999 resultados para Biologia Floral


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Some aspects of the reproductive biology of Solanum aculeatissimum and S. variabile (Solanaceae) were considered in this study with special reference to floral visitants and their behavior. The most frequent Solanum visitors are bees of the genus Centris, Epicharis, Bombus, Oxaea and Xylocopa that collect pollen from the anthers by means of body vibration. The behavior of those bees on the flowers and their flight distances makes them important pollinators mainly to Solanum aculeatissimum that bears cross-pollination. The guild of pollination of Solanum aculeatissimum and S. variable is composed by bees of the cited genus and by bees of the genus Thygather, Pseudaugochloropsis and Euglossa.

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Leaf discs obtained from the first or second non-cotyledonal leaf of cotton (Gossypium hirsutum L.) seedlings were used for the study of the biology of Polyphagotarsonemus latus on cotton IAC-20 cultivar. Seedlings were grown in pots and placed on a layer of cotton moistened with distilled water. The assays were carried out at 28.5 ± 0.3°C, relative humidity of 71.0 ± 2.6% and a 14 h photophase. The duration of immature phases was 4.1 ± 0.1 days for females and 4.1 ± 0.3 days for males, with a survival of 91.2%. After a pre-oviposition period of 1.1 ± 0.2 days, the females deposited 4.5 ± 0.9 eggs per day during 6.8 ± 1.3 days, i.e., 29.6 ± 7.3 eggs per female. The longevity was 10.0 ± 1.5 days for females and 8.8 ± 1.1 days for males. The intrinsic rate of increase (rm) was 0.323; finite rate of increase (λ) 1.38 individual per female per day; mean generation time (T) 9.54 days and net reproductive rate (Ro) 21.73.

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We investigated if differences in morphological characters in two species of Metrodorea (Rutaceae) from Brazilian semideciduous forests correspond to some pollination divergence. M. nigra and M. stipularis are sympatric species, display a similar floral morphology, are protandrous, self-incompatible, their flower periods overlap, and both are pollinated by flies. M. nigra main pollinators are Pseudoptiloleps nigripoda (Muscidae) and Fannia sp. (Fanniidae); M. stipularis major pollinators are Phaenicia eximia (Calliphoridae), Palpada sp. and Ornidia obesa (Syrphidae). The distinct floral odor (disagreeable in M. nigra and sweet in M. stipularis) and color (brownish violet vs. pale yellow) determine the differences on type and number of floral visitors observed. Several species from semideciduous forests initially considered to be pollinated by diverse insects, present flies as main pollinators, stressing the importance of fly pollination in such habitats.

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With the development of greenhouse grown crops, the whitefly Trialeurodes vaporariorum (West.) has become an important pest. Aiming at verifying the effect of host on the development of this species, the biology of the whitefly was studied on bean (Phaseolus vulgaris L.) cultivars IAC-Carioca Pyatã, IAPAR-57, Jalo Precoce, IAC-Bico de Ouro, IAC-Maravilha and on soybean (Glycine max L.) cultivar Cristalina. The study was conducted at the Laboratório de Entomologia Agrícola - FCA-UNESP, at 25 ± 3°C temperature, 80 ± 10% RH and 14h photophase. The biological parameters assessed were duration, viability and number of nymphal instars; male and female longevity, oviposition period, number of eggs per female and sex ratio; egg viability and incubation period and the life cycle duration. Based on data obtained, fertility life tables were constructed to allow a comparative analysis of the effect of cultivars on the biological development and consequent population growth of this species. The bean cultivars IAC-Maravilha and Jalo Precoce negatively influenced T. vaporariorum development, whereas, the other bean cultivars studied, as well as the soybean cultivar Cristalina, provided good conditions for development of this pest.

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The influence of four resistant and two susceptible genotypes of sweet potato to Euscepes postfasciatus Fairmaire on parasitism and biology of Catolaccus grandis Burks were evaluated under laboratory conditions. Six sweet potato roots of each genotype were infested with E. postfasciatus adults during 40 days. After this period the larvae were taken, weighted and encapsulated in parafilm. Five larvae were offered in free choice and no choice tests to C. grandis pregnant females for 12h. Five replications were used. The parasitized larvae and the eggs of the parasitoid were counted. Three daily observations were made to determine the developmental time of phases and parasitoid survival. C. grandis females can distinguish E. postfasciatus larvae reared on susceptible and resistant roots, prefering to parasitize larvae reared on susceptible roots. C. grandis survival was higher when the parasitoid was reared on larvae originated from susceptible roots and the number of emerged females was higher on larvae reared on hosts originated from susceptible roots.

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The objective of this work was to evaluate the effect of different artemisinin concentrations in the flowering induction of A. annua. Two genotypes of A. annua (CPQBA 239x1V and 3MxPOP) were atomized with four different artemisinin concentrations (0, 500, 5000, and 10000 mg L-1). The application of artemisinin didn't induce the flowering of both genotypes tested, in none of the used concentrations.

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A nest (12.7 m height) of Syrigma sibilatrix was studied on the campus of UNESP Rio Claro (São Paulo, Brazil). The nest was in a fork in the tree Machaerium nyctitans (Leguminosae). Focal observations (n = 103 h) were carried out from 13 September 2004 to 1 November 2004. The male and female both participated in nest building, which took 37 days, mainly between 05:00h - 11:00h. Sticks for the nest were collected at the rate of 5.7 ± 3.4 sticks hour -1, most by the male. The nest included 197 sticks, and was a fl at platform with diameter = 75cm, and depth = 14 cm. A single egg was laid and was incubated (by both sexes) for 66h57 (92% of the time of permanence of the individuals in the nest). The egg was moved 97 times (1.34 times/hour). A strong storm caused the egg to fall, interrupting the study.

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• Background and Aims: Eriocaulaceae (Poales) is currently divided in two subfamilies: Eriocauloideae, which comprises two genera and Paepalanthoideae, with nine genera. The floral anatomy of Actinocephalus polyanthus, Leiothrix fluitans, Paepalanthus chlorocephalus, P. flaccidus and Rondonanthus roraimae was studied here. The flowers of these species of Paepalanthoideae are unisexual, and form capitulum-type inflorescences. Staminate and pistillate flowers are randomly distributed in the capitulum and develop centripetally. This work aims to establish a floral nomenclature for the Eriocaulaceae to provide more information about the taxonomy and phylogeny of the family. • Methods: Light microscopy, scanning electron microscopy and chemical tests were used to investigate the floral structures. • Key Results: Staminate and pistillate flowers are trimerous (except in P. flaccidus, which presents dimerous flowers), and the perianth of all species is differentiated into sepals and petals. Staminate flowers present an androecium with scale-like staminodes (not in R. roraimae) and fertile stamens, and nectariferous pistillodes. Pistillate flowers present scale-like staminodes (except for R. roraimae, which presents elongated and vascularized staminodes), and a gynoecium with a hollow style, ramified in stigmatic and nectariferous portions. • Conclusions: The scale-like staminodes present in the species of Paepalanthoideae indicate a probable reduction of the outer whorl of stamens present in species of Eriocauloideae. Among the Paepalanthoideae genera, Rondonanthus, which is probably basal, shows vascularized staminodes in their pistillate flowers. The occurrence of nectariferous pistillodes in staminate flowers and that of nectariferous portions of the style in pistillate flowers of Paepalanthoideae are emphasized as nectariferous structures in Eriocaulaceae. © The Author 2006. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved.

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We studied the reproductive biology and visual signaling of Dendropsophus werneri, whose distribution is limited to the Atlantic Rain Forest. The fieldwork was carried out in the Estação 2 do IAPAR, municipality of Morretes, state of Paraná, Brazil, from August 2006 to March 2007. Additional information on reproduction was gathered in the Reserva Natural Salto Morato, municipality of Guaraqueçaba, state of Paraná, Brazil, from September 2006 to March 2007. Males were smaller than females. Males called throughout all the study period in Morretes, but were active only during three months in Guaraqueçaba; males called from low vegetation along the edge of temporary ponds in open areas. The visual signaling was observed in two contexts: (1) aggressive behaviors between two males and (2) during the reproduction, by amplectant males. In the territorial behavior, males exhibited both aggressive and mixed calls, visual signaling as well as physical combats. We also recorded satellite behavior in four males. The mean egg number per clutch was 244 ± 32 eggs, varying between 188 and 310 eggs. We observed two reproductive modes: Mode 1 and Mode 24. In the present study, Dendropsophus werneri showed elaborated social interactions involving visual signaling, territorial behavior, mating bahavior with tactile stimuli, and two different reproductive modes, demonstrating its complex reproductive biology.

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Data on the reproductive and feeding biology of elasmobranchs from Manoel Luís Reefs, Maranhão State, Brazil. Nine species were recorded and evidences that the area is important for the reproduction and feeding activity of sharks and rays were obtained.

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New data on floral morphology, development, and vasculature in two Brazilian genera of the monocot family Velloziaceae (Pandanales) are used to explore the homologies of their unusual floral structures, especially the corona of Barbacenia and the corona-like appendages and multiple stamens of some Vellozia species. All Velloziaceae have epigynous flowers. Some species of Vellozia are polyandrous, and stamen number can be variable within species. In Vellozia jolyi, there is a single stamen opposite each sepal and a stamen fascicle (of three secondary stamens) opposite each petal. Each stamen possesses a single vascular bundle, and these are united into a single aggregate bundle in proximal regions of the fascicle. Stamens mature centripetally within each fascicle. The coronal appendages of both genera are closely associated with the stamens, but they share some vasculature with the tepals and develop late in ontogeny. The coronal organs cannot readily be homologized with any of the typical floral organs, but they show partial homology with both tepals and stamens. They are most readily interpreted as a late elaboration of the region between the petals and stamens associated with epigyny and the hypanthium. © 2010 by The University of Chicago. All rights reserved.

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In order to provide efficient crop management which enables the scaling of the production of mango in semi-arid conditions and achieve a greater precision in the recommendation, evaluating the effect and the influence of uniconazole foliar spray, on the emission of vegetative flushes in the cultivar 'Kent', field tests were carried out in a productive orchard. Treatments tested were three uniconazole dosages, 500, 1,000 and 1,500 mg L-1, with one, two or three respective foliar sprayings. Another treatment with paclobutrazol was used at 2.0 g a.i./m of canopy diameter, with a single application via soil and a control (without spraying of plant growth regulators), where spreader-sticker was added and the pH was adjusted. With 30, 60 and 90 days after the first spraying of the flowering inducer the growth of branches were evaluated, as well as the percentage of flowering in all treatments after 120 days of first spraying. The sprayings started in the orchard after the emission of the second vegetative flush after pruning of production, through airassisted sprayer with flow rate of 1,000 L ha-1. The experimental design was done through randomized blocks with four replications, using three plants per plot. It was observed that paclobutrazol was significantly highlighted in relation to other treatments and that the uniconazole with one, two and three foliar sprayings presented inhibition of the vegetative growth in mango 'Kent' and showed, even at low proportions, signs of flowering.

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The objective of this research was to study the effect of previous herbivory in the chemical composition of soybean leaves, and its influence on Anticarsia gemmatalis (Hüeb.) and Piezodorus guildinii (West.) development. Two soybean genotypes, 'Embrapa 4' and 'BR 37', were chemically analyzed. The caterpillars were fed on these genotypes leaves and the bugs on string beans, both injured and non- injured (control), totalizing 4 treatments with 50 replications for each treatment. Herbivory was performed by releasing 3rd instar velvetbean caterpillar. The caterpillars were taken out when 30%-40% of foliar area were consumed. After that, leaves and string beans were used in the experiment. The results obtained during this research indicate that leaves chemical composition was altered and that, in general, A. gemmatalis larvae and P. guildinii nymph have presented better development when fed on non-injured soybean plants, being 'Embrapa 4' genotype the most efficient one concerning insects development.

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New comparative data are presented on the reproductive morphology and anatomy of two genera closely related to grasses, Flagellaria and Joinvillea, in which the flowers are superficially similar, especially in stamen morphology. This investigation demonstrates some anatomical differences between the two genera. For example, both genera depart from the 'typical' condition of tepal vasculature (three-traced outer tepals and one-traced inner tepals): in Flagellaria, each tepal receives a single vascular bundle and, in Joinvillea, each tepal is supplied by three vascular bundles. Joinvillea possesses supernumerary carpel bundles, as also found in the related family Ecdeiocoleaceae, but not in Flagellaria or grasses. In the anther, the tapetum degenerates early in Flagellaria, and is relatively persistent in Joinvillea, in which the pollen grains remain closely associated with the tapetum inside the anther locule, indicating a correlation between peripheral pollen (a feature that is common in grasses) and a persistent tapetum. This study highlights the presence of a pollen-tube transmitting tissue (PTTT) or solid style in the gynoecium of Flagellaria, as also in many Poaceae, but not in Joinvillea or Ecdeiocoleaceae. We speculate that the presence of a PTTT could represent one of the factors that facilitated the subsequent evolution of the intimately connected gynoecia that characterize grasses. © 2012 The Linnean Society of London.

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The floral anatomy of Cephalostemon, Monotrema, Rapatea, Spathanthus, and Stegolepis was studied for taxonomic purposes. All species studied share colleters between the floral parts; sepals, petals, anthers, and style covered by an ornamented cuticle; short epidermal cells with sinuous walls on the abaxial surface of the petals; tetrasporangiate anthers with phenolic idioblasts in the epidermis; endothecium with spiral thickenings; incompletely septate ovary; and anatropous, bitegmic ovules. The floral anatomy is useful not only for characterizing the family, but also for delimiting the subfamilies and genera. Sepals with silica bodies in the epidermal cells; mature anther wall composed of epidermis, endothecium, and middle layer; absence of phenolic idioblasts in the sepals, filaments, and ovary; and stylar epidermal cells with thickened external periclinal wall support Rapateoideae. Cephalostemon and Rapatea show a great number of similarities, corroborating their close relationship indicated in the phylogenetic analyses of the family. Monotrema shares few characters with the genera of Rapateoideae, corroborating its placement in Monotremoideae. Stegolepis shows several distinctive characters, probably related to the greater diversity found in this genus. © 2012 Springer-Verlag Wien.