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An analysis was made of the protein content of pollen loads produced by the bees in a hive situated in Viana do Bolo (Ourense, north-west Spain), to establish whether or not the relative quantity of protein in the pollen of each plant species influences the preference made by the bee of the flowers that supply pollen to the hive. This analysis was performed on all types of pollen that formed more than 5% of the pollen spectrum. Pollen load samples were collected directly from the hive from March to September. Pollen loads were separated by colour, and their specific homogeneity was confirmed microscopically. The Bradford method has been used for protein extraction and spectrophotometry was used for the determination of protein content. The results show that the different pollen loads have high protein content. Pollen of the plant species that reached relatively higher percentages in the pollen spectrum are also those that have the highest protein content. These were Cytisus scoparius type, uncultivated Poaceae, Quercus robur type, Sanguisorba minor, Salix fragilis and Spergularia rubra type. The pollen of the systematic units, which had pollen loads that could be identified at the level of species, maintained a constant value of protein content independently of the date the samples were obtained. The pollen of the systematic units, which had pollen loads that could be identified at the level of pollen type, has varied in protein content in the analyses performed on samples obtained on different dates. This result is due to the fact that the different species that integrate the pollen type flower on different dates, and thus have a pollenkitt with different characteristics. [ABSTRACT FROM AUTHOR]

A morphological study of three different types of dispersed Circumpolles pollen grains from the Toarcian-Aalenian of the Fuentelsaz section (Spain) was performed using conventional wide field and confocal laser scanning microscopy (CSLM). The CSLM data allowed scanning electron microscope-like three-dimensional reconstructions to be made and showed that the most part of the studied pollen have taxonomic features characteristic of the Mesozoic genus Classopollis. At the species level, Classopollis torosus and Classopollis classoides were identified. The third form studied is characterized by the presence of Ubisch bodies adhering to the pollen wall. [ABSTRACT FROM AUTHOR]