Palynological characterisation of sedra honeys (Ziziphus lotus) produced in Algeria

Abstract

A melissopalynological study was carried out on 46 samples of Ziziphus lotus honey from Laghouat and Djelfa region (central Algeria). The number of pollen types identified per honey sample ranges between nine and 39 with a mean of 24. These correspond to 52 botanical families with 79 different pollen types in the whole samples. Asteraceae and Fabaceae families were present in all the samples where as Apiaceae, Brassicaceae and Nitrariaceae (Peganum harmala) were identified in more than 90%. Other plant families as Boraginaceae, Cistaceae, Myrtaceae, Oleaceae, Salicaceae or Urticaceae were identified in more than 50% of the samples but frequently as minor pollen. Ziziphus lotus pollen had a mean content of 68.9% (with a range of 45.3% to 93.4%). The secondary pollen types were Ononis natrix, Peganum harmala, Brassica napus, Echium and Olea europaea. Regarding the important pollen it is highlighted the presence Lotus t., Eucalyptus, Pimpinella anisum t., Trifolium t., Eryngium campestre t., Centaurea t., Galega officinalis t., Citrus or Scrophularia t. The sedra honeys of the studied region are characterised by their high content in pollen grains with a mean content of 188 403 grains/10 g. The presence of some pollen types in the pollen spectra of honeys such as Peganum harmala, Thapsia garganica, Launaea, Muscari comosum, Carthamus or Limonium bonduellei together several Asteraceae as Centaurea, Taraxacum, Carduus, Artemisia and Matricaria was proposed as geographical markers of this honey type.     

Pollen from tree and shrub taxa in the atmosphere of Caxias do Sul (Rio Grande do Sul, Brazil)

An aerobiological study has been carried out in the region of Caxias do Sul in southern Brazil. Pollen monitoring was performed from January 1, 2001 through to December 31, 2002. A total of 30,469 pollen grains were collected during this period, and 40 pollen types were identified; of these, 23,389 pollen grains, representing 29 pollen types, originated from tree and shrub taxa. The maximum pollen concentration was registered in August 2001 and October 2002. In the study area, the pollen type Mimosa scabrella (18.8%) was much more abundant than all of the pollen types from tree and shrub taxa, such as: Urticaceae (18.4%), Myrtaceae (10.2%), Cupressaceae (7.7%), Myrsine (4.8%), Sorocea (3.9%), Pinaceae (2.9%), Asteraceae (2.2%) and Ricinus (2.1%). These nine pollen types accounted for the largest pollen concentrations of all the tree and shrub taxa. The pollen types Carya, Melastomataceae, Mimosa scabrella, Myrsine and Sorocea are reported for the first time in an aerobiological study in Brazil.     

Seed set,pollen morphology and pollen surface composition response to heat stress in field pea

Pea (Pisum sativum L.) is a major legume crop grown in a semi‐arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed–ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control‐treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid‐infrared attenuated total reflectance (MIR‐ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.     

The seasonal variation of airborne pollen grains that cause sugipollinosis in japan in the last three years

In Japan, the problems of Sugi (Cryptomeria japonica)-pollinosis have been much discussed in recent papers and journals. The author made an investigation on the airborne pollen grains from a scientific standpoint in connection with the incidence of pollinosis. By using the Cascade Impactor the author collected 600 liters of air sample a day, at the roof of the Pharmaceutical Science Building, Toho University, Funabashi, Chiba, Japan. Each air sampling for 2 hrs was repeated three times a week since 1969. The airborne pollen grains in each sample were counted under the microscope to identify the pollen types. The pollen grains were classified into six types according to the classification of pollen grains in Japan established by lkuse. The accumulated number of pollen of each species was analysed statistically by circular plot, Weibull plot, Edwards plot and semi-logarithmic plot. In this report mainly 3B type of pollen grains (Cryptomeria, Chamaecyparis), collected in the last three years are described. The total number of pollen grains in 1988 (2820 grains) was doubled in quantity as compared with that in 1987 (1177 grains) and in 1989 (1121 grains). The 3B type of pollen grains in 1988 (1450 grains) was 3.4 times as many as in 1987 (397 grains), and 12.9 times as in 1989 (112 grains). The 3B type of pollen grains represented the major portion of total pollen, and influenced the annual amount and the dispersal period.     

Airborne pollen and spores on the Arctic island of Jan Mayen

A survey of airspora collected on Jan Mayen, an isolated North Atlantic island (71°N, 8°30′W), using a Burkard seven-day volumetric trap from 24th April to 31th August, 1988, revealed only very small concentrations. A total of 10 different pollen types were recorded, constituting a seasonal sum of 29 pollen grains. The local pollen season was confined to July, with Oxyria digna and Salix as the most numerous pollen types recorded. Exotic pollen grains, namely Betula, Pinus and Castanea type, were recorded in three periods during June and July. Studies of back trajectories indicate North America and/or Iceland and Greenland as possible source areas for the Betula pollen. There were more diatoms than pollen in the local airspora. Fungal spores mainly occurred in late July and August. Cladosporium constituted less than 5% of the total seasonal sum of fungal spores, while basidiospores contributed nearly 12%. The highest diurnal average of Cladosporium was 27 spores m^?3 air. The seasonal maximum of unidentified fungal spores reached a diurnal average of 639 spores m^?1 air on 27th August.     

Pollen analyses of honey from Finland

The present study reports results of qualitative melissopalynological analyses of Finnish honey between the years 2000–2007 and changes in its pollen content from the period 1960–2007. Altogether the pollen content of 734 honey samples was analysed with an average of 415 pollen grains counted from a sample. Pollen of Trifolium repens type, Rubus spp., Salix spp. and the Brassicaceae family were present in more than 90% of the samples, and these pollen types were also found in the highest proportions. Annual variation in the relative amounts of the most numerous pollen types could be as high as 10%. On the basis of the pollen spectra of the honey samples, four regions of forage plants for bees could be identified in Finland. In the period between 1960 and 2007, the most marked change observed was that the percentage of the Trifolium spp. pollen type had decreased from 70% to 10%, while the proportions of Brassicaceae and Rosaceae pollen types showed a corresponding increase.     

Ambrosia sp. pollen in Switzerland

The presence of Ambrosia sp. pollen is very irregular inSwitzerland. South to the Alps (Ticino), the yearly meanquantities (1993 to 1997) reach 535 pollen grains in Lugano and114 in Locarno. To the West, 205 pollen grains of Ambrosiasp. are observed as yearly mean total in Geneva. In La Chaux-de-Fonds(100 a.s.l.), a yearly mean of 86 pollen is reached, 66 inNeuchâatel, 59 in Payerne and 74 in Basel. In the Swiss RhoneValley, in Visp, this yearly mean reaches 30 pollen ofAmbrosia sp. A little more in the center of the country, inBern, 31 pollen are monitored as yearly mean quantity. In therest of the helvetic territory, in the North and in the East, theyearly mean are below 15 pollen grains. Since 1991–1992, anincrease has been observed essentially in Ticino, in Geneva,Neuchâatel and La Chaux-de-Fonds. The presence of Ambrosiasp. pollen is often noticed in case of strong west or south-westwind flowing, probably coming from the Rhôone Valley and theBresse in France and the Po Valley in Italy.     

Pollen morphology of Adenandra (Rutaceae: Diosminae) and its taxonomic implications

The pollen morphology of Adenandra Willd. (Rutaceae: Diosminae) was investigated to determine its taxonomic significance. Pollen of 27 of the 30 infrageneric taxa (representing 16 of the 18 species) was investigated by LM, SEM and TEM. Adenandra differs from all other Diosminae in having 4-colporate rather than 3-colporate pollen grains. This supports the alleged monophyletic status of the genus. Exine morphology and structure, however, is extremely diverse considering the size of the genus, with eight distinct pollen types and four subtypes being discerned. In some members the grains have uniform macroreticulate, striate or striato-reticulate sculpturing, whereas in others the poles have striate, striato-reticulate or reticulate-perforate sculpturing with various types of reticulate or rugulate sculpturing at the mesocolpia. Taxonomic groupings revealed by the pollen characters suggest elationships between taxa that were not previously apparent. It is suggested that evolutionary diversification among species of Adenandra is often more strikingly reflected by pollen morphology than by macromorphology, hence the eurypalynous state of the genus.     

Heterospecific pollen transfer between sympatric species in a midsuccessional old-field community

The cumulative (season-long) incidence of heterospecific pollen transfer (HPT) was examined using nine sympatric species in a midsuccessional old field. Inflorescences were collected weekly during the flowering season, and the proportion of foreign pollen/stigma was recorded. Flowering phenologies of sympatric species and ovule and seed counts of study species were also recorded. Heterospecific pollen was detected on some stigmas of each species. Medicago sativa (Fabaceae) received the most foreign pollen; in some cases, all of the grains on a stigma were heterospecific. Lotus corniculatus (Fabaceae) received the least amount of foreign pollen; the incidence of heterospecific pollen was near zero in most cases. The mean and range of foreign pollen received varied by as much as an order of magnitude between species. The six species with zygomorphic flowers, all Fabaceae, received more heterospecific pollen than the three species with actinomorphic flowers, Potentilla recta and P. simplex (Rosaceae) and Ranunculus acris (Ranunculaceae). This probably reflects a bias because our data were analyzed on a cumulative basis and the Fabaceae had longer flowering phenologies. HPT was not correlated with the species' relative abundance within the community. Proportion of foreign pollen received varied temporally within species, and this variation generally was not related to phenology of any sympatric taxa or the species' own phenology. Pollen grain diameter was positively related to levels of foreign pollen received by species. This might be caused by poor adhesion of large pollen grains to small stigmatic papillae or if generalist pollinators carrying large amounts of heterospecific pollen visit the large-grained species and specialists with little foreign pollen visit the small-grained species. The large proportions of heterospecific pollen on stigmas of many species indicate that HPT occurs frequently in the community we studied and the implications may include reduced seed set because of occlusion by foreign grains. As yet, however, it is unclear how important a factor HPT is in mediating pollen limitation of reproductive success.     

Terminal settling velocity and physical properties of pollen grains in still air

Numerical simulation of wind pollination requires knowledge of pollen grain physical parameters such as size, shape factor, bulk density, and terminal settling velocity. The pollen grain parameters for Japanese cedar, Japanese cypress, short ragweed, Japanese black pine, and Japanese red pine were assessed for dry condition. Terminal settling velocities of dry pollen grains in still air were measured using image analysis of scattered light tracks in a dark settling tube. The measurement system was validated by comparing results to those obtained for standard microspheres of known size and density. Dry pollen grain shape factors indicate the resemblance of particles to spheres, except for pine pollen. Circularity factors of dry pine pollen grains were 0.90–0.86, suggesting more irregular shape than those of other pollen species. Aerodynamic diameters of dry pollen grains were calculated based on the terminal settling velocity. Aerodynamic diameters of Japanese cedar, Japanese cypress, and short ragweed closely resembled the projected area equivalent diameters, suggesting that aerodynamic behaviors of these pollen grains can be managed simply in numerical simulations. However, aerodynamic diameters of dry pine pollen grains were nearly 30 % smaller than projected area equivalent diameters. Sacci on dry pine pollen can reduce the terminal settling velocity through low density and shape effects attributed to their non-sphericity, engendering aerodynamic diameter smaller by more than 10 µm from area equivalent diameters.     

Arecaceae potential for production of monofloral bee pollen

Bees often collect pollen from plants that are near their colonies or apiaries. Arecaceae are characterised by having species that flower throughout the year and produce large quantities of pollen. Pollen grains of Arecaceae have two main forms, namely monosulcate and trichotomosulcate. The study area is located in the coastal region of the state of Sergipe, Brazil, where large amounts of bee pollen are produced by Apis mellifera. This study aims to evaluate how Arecaceae contribute to the production of monofloral bee pollen. Samples of bee pollen loads were collected each month for two years (totalling 24 samples), acetolysed, and mounted on permanent slides. At least 500 grains of pollen were counted for each sample, the data was analysed, and figures were made using the Tilia software. The pollen grains of Cocos nucifera were present in 23 samples (96%), and concentrations of this pollen type varied between 1.1 and 46.8% (but were commonly above 20%). The concentration of Arecaceae pollen grains is the result of the large-scale production of coconuts along the coastline. However, the presence of other pollen types, such as Mimosa arenosa, Mimosa pudica, Mikania and Myrcia, compliments the diets of bees in the region. The results show that even when in low frequency, Cocos nucifera pollen grains represent a large proportion of pollen content compared with other pollen types, because of the large size of Arecaceae pollen grains.     

Pollen Morphology of the Genus Malus and Its Taxonomic and Evolutionary Significance

The pollen morphology of 26 species and 5 hybrids of the genus Malus was investigated with aid of SEM. It is found that the pollen morphology of Malus is rather similar in shape, size, position and number of aperture and exine sculpture. The characters of polle morphology of sections and series are as follows: Sect. Malus Ser. Baccatae: Striae regular, parallel to colpi, and conjunct at pole; Ser. Pumilae: the same as in Ser. Baccatae, but more or less curved near pole. Sect. Docyniopes: Striae regular and parallel to colpi, but bent near pole. Sect. Chloromeles: Striae irregular, dense and interlock. Sect. Sorbormalus: Striae irregular, sparse and not interlock. Ser. Sieboldiance: pollen grains prolate, with perforation among striae, colpi narrow; Ser. Kansuenses: Pollen grains spheroidal, colpi wide in the middle but narrow at both ends, striae relatively dense and regular, mostly dichotomous, perforation present; Ser. Yunnanenses; Pollen grain spheroidae, colpi wide in the middle but narrow at both ends, striae obviously irregular, less dichotomous, perforation absent. The major evolutionary trend of exine sculpture of pollen may be from densely thin-striate to sparsely striate with perforation. Characters of the exine sculpture of hybrids can be used to recognize the rela-tionship between the parental species.     

Pollen and sensorial characterization of different honeys from El Hierro (Canary Islands)

The pollen content of 31 honey samples from 19 different apiaries of El Hierro (Canary Islands) were subject to qualitative and quantitative melissopalynological analysis. The quantitative analysis demonstrated that 13% of the honey belonged to Maurizio Class I (<2?000?grains), 68% to Class II (2?000–10?000?grains) and 19% to Class III (10?000–50?000?grains). The pollen density ranges from 1?042?grains/g of honey to 24?478?grains/g with an average of 7?471?grains/g. According to the qualitative analysis, six honeys were typified as unifloral and 25 as multifloral. The unifloral honey samples were broken down as follows: two of heather (Erica arborea L.), two of Chamaecytisus proliferus (L. f.) Link‐type (“tagasaste”), one of Fabaceae (Genisteae sp.) and one of Lamiaceae Origanum vulgare L. ssp. virens (Hoffmanns. &; Link) Ietsw.‐type (thyme: Micromeria hyssopifolia Webb &; Berthel.). Honeydew elements were practically absent. Sixty‐nine pollen types were identified belonging to 42 families. The number of pollen types range between 18 and 39 (mean of 27.42). Foeniculum vulgare Mill.‐type pollen is present in all the samples. Galactites tomentosa Moench‐type, Echium plantagineum L., Echium L. sp., Bituminaria bituminosa (L.) C. H. Stirt., Chamaecytisus proliferus ‐type and Origanum vulgare ssp. virens ‐type pollen were found in 96.8% of the samples. The sensorial analysis indicated that honey types are generally of good quality, because 62% were evaluated as very high (16%), high (23%), and good (23%).     

Pollen anomaly - a clue to natural hybridity in Argemone (Papaveraceae)

Studies in the pollen morphology of Argemone mexicana (a diploid species, 2n=28), A. ochroleuca (a tetraploid, 2n=56), the wild populations of which growing side by side, and of a triploid (2n=42) observed in the population of A. ochroleuca, have been carried out using light and scanning electron microscope. Pollen grains in both the species are 3 (-4)-zonocolpate with reticulate exine surface, and are distinguishable only on the basis of pollen size, the tetraploid species having larger pollen grains. In the triploid plant, a large number of grains deviates from the normal 3-zonocolpate condition showing a number of apertural types, such as 1-aperturate-operculate, 2-colpate, 3-syncolpate, 4-zonocolpate and spiraperturate. Besides, planaperturate 3-colpate-trilobed grains also occur. The triploid is also characterised by 'minigrains' (size 13-19 μm), a feature not observed in A. mexicana and A. ochroleuca. Since these species are reported to be genetically close, the occurrence of the triploids (forming nearly 5% of the population of A. ochroleuca) indicates the possibility of a natural hybridization between A. ochroleuca and A. mexicana, which is well pronounced on its anomalous pollen features serving as marker for such a hybrid occurring in nature.     

Status of airborne spores and pollen in a coir factory in Kerala,India

The prevalence of airborne fungal spores and pollen grains in the indoor and outdoor environments of a coir factory in Thiruvananthapuram district of Kerala state, India was studied using the Burkard Personal Sampler and the Andersen 2-stage Sampler for 2 years (September 1997 to August 1999). The concentration of pollen grains was remarkably lower than that of fungal spores (ratio of 1:28). There was no large difference in the concentrations and types of fungal spores between the indoor and outdoor environments, with 26 spore types found to be present indoors and 27 types outdoors; of these, 22 were common to both the environments. Aspergillus/Penicillium, Cladosporium, ‘other basidiospores’ and ascospores were the dominant spore types. The total spore concentration was highest in February and lowest in September, and it was significantly higher in 1998–1999 than in 1997–1998. Twenty viable colony-forming types were isolated from inside the coir factory. The most dominant viable fungi isolated were Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The total pollen concentration was higher in the outdoor environment of the coir factory than indoors, with 15 and 17 pollen types, respectively. Grass and Cocos nucifera pollen types were dominant. The dominant spore and pollen types trapped in the two environments of the coir factory are reportedly allergenic and, consequently, workers are at risk of catching respiratory/allergic diseases.     

Aperture variation in the pollen of Nelumbo (Nelumbonaceae)

The evolutionary and developmental origin of tricolpate pollen is of great interest because pollen of this kind defines a major clade of angiosperms (eudicots), a clade that is also well supported by molecular data. We examined evidence that tricolpate and monosulcate pollen types are produced alongside each other in the anthers of Nelumbo flowers, as has previously been reported. Observations of pollen in situ within individual anthers revealed mainly tricolpate pollen produced in tetrahedral tetrads, but also a small percentage of clearly aberrant pollen grains that have a great variety of aperture configurations. Previously published evidence for tetragonal tetrads is not supported, and previously reported monosulcate grains are part of a continuum of variation among the aberrant grains in aperture number, position and form. Other eudicots show similar variability in their pollen apertures. The variation in the pollen of Nelumbo is not exceptional, and may not be more significant than variation seen in the other taxa with regard to the origin of the tricolpate and tricolpate‐derived pollen characteristic of eudicots. Nevertheless further studies of aberrant pollen in Nelumbo and other eudicots, together with comparisons of pollen development in “normal” eudicots and closely related species that show radical, and developmentally fixed, reorganization of apertures and pollen polarity, may be helpful in understanding the processes that controlled the transition from the monosulcate to the tricolpate condition.     

锦鸡儿属花粉形态及其分类意义

在光学显微镜和扫锚电镜下对锦鸡儿属31种2变种植物花粉形态进行了观察。根据外壁表面纹饰,可分：类型I,表面具小穿孔;类型II, 具网状纹饰。 在类型II中据网眼大小和网脊宽度特征又分为两个亚类型。 根据花粉体积大小,可分4个类型。本属植物花粉形态较为一致,表明是一个自然类群。组、 系的花粉形态特征与一般形态变异不一定相对应,即形态上有明显区别的种类,在花粉形态上未必有很大区别,仅一些种类及矮锦鸡儿系 Ser. Pygmaeae的花粉形态相近。 本属花粉形态在种下等级的变异, 特别是青藏高原分布的种类的变异较为明显,例如 C.bicolor,C. jubata,C. erinacea 与各自的近缘种类。花粉形态为分类处理提供了参考。本属植物花粉形态是从表面具小穿孔向具网状纹饰演化,对应于羽状叶类群向掌状叶类群演化。     

Pollen Morphology and Its Taxonomic Significance of Caragana Fabr. (Fabaceae) from China

Pollen grains of thirty one species and two varieties of the genus Caragana Fabr. were observed under LM and SEM.The results revealed that the pollen exine ornamentation of the species examined could be divided into two types: perforate and reticulate.The later type consists of two subtypes according to lumina size and muri width. In the first subtype the lumina is round with d iameter equal to muri width,and the exine is perforate in two polar areas,while in the second subtype lumina is irregular or polygonal,with diameter sm aller than muri width.The pollen volume was divided into four types.The genus Caragana is a natural group which was indicated by the general resemblance of pollen morphology. In this genus the pollen morphological classification was not in concordance with the arrangement of the sections and series except Ser.Pygmeae and some species. The pollen variation at infraspecific level was obvious,especially the species distributed in Qinghai Xizang Plateau, such as C.jubata, C.bicolor and C. erinacea . The evolutionary trend of pollen morphology is from perforate to reticulate, which is congruous with the evolution from the pinnate leaf group to the almate leaf group in the genus.     

Specialist pollinators deplete pollen in the spring ephemeral wildflower Claytonia virginica

Pollinators that collect pollen – and specifically, pollen‐specialist bees – are often considered to be the best pollinators of a (host) plant. Although pollen collectors and pollen specialists often benefit host plants, especially in the pollen that they deliver (their pollination “effectiveness”), they can also exact substantial costs because they are motivated to collect as much pollen as possible, reducing the proportion of pollen removed that is subsequently delivered to stigmas (their pollination “efficiency”). From the plant perspective, pollen grains that do not pollinate conspecific stigmas are “wasted”, and potentially costly. We measured costs and benefits of nectar‐collecting, pollen‐collecting, and pollen‐specialist pollinator visitation to the spring ephemeral Claytonia virginica. Visits by the pollen‐specialist bee Andrena erigeniae depleted pollen quickly and thoroughly. Although all pollinators delivered roughly the same number of grains, the pollen specialist contributed most to C. virginica pollen delivery because of high visitation rates. However, the pollen specialist also removed a large number of grains; this removal may be especially costly because it resulted in the depletion of pollen grains in C. virginica populations. While C. virginica appears to rely on pollen transfer by the pollen specialist in these populations, nectar‐collecting visitors could provide the same benefit at a lower cost if their visitation rates increased. Pollen depletion affects a pollinator's value to plants, but is frequently overlooked. If they lower the effectiveness of future floral visitors, visits by A. erigeniae females to C. virginica may be more detrimental than beneficial compared to other pollinators and may, in some circumstances, reduce plant fitness rather than increase it. Therefore, A. erigeniae and C. virginica may vary in their degree of mutualism depending on the ecological context.     

Aeropalynologic analysis of La Plata City (Argentina) during a 3-year period

A continuous aeropalynologic survey of the atmosphere of La Plata was carried out between July 1998 and June 2001 in order to study flowering development from winter to summer using a Lanzoni volumetric spore trap. The total pollen spectrum was represented by 79 pollen types. Between 10 and 12 pollen types showed a relative concentration of more than 1% of the annual total. Airborne pollen was mainly represented by Platanus, Fraxinus, Cupressaceae, Poaceae, Urticaceae, Cyperaceae, Myrtaceae, Celtis, Casuarina and Morus during the 3-year period. Acer and Ambrosia pollen types were only dominant in the first 2 years. Maximum absolute concentrations were recorded in the the July 1998–June 1999 period, and the minimum concentrations were recorded in the July 2000–June 2001 period. The contribution of the arboreal pollen grains was higher than 68% relative to the annual total for each year. Two periods of maximum pollen emissions were found for each year: pollen from aboreal taxa predominated from July to October, and pollen from herbaceous taxa predominated from November to March. There was very little pollen in the atmosphere between April and June. The maximum arboreal and herbaceous pollen emissions were recorded during hours of daylight: at 10:00 and 14:00 hours.