1,721,009 research outputs found

    HISTOLOGICAL ANALYSIS OF COCOA SEEDS (THEOBROMA CACAO L.)

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    The cocoa (Theobroma cacao L.) is experiencing a considerable appreciation in recent years from the nutritional point of view. In addition to its economic importance, the cardioprotective effect of flavonoids in cocoa powder and dark chocolate was confirmed (Keen et al., 2005). To acquire, therefore, more information about the substances present in the various tissues of the seed of this species is of significant interest. The aim of this research was the localization of macronutrients, such as lipids, proteins and carbohydrates in the different tissues/organs of the cocoa seed, by hystochemical analysis and microscopic observations. The presence and localization of flavonoids were also investigated. Seeds were collected from a fresh fruit of cocoa and portions (2-3 mm of size) of the seed coat, endosperm, cotyledons and embryo were embedded in epoxy resin. In cyto-histological studies, semithin sections were stained with toluidine blue, while to localize macronutrients PAS staining and the osmium treatment were carried out. Our studies confirmed that all portions of the mature seeds contribute to store macronutrients. In the teguments soluble polysaccharides were detected, in the endosperm the polysaccharides and lipids; polyphenols and polysaccharide

    Correlation between sexual reproduction in Phragmites australis and die-back syndrome

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    The common reed Phragmites australis (Cav.) Trin. ex Steud. (syn. P. communis Trin.) is a member of Poaceae with a widespread distribution in both the hemispheres, in different habitat types from river/lake shores, wetlands, coastlands and estuarine habitats, to ruderal, disturbed and even urban areas, hence it is considered a sub-cosmopolite species (Bjork 1967, Haslam 1973, Ostendorp 1993, Brix 1999a) In the last decades, reeds are dying back at a fast rate in sizeable areas of Europe, with significant impacts on important wetland functions (biodiversity, stability of river and lake margins, water quality) and local economy (Den Hartog et al. 1989, Van Der Putten 1997, Brix 1999b). Similar symptoms have been detected even in central Italy (Gigante et al. 2011). Besides ecological, morphological or anatomical parameters studies concerning some reproductive aspects might also be interesting in order to detect the health condition of reed-dominated ecosystems. In all the plant species the flower biology can be a good indicator of the health condition as the seed production and the seed viability. In plants exhibiting both vegetative and sexual reproduction, the energy allocation can be shifted from one to the other strategy in response to environmental stress; it is well known that sexual reproduction decreases the vulnerability of a population to disturbances and biotic stresses by increasing the genetic variability (Lei 2010). On this ground, we took into account the reproductive features of a declining reed stand in central Italy, where the die-back syndrome was recently detected (Gigante et al. 2011), with the aims to extend knowledge on sexual reproduction in P. australis and to highlight links between sexual reproduction and die-back symptoms. In this frame, cyto-histological analyses of inflorescences at different developmental stages were carried out in permanent plots where morphological investigation and histochemical analyses were also carried out to verify pollen and seed viability. An interesting link between some decline symptoms and the rate of spikelets containing at least one viable seed was observed. In detail, it appears that higher rates of viable seeds are recorded in the declining reed stands

    Morpho-histological characterization and nutritional properties of prickly pear (Opuntia ficusindica L. Mill)

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    Opuntia ficus indica (L.) is a large genus of succulent shrubs native to Mexico. In 16th century it was introduced into several continents and is now widely grown in the warmer parts of the world. It has been shown that the prickly pear fruit is very rich in vitamins, minerals, amino acids and in sugars. Another important compositional factor of prickly pear is the presence of pigments, such as betalains, which make the fruit and its products particularly attractive. Betalains are vacuolar pigments present in all varieties of reported O. ficusindica. Their main function in the plant is to attract animals for pollen transfer facilitating plant propagation and to protect against UV radiation. Two betalain derivatives are present in cactus-pears: betacyanin, which gives the red-purple colour, and betaxanthin, which gives a yellow-orange colour. These pigments have important antioxidant activities without toxic effects to humans. Given the considerable interest aroused by this species, the aim of our research was to study the morphological and cyto-histological characteristics of the fruit from two different varieties of the prickly pear typical of Sicily (Italy):” Sanguigna” and “Muscaredda” or “Sciannarina”.Some functional compounds of prickly pear such as the betalains, the carotenoids and chlorophyll (a and b) were also quantified. There were no cyto-histological differences between the fruits of the two considered varieties; instead the content of betacyanins and chlorophyll was very different

    CORRELATION BETWEEN SEXUAL REPRODUCTION IN PHRAGMITES AUSTRALIS AND DIE-BACK SYNDROME

    No full text
    The common reed Phragmites australis (Cav.) Trin. ex Steud. (syn. P. communis Trin.) is a member of Poaceae with a widespread distribution in both hemispheres, in different habitat types from river/lake shores, wetlands, coastlands and estuarine habitats, to ruderal, disturbed and even urban areas, hence it is considered a subcosmopolite species. In the last decades, reeds are dying back at a fast rate in sizeable areas of Europe, with significant impacts on important wetland functions (biodiversity, stability of river and lake margins, water quality) and local economy. Similar symptoms have been detected even in central Italy. Besides ecological, morphological or anatomical parameters, studies concerning some reproductive aspects might also be interesting in order to detect the health condition of reed-dominated ecosystems. In all the plant species, traits related to the flower biology, as the seed production and the seed viability, can be a good indicator of the health condition. In plants exhibiting both vegetative and sexual reproduction, the energy allocation can be shifted from one to the other strategy in response to environmental stress; it is well known that sexual reproduction decreases the vulnerability of a population to disturbances and biotic stresses by increasing the genetic variability. On this ground, we took into account the reproductive features of a declining reed stand in central Italy, where the die-back syndrome was recently detected (Gigante et al., 2011), with the aim both to extend knowledge on sexual reproduction in P. australis and to highlight links between sexual reproduction and die-back symptoms. In this frame, cyto-histological analyses of inflorescences at different developmental stages were carried out in permanent plots where morphological investigations were also performed. Histochemical analyses were also carried out to verify pollen and seed viability. An interesting link between decline symptoms and reproductive aspects was pointed out, showing that higher rates of viable seeds are recorded in the dying-back reed stands
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