19 resultados para PUBESCENCE


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We have mapped and identified DNA markers linked to morphology, yield, and yield components of lucerne, using a backcross population derived from winter-active parents. The high-yielding and recurrent parent, D, produced individual markers that accounted for up to 18% of total yield over 6 harvests, at Gatton, south-eastern Queensland. The same marker, AC/TT8, was consistently identified at each individual harvest, and in individual harvests accounted for up to 26% of the phenotypic variation for yield. This marker was located in linkage group 2 of the D map, and several other markers positively associated with yield were consistently identified in this linkage group. Similarly, markers negatively associated with yield were consistently identified in the W116 map, W116 being the low-yielding parent. Highly significant positive correlations were observed between total yield and yield for harvests 1-6, and between total yield and stem length, tiller number, leaf yield/plant, leaf yield/5 stems, stem yield/plant, and stem yield/5 stems. Highly significant QTL were located for all these characters as well as for leaf shape and pubescence.

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Naked oat (Avena sativa f.sp. nuda L.) is the highest quality cereal in northern growing conditions. However the cultivation area of naked oat is remarkably small. Major challenges for naked oat production are to observe its nakedness. The caryopsis of naked oat is sensitive to mechanical damage at harvest, especially at high grain moisture content. The greater the grain moisture content of naked oat at harvest, the more loses of germination capacity was caused by threshing. For producing high quality naked oat seed, it is recommended that harvesting be done at as low grain moisture content as possible. However, if this is not possible, better germination can be ensure with gentle harvest by reducing the cylinder speed. In spite of conventional oat s excellent fat and amino acid composition in animal feed use, as far as nutritional value is concerned, the total energy yield of oat is weaker than other cereals because of the hulls. Also with naked oat the dehulling is not complete, while hull content on different cultivars mostly varied between one to six percent. In addition to genotype, environmental conditions markedly control the expression of nakedness. Thresher settings had only limited effects on hull content. The function of hulls is to protect the groat, but this was confirmed only for Finnish, small grain, cultivar Lisbeth. The oat kernel is generally covered with fine silky hairs termed trichomes. The trichomes of naked oat are partly lost during threshing and handling of grains. Trichomes can cause itchiness in those handling the grains and also accumulate and form fine dust and can block-up machinery. The cultivars differed considerably in pubescence. Some thresher settings, including increased cylinder speed, slightly increased grain polishing such that grains had some areas completely free of trichomes. Adjusting thresher settings was generally not an efficient means of solving the problems associated with naked oat trichomes. The main differences in cultivation costs between naked and conventional oat lie in the amount of seeds required and the drying costs. The main differences affecting the economic result lie in market prices, yield level and feed value. The results indicate that naked oat is financially more profitable than conventional oat, when the crop is sold at a specific price at all yield levels and when the crop is used as feed at highest yield level. At lower yield levels, conventional oat is, in spite of its lower feed value, the more profitable option for feed use. Dehulled oat did not achieve the same economic result as naked oat, as the cost of dehulling, including the hull waste, was considerable. According to this study naked oat can be cultivated successfully under northern conditions, when taking into consideration the soft, naked grain through cultivation chain.

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Gerade männliche Jugendliche nutzen in ihrer Pubertät und Adoleszenz zu einer gelingenden Gestaltung ihres Alltags und zur Ausbildung ihrer Identität zahlreiche Erscheinungsformen des Fantasy-Rollenspielens. In einem Prozess von Aneignung und Entäußerung integrieren dabei die Jugendlichen das überaus reiche multimediale Angebot, welches die Spiele bieten, in ihre Alltagsgestaltung, indem sie sich daraus spezifische Medien-, Text- und Ereignisarrangements bauen. Diese dienen einerseits der sozialen Integration und Distinktion, andererseits der Präsentation ihrer Identitätsentwürfe sich und anderen. Die Jugendlichen schaffen sich mittels dieser spezifischen Medien-, Text- und Ereignisarrangements eine in weiten Teilen von ihnen selbst bestimmte Welt, in der sie ihre Phantasie wie Kreativität mit großer Intensität, ja Obsession, innerhalb integrativer und solidarischer Interaktionsformen selbststeuernd und professionell ausleben. Diese Medien-, Text- und Ereignisarrangements zeigen Angebots- und Nutzungsformen, die sich nach einem medienkommunikativen Aneignungs- und Entäußerungsmodell in der Tradition der Cultural Studies (Stuart Hall) beschreiben lassen. Die Langzeitbeobachtung der Jugendlichen zeigt, dass sie alltagspragmatische Kulturtechniken zur selbstbestimmten Gestaltung von Alltag entwickeln: zunächst eine Strukturierung ihrer kognitiven, affektiven und pragmatischen Interaktion nach Kriterien erfolgreicher intrinsischer Interaktion, mit dem Ziel derer Perpetuierung im Flow-Erleben (Mihalyi Csikszentmihalyi), dann eine Ästhetisierung von Alltagswirklichkeit mittels kollektiver Fiktionalisierung in der Tradition des Collective Story Telling (Janet H. Murray). Diese Kulturtechniken stellen vor dem Hintergrund der Enkodierung und Dekodierung sozialer Codes spezifische Adaptionen von Prozessen der Bedeutungszuweisung und Subjekt- bzw. Identitätskonstitution dar. Die sie evozierenden und mit ihnen korrespondierenden handlungsleitenden Themen der Jugendlichen sind der Wunsch nach Rekonstitution von Gesamtheit in einer sich fragmentarisierenden Wirklichkeit, die Affirmation von Selbstbestimmung- und Autonomieerfahrungen, das Erleben von Reintegration und Solidarität für das sich dissoziiert erfahrende Individuum. Das Handeln der Jugendlichen basiert damit auf dem momentan dominanten Prozess einer Individualisierung von Lebenswelt unter den Bedingungen von Reflexivität und Erlebnisrationalität in der postmodernen Gesellschaft. Mit ihren Versuchen selbstbestimmter Gestaltung folgen sie dem aktuellen gesellschaftlichen Auftrag einer weitgehend in eigener Regie vorzunehmenden Lokalisierung dieses Prozesses. Zunehmend tritt diese von den Jugendlichen selbstgesteuerte Sozialisation neben die traditionell heteronome Sozialisation von gesellschaftlichen Instituten wie etwa die von Schule. Damit wird das Handeln der Jugendlichen zu einer Herausforderung an Pädagogik und Schule. Schule muss, wenn sie ihrem eigentlichen Auftrag von Förderung gerecht werden will, eine Sensibilität für diese Eigenständigkeit von Jugendlichen entwickeln und in der Beobachtung ihres Handelns didaktische Innovationen für Lehren und Lernen entwickeln. Im Mittelpunkt steht dabei die Wiederentdeckung des pädagogischen Dialogs, besonders aber die Entwicklung einer individualisierten Lernkultur und die Förderung jugendlicher Gestaltungskompetenzen, welche von deren alltagsästhetischen Erfahrungen und Kompetenzen im Umgang mit multimedialen Kulturprodukten ausgeht. Schule kann und muss für diese Prozesse selbstgesteuerten Lernens angemessene pädagogische Räume bereitstellen, in denen die Jugendlichen innerhalb eines geschützten Kontextes in der Auseinandersetzung mit eigenen wie fremden Entwürfen ihre Identität entwickeln können.

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Question: What are the correlations between the degree of drought stress and temperature, and the adoption of specific adaptive strategies by plants in the Mediterranean region? Location: 602 sites across the Mediterranean region. Method: We considered 12 plant morphological and phenological traits, and measured their abundance at the sites as trait scores obtained from pollen percentages. We conducted stepwise regression analyses of trait scores as a function of plant available moisture (α) and winter temperature (MTCO). Results: Patterns in the abundance for the plant traits we considered are clearly determined by α, MTCO or a combination of both. In addition, trends in leaf size, texture, thickness, pubescence and aromatic leaves and other plant level traits such as thorniness and aphylly, vary according to the life form (tree, shrub, forb), the leaf type (broad, needle) and phenology (evergreen, summer-green). Conclusions: Despite conducting this study based on pollen data we have identified ecologically plausible trends in the abundance of traits along climatic gradients. Plant traits other than the usual life form, leaf type and leaf phenology carry strong climatic signals. Generally, combinations of plant traits are more climatically diagnostic than individual traits. The qualitative and quantitative relationships between plant traits and climate parameters established here will help to provide an improved basis for modelling the impact of climate changes on vegetation and form a starting point for a global analysis of pollen-climate relationships

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Background and aims Medicago sativa L. is widely grown in southern Australia, but is poorly adapted to dry, hot summers. This study aimed to identify perennial herbaceous legumes with greater resistance to drought stress and explore their adaptive strategies. Methods Ten herbaceous perennial legume species/accessions were grown in deep pots in a sandy, low-phosphorus field soil in a glasshouse. Drought stress was imposed by ceasing to water. A companion M. sativa plant in each pot minimised differences in leaf area and water consumption among species. Plants were harvested when stomatal conductance of stressed plants decreased to around 10% of well watered plants. Results A range of responses to drought stress were identified, including: reduced shoot growth; leaf curling; thicker pubescence on leaves and stems; an increased root:shoot ratio; an increase, decrease or no change in root distribution with depth; reductions in specific leaf area or leaf water potential; and osmotic adjustment. The suite of changes differed substantially among species and, less so, among accessions. Conclusions The inter- and intra-specific variability of responses to drought-stress in the plants examined suggests a wide range of strategies are available in perennial legumes to cope with drying conditions, and these could be harnessed in breeding/selection programs.

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Urban greening solutions such as green roofs help improve residents’ thermal comfort and building insulation. However, not all plants provide the same level of cooling. This is partially due to differences in plant structure and function, including different mechanisms that plants employ to regulate leaf temperature. Ranking of multiple leaf/plant traits involved in the regulation of leaf temperature (and, consequently, plants’ cooling ‘service’) is not well understood. We therefore investigated the relative importance of water loss, leaf colour, thickness and extent of pubescence for the regulation of leaf temperature, in the context of species for semi-extensive green roofs. Leaf temperature were measured with an infrared imaging camera in a range of contrasting genotypes within three plant genera (Heuchera, Salvia and Sempervivum). In three glasshouse experiments (each evaluating three or four genotypes of each genera) we varied water availability to the plants and assessed how leaf temperature altered depending on water loss and specific leaf traits. Greatest reductions in leaf temperature were closely associated with higher water loss. Additionally, in non-succulents (Heuchera, Salvia), lighter leaf colour and longer hair length (on pubescent leaves) both contributed to reduced leaf temperature. However, in succulent Sempervivum, colour/pubescence made no significant contribution; leaf thickness and water loss rate were the key regulating factors. We propose that this can lead to different plant types having significantly different potentials for cooling. We suggest that maintaining transpirational water loss by sustainable irrigation and selecting urban plants with favourable morphological traits is the key to maximising thermal benefits provided by applications such as green roofs.

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

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The genus Stryphnodendron (S.) belongs to the family Leguminosae, subfamily Mimosoideae, which includes mostly trees of tropical and subtropical South America. Extracts of the stem bark are used traditionally by the local population to treat leucorrhoea and diarrhoea, as anti-inflammatory and antiseptic agents (antimicrobial) and to promote blood clotting and wound healing, and in a few cases of gastric ulcers. A review of the literature presented a previous morpho-anatomical study only for S. adstringens (Mart.) Coville. The aim of the present work is to compare morpho-anatomically the stem bark and leaves of three species of Stryphnodendron, known popularly as barbatimão: S. adstringens, S. polyphyllum and S. obovatum, in order to help botanical identification and contribute to quality control. Macro- and microscopical evaluation of the stem barks revealed no significant differences among the species. Morphological analyses of the leaves revealed differences in size, coloration, and pubescence. The leaves of S. adstringens are the largest, glabrous, and concolor. The leaves of S. polyphyllum are smaller, pubescent, and discolor; whereas the leaves of S. obovatum are the same size as those of S. polyphyllum, however, they are glabrous, and discolor.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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New species described and illustrated: Adesmus nigrolineatus sp. nov from Mexico (Oaxaca). From Costa Rica: A, moruna sp. nov. (Heredia); Corcovado bezarki sp. nov. (Guanacaste); Alampyris fuscus sp. nov. (Guanacaste), Cariua gen. nov type species C. sulphurea sp. nov. (Guanacaste). From Bolivia: Phoebemima albomaculata sp. nov. (Cochabamba); Ipepo gen. nov type species I. dilatatus sp. nov. (Santa Cruz). From Brazil: Adesmus facetus sp. nov and Canarana arguta sp. nov. (Rondonia). A new record from Costa Rica of Piruanycha pitilla Galileo & Martins, 2005 is added. The three new species of Adesmus are recognized: A. nigrolineatus by the longitudinal black stripes on elytra; A. moruna by the elytra entirely black; A. facetus by the white belts behind the middle of the elytra and white maculae on apical quarter. Phoebemima albomaculata is characterized by the white macula on the elytral suture. Corcovado bezarki sp. nov is distinguished by the black antennal scape and whitish flagelomeres. Canarana arguta sp. nov has prothorax and urosternites I-IV covered by dense yellowish pubescence. Alampyris fusca sp. nov differs from A. cretaria by the antenomere III longer than scape. Cariua sulphurea sp. nov is distinguished by the urosternites covered by compact white pubescence and Ipepo dilatatus is characterized by the elytra with three carinae.

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The objective of this work was to determine the reciprocal gene flow between two soybean cultivars, one tolerant and the other sensitive to glyphosate, as well as to use estimators to determine the outcrossing rate in the population and the number of hybrid seeds in the progeny. The experiment was composed of four blocks of 40 soybean rows, of which 20 rows of each cultivar (CD217 and CD219RR). At the R8 stage, five rows, distant 0.5, 1, 2, 4 and 8 m from the adjacent cultivar, were harvested, threshed and analyzed as for the occurrence of gene flow. As phenotypical markers, the trait color of flowers, hypocotil and pubescence, as well as the tolerance to glyphosate were used. The cultivars contrast for all the analyzed traits, each one conditioned by a single gene with two alleles, in a complete dominance interaction. In the tolerant cultivar progeny, the largest outcross rate was 0.27%, and in the sensitive cultivar progeny, 0.83% was identified; by the dilution effect hypothesis, the outcross rates in natural populations would be 0.104 and 0.388%, respectively. The reciprocal gene flow between CD217 and CD219RR cultivars is not the same in both directions. The proposed estimators are useful for determining the hybrid rates in seed samples.

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Since it was first reported in Brazil in the 1990s, the B biotype of silverleaf whitefly (Bemisia tabaci [Genn.], Hemiptera: Aleyrodidae) has been recognized as an important pest in soybeans (Glycine max L.), reducing the productivity of this legume species in some areas of the country. As an alternative to chemical control, the use of resistant genotypes represents an important tool for integrated pest management (IPM). This study evaluated the performance of 10 soybean genotypes prior to whitefly infestation, by testing attractiveness and preference for oviposition in the greenhouse and antibiosis in the laboratory. In a multiple-choice test, 'IAC-17' was the least attractive to insects. In a no-choice test, 'IAC-17' was the least attractive for, egg deposition, indicating the occurrence of non-preference for oviposition on this genotype. Trichome density was positively correlated with the oviposition site and may be associated with the resistance of 'IAC-17' to infestation. The genotypes 'IAC-PL1', 'IAC-19', 'Conquista', 'IAC-24' and 'IAC-17' extended the insect's life cycle, indicating the occurrence of a small degree of antibiosis and/or non-preference for feeding.