Desempenho e Digestibilidade in vivo de Cordeiros Alimentados com Dietas Contendo Canola em Grão Integral em Diferentes Formas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito da adubação potássica e da época de colheita na produtividade de canola

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Quantifying seed production by volunteer canola (Brassica napus) and Sinapis arvensis

Volunteer canola (Brassica napus) and Sinapis arvensis are well identified weeds of different cropping systems. Quantitative information on regarding seed production by them is limited. Such information is necessary to model dynamics of soil seed banks. The aim of this work was to quantify seed production as a function of the size of those weeds. A wide range of plant size was produced by using a fan seeding system performed at two sowing dates (environments). Plant size varied from 3 to 167 g per plant for canola and from 6 to 104 g per plant for S. arvensis. Seed production ranged from 543 to14,773 seeds per plant for canola, and from 264 to 10,336 seeds per plant for S. arvensis. There was a close relationship between seed production per plant and plant size which was well-described by a power function (y = 130.6x0.94; R² = 0.93 for canola and y = 28x1.27; R² = 0.95 for S. arvensis). There was also strong relationships among the number of pods produced in individual plants and the quantity of seeds produced (g per plant) with the size of the plant. The relationships found in this study can be used in dynamic seed bank models of volunteer canola and S. arvensis.

Changes in canola plant architecture and seed physiological quality in response to different sowing densities

The aim of this study was to evaluate changes in canola yield components and seed physiological quality in response to different sowing densities. The study was made in a greenhouse at the REIPESOL Company Technological Center, Madrid - Spain, with the commercial "Toccata" hybrid variety. The initial sowing density was 360,000 plants/ha and the plant population was later thinned down to include treatments of 250 and 180 thousand plants/ha. Harvested seeds were sent to the Seed Technology Center Laboratory (CATES) at the Madrid Polytechnic University (UPM) to evaluate changes in plant architecture and yield components, as well as the seed physiological quality of different plant parts. Results demonstrated that canola plants showed changes in morphology and yield components in response to different sowing densities. The population of 250,000 plants/ha showed the best seed yield demonstrating that maximum yield is directly related to a correct sowing density. The number of pods/plant was the most important component for increased seed yield/plant and seed yield/area. The spatial distribution of canola seeds in the plant and canola sowing density did not affect seed physiological quality.

Produtividade e qualidade de grãos de canola em função da adubação nitrogenada e sulfatada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produtividade e qualidade de grãos de canola em função da adubação nitrogenada e sulfatada

The canola (Brassica napus, L.) cultivation was encouraged for grain and oil production at the 80's, and it is also considered a good option for crop rotation. The nitrogen is one of the most required nutrients by the plant to increase its production, while sulfur is essential to provide seed quality. Thus, the objective of this study was, at Cerrado region, evaluate the effects of nitrogen and sulfur fertilization at yield and contents of oil and crude protein in the grains. We also sought relate to grain yield the S content in the soil and concentrations of N and S in the diagnosis leaf. The experiment was conducted in Uberaba County, State of Minas Gerais, Brazil, in an Oxisol, utilizing the Hyola 401 hybrid. The treatments consisted in a factorial scheme 5 x 4 (five N rates: 0, 60, 100, 140 and 180 kg ha(-1) and; four S rates: 0, 15, 30 and 60 kg ha(-1)) in a randomized blocks design, with four replicates. The nitrogen and sulfur fertilization increased canola grain yield, without significantly alter contents of oil and crude protein. Rates higher than to 140 kg ha(-1) of N and 15 kg ha(-1) of S provided grain yield above 1100 kg ha(-1). Plots with yield higher than to 1000 kg ha(-1) presented foliar concentration of N above 52 g kg(-1). The highest S content was observed at the 0.15-0.30 m layer, proving the sulfate anion mobility. The lowest grain yield were observed when the S content in the soil at this layer were less than 4 mg dm(-3). The N concentrations in the diagnostic leaf and S-SO4-2 content in the 0.15-0.30 m layer correlated positively with crop yield.

The Cratylia Mollis Seed Lectin Induces Membrane Permeability Transition In Isolated Rat Liver Mitochondria And A Cyclosporine A-insensitive Permeability Transition In Trypanosoma Cruzi Mitochondria.

Previous results provided evidence that Cratylia mollis seed lectin (Cramoll 1,4) promotes Trypanosoma cruzi epimastigotes death by necrosis via a mechanism involving plasma membrane permeabilization to Ca(2+) and mitochondrial dysfunction due to matrix Ca(2+) overload. In order to investigate the mechanism of Ca(2+) -induced mitochondrial impairment, experiments were performed analyzing the effects of this lectin on T. cruzi mitochondrial fraction and in isolated rat liver mitochondria (RLM), as a control. Confocal microscopy of T. cruzi whole cell revealed that Cramoll 1,4 binding to the plasma membrane glycoconjugates is followed by its internalization and binding to the mitochondrion. Electrical membrane potential (∆Ψm ) of T. cruzi mitochondrial fraction suspended in a reaction medium containing 10 μM Ca(2+) was significantly decreased by 50 μg/ml Cramoll 1,4 via a mechanism insensitive to cyclosporine A (CsA, membrane permeability transition (MPT) inhibitor), but sensitive to catalase or 125 mM glucose. In RLM suspended in a medium containing 10 μM Ca(2+) this lectin, at 50 μg/ml, induced increase in the rate of hydrogen peroxide release, mitochondrial swelling, and ∆Ψm disruption. All these mitochondrial alterations were sensitive to CsA, catalase, and EGTA. These results indicate that Cramoll 1, 4 leads to inner mitochondrial membrane permeabilization through Ca(2+) dependent mechanisms in both mitochondria. The sensitivity to CsA in RLM characterizes this lectin as a MPT inducer and the lack of CsA effect identifies a CsA-insensitive MPT in T. cruzi mitochondria.

Seed dispersal of Solanum thomasiifolium Sendtner (Solanaceae) in the Linhares Forest, Espírito Santo state, Brazil

The aim of this study was to analyse seed dispersal and establishment of Solanum thomasiifolium in an area of nativo vegetation in Espirito Santo state on the southeastern Brazilian coast. Ten species of birds, the crab-eating fox (Cerdocyon thous), and one species of lizard (Tropidurus torquatus) fed on S. thomasiifolium fruits and dispersed viable seeds in their faeces. The proportional contribution of each of these groups to seed dispersal was 77% (birds), 19% (crab-eating fox) and 4% (lizards). Ants also contributed to seed dispersal. More seeds were deposited in vegetation islands than in the surrounding open areas. Germination rates of seeds collected directly from fruit (control), bird droppings, the faeces of crab-eating foxes and lizards were, respectively, 64, 64, 53, and 80 %. Differences among these rates were all significant, except between birds and control. Lizards were important as seed carriers between nearby islands and they expelled a higher proportion of viable seeds. Birds and the crab-eating foxes did not enhance seed germination, but promoted seed dispersal over a wider area. Plant architecture, fruit productivity, fruit characteristics and the diversity of frugivores are important for the success of S. thomasiifolium in habitat colonization.

Seed rain in areas with and without bamboo dominance within an urban fragment of the Atlantic Forest

Understanding the flow of diaspores is fundamental for determining plant population dynamics in a particular habitat, and a lack of seeds is a limiting factor in forest regeneration, especially in isolated forest fragments. Bamboo dominance affects forest structure and dynamics by suppressing or delaying the recruitment of and colonization by tree species as well as by inhibiting the survival and growth of adult trees. The goal of the present study was to determine whether dominance of the bamboo species Aulonemia aristulata (Döll) McClure in the forest understory influences species abundance and composition. We examined the seed rain at two noncontiguous sites (1.5 km apart) within an urban forest fragment, with and without bamboo dominance (BD+ and BD- areas, respectively). Sixty seed traps (0.5 m², with a 1-mm mesh) were set in the BD+ and BD- areas, and the seed rain was sampled from January to December 2007. Diaspores were classified according to dispersal syndrome, growth form and functional type of the species to which they belonged. There were significant differences between the two areas in terms of seed density, species diversity and dispersal syndrome. The BD+ area showed greater seed density and species diversity. In both areas, seed distribution was limited primarily by impaired dispersal. Bamboo dominance and low tree density resulted in fewer propagules in the seed rain. Our results suggest that low availability of seeds in the rain does not promote the maintenance of a degraded state, characterized by the presence of bamboo.

Farelo de canola em dietas para o pacu Piaractus mesopotamicus (Holmberg 1987): efeitos sobre o crescimento e a composição corporal

Avaliaram-se os efeitos da inclusão de farelo de canola em dietas de juvenis de pacu (Piaractus mesopotamicus) sobre parâmetros de crescimento e composição corporal. Um total de 192 alevinos (9 a 15g) foram estocados em 24 tanques de cimento, de 100l de capacidade, durante 103 dias. O farelo de canola foi utilizado em quatro proporções: zero; 9,5%; 19% e 38% da dieta, com ou sem farinha de peixe (12%/dieta), totalizando oito tratamentos. A presença de farinha de peixe não afetou os parâmetros de crescimento avaliados. A inclusão de 38% de farelo de canola na dieta diminuiu o ganho de peso dos peixes, valores médios de 28,74g a 50,70g, e piorou a conversão alimentar aparente, de 1,66 para 2,85. A taxa de eficiência protéica também foi menor nos peixes alimentados com 38% de farelo de canola. As várias proporções de farelo de canola das dietas alteraram os teores de umidade, proteína bruta e lipídios dos peixes. A presença da farinha de peixe, nas dietas, somente influiu no teor de lipídios dos peixes alimentados com dietas contendo 9,5% de farelo de canola. Conclui-se que até 19% de farelo de canola pode ser adicionado às dietas de juvenis de pacu, sem que seu desenvolvimento seja prejudicado.

Two-dimensional gel electrophoretic protein profile analysis during seed development of Ocotea catharinensis: a recalcitrant seed species

The aim of the present work was to characterize changes in the protein profile throughout seed development in O. catharinensis, a recalcitrant species, by two-dimensional gel electrophoresis. Protein extraction was undertaken by using a thiourea/urea buffer, followed by a precipitation step with 10% TCA. Comparative analysis during seed development showed that a large number of proteins were exclusively detected in each developmental stage. The cotyledonary stage, which represents the transition phase between embryogenesis and the beginning of metabolism related to maturation, presents the highest number of stage-specific spots. Protein identification, through MS/MS analysis, resulted in the identification of proteins mainly related to oxidative metabolism and storage synthesis. These findings contribute to a better understanding of protein metabolism during seed development in recalcitrant seeds, besides providing information on established markers that could be useful in defining and improving somatic embryogenesis protocols, besides monitoring the development of somatic embryos in this species.

Physiological and biochemical characterization of the assai palm (Euterpe oleracea Mart.) during seed germination and seedling growth under aerobic and anaerobic conditions

Physiological and biochemical aspects of assai palm during seed germination and early seedling growth were investigated. Seeds collected from plants growing in flooded and upland forests were used to determine the influence of normoxic (aerobic) and anoxic (anaerobic) conditions in germination and the initial and average time of development in the roots and shoots. After 75 days, seedlings germinated under normoxia were transferred to trays and submitted to flooding. Seed reserves (lipids, proteins, soluble sugars and starch) were monitored for quiescent and germinated seeds maintained under normoxic and anoxic conditions, as well as after 5, 10 and 20 days of seedling growth. Alcohol dehydrogenase (ADH) activity was quantified in roots and leaves of seedlings without or with flooding (partial and total). Seeds were not able to germinate under anoxia. Different strategies of storage mobilization of lipids, proteins, soluble sugars and starch were observed in seeds of each environment. ADH activity was induced by anoxia, with the highest level observed in the leaves. This study showed that, under normoxic conditions, the best developmental performance of assai palm seeds, from flooded or upland forest areas, during germination was associated with primary metabolites mobilization and seedling flooding tolerance with increased ADH activity. We conclude that the assai palm is well adapted to the anoxic conditions provoked by flooding.

Influence of light and temperature on seed germination of Cereus pernambucensis Lemaire (Cactaceae)

The objective of the present study was to evaluate the effects of light and temperature on germination of Cereus pernambucensis seeds, a species of columnar cactus native to Brazil and naturally incident in the restinga. Cereus pernambucensis seeds were incubated under different temperatures, from 5 to 45 °C, with 5 °C intervals, and under alternating temperatures of 15-20 °C, 15-30 °C, 20-25 °C, 20-30 °C, 20-35 °C, 25-30 °C, 25-35 °C, and 30-35 °C, both under continuous white light and dark. The seeds were also incubated in a gradient of phytochrome photoequilibrium at 25 °C. The highest percentage germination in this species was between 25 and 30 °C. The minimum temperature was between 15 and 20 °C and the maximum between 35 and 40 °C. Alternating temperatures did not affect the percentage of seed germination, but it did alter the rate and synchronization indexes. Seeds incubated in the dark did not germinate under any of the conditions tested, indicating that this species when cultivated present light sensitive seeds controlled by phytochrome. The seeds can tolerate a lot of shade conditions, germinating under very low fluence response of phytochrome.

Frugivory and seed dispersal of golden lion tamarin (Leontopithecus rosalia (Linnaeus, 1766)) in a forest fragment in the Atlantic Forest, Brazil

The influence of the golden lion tamarin (Leontopithecus rosalia) as a seed disperser was studied by monitoring two groups of tamarins from December 1998 to December 2000 (871.9 hours of observations) in a forest fragment in south-east Brazil. The tamarins consumed fruits of 57 species from at least 17 families. They ingested the seeds of 39 species, and 23 of these were put to germinate in the laboratory and/or in the field. L. rosalia is a legitimate seed disperser because the seeds of all species tested germinated after ingestion, albeit some in low percentages. These primates do not show a consistent effect in final seed germination, because they benefit some species while damaging others. Feces were examined for seeds that had been preyed upon or digested.