83 research outputs found

    DSC of Milk Fats from Various Animals with High Levels of Medium-Chain, Unsaturated and Polyunsaturated Fatty Acids

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    Mammals of different species provide milk lipids with a wide variety of fatty acid composition yet with common stereospecific features. This allows the investigation of crystallographic properties of milk lipids that cannot be achieved by interesterified lipids due to the random stereospecific distribution that is obtained. The milk fats of elephant and white rhinoceros contain high amounts of 8:0, 10:0 and 12:0 which form triglyceride species that melt between 8 and 22 °C. The crystallographic behaviour of the milk lipids from blesbok and blue wildebeest differ from the other ruminant lipids, and that of horse and vervet monkey differ from the other non-ruminant lipids. It seems that a low content of 18:0 and 18:1, and a high content of saturated short- to medium-length fatty acids prevent the formation of the high and low temperature melting isotherms, between 35 and 42 °C, and between –45 and –10 °C, respectively, which are normally observed for milk fats.Keywords: Triglyceride, differential scanning calorimetry, milk, medium-chain fatty acid, polyunsaturated fatty aci

    Next Generation Mapping of Enological Traits in an F2 Interspecific Grapevine Hybrid Family

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    In winegrapes (Vitis spp.), fruit quality traits such as berry color, total soluble solids content (SS), malic acid content (MA), and yeast assimilable nitrogen (YAN) affect fermentation or wine quality, and are important traits in selecting new hybrid winegrape cultivars. Given the high genetic diversity and heterozygosity of Vitis species and their tendency to exhibit inbreeding depression, linkage map construction and quantitative trait locus (QTL) mapping has relied on F1 families with the use of simple sequence repeat (SSR) and other markers. This study presents the construction of a genetic map by single nucleotide polymorphisms identified through genotyping-by-sequencing (GBS) technology in an F2 mapping family of 424 progeny derived from a cross between the wild species V. riparia Michx. and the interspecific hybrid winegrape cultivar, ‘Seyval’. The resulting map has 1449 markers spanning 2424 cM in genetic length across 19 linkage groups, covering 95% of the genome with an average distance between markers of 1.67 cM. Compared to an SSR map previously developed for this F2 family, these results represent an improved map covering a greater portion of the genome with higher marker density. The accuracy of the map was validated using the well-studied trait berry color. QTL affecting YAN, MA and SS related traits were detected. A joint MA and SS QTL spans a region with candidate genes involved in the malate metabolism pathway. We present an analytical pipeline for calling intercross GBS markers and a high-density linkage map for a large F2 family of the highly heterozygous Vitis genus. This study serves as a model for further genetic investigations of the molecular basis of additional unique characters of North American hybrid wine cultivars and to enhance the breeding process by marker-assisted selection. The GBS protocols for identifying intercross markers developed in this study can be adapted for other heterozygous species

    Are food-deceptive orchid species really functionally specialized for pollinators?

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    Food-deceptive orchid species have traditionally been considered pollination specialized to bees or butterflies. However, it is unclear to which concept of specialization this assumption is related; if to that of phenotypic specialization or of functional specialization. The main aim of this work was to verify if pollinators of five widespread food-deceptive orchid species (Anacamptis morio (L.) R.M. Bateman, Pridgeon & M.W. Chase, Anacamptis pyramidalis (L.) Rich., Himantoglossum adriaticum H. Baumann, Orchis purpurea Huds. and Orchis simia Lam.) predicted from the phenotypic point of view matched with the observed ones. We addressed the question by defining target orchids phenotypic specialization on the basis of their floral traits, and we compared the expected guilds of pollinators with the observed ones. Target orchid pollinators were collected by conducting a meta-analysis of the available literature and adding unpublished field observations, carried out in temperate dry grasslands in NE Italy. Pollinator species were subsequently grouped into guilds and differences in the guild spectra among orchid species grouped according to their phenotype were tested. In contradiction to expectations derived from the phenotypic point of view, food-deceptive orchid species were found to be highly functionally generalized for pollinators, and no differences in the pollinator guild spectra could be revealed among orchid groups. Our results may lead to reconsider food-deceptive orchid pollination ecology by revaluating the traditional equation orchid-pollination specialization

    Plant community attributes affect dry grassland orchid establishment

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    Several factors have been taken into account to explain the distribution of orchid species. We explored the extent to which plant community attributes affect the abundance and reproductive fitness of three orchid species (Anacamptis morio, Himantoglossum adriaticum and Ophrys sphegodes), native to dry grasslands. Structural attributes of plant community (e.g. cover and height) were assessed in ninety 4 m(2) plots scattered on three hill massifs of the Veneto Region (NE Italy). For the three target orchid species, the height of the flowering stalk, the relative ramet height and the number of flowers and fruits were recorded in 203 tagged ramets. Generalized Linear Model revealed that plant community attributes such as cover and height of the herb layer exert a negative effect on the abundance of orchid populations. Furthermore, regression models indicated that O. sphegodes and H. adriaticum reproductive fitness, determined as fruit/flower ratio, was positively affected by relative ramet height. Our results revealed that local herbaceous vegetation structure influences the cover and fruit set of target orchid species. However, there can be substantial variation in the response of different species and variation in the structural attributes of surrounding vegetation may be associated with differences in the strength of selection. In order to achieve effective results in orchid species conservation, protocols for the in situ conservation must detail the range of vegetation covers and heights at which orchid species are favoured and can produce the most effective inflorescences
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