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Samples of honey, called marmeleiro honey by its producers, from the state of Piauí, Brazil, were analysed to study their pollen contents. Samples were dissolved in water, alcohol was added to the solution and the samples were subjected to acetolysis. The absolute concentration of pollen grains in the samples was established using an exotic marker. Multivariate cluster analysis was performed to determine the similarity amongst samples. A total of 158 pollen types were identified from 48 families and 103 genera of plants. The most prevalent families in the pollen spectra were Leguminosae, Myrtaceae, Rubiaceae and Euphorbiaceae. The pollen types Mimosa caesalpiniifolia and Pityrocarpa moniliformis were predominant in 12 samples. Other notable pollen types were Borreria verticillata, Combretum and Mitracarpus salzmannianus. Similarity analysis did not distinguish samples produced on different vegetation types or in the Piauí microregions. Only three samples were considered monofloral. In contrast to beekeepers' designations, only two of the samples studied can potentially be considered monofloral marmeleiro honeys (Croton spp.). Our results stress the need for further studies on the pollen/nectar contribution to honey by the Croton species in this semi-arid region and demonstrate the importance of melissopalynology in investigating the botanical origin of honeys.
During the late Quaternary, extensive forests covered the slopes of the southern section of the Lebanon Mountains. Investigating the response of these forests to the climate change at the Last Interglacial—Last Glacial transition provides insight into their response to an abrupt and extensive deterioration in climate. Here we present the results of a new sedimentary sequence from the southern Bekaa Valley, Lebanon, which spans the late Last Interglacial marine isotope stage (MIS) 5e to early MIS 5c of the Last Glacial. High-resolution analyses for pollen, carbon isotopes and total organic carbon have been undertaken and reveal dramatic shifts in the vegetation composition during this transition. At the Last Interglacial (MIS 5e) to glacial (MIS 5d) transition an environmental threshold was crossed in response to a significant reduction in precipitation with the development of grassland/steppe dominated by Chenopodiaceae and Artemisia. The arid conditions led to the loss of the temperate deciduous arboreal species (Betula, Alnus and Corylus) and significant reduction in the populations of coniferous trees Cedrus libani and Pinus that populated the slopes of the Lebanon Mountains during the Last Interglacial. At the onset of the MIS 5c interstadial an increase in arboreal pollen is observed, in particular Cedrus libani, as the grassland/steppe transitioned into an open forest-steppe. The response of the vegetation during the Last Interglacial to temperatures that were at least as high as or higher than present, and the onset of the Last Glacial, when precipitation declined significantly, has the potential to indicate how eastern Mediterranean biotic communities will respond to changes in these climatic parameters that are predicted to occur in the near future.
Gathering information on the bee foraging plants in a given area is of primary importance in the development of any apiculture industry. Analysis of the honey produced in hives as well as the stored pollen loads help to evaluate the sources of nectar and pollen used by honey bees and their behavioural pattern in the selection of preferences for certain plants as food. Our previous melissopalynology study focused on the analysis of the Omani honey from hives in 14 locations of Muscat and the Al Batinah regions. Our current study examines the pollen pellets collected from those same areas. A total of 249 pollen pellets from 22 honeycombs that were collected by Apis florea and Apis mellifera honeybees were processed and the pollen types were identified using light and scanning electron microscopy. Each pollen load was designated as a unifloral, bifloral or multifloral type. Each plant taxon identified was categorized as being utilized by honeybees for pollen only, nectar only or for both pollen and nectar. A pollen reference collection of 105 local flowering plants was prepared that enabled us to identify most of the pollen types. The quantification of 94 pollen types revealed that 67 of them belonged to 39 plant families, all of which are represented in both the pollen loads and the honey samples. Seven pollen genera were found in the pollen loads only and suggest that those plants were visited by bees just for pollen. Twenty pollen types appear only in the honey samples and suggest that bees visited them only for nectar. Major bee foraging plant species include: Ziziphus spinachristi, Acacia tortilis, Prosopis cineraria, Prosopis juliflora, Maerua crassifolia, Citrus spp., Zygophyllum spp. and Fagonia spp. These data provide a guide to the optimal utilization of floral resources by honeybees in these regions.
The palynological characters of selected species of Periplocoideae and Asclepiadoideae were assessed and a taxonomic key made. We observed that translators of Periplocoideae are taxonomically more important structures than pollen tetrads. Within Periplocoideae, the flatter translators of Periploceae are evolutionarily more primitive than the spatulate translators of Cryptolepideae. The quantitative characters of pollinia are important for the genusand species-level taxonomy in Asclepiadoideae. Pollinium length/width ratio was studied for the first time and it was observed to be a useful character for the delimitation of the tribes and sub-tribes of Asclepiadoideae. The position of attachment of caudicles to pollinia is an overlapping character amongst the tribes and sub-tribes and can be utilised only for the taxonomy of genera. True sterile margins of pollinia are present only in Ceropegieae and pseudo-sterile margins are rarely present in other tribes. Asclepiadoideae within Apocynaceae, and Ascelpiadeae within Asclepiadoideae are separate entities, and Secamonoideae is closer to Periplocoideae than Asclepiadoideae on evolutionary grounds.
The aim of this study was to evaluate the pollen viability and longevity of Cannabis sativa, which is a significant economic crop. Viability and longevity are evaluated using different staining techniques: Alexander's, Triphenyl Tetrazolium Chloride (TCT) and Fluorochromatic Reaction (FCR). The results of this study show that FCR is the most reliable and accurate for assessing viability and longevity in C. sativa. Viability was measured over days and across 2010. Viability was greatest between 0 - 3 days of anther dehiscence and during April, whilst December had the lowest pollen viability. For Cannabis sativa the first 3 days after anthesis are the most important for fertilization, following the 3rd day there is a rapid decline in viability.
Since the beginning of honey production, certain honey types have been favored because they taste better, are better for cooking or do not rapidly crystallize. Thus, they are preferred over others, are in high demand and are sold at higher prices. The pollen of 37 honey samples from East Texas was examined. Pollen was recovered from the honey by using an alcohol-dilution method. Overall, 431 taxa identified into 61 families, 104 genera and 85 species were found in the samples. The number of taxa per sample varied from 17–52. Half of the samples contained 31–40 taxa, indicating a high diversity in botanical origin. Three taxa were found in >50% of the samples and are the most important: Berchemia scandens, Salix nigra and Toxicodendron radicans. Berchemia scandens was found in 89% of the samples and was a predominant type in three samples and an important secondary type in 14. Both Salix nigra and Toxicodendron radicans pollen occurred in 83% of the samples and neither occurred as a predominant or secondary type. Three samples were Berchemia scandens unifloral honey. By examining the pollen in honey, it can determined which habitats honeybees visit, which plants honeybees use as food, if they visit row crops and orchards and their role in pollination. In order to differentiate honey from the United States of America (USA) from honey produced in other countries, the honey from each state must be analyzed. Only by analyzing the pollen in the honey of the USA can it be reliably differentiated from foreign honey that is being sold as produced in the USA.
A palynological investigation of 15 ditch cutting samples from Borehole 8, located off the Angolan coast, westcentral Africa, revealed Late Oligocene (Chattian) to latest Middle to earliest Early Miocene (Serravallian/earliest Tortonian?) marine dinoflagellate cysts, freshwater colonial algae and terrestrial palynomorphs. Various early Miocene pollen characterising the Verrutricolporites rotundiporus Zone of Legoux (1978) confirm the location of the Oligocene—Miocene boundary in relation to a new short-ranging early Miocene dinoflagellate cyst taxon Cristadinium headii sp. nov. The Oligocene to Miocene dinoflagellate cyst assemblages reflect three periods, A–C, with high palaeoproductivity, corresponding to periods in the latest Oligocene (late Chattian), Early Miocene (late Aquitanian—early Burdigalian?) and the base of the Middle Miocene (Langhian). Early to middle Miocene acme intervals of Cleistosphaeridium placacanthum and Cribroperidinium tenuitabulatum are considered to reflect two regional oceanographic events due to intense upwelling along the West African coast. A distinct Early Miocene episode of brackish-water outflow from the nearby Angolan mainland is also reflected by the palynological assemblages, perhaps linked to the global Mi-1 event. Changes in relative abundance of grass pollen indicate a gradual change towards a drier and perhaps also warmer Burdigalian—Langhian climate during which the Angolan savanna developed, followed by cooler and perhaps more humid conditions following the Miocene Climatic Optimum.
A detailed pollen record for the time interval of ∼2500–500 BCE, which covers the time period of the Intermediate Bronze Age (Early Bronze Age IV) into the Iron Ages in the Levant, is presented. The study was conducted in the Ze'elim Gully, which drains the southern Judean Highlands into the Dead Sea. During the Bronze and Iron Ages, the Judean Highlands exhibited dramatic settlement fluctuations. To better understand these oscillations, high-resolution fossil pollen data were combined with a recent pollen data set, lithological features, radiocarbon dating and palaeohydrological information derived from the Dead Sea levels. Due to the occurrence of hiatuses in this fluvial environment, we used a composite profile which was based on two palynological-sedimentological profiles. This integrated information enabled us to reconstruct in great detail for the first time the environmental conditions in relation to the picture derived from archaeological field-work in the Judean Highlands. Evidence for drier climate conditions at the end of the Late Bronze Age may account for the dramatic changes in the settlement pattern which include the destruction of a large number of urban centres and shrinkage of other major sites, not only in the Judean Highlands but in the entire southern Levant. This arid phase may have been one of the reasons for the collapse of eastern Mediterranean civilizations in the mid-thirteenth and twelfth centuries BCE. The improved conditions in the Judean highlands during the Iron Age I (evident by the increasing percentages of both Mediterranean elements and agricultural taxa, e.g. olive and cereals) enabled the recovery of settlement activity, which is the backdrop for the rise of ancient Israel.
Small spiny marine palynomorphs have been the focus of recent palynological studies since their high proportions in Antarctic Late Cretaceous and Cenozoic assemblages were noted. These palynomorphs were assigned to the dinoflagellate cyst Impletosphaeridium clavus and they were believed to have had an affinity with some modern round brown spiny cysts (RBSCs). Our study aims to analyse there together with potential modern analogues by comparing Late Cretaceous and Cenozoic Antarctic specimens with some RBSCs recorded from the Holocene of southern Argentina. We confirm several features in common between these specimens, although differences in processes and the cyst wall are observed. The species could have been produced by dinoflagellates similar to those that generate some RBSCs. Their abundance in the Late Cretaceous may have occurred in response to short term cooling pulses without development of sea-ice cover. Cenozoic records are considered to be reworked, restricting the stratigraphical range of Impletosphaeridium clavus.
The pollen morphology of Nepenthes khasiana (the pitcher plant) from India, was investigated using both light microscopy and scanning electron microscopy. This was to investigate fine details that may contribute to the taxonomic characterisation of species, as well as to utilise the knowledge of its morphology in order to correlate it with Bornean Nepenthes species. The size of the tetrad is the defining feature. The pollen grain is non-aperturate, the sexine is spinuliferous and thicker than the nexine. The study indicates that the species is similar in shape, aperture and ornamentation, and can be discriminated by the size of the tetrad, the length of the spines and the exine thickness. The size of the tetrad (30.7 µm) is closer to two Bornean species such as N. rafflesiana and N. mirabilis (30.5 and 31.0 µm respectively). These observations will be helpful in morphotaxonomy for accurate identification. This will help in finding these taxa from modern and sub-surface soils in order to study the present status of pollen preservation and decipher the palaeovegetation and past climate of the region.
Since the publication of two literature compilations in 2012 and 2013, 89 further contributions on Triassic, Jurassic and earliest Cretaceous (Berriasian) dinoflagellate cysts have been discovered or were issued recently (i.e. between April 2013 and March 2014). These studies are mostly on the Late Jurassic and Early Cretaceous of Europe. They are all listed herein with digital object identifier (doi) numbers where applicable, and a description of each item as a string of keywords. The 15 most significant publications are briefly summarised.
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