Palynologists use compound light microscopy (LM) for pollen identification and interpretation and scanning electron microscopy (SEM) for morphological comparisons and taxonomy. As we are unaware of any published reports comparing LM and SEM pollen counts and identifications of the same sample, we decided to examine a surface soil sample using both microscopes. Standard palynological extraction ...

To investigate whether the high expression levels of actin-depolymerizing factor genes are related to pollen development, three GhADF genes (cDNAs) were isolated and characterized in cotton. Among them, GhADF6 and GhADF8 were preferentially expressed in petals, whereas GhADF7 displayed the highest level of expression in anthers, revealing its anther specificity. The GhADF7 transcripts in anther...

OBJECTIVES Since the well-observed spring peak of suicide incidents coincides with the peak of seasonal aeroallergens as tree-pollen, we want to document an association between suicide and pollen exposure with empirical data from Denmark. DESIGN Ecological time series study. SETTING Data on suicide incidents, air pollen counts and meteorological status were retrieved from Danish registries....

Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L.) Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl.) Schult.f., Billbergia distachia (Vell.) Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb.) Li...

BACKGROUND Pollutants may affect pollen allergenicity and thus the prevalence of allergies. Although a few studies are available in literature, the connection between pollution and the allergenic potential of pollen has yet to be clearly defined. The objective of this study was to evaluate the effect of traffic-related pollution on the allergenicity of ragweed (Ambrosia artemisiifolia L.) polle...

During fair-weather conditions, a 100Vm 1 electric field exists between positive charge suspended in the air and negative charge distributed on the surfaces of plants and on the ground. The fields surrounding plants are highly complex reaching magnitudes up to 3 10Vm . These fields possibly influence the capture of charged wind-dispersed pollen grains. In this article, we model the electric fie...

The anther, pollen and ovule development in Achillea tenuifolia were studied with a bright field microscopy. Results showed that the anther is of tetrasporangiate type and the anther wall is composed by four layers: an epidermis, an endothecium, one middle layer and a tapetum layer. Tapetum is of secretory type and its cells showed polyploidy. Pollen tetrads were tetrahedral, microspores were v...

In angiosperm reproduction, pollen tubes elongate from the stigma through the stylar transmitting tissue to the ovary to deliver the male gametes for fertilization. This article reviews different forms of pollen tube transmitting tracts within the style as well as possibilities for bridging the gap from the transmitting tissue to the ovule. The pollen tube transmitting tissue is the place of po...

The differentially expressed proteins in pollen tubes indicate their specific roles in this stage of male gametophyte development. To isolate these proteins, 2-DE was done using ungerminated pollen and 2-day-old pollen tubes of Pinus strobus. Results show that 645 and 647 protein spots were clearly resolved from pollen grains and pollen tubes, respectively. Thirty-eight protein spots were expre...

The purpose of this work is to identify pollen grains from its sample images. Pollen grain recognition is used for the classification of the apiaria samples. In this paper we present an image retrieval technique that is being applied to pollen grain identification, based on querying a database of reference neural networks.