered one specie with big phenotype plasticity, even so of the photochemical rendiment of fluorescent of chlorophyll it’s not ideal in the treatment of dun, the same show outline the problem and keep a good growing and adaptation of the new sun conditions. Perobaamarela, P. peroba, can’t be considered a sun plant, but a shadow plant. Although the same didn’t have good results in all parameters analyzed when were in sun treatment. The same specie had anatomics anomalies in the leaves, caused by the high luminosity intensity. Therefore, the species can be used for recuperation of degraded areas, but the suggestion is first plant seedlings of Jequitibá to shade the place, and then plant the seedlings of Peroba. However, a lot of studies about ecophysiology of this species still have to be done, to have a better comprehension of comportament before the ambiental conditions, both biotic as abiotic.
Efeitos da pulverização foliar com silício na tolerância de Theobroma cacao L. (Malvaceae) ao défice hídrico
(Universidade Federal do Espírito Santo, 2013-02-28) Zanetti, Leonardo Valandro; Aguilar, Marco Antonio Galeas; Milanez, Camilla Rozindo Dias; Cuzzuol, Geraldo Rogério Faustini; Spaggiari, Carlos Alberto
As in many Brazilian regions, the northern of Espírito Santo, a polo cocoa producer, has intense periods of drought that causes decline in agricultural production. Every farmer longs for the development of good quality and low cost technologies for increasing production, and it is in this context that arise the fertilization with silicon (Si), a technology little explored in Brazil and already shows promise in maintaining or increasing productivity in situations of drought stress. Therefore, the aim of this work was to check anatomic and physiological responses of a clone of cocoa (PH 16) subjected to water deficits cycle, after foliar feeding with silicon, to determine whether Si confers drought tolerance. The experiment was conducted in a greenhouse in a randomized block design with four replications in a 2 x 3 factorial, with two levels of irrigation, irrigated or non-irrigated, and three silicon doses: 0.0, 1.5 and 3.0 mg/mL, with a wettable powder of SiO2. After twenty days without irrigation, evaluations were performed in the 2nd or 3rd fully expanded leaf from the apex of the orthotropic axis.The results showedthat the phenol content was higher with SiO2 application independent of dose.The useof SiO2improved cell membranes stability in plants under water deficitsand the antioxidant activity of some enzymes including catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD) and polyphenoloxidase (PPO), and the use of 1.5 mg/ml was the best dose. The application of this dose favored the photochemical reactions, photosynthetic rate, water-use efficiency and carboxylation rateof the cocoa plants under water deficits. Stomatal density was not reduced in plants irrigated with the higher dose of Si. However, the application of Si did not affect the water content of the leaves under deficit, despite reducing leaf water potential. It is supposedthat themucilage has an important role in maintaining the water content of T. cacao leaves.The thickness of leaf tissues (epidermis, palisade and spongy parenchyma), as well as the photosynthetic pigment content and the content of silicon in the leaves also were not influenced by the different doses of silicon.Thus, it is suggested that the accumulation of Si on the leaves was beneficial, with the dose of 1.5 mg / mLbeingthe most efficient for the cocoa plant tolerance to water deficit.
Efeitos do regime hídrico e da adubação foliar com silício em plantas de Fisális (Physalis peruviana L.)
(Universidade Federal do Espírito Santo, 2015-02-27) Souza, Fabiano Mayrink Dutra; Batitucci, Maria do Carmo Pimentel; Corte, Viviana Borges; Aguilar, Marco Antonio Galeas; Gomes, Tarsila Daysy Ursula H.
The climate changes are in focus, and they can change the rainfall patterns. To maintain crop yields in drought conditions, silicon fertilization has proven to be a great alternative. It is clean, sustainable and has a low cost. Several studies using silicon have shown positive effects in plants subjected to water estresse. Physalis peruvianaL. (Solanaceae) is a fruit that has a great nutritional and economic value. Due to the unknown physiological behavior of this species across the different soil and climatic conditions, this study aims to describe the physiological responses of P. peruvianaplants to variation in fertilization of silicon, and two water regimes. Therefore, the experiment was conducted in a 2x4 factorial arrangement in a completely randomized design. The P. peruvianaplants were subjected to 30 days of controlled water regime, 100% of water holding capacity and 35% of water holding capacity, the plants were fertilized with SiO2(4 applications) at doses of 0.0, 1.0; 2.0 and 3.0 g/L. To evaluate the effects of treatments on cape gooseberry, it was used growth analysis, namely: leaf area, stem length, stem diameter, dry matter, absolute growth, net assimilation rate, leaf area ratio, specific leaf area and leaf weight ratio. In addition, it was determined the relative water content in the leaves and measured the content of photosynthetic pigments. Silicon has increased the water content of the leaf in both water regimes. The chlorophyll content has increased by increasing SiO2dose in 100% field capacity water regime, but not in 35% CC. The chlorophyll b, total chlorophyll and carotenoids showed results must like chlorophyll a, differing in the maximum point at regression analysis. Growth was decreased by water treatment in 35% field capacity. However, the stem length increases in associated condition between full irrigation and fertilization with silicon. It was not formed regression for dry weight of leaves, root and total dry mass in both water regimes, but was formed regression to dry mass of stem in the water system of 100% ofwaterfield capcity, showing that in appropriate water regime silicon was effective in promoting dry mass gains in this parameter. The SiO2increased the absolute growth rate and relative growth rate, showing that the net productivity of the crop has benefited from the silicate fertilization under water deficit. Plants of both water regimes fertilized with silicon presented higher leaf area ratio for the occurrence of photosynthesis, and greater specific leaf area. The fertilization with silicon associated with adequate water regime promoted greater exportation ofphotosynthatesfrom leaveto the rest of the plant. Thespecific leaf area presented inboth water regimes larger values by the aplication of SiO2. The assimilation rate formed regression only in 100% ofwaterfield capcity.In general, foliar fertilization with silicon is a benefit;because it has increased the water content in the leaves, promote higher leaf content of carotenoids, higher growth and higher accumulation of dry matter in different parts of the plantsof cape gooseberry
Estudo morfofisiológico e anatômico de dois genótipos de cacaueiro (Theobroma cacao L.) submetidos a diferentes condições de radiação solar
(Universidade Federal do Espírito Santo, 2013-02-27) Furlan, Larissa Maria; Aguilar, Marco Antonio Galeas; Milanez, Camila Rozindo Dias; Fontes, Renata Venturim; Dallaqua, Marina Aparecida Moraes
The luminosity emerges as one of the most important abiotic factors in the establishment of plants and can cause changes in physiological and anatomical, interfering directly in their development and consequently their productivity. The cocoa tree (Theobroma cacao - Malvaceae ) has great economic interest due to the use of its seeds to produce cocoa butter and chocolate. In this sense, the objective of this study was to compare physiological and anatomical characteristics of two genotypes of cacao (PH 16 and IPIRANGA 01), subject to different conditions of solar radiation in order to infer about the lighting conditions most favorable to their development. Analyses of growth, pigment content, gas exchange and anatomical stem and leaf. The experimental design was randomized blocks (DBC), with four replications in a factorial 2 x 5 , consisting of two genotypes and 5 brightness levels ( 0 % - full sun - 18 % , 30 % , 50 % and 80% shading), totaling 40 plots with 10 plants each. Data were subjected to analysis of variance and regression. The results indicate higher growth adaptation in both genotypes under conditions of moderate to high irradiance. The quality index Dickson demonstrated greater ability to survive under field conditions with high levels of irradiance for genotype PH 16 and moderate levels of irradiance for IPIRANGA 01. The content of photosynthetic pigments of IPIRANGA 01 show up higher in the condition of 30% shade, while for PH 16 the highest levels were observed in 50% shade . Both genotypes showed high rates of A, C , E, A / E , A / Gs and A / Ci, under high irradiance, as well as stem and leaf anatomical adaptations to higher luminosities, such as greater thickening of the leaf, parenchyma palisade and spongy, leaf blade, adaxial stomatal density, higher density, frequency of vessel elements and thickness of secondary xylem . Genotypes PH 16 and IPIRANGA 01 showed a large plasticity in relation to different levels of irradiance, however, it was found that PH 16 performed better under high irradiance, as obtained from treatments in full sun and 18% shade, while IPIRANGA 01 was more adapted under moderate shading, 30% shading.
Fotossíntese, crescimento e composição química em plantas de Theobroma cacao L. submetidas a diferentes concentrações de silicato de potássio e sua interação com insetos-praga
(Universidade Federal do Espírito Santo, 2011-02-18) Pinto, Diego Guimaraes; Silva, Diolina Moura; Aguilar, Marco Antonio Galeas; Almeida, Alex-Alan Furtado de; Milanez, Camilla Rozindo Dias
The control of insect pests through the use of pesticides, is still the most method used in the cultivation of cocoa. However, due to environmental issues, there need to seek new alternatives of control less harmful the environment and to humans. In this context, silicon is a nutrient that is being used in various cultures, due to its beneficial effects on plant physiology and protection to the attack of insect pests and disease. The aim of this study was to evaluate the photosynthesis, growth and chemical composition in three cacao genotypes under different concentrations of potassium silicate and its interaction with insect pests. Two experiments were conducted, the first being installed under an agroforestry system comprising Bactris gasipaes and Theobroma cacao, in a randomized block design, with four replications, in a factorial 3 x 3, consisting of three genotypes (TSH 1188, CCN 51 and Catongo), three doses of potassium silicate (0, 3 and 6 mL L-1) applied to leaves. Were conducted evaluations of vegetative growth, of kinetics of fluorescence emission from chlorophyll a, of chlorophyll content, of incidence and degree of damage caused by insect pests, beyond from the silicon content in the leaves. The growth of cacao genotypes was reduced with the application of doses of potassium silicate, possibly due to the partition of assimilates that were being used in the biosynthesis of compounds involved in plant resistance to insects. The genotype TSH 1188 showed the highest increase in growth and dry matter compared to CCN 51 and Catongo, being the only genotype that showed the highest content of chlorophyll and improvement in parameters of chlorophyll fluorescence when applied to 3 mL L-1potassium silicate, mainly in the energy flow of photosystem II and the index of performance of the plant for absorption (PIABS) and total (PITOTAL). The application of potassium silicate at dose 6 mL L-1 significantly reduced the incidence and level of damage by insect pests in cocoa genotypes. However, did not have significant effect of the application of potassium silicate on the silicon content in the leaves of the genotypes of cacao studied in relation to the control. The second experiment was conducted in a greenhouse with the same treatments and statistical design of experiment previous. In it were evaluated gas exchange, foliar concentrations of soluble phenolic compounds total, the chlorophyll fluorescence a, besides a preference test with a chance of free choice with aphids. The highest rates of photosynthesis and stomatal conductance were found in TSH 1188 and CCN 51. These same genotypes showed higher index of performance (PIABS and PITOTAL), a result of increased density of centers reaction active of photosystem II (RC/ABS), quantum yield of PSII (fP0 / (1-fP0)) and efficiency of reactions redox beyond the quinone a-(?0/1-?0). The application of potassium silicate increased net photosynthesis, but did not affect the performance indices (PIABS and PITOTAL). The phenolic content increased in genotypes CCN 51 and Catongo, the preference of the aphid was reduced with application of 6 mL L-1 of potassium silicate only in TSH 10 1188. Due on the results from the two experiments, application of silicon is promising to increase the resistance of cacao insect pests, since it promotes the increase of photosynthetic activity and production of plant metabolites involved in defense mechanisms of the cacao tree.
Influência da modalidade de enxertia e interação entre enxertos e porta-enxertos em mudas de Theobroma cacao L. submetidas a um ciclo de défice hídrico
(Universidade Federal do Espírito Santo, 2006-03-07) Marinato, Claudio Sergio; Silva, Diolina Moura; Aguilar, Marco Antonio Galeas; Almeida, Alex Alan Furtado de
The cocoa tree (Theobroma cacao L.) is comercially cultivated in large scale (great quantities). Nowadays, a production breakdown, caused by a prague named witches’ broom, came up with new challenges to the farmers. An option of strategy used to face it is the substitution of vulneable plants for more resistant genotypes. A good way to proceed this process is the use fo grafting techniques to accelerate the substitution of the tree pantry or to the speed uo the production of the trees. This method is also used to obtain plants with the desirable characteristics, more tolerant to dry weather periods and greater productivety. However, the success of grafting can be influenced by many factors, including the interaction between the graft and the rootstock, which can be influenced by both genotypes. The main goal was evaluating the level of resistance of the T. cacao grafts, applying two methods of precocious grafting, and the physiological characteristics of grafted trees when submitted to few quantities of water. The experience was conducted in green houses with controlled temperature and relative humidity of air. There have been used vegetable material the genotypes ESFIP 02, TSH 1188, CCN 51 and ‘Common Cocoa’. There have been tests of hipocotiledonar grafting by wrip grafting and soft wood. Taxes of survival and characteristics of the vegetative growth were analised. The experience was installed in delineation of randomized blocks with four repetitions in factorial arrangement 2x5, based on two two grafting methodsand four rootstocksadded to a frank foot. The percentage of survival was not influenced by the grafting methods. In the precociuos grafting the rootstock genotype influenced, meaningfully, the survival of genotypes TSH 1188 grafts. The ESFIP 02 genotupes, the grafting method of soft wood provided greater growth than the wrip grafting method. On the other hand, the hidric deficit reduced the quantities of height, leaf area, the stem dry mass and the leaves dry mass. The dry mass from the roots was higher in the stressed trees. The stress decreased the levels of leaf nitrogen; the levels of phosphorus and potassium increased, though. The hidric deficit influenced the levels of chlorophill, its fkuorescence, the gas exchanges and the leaves hidric potential negativelly. O rootstock genotype influenced meaningfully the tolerance to hidric deficit and in the analised topics. The ESFIP 02 genotype, when used as rootstock permitted, generally higher levels of vegetative growth, dry mass accumultated, the leaves hidric potencial, chlorophill fluorescence and liquid photosynthesis
Respostas fisiológicas de Theobroma cacao L. a diferentes concentrações de ferro sob alagamento
(Universidade Federal do Espírito Santo, 2015-03-10) Braga, Priscila da Conceição de Souza; Fernandes, Adriano Alves; Aguilar, Marco Antonio Galeas; Paterlli, Fabio Luiz; Souza, Carlos Alberto Spaggiari
Flooding is a limiting barrier for the initial growth and cocoa establishment in places subject to periodic flooding, given that it can cause changes in leaf gas exchange, nutrition and in optimum conditions of plant growth. Furthermore, they have been found large amounts of Fe in the irrigation water cocoa culture, and, under flooding conditions, the availability of this element in the plant is increased, generating a double stress condition. In this context, the aim of this study was to evaluate the effects of different concentrations of iron in the presence and absence of aeration in different cacao genotypes. We evaluated two cacao genotypes, TSH 1188 and SIAL 70, with and without aeration and excess iron, an experiment installed in a randomized block design with three replications and treatments distributed in a factorial arrangement (2x2x3) consisting of two genotypes, with and without aeration and three Fe concentrations: 44.5 µmol L-1 (recommended dose); 133.5 µmol L-1 (high dose) and 400.5 µmol L-1 (very high). Were evaluations of oxidative enzyme activity and the content of total soluble phenols, chlorophyll indices a, b and total and gas exchange at leaf level, mineral composition of leaves and growth. The enzymatic activity and total soluble phenolic content increased at the highest dose of Fe without aeration for TSH 1188 genotype (36.2% of guaiacol peroxidase and 205.1% for phenols). In SIAL 70 genotype the above the recommended doses promoted higher enzymatic activity of the peroxidase guaiacol with aeration and Polyphenoloxidase without aeration. The contents of chlorophyll a, b and total, were affected to a greater extent by iron stress for both genotypes, however, the TSH 1188 genotype had higher chlorophyll content. The gas exchange were altered adversely due to the excess iron and lack of aeration, and the photosynthetic rate for TSH 1188 genotype without aeration at the highest dose of iron decreased from 45.0% to 18.1 days, however at the end of 35th day recovered 94.1% of the initial photosynthetic rate. SIAL 70 genotype, this reduction was observed due to the excess iron independent of interference from aeration. The stomatal conductance and transpiration were reduced by the independent Fe excess of environmental conditions (aeration) for the two genotypes, and for the internal concentration of CO2 that result was observed only in TSH 1188 genotype. The nutrient absorption was also amended by excess iron and aeration. TSH 1188 genotype showed the highest growth when compared to SIAL 70 genotype, with the highest concentration of Fe (400.5 µmol L-1), independent of environmental conditions, there was an increase in dry mass in relation to the recommended dose iron. Depending on the results, the two cocoa genotypes tolerance absence of aeration and iron overload, however, it was found different mechanisms to handle each type of stress.
Respostas morfofisiológicas de plantas jovens de pau-brasil (Caesalpinia echinata Lam., Leguminosae) à radiação solar
(Universidade Federal do Espírito Santo, 2010-02-23) Mengarda, Liana Hilda Golin; Cuzzuol, Geraldo Rogério Faustini; Aguilar, Marco Antonio Galeas; Milanez, Camilla Rozindo Dias; Penchel Filho, Ricardo Miguel
Caesalpinia echinata Lam. is native specie from the Brazilian Atlantic Forest and is on extinction risk. The informations about the ecophysiological and the successional stage of this specie are contradictory, what dificult its management and conservation. The ecophysiological behavior of young plants of brazilwood affected by light was evaluated through the growth analysis and morphophysiological responses. One-year-old plants were cultivaded under 0%, 50%, 80% artificial shading and natural shading for a period of 392 days, and growth parameters were measured. Higher leaf area, dry mass and relative growth rate were obtained under moderate shade (50%). Under full sunlight the plants showing higher ratio root/shoot and specific leaf mass. Growth was inhibited under 80% artificial shading and natural shade. Plants cultivated under 50% shading were transferred to full sunlight, and at 0, 3, 24, 48 and 192 hours, were measured gas exchange and the potential maximum quantum efficiency of photosystem II (PSII) (FV/FM). Plants leaflets presented burning and abscission, inhibition of net photosynthesis (A) and reduction of FV/FM. Thus, 50% shading presented as ideal lighting conditions for the development of brazilwood young plants. Subsequently, one-year-old plants cultivated under 50% shading were subjected to direct sunlight. At 0, 2, 4, 7, 14, 20, 30, 40, 50, 60, 120 and 180 days were analyzed leaf morphophysiology. Plants transferred to the sunligth showing leaflets abscission after 2 days, and issued new leaves up to 14 days. There was significant increase in specific leaf mass and water content, increasing blade thickness, cuticle, adaxial epidermis and palisade parenchyma. There was reduction in the chlorophyll a/b and chlorophyll/carotenoids ratios. The soluble carbohydrates levels, especially sucrose, increased with plant exposure to full sunlight during 7- 60 days. Glucose and fructose showed higher level at 7 days. Morphoanatomical changes, in the pigments and carbohydrates levels indicate morphophysiological plasticity. However, there was significant reduction of FV/FM, effective maximum quantum efficiency of PSII (FV/F0) and performance index (P.I.) to 14 days. There were observed values below the control until 180 days. Thus, it was observed that full sunlight exposure decreases the plants photochemical efficiency, indicating that C. echinata is not pioneer-sucession species. Growth was inhibited under intense shading, not characterizing the climax specie. Thus, brazilwood has the characteristics of intermediate specie. Although they presented photoinhibition, the young plants have plasticity and capacity of tolerance to high-light stress

Navegar

Navegando Biologia Vegetal por Autor "Aguilar, Marco Antonio Galeas"

Resultados por página

Opções de Ordenação