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Pollen Types (pollen + type)

Distribution by Scientific Domains

Life Sciences	68%
Chemistry	12%

Selected Abstracts

Pollen types of the Egyptian species of the genus Salvia (Lamiaceae)

FEDDES REPERTORIUM, Issue 7-8 2009
N. Hassan
Pollen morphology of seven species of genus Salvia (Lamiaceae) was investigated using light and scanning electron microscopy. Pollen was studied to show all possible characteristic features like shape, size, apertures, wall stratification, etc., with special reference to the specific characters of each pollen type. Four pollen types were recognized viz. Salvia aegyptiaca pollen type, Salvia deserti pollen type, Salvia palaestina pollen type and Salvia spinosa pollen type. Description of each type, a key to the investigated taxa as well as SEM micrographs of pollen types are provided. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Pollen morphology, leaf surfaces, mycobiota diversity and leaf spots of three species of Zygophyllum growing along Cairo-Suez desert road, Eastern (Arabian) desert in Egypt

FEDDES REPERTORIUM, Issue 1-2 2007
S. M. El Naggar
Three native species of Zygophyllum: Z. coccinum L., Z. decumbens L. and Z. simplex L. (Zygophyllaceae) have been investigated morphologically, palynologically and mycologically. Twenty-two fungal species belonging to 11 genera were collected from leaf surfaces (11 genera and 22 species) and anthers/ pollen grains (7, 13) of Zygophyllum coccinum, Z. decumbens and Z. simplex on Czapek-Dox agar at 25 °C. Fungal diversity of the two microhabitats is basically similar and the most prevalent fungi were Alternaria alternata /A. phragmospora, Cladosporium cladosporioides /C. herbarum and Ulocladium botrytis /U. consortiale. Alternaria alternata, Cladosporium cladosporioides and C. herbarum -leaf spots were rarely recorded in the three studied plant species. Leaf lamina size and sculpture of the studied taxa almost seem to be the most reliable factors of the fungal biodiversity on the studied plant species. On the other hand, reticulate-micro reticulate pollen type is the only pollen type recorded in the present study which reflects that the very narrow range of spectrum of fungal biodiversity between the studied plant species. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Pollenmorphologie, Blattoberfläche, mykobiotische Diversität und Blattflecken von drei Zygophyllum -Arten entlang der Wüstenstraße Kairo,Suez, Östliche (Arabische) Wüste Ägyptens Drei einheimische Zygophyllum -Arten (Z. coccinum, Z. decumbens und Z. simplex (Zygophyllaceae) wurden morphologisch, palynologisch und mykologisch untersucht. 22 Pilzarten aus elf Gattungen wurden von Blattoberflächen gesammelt (11 Gattungen, 22 Arten) und Antheren/Pollenkörner (7, 13) von Zygophyllum coccinum, Z. decumbens und Z. simplex mittels Czapek-Dox agar bei 25 °C untersucht. Die Pilzdiversität beider Mikrohabitate ist basisähnlich und die häufigsten Taxa sind: Alternaria alternata /A. phragmospora, Cladosporium cladosporioides /C. herbarum und Ulocladium botrytis /U. consor- tiale. Blattflecken von Alternaria alternata, Cladosporium cladosporioides und C. herbarum wurden auf den untersuchten Pflanzen selten verzeichnet. Die Größe der Blattlamina und die Skulptur der untersuchten Taxa scheinen die zuverlässigsten (häufigsten) Faktoren für die Pilz-Biodiversität auf den untersuchten Pflanzen zu sein. Andererseits ist der retikulate-microretikulate Pollentyp in vorliegender Studie der einzige Pollentyp, der dieses enge Spektrum der Pilz-Biodiversität zwischen den untersuchten Pflanzen aufzeigt (widerspiegelt). [source]

Nectar and Pollen Sources for Honeybee (Apis cerana cerana Fabr.) in Qinglan Mangrove Area, Hainan Island, China

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 11 2006
Yi-Feng Yao
Abstract In the present study, nectar and pollen sources for honeybee (Apis cerana cerana Fabr.) were studied in Qinglan mangrove area, Hainan Island, China, based on microscopic analysis of honey and pollen load (corbicular and gut contents) from honeybees collected in October and November 2004. Qualitative and quantitative melittopalynological analysis of the natural honey sample showed that the honey is of unifloral type with Mimosa pudica L. (Mimosaceae) as the predominant (89.14%) source of nectar and pollen for A. cerana cerana in October. Members of Araceae are an important minor (3%-15%) pollen type, whereas those of Arecaceae are a minor (<3%) pollen type. Pollen grains of Nypa fruticans Wurmb., Rhizophora spp., Excoecaria agallocha L., Lumnitzera spp., Bruguiera spp., Kandelia candel Druce, and Ceriops tagal (Perr.) C. B. Rob. are among the notable mangrove taxa growing in Qinglan mangrove area recorded as minor taxa in the honey. The absolute pollen count (i.e. the number of pollen grains/10 g honey sample) suggests that the honey belongs to Group V (>1 000 000). Pollen analysis from the corbicular and gut contents of A. cerana cerana revealed the highest representation (95.60%) of members of Sonneratia spp. (Sonneratiaceae), followed by Bruguiera spp. (Rhizophoraceae), Euphorbiaceae, Poaceae, Fabaceae, Arecaceae, Araceae, Anacardiaceae, and Rubiaceae. Of these plants, those belonging to Sonneratia plants are the most important nectar and pollen sources for A. cerana cerana and are frequently foraged and pollinated by these bees in November. (Managing editor: Ya-Qin Han) [source]

Colour characteristics of honeys as influenced by pollen grain content: a multivariate study

JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2004
Anass Terrab
Abstract A chromatic analysis by tristimulus colorimetry and a pollen analysis (pollen grains contained in each honey sample, considering their volume and geometrical shape) were carried out on 33 Eucalyptus unifloral honeys; the colour of the pollen grains was also considered. Multiple linear regression (MLR) and partial least squares regression (PLSR) were used to establish equations relating the chromatic variables to the pollen data, ie number and morphology of the pollen grains, thus allowing the prediction of the ultimate colour from the botanical characteristics. The results obtained show that lightness (L*) is significantly (p < 0.05) related to the pollen type Olea europaea; on the other hand, the variable that better relates to the chroma is the Zea mays pollen type. Copyright © 2004 Society of Chemical Industry [source]

Pollen studies in subtribe Centaureinae (Asteraceae): the Jacea group analysed with electron microscopy

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2000
JOAN MARÍN VILLODRE
Although it has been recognized for many years that the genus Centaurea L. is an artificial assemblage of taxa, its partition into more natural affiliations has been impossible due to its incredible complexity. One of the most reliable characteristics for establishing the phylogeny within this group is the type of pollen. Most of the classification difficulties centre in the Jacea group, which has a characteristic Jacea pollen type. Recent molecular studies indicate that this assemblage is probably polyphyletic. Specifically, previous DNA sequence analyses indicate that Centaurea pulchella and the genera Oligochaeta and Zoegea represent different lineages. This finding prompted an investigation of their pollen types, using scanning electron microscopy, and for some species, transmission microscopy. For a rigorous comparison, the study also included a wide representation of other species across the entire Jacea group. Results showed that both Oligochaeta and Zoegea, but not C. pulchella, can be clearly distinguished from the Jacea group on the basis of pollen morphology. The genus Oligochaeta has a peculiar pollen type that may represent a simplified form of the Serratula pollen type, and the genus Zoegea has Serratula pollen type. [source]

Pollen types of the Egyptian species of the genus Salvia (Lamiaceae)

Taxonomic significance of pollen morphology in some taxa of Resedaceae

FEDDES REPERTORIUM, Issue 7-8 2002
S.M. El Naggar
Pollen morphology of 13 species and two subspecies belonging to five genera: CayluseaSt.-Hil., OchradenusDelile, RandoniaCoss., OligomerisCambess., and Reseda L. of Resedaceae in Egypt were investigated by light and scanning microscopy. The pollen grains were examined and separated into three pollen types and six subtypes representing the different taxonomic categories on the basis of pollen morphological characters, principally pollen shape, size and exine sculpture. The palynological results are discussed with respect to current systematic treatments of Resedaceae. According to the present palynological results, Resedaceae is a eurypalynous and not a stenopalynous family. In addition, this work came to the conclusions that further studies on the pollen of Resedaceae will be useful in establishing a phylogenetic relationship. Zur taxonomischen Bedeutung der Pollenmorphologie bei einigen Taxa der Familie Resedaceae Mittels Licht- und Rasterelektronen-Mikroskopie wurde die Morphologie der Pollen von 13 Arten und zwei Unterarten aus fünf Gattungen der Familie Resedaceae Ägyptens untersucht: CayluseaSt.-Hil., OchradenusDelile, RandoniaCoss., OligomerisCambess. und Reseda L. Die untersuchten Pollen wurden in drei Typen mit sechs Subtypen unterteilt. Auf der Basis dieser Pollenmorphologie repräsentieren sie verschiedene taxonomische Kategorien: Pollenform, Größe und Skulptur der Exine. Die erzielten Ergebnisse werden in Bezug auf die gegenwärtige Systematik der Resedaceen diskutiert. Entsprechend den hier vorgelegten Daten sind die Resedaceae eine eury- und nicht stenopalynologische Familie. Zusätzlich ergibt sich aus dieser Studie, dass weitere Untersuchungen an Resedaceen-Pollen sinnvoll sind, um phylogenetische Beziehungen aufzufinden. [source]

Palynological, physico-chemical and colour characterization of Moroccan honeys: I. River red gum (Eucalyptus camaldulensis Dehnh) honey

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2003
Anass Terrab
Summary The melissopalynological, physico-chemical and colour characteristics of Eucalyptus honeys from Morocco were studied. It is generally accepted that a minimum content of 70% of Eucalyptus pollen is necessary to classify an Eucalyptus honey as unifloral. Twenty-eight physico-chemical and five colour parameters were measured, including the content of sugars and minerals, proline, water content, pH, acidity, hydroxymethylfurfural, diastase activity, ash, electrical conductivity, colour coordinates (L*, a*, b*), chroma (C*ab) and hue angle (hab). Pollen analysis was included, and samples contained a mean of six pollen types (range 2,12). The majority of the samples (75%) contained more than 90%Eucalyptus pollen. The presence of Quercus, Plantago and Thymelaea pollen allows the differentiation of these honeys from those with a different geographical origin. Physico-chemical analysis showed that there was a low percentage of sucrose ( = 0.01%) and trisaccharides. Mineral analysis showed a low percentage of Mg ( = 25.99 ppm) and K ( = 205 ppm), while electrical conductivity ( = 721 ,S cm,1) and diastase activity ( = 39.05 °Gothe) showed medium-high values. The colour parameters lightness (L*) and chroma (C*ab) showed relatively low values. [source]

Modern pollen,vegetation relationships in subarctic southern Greenland and the interpretation of fossil pollen data from the Norse landnám

JOURNAL OF BIOGEOGRAPHY, Issue 3 2007
J. Edward Schofield
Abstract Aim, The objective of this paper is to explore the relationships that exist between vegetation and modern pollen rain in the open, largely treeless landscape of subarctic Greenland. The implications of these results for the interpretation of fossil pollen assemblages from the time of the Norse landnám are then examined. Location, The study area is the sheep farming district of Qassiarsuk in the subarctic, subcontinental vegetational and climatic zone of southern Greenland (61° N, 45° W). Between c.ad 1000,1500 this region was contained within the Norse Eastern Settlement. Methods, Detrended Correspondence Analysis (DCA) of harmonized plant,pollen data sets is used to compare plant cover in 64 vegetation quadrats with pollen assemblages obtained from moss polsters at matching locations. Presence/absence data are also used to calculate indices of association, over- and under-representation for pollen types. Results, Good correspondence between paired vegetation,pollen samples occurs in many cases, particularly in locations where Salix glauca,Betula glandulosa dwarf shrub heath is dominant, and across herbaceous field boundaries and meadows. Pollen samples are found to be poor at reflecting actual ground cover where ericales or Juniperus communis are the locally dominant shrubs. Dominant or ubiquitous taxa within this landscape (Betula, Salix and Poaceae) are found to be over-represented in pollen assemblages, as are several of the ,weeds' generally accepted as introduced by the Norse settlers. Main conclusions, Due to their over-representation in the pollen rain, many of the Norse apophytes and introductions (e.g. Rumex acetosa and R. acetosella) traditionally used to infer human activity in Greenland should be particularly sensitive indicators for landnám, allowing early detection of Norse activity in fossil assemblages. Pteridophyte spores are found to be disassociated with the ground cover of ferns and clubmosses, but are over-represented in pollen assemblages, indicating extra-local or regional sources and long residence times in soil/sediment profiles for these microfossils. A pollen record for Hordeum -type registered in close proximity to a field containing barley suggests that summer temperatures under the current climatic regime are, at least on occasion, sufficient to allow flowering. [source]

Pollen,plant,climate relationships in sub-Saharan Africa

JOURNAL OF BIOGEOGRAPHY, Issue 3 2007
Julie Watrin
Abstract Aim, To demonstrate that incorporating the bioclimatic range of possible contributor plants leads to improved accuracy in interpreting the palaeoclimatic record of taxonomically complex pollen types. Location, North Tropical Africa. Methods, The geographical ranges of selected African plants were extracted from the literature and geo-referenced. These plant ranges were compared with the pollen percentages obtained from a network of surface sediments. Climate-response surfaces were graphed for each pollen taxon and each corresponding plant species. Results, Several patterns can be identified, including taxa for which the pollen and plant distributions coincide, and others where the range limits diverge. Some pollen types display a reduced climate range compared with that of the corresponding plant species, due to low pollen production and/or dispersal. For other taxa, corresponding to high pollen producers such as pioneer taxa, pollen types display a larger climatic envelope than that of the corresponding plants. The number of species contained in a pollen taxon is an important factor, as the botanical species included in a taxon may have different geographical and climate distributions. Main conclusions, The comparison between pollen and plant distributions is an essential step towards more precise vegetation and climate reconstructions in Africa, as it identifies taxa that have a high correspondence between pollen and plant distribution patterns. Our method is a useful tool to reassess biome reconstructions in Africa and to characterize accurately the vegetation and climate conditions at a regional scale, from pollen data. [source]

Manipulation of in vivo pollination techniques to improve the fertilization efficiency of interspecies crosses in the genus Phaseolus

PLANT BREEDING, Issue 2 2007
V. Gurusamy
Abstract Phaseolus angustissimus A. Gray contains genes for traits of interest for dry bean (P. vulgaris) breeders. F1 hybrids can be produced but introgression through backcrossing has been a problem. One of the main impediments is the time required between pollination and fertilization when F1 hybrids of P. vulgaris/P. angustissimus are backcrossed with P. vulgaris. In an attempt to reduce this time, the effect of alternative pollination techniques was studied. The rate and the time of fertilization were ascertained using three different pollen types (pollen germinated in vitro, fresh pollen (FP) mixed in pollen-germinating media and FP), and two methods of pollination (cut-style and stigmatic pollinations). An optimal in vitro pollen germination medium for Phaseolus pollen was developed. Low temperatures (6,9°C) were demonstrated to be necessary for Phaseolus pollen germination. Pollination using a cut-style technique coupled with pregerminated pollen reduced the time for fertilization in the backcrosses of interspecies hybrids by approximately 28 h. This technique improved the success rate of fertilization in wide crosses of Phaseolus designed to introgress genes from wild relatives. [source]