Efeitos de fontes de fósforo e da calagem na produção de amendoim

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of tegument integrity on the light sensitivity in seeds of Cucumis anguria L

Cucumis anguria present dark germinating seeds at 25 degrees C. Seeds without the tegument are photosensitive germinating better in darkness than under continuous white light. However, pre-incubation at 40 degrees C for 48 hours allows the seeds to germinate under continuous white light and the incubation of naked seeds at -0.6MPa restored the light inhibition of seed germination. Our results suggest that the tegument interact with the phytochrome in the control of seed germination in part of the population of seed of C. anguria.

Maturação de sementes de aveia-preta (Avena strigosa Schreb). II. Maturidade da panícula e da espigueta

The present work aims at defining the panicle and spikelet maturity of Avena strigosa Schreb. Four experiments were carried out under field conditions during 1989 (E1 and E2) and 1990 (E3 and E4) in Botucatu county, São Paulo State, Brazil. The sowings were made in 04.19.89 (E1) and 06.18.89 (E2). Maturity of panicle was evaluated by weekly (E1) or biweekly harvests (E2) beginning at total emergence of the panicle. In E3 and E4, sowing was made in 06.04.90 and each experiment had a single harvest date (E3 = 11.01.90 and E4 = 11.07.90). After harvest, the spikelets with similar stage of development were grouped and evaluated. Based on dry matter accumulation and germination percentage of the seeds, it was observed that the maturity of the seeds in the panicle was reached at 28 and 35 days after total emergence of the panicle in the April sowing, and between 24.5 and 28 days in the June sowing. During this period a few percentage of panicles not yet yellow became all yellow, the cariopsis at semi-hard stage became hard and moisture of the seeds dropped from 32% to 12%. The maturity of the seeds in the spikelet was reached when the glumes changed their color from yellowish to yellow, the lemma and palea changed from yellow with black strips to black, the cariopsis changed from farinaceous stage to semi-hard and the moisture content of the seeds changed from 40% to 25%.

Peanut seed tegument is affected by liming and drying method

Calcium plays a fundamental role in cell division and growth, and is an important constituent of the cell wall. An increase in Ca concentration in the tegument of peanut (Arachis hypogea L.) seeds in response to lime application can affect its structure. The tegument structure can also be affected by the drying method of the seeds. The effects of lime application and drying methods as affecting the peanut seed tegument structure were studied in seeds from a field experiment conducted in Sao Manuel, São Paulo, Brazil. Peanut (cv. Botutatu, Valencia Type) was grown in presence or absence of 2.1 Mg ha(-1) of lime and dried in an oven, in shade and in the field. The tegument anatomical features were described and its structure was analysed. Pectic substances, lipidic reserves and starch accumulation were studied. The peanut tegument exhibited well differentiated exotesta, mesotesta and endotesta rich in pectates and covered by a cuticle. Tannin was not observed but there was lipid accumulation in mature teguments. Lignin was observed in the vascular bundles. Lime increased the tegument thickness and decreased the central cavity mainly in the exotesta cells when the period of seed drying was shortened. The effect of drying method upon the tegument was more noticeable in seeds grown without lime. It can be inferred that liming increased the resistance of the tegument.

Effects of recovery type after a judo combat on blood lactate removal and on performance in an intermittent anaerobic task

Aim. The objective of this study was to verify the effects of active (AR) and passive recovery (PR) after a judo match on blood lactate removal and on performance in an anaerobic intermittent task (4 bouts of upper body Wingate tests with 3-min interval between bouts; 4WT).Methods. The sample was constituted by 17 male judo players of different competitive levels: A) National (Brazil) and International medallists (n. 5). B) State (São Paulo) medallists (n. 7). Q City (São Paulo) medallists (n. 5). The subjects were submitted to: 1) a treadmill test for determination of VO2peak and velocity at anaerobic threshold (VAT); 2) body composition; 3) a 5-min judo combat, 15-min of AR or PR followed by 4WT.Results. The groups did not differ with respect to: body weight, VO2peak, VAT, body fat percentage, blood lactate after combats. No difference was observed in performance between AR and PR, despite a lower blood lactate after combat (10 and 15 min) during AR compared to PR. Groups A and B performed better in the high-intensity intermittent exercise compared to athletes with lower competitive level (C).Conclusion. The ability to maintain power output during intermittent anaerobic exercises can discriminate properly judo players of different levels. Lactate removal was improved with AR when compared to PR but AR did not improve performance in a subsequent intermittent anaerobic exercise.

Differences and similarities in the pore size distribution of soybean seed coats

In this work we apply the mercury porosimetry technique to determine the pore size distribution in soybean seed coats of different varieties. The analyses show that the porosity of soybean seed coats is different when seeds of different genotypes are compared. This result points the possibility of using pore size distribution to varietal discrimination.

Ontogenic development of Guazuma ulmifolia (Sterculiaceae) sapplings

Guazuma ulmifolia is as popular reforestation tree all over Latin America. It is characteristic of the initial stages of the secondary sucession and presents potential utility in the restoring of degraded areas. There is no information about fruit,seed and seedling morphology, which is of fundamental importance for identification, extraction, management and seed germination as well as for the characterization of post-seminal development and normal seedling pattern. To obtain such information, external fruit, and external and internal seed structures were studied considering shape, size, micropile and embryo localization; and tegumentar structures. All stages of this work were conduced in the Universidade Estadual Paulista (UNESP), Campus of Jaboticabal city. The fruits were collected in a mixed plantation in Jaboticabal city, State of São Paulo, Brazil. For the bio metric study eight repetitions of ten fruits and eight repetitions of 100 seeds were utilized. For seed internal traits study, 50 seeds were drenched in a distiled water, cut, and observed with a scanning electron microscope and a stereomicroscope, For post-seminal study ten repetitions of seven seeds were scarificated chemically with sulphuric acid during 50 min, and placed to germinate ina culture medium, at 30 degrees C, and eight hours of photoperiod. We found elipsoid, woody, indehiscent, pentacarpelar fruits, with a mean lenght of 22.61 mm (diameter 24.88 mm) and 64.0 seeds per fruit. Seed shape varies, mean length is 3.07 mm (width of 2.36 mm). The seed is bitegumented, tegmic, with a continuous, axial and curved embryo. The germination is epigeal and the seedlings are fanerocotiledoneus. Drawings of all stages are included.

Maturação de sementes de aveia-preta (Avena strigosa Schreb). I. Maturidade do campo

The present work aimed to define the field maturity of Avena strigosa Schreb seeds cv. Comum. Three experiments were carried out in field conditions during 1986, 1987 and 1989 in Botucatu, SP, Brazil. The sowings were made in May. The characteristics evaluated were: panicles and spikelet aspects, the weight of the dry matter of 100 seeds with and without glumes, the seed moisture, the percentage of germinated seeds (sum of normal + abnormal seedlings), the percentage of germination and vigor (first count of germination test). Based on the dry matter accumulation and the gemination percentage of the seeds, it was concluded that the field maturity of the seeds was reached around 28 and 3 5 days after 100% of panicles emergence of the field. At this stage, the field presented a few percentage of particles (+/- 20%) not yet all yellowish, with spikelets at semi-hard stage and the seeds with 20 to 30% of moisture.

Electrical conductivity of soybean seed and correlation with seed coat lignin content

The effects of soybean genotype and seed coat lignin content on bulk electrical conductivity were investigated. Seeds of nine soybean cultivars were hand harvested at R8 maturation stage in Londrina, PR., Brazil in 1995/96. Seeds were electrical conductivity tested using four replicates of 50 seeds per cultivar soaked in 75 mi of deionized water at 25 degrees C for 24 hours. Seed coat lignin content was determined using the potassium permanganate method. There was a significant relationship (R-2 = 0.84**) between electrical conductivity and seed coat lignin content, the latter being a characteristic that varies among soybean genotypes; the higher the amount of lignin in the seed coat, the lower the levels of seed exudates to the soaking solution and consequently the lower the electrical conductivity. It was concluded that seed soaking electrical conductivity is influenced by the seed coat lignin content, which is a characteristic that varies among soybean genotypes. Additionally, the EC test can be used as a valuable tool in the screening process for this characteristic, which is desirable for genetically improving soybean seed quality.

Seed dispersal by fishes in tropical and temperate fresh waters: The growing evidence

Fruit-eating by fishes represents an ancient (perhaps Paleozoic) interaction increasingly regarded as important for seed dispersal (ichthyochory) in tropical and temperate ecosystems. Most of the more than 275 known frugivorous species belong to the mainly Neotropical Characiformes (pacus, piranhas) and Siluriformes (catfishes), but cypriniforms (carps, minnows) are more important in the Holarctic and Indomalayan regions. Frugivores are among the most abundant fishes in Neotropical floodplains where they eat the fruits of a wide variety of trees and shrubs. By consuming fruits, fishes gain access to rich sources of carbohydrates, lipids and proteins and act as either seed predators or seed dispersers. With their often high mobility, large size, and great longevity, fruit-eating fishes can play important roles as seed dispersers and exert strong influences on local plant-recruitment dynamics and regional biodiversity. Recent feeding experiments focused on seed traits after gut passage support the idea that fishes are major seed dispersers in floodplain and riparian forests. Overfishing, damming, deforestation and logging potentially diminish ichthyochory and require immediate attention to ameliorate their effects. Much exciting work remains in terms of fish and plant adaptations to ichthyochory, dispersal regimes involving fishes in different ecosystems, and increased use of nondestructive methods such as stomach lavage, stable isotopes, genetic analyses and radio transmitters to determine fish diets and movements. (C) 2011 Elsevier Masson SAS. All rights reserved.

Potencial alelopático de extrato etanólico de Anadenanthera macrocarpa e Astronium graveolens

The objective of this study was to evaluate the allelophatic potential ethanol extract of leaves of Anadenanthera macrocarpa (Benth.) Brenan (angico) and Astronium graveolens Jacq (aroeira) on the biomonitor germination of Brassica chinensis (Malaysia's cabbage) and Lactuca sativa (lettuce). For the test of allelopathy was the bioassay of germination of B. chinensis and L. sativa using solutions of ethanol extracts in different concentrations (5, 10 and 20 mg / mL) with continuous light for 11 days. The experimental and control groups were divided into the Petri dish containing 50 seeds of B. chinensis and L. sativa each. Were performed six replicates for each concentration of extract of leaves of A. macrocarpa and A. graveolens and the negative control (water). The rolling action of the treatments was performed by quantitative observation and monitoring of germination every six hours. The results show that the ethanol extract of A. macrocarpa and A. graveolens presents allelopathic potential, regardless of the concentration used, but with answers dose-dependent, and thus able to interfere directly in germination, average speed and time of germination biomonitor of B. chinensis and L. sativa.

Emergence and initial growth of rambutan seedlings as a function of seed storage conditions

Introduction. Rambutan is a tropical fruit species with recalcitrant seeds. Despite the expansion of exotic fruit cultivation in Brazil, lots of which fruit species, including rambutan, need basic information, especially in relation to propagation and storage of seeds, which are important for genetic improvement studies, maintenance of genetic sources and seedling production. Materials and methods. A completely randomized design was adopted with treatments distributed in a factorial arrangement, 3 x 4, referring to three seed storage conditions [room temperature conditions; a dry chamber with (18 +/- 2) degrees C and 60% relative humidity; and a cold chamber with (10 +/- 2) degrees C and 70% relative humidity] and four storage times ( 0, 7, 14 and 21 d). Each treatment of 10 seeds was replicated five times. Data on seedling emergence, emergence rate, plant height, number of leaves and length of main root were submitted to variance analysis and means were separated using Tukey's test. Correlation analysis between seed moisture and seedling emergence was performed. Results and discussion. Our results indicated that dry chamber conditions promoted the statistically significantly highest seedling emergence after 7 d of storage. Cold chamber conditions promoted an extremely low seedling emergence independently of time. Conclusion. Rambutan seeds can be stored in a dry chamber for 7 d without losing viability; after 14 d of storage the loss of emergence is 60%.

Efeito de diferentes espaçamentos e densidades de semeadura sobre o desenvolvimento do feijoeiro (Phaseolus vulgaris L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Adubação fosfatada, produção e qualidade de sementes de populações de amendoim

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)