Search results for "POLLEN"

POLLEN MORPHOLOGY AND REPRODUCTIVE PERFORMANCES IN OPUNTIA FICUS-INDICA (L.) MILL.

2015

The fruits of Opuntia ficus-indica (L.) Mill., the most worldwide cultivated species of Cactaceae family, contain viable seeds (100-250) of large size. This characteristic influences the commercial quality of the fruit. The study of floral biology in Opuntia allows to understand the behaviour of the plant during reproductive phase and perhaps to distinguish clones with different fruits behaviour (with seed and seedless). The study resulted in a palynological characterization by optical and scanning microscopy (SEM), followed by a qualitative analysis on the male line with pollen viability and in vitro germination tests, in addition to a pollen-pistil interaction survey. The plant material c…

Micromorphological observations on leaf and pollen ofCapparisL. sect.Capparis(Capparaceae)

2004

Sect. Capparis is represented by a single species, Capparis spinosa L., divided into several intraspecific taxa showing plesiomorphic features and disjunct distributions in the Old World. Leaf surface and pollen features were investigated in the whole group by SEM and light microscope observations. The section is characterized by simple hairs, a reticulate to undulate cuticle, anomocytic stomata surrounded by a peristomal rim, and trizonocolporate, prolate pollen grains. The characteristics of the indumentum appear constant, while the studied taxa are fairly differentiated with respect to cuticular patterns and dimensions of the stomata, and show slight differences in pollen size and exine …

Effects of high and low intensità magnetic fields on pollen behaviour of Citrus clementina Hort. ex Tan. and Pinus pinea L.

2003

Genetic structure in the paleoendemic and endangered Petagnaea gussonei (Spreng.) Rauschert (Saniculoideae, Apiaceae) and implications for its conser…

2012

Our investigation aims to understand the genetic structure and evolutionary history of Petagnaea gussonei, an ancient and endangered species belonging to the Saniculoideae subfamily (Apiaceae). It is paleoendemic to Sicily, with a small number of populations in the Nebrodi Mountains. A total of seven chloroplast microsatellite repeat loci and 12 AFLP primer combinations were used to screen 115 individuals corresponding to 17 populations. The ratio of seed to pollen flow was also calculated using the modified Ennos equation. A relatively high level of genetic diversity was detected with AFLPs (e.g., 0.045 < H < 0.278), and a moderate variation was also found using cpSSRs (0 < Hk < 0.667). Tw…

Signals involved in the early TH1/TH2 polarization of an immune response depending on the type of antigen.

1999

Abstract Background: The early production of distinct cytokines by epidermal cells (ECs) in response to antigen exposure may govern the development of T H1 -like immune responses, such as contact sensitivity, or T H2 -like immune responses, such as IgE-dependent allergies of the immediate type, depending on the type of antigen. Objective: The aim of this study was to compare the signals induced by protein allergens with those induced by haptens in ECs and subsequently in local draining lymph node cells (LNCs) or splenocytes. Methods: BALB/c mice were primed in vivo with the protein allergens ovalbumin or birch pollen or the haptens 2,4-dinitrofluorobenzene or trinitrochlorbenzene, respectiv…

Morphological, karyological and taxonomic remarks on Ferulago nodosa (L.) Boiss. (Apiaceae)

2012

Abstract Western (Sicilian) and eastern (Balcan-aegean) populations of the Balcan-tyrrhenian Ferulago nodosa are reported to be different in some morphological characters, and were considered different species by some authors in XIX century. In this work, fruit and pollen morphologies have been compared in Sicilian and Cretan plants; also, the chromosome number of Sicilian plants has been ascertained. Preliminary results highlight a general homogeneity between the two populations, nevertheless showing significant differences in some parameters (fruit form, pollen size). For this reason, and considering the geographic disjunction of the Sicilian plants, the two populations are proposed to be…

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 …

Archäobotanik ˗ Pollenkörner und Makroreste. Von der Grabung ins Labor: Untersuchungsmethoden und Arbeitsweise

2019

Catalogue de l'exposition au parc archéologique de Belginum, du 12 mai au 3 novembre 2019; International audience

Ontogeny of the Calliandra – massulae (Mimosaceae: Ingeae), and the associated viscin body

2006

Abstract Polyads, called also massulae, are common in the Mimosaceae. Within this family, only in Calliandra (s. l.) polyads show a remarkable morphological variation: 16-grained lens-shaped massulae in the neotropical Zapoteca (syn. Calliandra p.p.), and highly asymmetric eight-grained massulae in Calliandra (s. str.). As a further specialisation the massulae in Calliandra (s. str.) possess a sticky appendage called a viscin body. The form and ontogeny of this unique two-dimensional construction of the massula is of particular interest. In Calliandra (s. str.) the octad is normally the developmental product of the initiation stage, beginning with one pollen mother cell (PMC). In total, Cal…

The chemical composition of the floral extract of Epipogium Aphyllum sw. (Orchidaceae): A cluefor thier pollination biology

2014

Epipogium aphyllum is a rare European obligate mycoheterotrophic orchid lacking chlorophyll. It has not been studied previously with respect to pollination biology. We studied the association between the composition of floral scent emission and its pollination systems. Field observation indicates that the main pollinators of Epipogium aphyllum are representatives of the genus Bombus (Hymenoptera), B. lucorum, B. hortorum, B. terrestris, B. pascuorum and B. proteus, and the genus Apis (Hymenoptera) namely A. mellifera. The main potential vector (observed to accidentally carry pollen), is most likely Episyrphus balteatus (Diptera, Syrphidae). The chemical composition of the floral extracts of…