Superação de dormência de sementes e crescimento inicial de plântulas de umbuzeiro

Pre-germination treatments such as scarification and the use of growth regulators can provide the overcoming of dormancy in seeds and enhance the emergence and development of seedlings. The aim of this study was to determine appropriate treatments to overcoming seed dormancy and enhance the initial growth of seedlings of Spondias tuberosa. We used a randomized design in factorial 2 x 4, with the following factors: seeds scarified or not scarified and then soaked in water or aqueous solutions of gibberellin, cytokinin and ethylene, with 4 replicates and 15 seeds. There was no significant interaction between scarification treatments and use of growth regulators. Mechanical scarification and soaking of seed of umbuzeiro in solutions containing growth regulators does not increase the percentage of seedling emergence, however soaking in a solution of Ethrel at 100 ppm provides higher speed of emergence and root development.

Structure of the Lining Epithelium of the Cauda Epididymis of the Golden Hamster

The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes (3/4 of basal cytoplasm), and vacuoles and vesicles (1/4 of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster.

Scarification, temperature and light in germination of Senna occidentalis seed (Caesalpinaceae)

The purpose of the present work was to study various aspects of the germination of seeds of Senna occidentalis Link, which had presented promising results in biological activity against the etiological agent of malaria. These aspects were dormancy, temperatures of germination and photoblastic response. In the dormancy studies, the treatments used were: unscarified seed (control); tegument puncture with sharp point; and scarification with sand-paper and immersion in concentrated sulfuric acid during 5, 10, 15 and 20 minutes. For the study of temperature and photoblast, the seeds were immersed in sulfuric acid for 20 minutes, submitted to temperatures of 10 to 45degreesC, at intervals of 5degreesC, both under light and in the dark. The seeds presented dormancy related to tegument, the best treatments for breaking dormancy were immersion in sulfuric acid for 15 and 20 minutes. At temperatures 25 and 30degreesC, the best results of percentage and index of velocity of germination were observed, at which the seeds behaved as neutral photoblastic; there was no germination at 10 or at 45degreesC.

Fotoperíodo, temperatura e reguladores vegetais na germinação de sementes de Passiflora cincinnata Mast.

A espécie Passiflora cincinnata Mast., pertencente à família Passifloraceae, é silvestre e popularmente conhecida como maracujá-do-mato, sendo considerada importante na produção de porta-enxertos, uma vez que é tolerante à seca, a doenças causadas por bactérias e a nematóides, além de poder ser utilizada em programas de melhoramento genético. O trabalho teve como objetivos estudar o efeito da luz e da temperatura e a interação entre temperatura e reguladores vegetais na germinação de sementes de Passiflora cincinnata Mast. Foi constituído de três experimentos: no primeiro, estudou-se o efeito da luz e da temperatura na germinação de sementes; no segundo, o efeito de diferentes concentrações dos reguladores vegetais GA4+7 + N-(fenilmetil)-aminopurina na germinação das sementes e, no terceiro, a interação entre temperatura e reguladores vegetais na germinação das sementes. O delineamento experimental foi inteiramente casualizado para todos os experimentos e os dados foram submetidos à análise de variância e comparação das médias pelo teste Tukey, a 5% de probabilidade. É possível observar que a luz exerce efeito inibitório sobre a germinação das sementes, e que os reguladores vegetais, GA4+7 + N-(fenilmetil)-aminopurina, são eficientes na superação da dormência, além de ampliarem os limites de temperatura da germinação. A temperatura alternada 20-30ºC mostra-se a mais adequada para a germinação de sementes dessa espécie.

Combinações entre GA4+7 + N-(fenilmetil)-aminopurina e ethephon na germinação de sementes de Passiflora cincinnata Mast.

Neste experimento, objetivou-se avaliar a germinação de sementes de Passiflora cincinnata Mast., com o uso de diferentes combinações de GA4+7 + N-(fenilmetil)-aminopurina (zero, 100, 200, 300, 400, 500mg.L-1) e ethephon (zero, 25, 50, 75, 100mg.L-1), sob delineamento experimental inteiramente casualizado, com 5 repetições de 20 sementes por parcela. Para tanto, as sementes foram embebidas nas diversas soluções durante cinco horas, sob oxigenação constante. A seguir, foram transferidas para gerbox preto, sobre duas folhas de papel mata-borrão umedecidas, onde permaneceram sob temperaturas alternadas 20-30ºC (16/8h). Foram avaliadas as porcentagens de germinação, de sementes mortas e de sementes dormentes, o tempo e a velocidade médios de germinação. A contagem do número de sementes germinadas foi realizada diariamente, durante 44 dias. Pelos resultados, verificou-se que o uso de GA4+7 + N-(fenilmetil)-aminopurina promove incremento no percentual e na velocidade de germinação, pela redução da dormência de sementes de Passiflora cincinnata Mast. Além disso, o produto Ethephon, quando aplicado isoladamente, não é eficiente para superação da dormência de sementes dessa espécie.

Métodos de superação da dormência e temperatura na germinação de sementes de dioclea violácea

The aim of this experiment was to overcome the dormancy and the effect of different temperatures in Dioclea violacea seeds' germination. Two experiments were developed. In the first, it was studied the use of chemical and mechanical scarification in the overcome dormancy seeds. Therefore, were accomplished seven treatments with four replications of 15 seeds each. The experiment constituted of one testify treatment, five chemical scarification treatments (1, 2, 3, 4 and 5 hours of immersion in concentrated sulfuric acid - H(2)SO(4)) and one mechanical scarification treatment. In the second experiment, was studied the temperature effects on germination seeds; it was constituted on six treatments with four replications with 12 seeds each. The treatments constituted of constant temperatures 15 degrees C, 20 degrees C, 25 degrees C, 30 degrees C and 35 degrees C and the alternate temperature 20-30 degrees C ( 16 and 8 hours, respectively). Germination, died seeds, hard seeds percentages, medium time germination and germination speed index were determined. The data were submitted to the variance analysis, and the averages compared by the Tukey test to 5% of probability and regression analysis. It was observed that the dormancy overcome of Dioclea violacea seeds can be done with chemical scarification, 3 to 5 hours in H(2)SO(4), as much as with mechanical scarification. Also, it was possible to conclude that Dioclea violacea seeds germinate in a wide temperature strip, with constant temperatures of 20 degrees C, 25 degrees C and 35 degrees C benefit the germination process.

Cytochemical characterization of the endomembranous system during the oocyte primary growth in Serrasalmus spilopleura (Teleostei, Characiformes, Characidae)

The morphophysiological changes that occur during oocyte primary growth in Serrasalmus spilopleura were studied using ultrastructural cytochemical techniques. In the previtellogenic oocytes endoplasmic reticulum components, Golgi complex cisternae and vesicles, lysosomes, multivesicular bodies and some electron-dense vesicles react to acid phosphatase (AcPase) detection. The endoplasmic reticulum components, Golgi complex cisternae and vesicles also react to osmium tetroxide and potassium iodide impregnation (KI). These structures, except for the Golgi complex cisternae, are strongly contrasted by osmium tetroxide and zinc iodide impregnation (ZIO). Some electron-dense vesicles are ZIO-stained, while microvesicles in the multivesicular bodies and other large isolated cytoplasmic vesicles are contrasted by KI. At primary oocyte growth, the activity of the endomembranous system and the proliferation of membranous organelles are intense. The biosynthetic pathway of the lysosomal proteins such as acid phosphatase, involves the endoplasmic reticulum, Golgi complex, vesicles with inactive hydrolytic enzymes and, finally, the lysosomes. The oocyte endomembranous system have reduction capacity and are involved in the metabolism of rich in SH groups. (c) 2005 Published by Elsevier Ltd.

Maternal protein restriction induce skeletal muscle changes without altering the MRFs MyoD and myogenin expression in offspring

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

Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions

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

Frugivory on Margaritaria nobilis L.f. (Euphorbiaceae): poor investment and mimetism.

Dehiscent fruits of Euphorbiaceae usually have two stages of seed dispersal, autochory followed by myrmecochory. Two stages of Margaritaria nobilis seed dispersal were described, the first stage autochoric followed by ornithocoric. Their dehiscent fruits are green and after they detached from the tree crown and fall on the ground, they open and expose blue metallic cocas. We studied the seed dispersal system of Margaritaria nobilis in a semi-deciduous forest in Brazil. In 80 h of focal observations, we recorded only 12 visits of frugivores, however the thrush Turdus leucomelas was the only frugivore that swallowed the fruits on the tree crown. Pitylus fuliginosus (Fringilidae) and Pionus maximiliani (Psittacidae) were mainly pulp eaters, dropping the seeds below the tree. on the forest floor, after fruits dehiscence, jays (Cyanocorax chrysops), guans (Penelope superciliaris), doves (Geotrygon montana) and collared-peccaries (Pecari tajacu) were observed eating the blue diaspores of M. nobilis. Experiments in captivity showed that scaly-headed parrots (Pionus maximiliani), toco toucans (Ramphastos toco), jays (Cyanochorax chrysops), and guans (Penelope superciliaris) consumed the fruits and did not prey on the seeds before consumption. The seeds collected from the feces did not germinate in spite of the high viability. The two stages of seed dispersal in M. nobilis resembles the dispersal strategies of some mimetic species. However M. nobilis seeds are associated with an endocarp, it showed low investment in nutrients, and consistent with this hypothesis, M. nobilis shared important characteristics with mimetic fruits, such as bright color display, long seed dormancy and protection by secondary compounds.

Seed germination and removal of Michelia champaca L. (Magnoliaceae) in eucalypt stands: the influence of the aril

Testou-se o efeito do arilo na germinação de M. champaca em condições controladas, bem como na sua remoção, em ambiente natural. Os ensaios de germinação foram mantidos a 25 ± 2 °C, sob luz branca constante. Os experimentos de remoção foram levados a cabo em três talhões velhos (idades de 39 a 62 anos) e três novos (15 anos de idade) de eucalipto mantidos no Horto Florestal Navarro de Andrade, em Rio Claro, SP. Os resultados indicaram que o arilo inibe a germinação, sendo as sementes fotoblásticas positivas. Observou-se que a remoção de sementes foi maior em talhões velhos do que em novos, provavelmente devido à maior densidade de roedores nos talhões velhos. Nos talhões novos, verificou-se que formigas removiam mais sementes ariladas. Esses insetos são importantes agentes na remoção do arilo de sementes derrubadas por pássaros, promovendo, assim, aumento na germinação e evitando a possível predação das sementes por roedores.

Achene dimorphism in Bidens pilosa L. (Asteraceae) as determined by germination test

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

Seed biometry and the effect of pre germinative treatments, temperature, and light on seed germination and subsequent growth of three Stryphnodendron species

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seasonal metabolic depression, substrate utilisation and changes in scaling patterns during the first year cycle of tegu lizards (Tupinambis merianae)

The tegus increase in body mass after hatching until early autumn, when the energy intake becomes gradually reduced. Resting rates of oxygen consumption in winter drop to 20% of the values in the active season (Vo(2)=0.0636 ml g(-1) h(-1)) and are nearly temperature insensitive over the range of 17-25degreesC (Q(10)=1.55). During dormancy, plasma glucose levels are 60% lower than those in active animals, while total protein, total lipids and beta-hydroxybutyrate are elevated by 24%, 43% and 113%, respectively. In addition, a significant depletion of liver carbohydrate (50%) and of fat deposited in the visceral fat bodies (24%) and in the tail (25%) and a slight loss of skeletal muscle protein (14%) were measured halfway through the inactive period. Otherwise, glycogen content is increased 4-fold in the brain and 2.3-fold in the heart of dormant lizards, declining by the onset of arousal. During early arousal, the young tegus are still anorexic, although Vo(2) is significantly greater than winter rates. The fat deposits analysed are further reduced (62% and 45%, respectively) and there is a large decrease in tail muscle protein (50%) together with a significant increase in glycogen (2-3-fold) and an increase in plasma glucose (40%), which suggests a role for gluconeogenesis as a supplementary energy source in arousing animals. No change is detectable in citrate synthase activity, but beta-hydroxyacyl CoA dehydrogenase activities are strongly affected by season, reaching a Mold and 5-fold increase in the liver tissue of winter and arousing animals, respectively, and becoming reduced by half in skeletal muscle and heart of winter animals compared with late fall or spring active individuals. From hatching to late autumn, the increase of the fat body mass relatively to body mass is disproportionate (b=1.44), and the mass exponent changes significantly to close to 1.0 during the fasting period. The concomitant shift in the Vo(2) mass exponent in early autumn (b=0.75) to values significantly greater than 1.0 in late autumn and during winter dormancy indicates an allometric effect on the degree of metabolic depression related to the size of the fat stores and suggests greater energy conservation in the smaller young.

Seasonal changes in blood oxygen transport and acid-base status in the tegu lizard, Tupinambis merianae

Oxygen-binding properties, blood gases, and acid-base parameters were studied in tegu lizards, Tupinambis merianae, at different seasons and temperatures. Independent of temperature and pH, blood oxygen affinity was higher in dormant lizards than in those active during the summer. Haematocrit (Hct) and hemoglobin content ([Hb]) were greater in active lizards resulting in a higher oxygen-carrying capacity. Nucleoside triphosphate content ([NTP]) was reduced during dormancy, but the ratio between [NTP] and [Hb] remained unchanged. Dormancy was accompanied by an increase in plasma bicarbonate ([HCO(3)(-)]PI) and an elevation of arterial CO(2) partial pressure (P(aCO2)) and CO(2) content in the plasma (C(PlCO2)). These changes in acid-base parameters persist over a broad range of body temperatures. In vivo, arterial O(2) partial pressure (Pa(O2)) and O(2) content (Ca(O2)) were not affected by season and tended to increase with temperature. Arterial pH (pH(a)) of dormant animals is reduced compared to active lizards at body temperatures below 15 degreesC, while no significant difference was noticed at higher temperatures. (C) 2003 Elsevier B.V. All rights reserved.