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Nectar Production (nectar + production)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

Passerine Pollination of Rhodoleia championii (Hamamelidaceae) in Subtropical China

BIOTROPICA, Issue 3 2010
Lei Gu
ABSTRACT The pollination ecology and breeding system of the Hamamelidaceae tree species Rhodoleia championii were studied in an evergreen broad-leaved forest in Nankunshan National Forest in Guangdong Province in China. Rhodoleia championii produces lipid-rich pollen grains and dilute nectar (averaging 0.7 mL/d and 9% sugar), with nectar production peaking before 0800 h; the species is self-incompatible and does not set seed asexually. Seven species of nectar-foraging birds visited the inflorescences, with the most common visitors being Japanese white-eyes (Zosterops japonicus, Zosteropidae) and fork-tailed sunbirds (Aethopyga christinae, Nectariniidae). Bumblebees and honeybees played limited roles as pollinators. As documented by fossils from Europe, the Rhodoleia stem lineage dates back at least to the Paleocene. Bird pollination, however, is unlikely to have evolved before the Oligocene when sunbirds arrived in Europe, and pollination by Z. japonicus cannot be much older than 250,000 million years ago, when Z. japonicus diverged from its closest relative. [source]

Comparative micromorphology of nectariferous and nectarless labellar spurs in selected clades of subtribe Orchidinae (Orchidaceae)

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009
ALEXANDRA K. BELL
Floral nectar spurs are widely considered to influence pollinator behaviour in orchids. Spurs of 21 orchid species selected from within four molecularly circumscribed clades of subtribe Orchidinae (based on Platanthera s.l., Gymnadenia,Dactylorhiza s.l., Anacamptis s.l., Orchis s.s.) were examined under light and scanning electron microscopes in order to estimate correlations between nectar production (categorized as absent, trace, reservoir), interior epidermal papillae (categorized as absent, short, medium, long) and epidermal cell striations (categorized as apparently absent, weak, moderate, strong). Closely related congeneric species scored similarly, but more divergent species showed less evidence of phylogenetic constraints. Nectar secretion was negatively correlated with striations and positively correlated with papillae, which were especially frequent and large in species producing substantial reservoirs of nectar. We speculate that the primary function of the papillae is conserving energy through nectar resorption and explain the presence of large papillae in a minority of deceit-pollinated species by arguing that the papillae improve pollination because they are a tactile expectation of pollinating insects. In contrast, the prominence of striations may be a ,spandrel', simply reflecting the thickness of the overlying cuticle. Developmentally, the spur is an invagination of the labellum; it is primarily vascularized by a single ,U'-shaped primary strand, with smaller strands present in some species. Several suggestions are made for developing further, more targeted research programmes. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160, 369,387 [source]

Analysis of amino acids in nectar from Silene colorata Poiret (Caryophyllaceae)

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2007
ANASS TERRAB
Nectar samples were collected from Silene colorata Poiret (Caryophyllaceae), in three different populations from south-western Spain: Zahara de la Sierra (Cádiz), Bornos (Cádiz) and Bormujos (Seville). Samples were analysed for amino acids by reverse-phase high-performance liquid chromatography with precolumn phenylisotiocyanate (PITC) derivatization. The method has the advantage of being highly sensitive, capable of detecting nanogram (ng) quantities of amino acids. Eighteen amino acids were identified and quantified. The mean number of amino acids in a nectar sample was 14 (SD = 2.8). Six amino acids (threonine, alanine, arginine, proline, tyrosine and methionine) were detected in all samples, accounting for 83% of the total amino acids content; proline and arginine were the most abundant amino acids, accounting for 40% and 20% of the total amino acids, respectively. The mean amounts of amino acids in nectar samples per population were 824, 782 and 356 µm in Zahara de la Sierra, Bornos and Bormujos, respectively. Environmental variations such as temperature and sunlight are factors influencing the metabolic processes of nectar production. Our results may contradict the theory that the chemical constituents of floral nectar vary according to the kinds of pollinators. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 49,56. [source]

The role of nectar production, flower pigments and odour in the pollination of four species of Passiflora (Passifloraceae) in south-eastern Brazil

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2001
ISABELA GALARDA VARASSIN
The pollination biology of four species of passionflower was studied in south-eastern Brazil, specifically the importance of chemical features of floral nectar, pigments and odours. All species required pollinators to produce fruits: P. alata was pollinated by bees, P. speciosa by hummingbirds, and P. galbana and P. mucronata by bats. Pollinators consumed nectar as a food source. The activity of vertebrate pollinators reflected resource availability: they foraged when large amounts of nectar were available and when quantitative resource predictability was greater. The nectar of the vertebrate-pollinated species was richer in cholesterol and phospholipids, and had a potassium-sodium ratio higher than 1.0. For all species, the light absorption of flowers was paralleled by the pollinators' visual spectral sensitivity. This first report on Passiflora floral volatile compounds showed that there was a greater chemical class diversity among the species pollinated by animals with an acute olfactory sense, such as bees and bats. Benzenoid alcohols were the most represented compounds. The fragrances contained compounds that occur in other plant species and in the exocrine secretions of bees. This study shows a strong association between pollinators and the attracting and rewarding features of flowers. [source]