Search results for "Pollen"

STOP 3: Late-glacial and early postglacial environmental processes and the history of the River Triečupīte valley and surroundings, in the foreland o…

2014

A late Eemian aridity pulse in central Europe during the last glacial inception

2005

How do ice ages begin? It's an obvious question to ask as we enjoy the relative luxury of an interglacial, but a hard one to answer. A look at past transitions may give some clues as to how this period will one day come to an end. A climate reconstruction based on sediments found beneath a lake in the Eifel mountains in Germany provides evidence of an extreme climate event lasting 468 years right at the end of the last interglacial. Dust storms, aridity, bushfires and the loss of trees associated with a warm climate coincided with a southward shift of the warm waters of the North Atlantic drift. In terms of insolation — the rate of delivery of the Sun's radiation to Earth — conditions then …

Variable mycorrhizal benefits on the reproductive output ofGeranium sylvaticum, with special emphasis on the intermediate phenotype

2012

In several gynodioecious species, intermediate sex between female and hermaphrodite has been reported, but few studies have investigated fitness parameters of this intermediate phenotype. Here, we examined the interactions between plant sex and arbuscular mycorrhizal (AM) fungal species affecting the reproductive output of Geranium sylvaticum, a sexually polymorphic plant species with frequent intermediate sexes between females and hermaphrodites, using a common garden experiment. Flowering phenology, AM colonisation levels and several plant vegetative and reproductive parameters, including seed and pollen production, were measured. Differences among sexes were detected in flowering, fruit …

Preliminary identification of self-incompatibility genotypes of Sicilian almond landraces

2018

Sicily is the main almond producer in Italy. The almond tree is one of the main protagonists of the Sicilian agrarian landscape, especially in the winter, when the bare branches are covered by white or pinkish flowers. Its presence is particularly significant in the province of Agrigento, in Syracuse and in Ragusa areas, where the almond nut is used for fresh consumption and for the preparation of typical sweets. The extremely rich Sicilian almond germplasm can be useful for genetic improvement, since many local landraces possess aromatic characteristics of the nuts of high value. Self-incompatibility in this species is gametophytic and controlled by a multi-allelic S locus, coding for the …

Floral and Vegetative Morphogenesis in California Poppy (Eschscholzia californicaCham.)

2005

For studies of the evolution of development in angiosperms, early‐diverging eudicot taxa are of particular interest for comparisons with established core eudicot model plants, such as Arabidopsis. Here we provide a detailed description of shoot and floral development of the basal eudicot California poppy (Eschscholzia californica). Rosette formation in the vegetative phase is accompanied by increased leaf complexity and shoot apex size. The flowering phase is characterized by internode elongation, formation of dissected cauline leaves, terminal flowers, and basipetal inflorescence branching. For developing flowers and fruits, we have defined 14 stages according to important landmark events,…

Effects of tetraploidy on olive floral and fruit biology

2014

Floral biology and fruit development were studied in Leccino Compact (LC), a polyploid olive mutant of cultivar Leccino (L). This mutant, considered a mixoploid with both diploid and tetraploid cells, has thicker leaves and fruit size similar to the diploid cultivar. So far, no information is available on its floral biology. In this study, the ploidy level of the LC fruit epicarp, analyzed by flow cytometry, was determined to be tetraploid. Pollen size distribution confirmed that most flowers were tetraploid. Morphological and histological measurements of various floral structures and fruits were carried out on the two genotypes, and LC showed larger floral structures (i.e. rachis, flower a…

Assessment of quality of air in Palermo by chemical (ICP-OES) and cytological analyses on leaves of Eucalyptus camaldulensis

2013

In this work, we studied the influence of air pollution on the morpho-structural, biochemical and chemical composition of Eucalyptus camaldulensis leaves. Analyses were carried out on 22 samples collected in Palermo (Italy) area. Considering the mean concentrations (in unwashed leaves) of investigated metals, nutrient elements as Fe (214 mg kg(-1) dry weight (d.w.)), Mn (160 mg kg(-1) d.w.) and Zn (39 mg kg(-1) d.w.) were the most abundant, whereas Pb (5.6 mg kg(-1) d.w.) and Cd (0.072 mg kg(-1) d.w.) showed the lowest concentrations. The values of metal pollution index (MPI) ranged from 6.0 (station no. 15) to 25 (station no. 8) and from 4.0 (station no. 16) to 17 (stations no. 7 and no. 1…

Diurnal variation of tree pollen in the air in finland

1984

Abstract The pollen was collected with Burkard spore traps in Turku and Jyvaskyla, in southern and central Finland. Selected days of high concentration were analysed for hour to hour concentrations. The diurnal variation of pollen concentration was variable in Alnus, Betula, Juniperus and Pinus, while Picea, Populus, Quercus, Salix and Ulmus had regular daytime maxima och nightly minima. The pollen concentrations were closely correlated with increasing temperatures and decreasing relative humidities. A significant relationship with wind speed was also found, except in Alnuts and Betula. The most significant relationships with wind speed were found in Salix and Quercus, the pollen of which t…

Effects of Dietary Supplementation with Honeybee Pollen and Its Supercritical Fluid Extract on Immune Response and Fillet’s Quality of Farmed G…

2022

The awareness of the correlation between administered diet, fish health and products’ quality has led to the increase in the research for innovative and functional feed ingredients. Herein, a plant-derived product rich in bioactive compounds, such as honeybee pollen (HBP), was included as raw (HBP) and as Supercritical Fluid Extracted (SFE) pollen (HBP_SFE) in the diet for gilthead seabream (Sparus aurata). The experiment was carried out on 90 fish with an average body weight of 294.7 ± 12.8 g, divided into five groups, according to the administration of five diets for 30 days: control diet (CTR); two diets containing HBP at 5% (P5) and at 10% (P10) level of inclusion; two diet…

Inhibition of human allergic T-helper type 2 immune responses by induced regulatory T cells requires the combination of interleukin-10-treated dendri…

2006

Summary Background In grass pollen-allergic individuals, T cell anergy can be induced by IL-10-treated dendritic cells (IL-10-DC) resulting in the suppression of T helper type 1 (Th1) as well as Th2 cells. This study was performed to analyse whether such IL-10-DC-treated T cells are able to act as regulatory T cells (Treg) suppressing the function of other T cells in the periphery. As transforming growth factor (TGF)-β is also a potential inducer of Treg, we additionally analysed the inhibitory capacity of TGF-β-treated T cells in this system. Materials and Methods Freshly isolated CD4+ or CD4+CD25− T cells from grass pollen-allergic donors were stimulated with autologous mature monocyte-de…