1,161 research outputs found

    Imbibition, germination, and early seedling growth responses of light purple and yellow seeds of red clover to distilled water, sodium chloride, and nutrient solution

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    The seeds of red clover are heteromorphic and two color morphs can be visually recognized, light purple and yellow, resulting from heterozygosity and recessive homozygosity at two loci. Here, we report the responses of seed imbibition, seed germination, and early seedling growth of the two morphs to distilled water, sodium chloride, and complete nutrient solution. The sensitivity of red clover seeds to treatments increased with the stage of development in what seems to be a cumulative process. No differences were found in seed imbibition between morphs or between treatments. In seedling growth, on the contrary, treatments were always effective, but differences between morphs were only observed in seeds that were treated with nutrient solution, whereas in the intermediate stage of seed germination, the effects by treatments were observed together with the appearance of differences between morphs in distilled water and in the treatment by sodium chloride solution. Simultaneously, the superior performance of the yellow morph that was found in germination, which appears to be a trait stable across cultivars of red clover seeds, turned into a superior performance of the light purple morph in seedling growth

    The relationship between shape and size of diaspores depends on being seeds or fruits

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    The relationship between the size and shape of diaspores was investigated in angiosperms and gymnosperms including determining if being a seed or fruit was a factor. Size was expressed as volume and shape as the departure from a perfect idealized sphere. Departure from sphericity in seeds was found to be independent from volume. Conversely, an inverse relationship was found between departure from sphericity and volume in fruits. Therefore, whether a diaspore is a seed or a fruit should be considered and included in analyses when ecological, functional or evolutionary correlates of diaspore morphology are under investigation

    Responses of germination to light and to far-red radiation—can they be predicted from diaspores size?

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    This paper presents an update of a dataset of seed volumes previously released online and combines it with published data of the photoblastic response of germination of fruits or seeds (light or dark conditions), and of the effects of enhanced far-red radiation on germination. Some evidence was found to support that germination in larger diaspores might be indifferent to light or dark conditions. Similarly, germination in smaller diaspores might be inhibited by far-red radiation. However, the length, width, thickness, volume, shape, type of diaspore, or relative amplitude of volume is essentially useless to predict photoblastic responses or the effects of far-red radiation on germination of diaspores

    “Language is the place from where the World is seen”—On the gender of trees, fruit trees and edible fruits in Portuguese and in other Latin-derived languages

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    Trees have always been important as natural entities carrying a strong symbolic and metaphorical weight, not to mention their practical uses. Therefore, words and their gender, used to name natural entities as important as trees and particularly fruit-trees and their fruits, are also important. Starting from the finding that Portuguese and Mirandese, the second official spoken language of Portugal, are Latin-derived languages in which ‘tree’ has feminine gender like it had in Latin, we investigated (1) the gender of ‘tree’ in Portuguese from the 10th to the 17th centuries sampling legal, literary, historical, scholar (mostly grammars and dictionaries), and religious manuscripts or printed sources; (2) the presumed variation in the gender of ‘tree’ during a short period in the 16th and 17th century; (3) the likely causes for that variation, which we found to be mostly due to typographic constraints and to compositors’ errors; (4) the gender distribution of fruit trees and fruits produced by fruit trees in Latin and in twelve Latin-derived languages. Portuguese, together with the intimately related Mirandese and Barranquenho, forms a cluster distinct from all other Latin-derived languages in its use of the feminine in the names of fruit trees and fruits, and in the gender agreement between them

    Porque «Uma língua é o lugar donde se vê o mundo» - Considerações sobre a forma de ver a árvore

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    Conforme um dia afirmou Vergílio Ferreira, «Uma língua é o lugar donde se vê o mundo e de ser nela pensamento e sensibilidade». Nessa medida, a palavra usada para designar uma entidade natural tão importante como é a árvore e em particular a árvore de fruto, não pode deixar de ser importante. Da mesma forma, o género da palavra usada para «árvore» é particularmente significativo no âmbito da representação e leitura humana da Natureza, profundamente alicerçada na linguagem, e neste aspecto, o português distingue-se curiosa e intrigantemente da generalidade das línguas latinas

    Herbs and spices in traditional recipes of Alentejo (Portugal)

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    Alentejo, representing about 30% of the area and 5% of the population of Portugal, is a semi-arid region of undulated plains with a Mediterranean climate softened by the Atlantic, with mild winters but hot and dry summers. With an old history of scarcity and pauperism, it shows very particular cultural traits, including a unique culinary tradition, with a high use of wild plants, herbs, and bread-based dishes. An inventory of traditional recipes of Alentejo was built from various sources, including culinary books, field inquiries, and personal reports. The resulting database includes dishes based upon vegetables, eggs, fish and meat, but sweets were not included. A characterization of recipes was made based on its constituents, with a special emphasis in herbs, spices, and wild plants. The availability of wild plants in the traditional markets and the sustainability of its harvest are discussed. Multivariate analyses of correspondences, automatic classification, and discriminant analyses were used to identify and characterize the affinities among recipes and among their constituents. The usefulness of these analytical procedures is assessed in view of a wider, multi regional screening of the use of wild plants, herbs, and spices in traditional culinary

    Sabores do Sul. Plantas aromáticas e condimentos nas receitas tradicionais do Sul de Portugal

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    Na aromatização dos alimentos conseguida com recurso à adição de pequenas quantidades de plantas aromáticas reside muitas vezes grande parte do segredo dos sabores característicos de um prato tradicional. Não deixa de ser espantoso o poder aromatizante destas plantas que pode operar alterações tão profundas e influenciar de uma forma tão dramática o sabor dos cozinhados. Efectivamente destes gestos banais de temperar, resulta de certa forma um pequeno milagre que se repete em cada cozinhado mas que exige e tem por base um saber precioso, o conhecimento das propriedades dos alimentos e condimentos, ou seja por outras palavras o saber dos seus sabores. Apesar de aparentemente banais, temperar e cozinhar são exercícios de sabedoria que exigem um conhecimento profundo dos sabores originais que alquimicamente se misturam para que nasça algo de novo, um sabor diferente que se pretendia e almejava. Esta sabedoria implícita revela-se na confusão dos significados. De facto, estas palavras tão próximas «saber» e «sabor» confundem-se nalguns casos pois a palavra «saber» tanto pode significar conhecer, estar informado com ter sabor, dependendo do contexto em que seja usada. Conhecer os sabores é fundamental na construção de qualquer culinária, quer seja ela uma pretensiosa cozinha de autor quer sejam as diversas culinárias regionais de cariz tradicional. Mas será porventura preciso não esquecer que, apesar de terem efeitos milagrosos, os saberes dos sabores não nascem do nada por súbito milagre. Há todo um passado de que se perdeu o rasto e a origem, já imersos em brumas sem memória, que se encontra na base destes conhecimentos. Deste passado longo, em que se foram realizando experiências, tentando inovações, conseguido resultados variáveis em que os mais apreciados se foram fixando e transmitindo de geração em geração para depois se alterarem em função de outros gostos e modas em épocas diversas, acabou por resultar uma cristalização (provavelmente temporária) de conhecimentos e práticas em inúmeros livros de receitas. Estes, muitos manuscritos, espalhados por cozinhas de vários tempos e vários territórios, formam neste pequeno país, uma colecção imensa e ignorada de que não há história nem estatísticas. A face mais visível que constitui de certa forma a porção emersa deste imenso iceberg é também uma vasta colecção de livros de cozinha impressos e mais ou menos disponíveis para o grande público. Foi a partir de uma selecção deste universo dos livros de cozinha impressos sobre a culinária tradicional portuguesa que se elaborou o estudo que agora se apresenta sobre as plantas aromáticas e condimentos que caracterizam a culinária do Sul de Portugal. Mas nem todos os livros sobre este tema nos puderam auxiliar nesta pesquisa, já que só os que cobrem todo o país e simultaneamente apresentam uma discriminação por regiões geográficas ou por povoações nos poderiam servir, uma vez que intentamos a prazo distinguir e caracterizar, área a área, região a região, a culinária tradicional deste pequeno mas surpreendentemente diversificado país que é Portugal. No presente trabalho a nossa atenção recai apenas nas regiões vizinhas mas bem demarcadas, geográfica, cultural e também culinariamente que são o Alentejo e o Algarve

    Defensive role of allelopathic secondary compounds in plants I: testing two independent general hypotheses

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    This study tests two general and independent hypotheses with the basic assumption that phytoactive secondary compounds produced by plants evolved primarily as plant defences against competitor plant species. The first hypothesis is that the production and main way of release of phytoactive compounds reflect an adaptive response to climatic conditions. Thus, higher phytoactivity by volatile compounds prevails in plants of hot, dry environments, whereas higher phytoactivity by water-soluble compounds is preponderant in plants from wetter environments. The second hypothesis is that synergy between plant phytoactive compounds is widespread, due to the resulting higher energy efficiency and economy of resources. The first hypothesis was tested on germination and early growth of cucumber treated with either water extracts or volatiles from leaves or vegetative shoot tops of four Mediterranean-type shrubs. The second hypothesis was tested on germination of subterranean clover treated with either water extracts of leaves or vegetative shoot tops of one tree and of three Mediterranean-type shrubs or with each of the three fractions obtained from water extracts. Our data do not support either hypotheses. We found no evidence for higher phytoactivity in volatile compounds released by plants that thrive in hot, dry Mediterranean-type environments. We also found no evidence for the predominance of synergy among the constituents of fractions. To the contrary, we found either antagonism or no interaction of effects among allelopathic compounds

    Ionic effects of NaCl counter osmotic inhibition of germination and seedling growth of Scorzonera hispanica and subsequent plantlet growth is not affected by salt

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    Scorzonera (Scorzonera hispanica) is experiencing range reduction in Portugal while its distribution in the Iberian Peninsula largely coincides with areas affected by salinization. Thus two experiments were conducted to evaluate the response of scorzonera to salinity. In the first experiment, seed germination and seedling growth were investigated under osmotic potentials down to −1.21 MPa using NaCl or iso-osmotic polyethylene glycol (PEG) solutions. Results of PEG treatments show that osmotic potential alone reduces germination and seedling growth while on NaCl reductions were much lower. Ionic effects of NaCl are stimulatory and clearly counteract osmotic effects. Most seeds completed germination after being transferred from PEG to distilled water. Conversely, on NaCl recovery results essentially from more time allowed for seeds to complete germination. In the second experiment, young plantlets were treated with NaCl solutions up to 250 mM. In general plantlets were insensitive to NaCl except for a concentration-dependent increase of relative chlorophyll content suggesting that scorzonera tolerance to NaCl might depend upon nitrogen availability. Altogether, results support the conclusion that scorzonera may be a naturally salt tolerant species able to accumulate and sequester NaCl, its tolerance increasing as plants grow older

    Defensive role of allelopathic secondary compounds in plants: a review of data on two independent general hypotheses

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    This review examines and whenever appropriate, reanalyses published literature related to two general and independent hypotheses having the underlying assumption that phytoactive secondary compounds produced by plants evolved primarily as plant defences against competitor plant species. The first hypothesis is that production and the main way of release of phytoactive compounds reflect an adaptive response to climate conditions. Thus, higher phytoactivity by volatile-compounds should prevail in plants of hot, dry environments whereas higher phytoactivity by water- solubles should be preponderant in plants from wetter environments. The second hypothesis is that the synergy between phytoactive compounds of plants should be widespread while antagonism or absence of interaction of effects should be rare because of the higher efficiency of energy and use of resources provided by synergy. Published literature does not support either hypotheses. We found no pattern of association between higher phytoactivity in volatile compounds in plants from drier environments or in water-soluble compounds in plants from wetter environments. Neither did we found evidences for the predominance of synergy. On the contrary, antagonism or no interaction of effects among allelopathic compounds largely prevailed
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