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The drivers of spatial variation in ragweed pollen concentrations, contributing to severe allergic rhinitis and asthma, are poorly quantified. We analysed the spatiotemporal variability in 16-year (1995–2010) annual total (66 stations) and annual total (2010) (162 stations) ragweed pollen counts and 8 independent variables (start, end and duration of the ragweed pollen season, maximum daily and calendar day of the maximum daily ragweed pollen counts, last frost day in spring, first frost day in fall and duration of the frost-free period) for Europe (16 years, 1995–2010) as a function of geographical coordinates. Then annual total pollen counts, annual daily peak pollen counts and date of this peak were regressed against frost-related variables, daily mean temperatures and daily precipitation amounts. To achieve this, we assembled the largest ragweed pollen data set to date for Europe. The dependence of the annual total ragweed pollen counts and the eight independent variables against geographical coordinates clearly distinguishes the three highly infected areas: the Pannonian Plain, Western Lombardy and the Rhône-Alpes region. All the eight variables are sensitive to longitude through its temperature dependence. They are also sensitive to altitude, due to the progressively colder climate with increasing altitude. Both annual total pollen counts and the maximum daily pollen counts depend on the start and the duration of the ragweed pollen season. However, no significant changes were detected in either the eight independent variables as a function of increasing latitude. This is probably due to a mixed climate induced by strong geomorphological inhomogeneities in Europe.

The drivers of spatial variation in ragweed pollen concentrations, contributing to severe allergic rhinitis and asthma, are poorly quantified. We analysed the spatiotemporal variability in 16-year (1995–2010) annual total (66 stations) and annual total (2010) (162 stations) ragweed pollen counts and 8 independent variables (start, end and duration of the ragweed pollen season, maximum daily and calendar day of the maximum daily ragweed pollen counts, last frost day in spring, first frost day in fall and duration of the frost-free period) for Europe (16 years, 1995–2010) as a function of geographical coordinates. Then annual total pollen counts, annual daily peak pollen counts and date of this peak were regressed against frost-related variables, daily mean temperatures and daily precipitation amounts. To achieve this, we assembled the largest ragweed pollen data set to date for Europe. The dependence of the annual total ragweed pollen counts and the eight independent variables against geographical coordinates clearly distinguishes the three highly infected areas: the Pannonian Plain, Western Lombardy and the Rhône-Alpes region. All the eight variables are sensitive to longitude through its temperature dependence. They are also sensitive to altitude, due to the progressively colder climate with increasing altitude. Both annual total pollen counts and the maximum daily pollen counts depend on the start and the duration of the ragweed pollen season. However, no significant changes were detected in either the eight independent variables as a function of increasing latitude. This is probably due to a mixed climate induced by strong geomorphological inhomogeneities in Europe.

Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread. We used the model to simulate the invasion of Europe by common ragweed (Ambrosia artemisiifolia), a globally invasive plant that causes serious harm as an aeroallergen and crop weed. Simulations starting in 1950 accurately reproduced ragweed's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways. We conclude that invasion models would benefit from integrating introduction processes (transport and release) with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion ris

Biological invasions are a major driver of global change, for which models can attribute causes, assess impacts and guide management. However, invasion models typically focus on spread from known introduction points or non-native distributions and ignore the transport processes by which species arrive. Here, we developed a simulation model to understand and describe plant invasion at a continental scale, integrating repeated transport through trade pathways, unintentional release events and the population dynamics and local anthropogenic dispersal that drive subsequent spread. We used the model to simulate the invasion of Europe by common ragweed (Ambrosia artemisiifolia), a globally invasive plant that causes serious harm as an aeroallergen and crop weed. Simulations starting in 1950 accurately reproduced ragweed's current distribution, including the presence of records in climatically unsuitable areas as a result of repeated introduction. Furthermore, the model outputs were strongly correlated with spatial and temporal patterns of ragweed pollen concentrations, which are fully independent of the calibration data. The model suggests that recent trends for warmer summers and increased volumes of international trade have accelerated the ragweed invasion. For the latter, long distance dispersal because of trade within the invaded continent is highlighted as a key invasion process, in addition to import from the native range. Biosecurity simulations, whereby transport through trade pathways is halted, showed that effective control is only achieved by early action targeting all relevant pathways. We conclude that invasion models would benefit from integrating introduction processes (transport and release) with spread dynamics, to better represent propagule pressure from native sources as well as mechanisms for long-distance dispersal within invaded continents. Ultimately, such integration may facilitate better prediction of spatial and temporal variation in invasion ris

Investigations of flag leaves anatomy of three winter wheat cultivars: Almari, Gama and Weneda were carried out as it was state that there are great differences in the intensity of cereal leaf beetle feeding on the leaves. In order to determine the features conditioning the differentiated resistance of these cultivars following parameters were measured: the thickness of leaf blade, the length of trichomes and their density in the adaxial epidermis, the number of silicon cells in 1 mm2 epidermis and the thickness of the external cell walls of epidermis. The observations of cross section of the leaves were made in a light microscope and that of surface of the adaxial epidermis in a scanning electron microscope. In this study it was shown that Gama cv. distinguishes of the shortest trichomes with poor density, the lowest number of the silicon cells in 1 mm2 and epidermis cells with the thinest walls. This features indicate a poor resistance of Gama cv. against feeding of the pests and give reasons for the presence a much higher number of the cereal leaf beetle larvae (about 100%) than at the extant two cultivars. Dependence between the thickness of leaf blades and the number of larvae of the infesting pests has not been stated.

An investigation was conducted on the number and morphology of the chromosomes of four species from the family Commelinacene: Spironema fragrans Lindl., Setereasea purpurea Boom, Tradescantia albiflora Kunth. and Tradescantia blossfeldiana Mildbr. It was found that the karyotype of Spironema fragrans Lindl. was 2n = 12 chromo­somes whose total length was 6.9-13.7 µm and the formula of the karyotype was: 2m+2sm +2m+2t+2stsat +2st Setcreasea purpurea Boom. had 2n = 24 chromosomes, 9.1-12.1 µm in length and the centromere positioned as represented by the formula 24m. The karyotype of Tradsescantia albiflora Kunth. had 2n = 60 chromosomes whose lengths ranged from 1.4 to 4.5 µm, and is described by the formula: 4sm+6m+10st+10sm+10m+20sm. The complex of chromosomes from Tradescantia blossfeldiana Mildbr. consisted of 2n = 60. Their length was 1.3-4.8 µm. The morphological types of the chromosomes are represented by the formula 6st+2m+2sm+6st+2sm+12m+10M+l4m+6sm. It is suggested on the basis of mor­phological analysis of chromosomes that Setereasea purpurea Boom is a tetraploid species and Trudescantia albiflora Kunth. and T. blossfeldiana Mildbr. are decaploids.

The study of the structure of the pollen presenter of Taraxacum officinale and morphology of pollen grains was conducted based on plant material sampled from three different sites. One of them was a forest meadow situated away from the city, and the other two were located in the city centre of Lublin. Light and electron scanning microscopy were used in the study. The pollen presenter in Taraxacum officinale occurs at the upper part of the style situated over the androecium and on the outer part of the stigma. Numerous unicellular trichomes are found on the entire surface of the epidermis of the presenter. The function of the presenter consists in transferring pollen grains above the androecium and corolla petals. Its activity does not stop after pollen release from anthers. Taraxacum pollen grains represent the Crepis - type. Most frequently, they are tricolporate, radially symmetric and isopolar. In terms of the size, they are included in medium-sized grains. In the material examined, many deformed and asymmetric grains were observed, though they were marked by high viability at the level of 96.5-99%. Grains with the largest average lengths of the equatorial and polar axes were found in plants sampled from the meadow situated out of town. In the plant material from all sites, grains with disturbances of the external structure occurred.

The micromorphology of the epidermis as well as the anatomy of the pericarp and fruit pedicle in Capsicum annuum L., cv. 'Red Knight F1', were studied using light and scanning electron microscopy. The pericarp was found to consist of an epidermis with strongly thickened outer walls, several layers of tangential and angular collenchyma as well as multi-layered parenchyma composed of cells of varying size in which very large lobed nuclei were observed. Chromoplasts were found in the cells of the above-mentioned tissues. The inner epidermis of the pericarp was characterized by thick cell walls and numerous straight pits. Among the tissues of the fruit pedicle, we observed epidermis with numerous stomata, collenchyma, chlorenchyma with very large intercellular spaces, small clusters of sclerenchyma, secondary phloem and xylem as well live and dead cells of the pith which were characterized by the presence of thin walls with numerous pits. The structural traits of the pericarp of the red pepper cultivar under study show adaptations to significantly reduced transpiration, which is an important feature during storage. At the same time, the strongly thickened and cutinized walls of the fruit contribute to a reduction in its digestibility and impede nutrient penetration in non-root feeding.

The present study is a continuation of our research on the structure of healthy leaves of Aesculus hippocastanum and leaves damaged by larvae of Cameraria ohridella. In this study, the epidermal micromorphology of both leaf surfaces in A. hippocastanum was investigated by scanning electron microscopy (SEM). Light microscopy was used to examine on which side of the leaf blades eggs of Cameraria ohridella were laid. The characteristic features of the adaxial and abaxial epidermis were shown. In the hypostomatic leaves of the studied species, the stomata occurred at a density of 173 × mm-2 and they represented the cyclocytic type. A striated layer of the cuticle was observed only in the adaxial epidermis in which glandular hairs were also present along the midribs. Non-glandular trichomes grew only on the surface of the midribs or in their axils in the abaxial epidermis. We found eggs of C. ohridella only on the adaxial surface of the epidermis. Using SEM, we also observed in the mines leaf tissues damaged by C. ohridella. We found palisade parenchyma to be absent, whereas in the spongy parenchyma there could be seen large intercellular spaces and at places a dense mass of organic matter, formed from damaged cells and larval excrement. The vascular bundles and calcium oxalate crystals remained in the feeding places. We found numerous bacteria, fungal spores and hyphae as well as cleistothecia of Erysiphales in the mines on the surface of the damaged mesophyll. The glandular trichomes occurring only locally on the leaves, the relatively thin cell walls of the epidermis and a not well-developed cuticle layer on their surface do not protect sufficiently these leaves against the invasion of C. ohridella. On the other hand, damaged tissue areas are a convenient place for the growth of bacteria and fungi.

In its stems and leaves, Heracleum sosnovskii Manden. contains furanocoumarins, which exert a phototoxic effect on humans. The aim of the investigations was to describe the external secretory structures of the epidermis and internal secretory tissues in organs responsible for emission of secretion that is toxic to human skin. The study was conducted using light and fluorescence microscopy. On the stems and leaves, various types of secretory trichomes with dispersed or deposited secretion were found. The trichomes were most abundant on the abaxial leaf surface. Epidermal cells and the secretion present on the trichomes exhibited intense fluorescence, which may indicate the presence of furanocoumarins in the tissue and trichome secretions.

Anemophilous trees of Betula and Alnus genera produce very high amount of easily spreading pollen. Carpinus and i discharge lower amount of pollen to the atmosphere. Trees belonging to the mentioned genera occur in vegetation cover of Lublin and the Roztocze region where the comparative studies were carried out in the years 1998-2004. The objective of these studies was to determine pollen concentration of four tree taxa in these study areas located 120 km apart. Annual pollen sums, obtained by means of three methods, were compared in order to find similarity of alternating high and low pollen production by trees in particular years. In the Roztocze region the studies were continued during the mentioned seven years as a part of Pollen Monitoring Programme, which provides multi-annual data for the palaeoecological reconstructions of Quaternary and the interpretations of phenologic-climatic nature. Standard Tauber traps were used in the Roztocze area. In Lublin the gravimetric method was used in the years 1999-2000, and the volumetric method - in the years 2001- 2004. Similar trends were found in Lublin and in the Roztocze region as to the concentrations in the air of pollen of the mentioned four taxa in particular years of the research period. Betula and Alnus discharged the greatest amount of pollen. In 1999 the great similarity of annual pollen sums of three taxa was recorded by means of the gravimetric method in all measurement points. Fagus was an exception, as its pollen concentration was much higher in the Roztocze region than in Lublin. In the case of Carpinus the enhanced pollen concentration was recorded in both study areas in 2002, and the highest concentration of Fagus occurred in 2003. During several years of studies we recorded great similarity of the obtained results in two study areas far apart.

Birch pollen contains allergens belonging to those with the strongest allergenic properties. In order to trace pollen season patterns of this taxon and pollen annual sums at a wider regional scale, cooperation was established with the University of Latvia in Riga (Latvia). A comparison of the results obtained in the years 2003-2008 in Lublin and in Riga, using volumetric samplers, shows that there was a similar trend in the abundance of birch pollen. The highest sums were noted at both sites in 2003. In all the study years, more birch pollen grains were recorded in Lublin than in Riga, on the average by 7110. The birch pollen seasons started earlier in Lublin than in Riga, on the average by 6 days, and they ended earlier in Lublin, on the average by 18 days. In Riga the birch pollen seasons were longer and less abundant than in Lublin. In addition, in both the regions, i.e. in SE Poland (the Roztocze area) and in Latvia (the area of Marupe near Riga, Taurene, Teici and Rucava), there is pollen data series available obtained from annual pollen deposition monitoring conducted using the modified Tauber traps. These pollen counts have been carried out under the Pollen Monitoring Programme (http://pmp.oulu.fi) since 1998. The 11- year data series in Roztocze and the 10-year data series in Latvia allowed the trends in the occurrence of years of abundant or poor birch pollen release to be traced. In Roztocze maximum Betula pollen deposition occurred in the year 2003, in Latvia - in 1999. The absence of a significant correlation between SE Poland and Latvia with regard to the trends in the occurrence of years of abundant Betula pollen deposition induced the authors to seek climatic factors responsible for increased birch pollen production. The analysis of the Spearman's rank correlation coefficients between annual Betula pollen sums in Roztocze and mean air temperature in June, July and August in the year preceding pollen emission as well as in spring (January-April) of the

The intensely fragrant flowers of the Rosa rugosa Thunb. have been applied in medicine, and food and cosmetic industries. The species is cultivated for production of rose essential oil (Oleum Rosae) from its flowers. R. rugosa petals secrete the largest quantities of essential oil. The aim of the study was to identify the characteristics of the epidermis of both sides of the petal and to observe whether adaxial and abaxial epidermal cells can secrete essential oil. The investigations were conducted using light and scanning electron microscopy. The analyses were focused on petal thickness and characteristics of the mesophyll. The study has demon- strated that only adaxial epidermal cells form conical papillae covered by massive cuticular striae. The surface of the papillae displayed remnants of a secretory substance. In turn, the inner walls of the abaxial epidermal cells were flat and covered by a striated cuticle, which exhibited various striation patterns. Frarant substances stored under the cuticle caused local stretching thereof and disappearance of striation. The results of our observations allow a statement that the cells of the adaxial and abaxial epidermis of R. rugosa petals differ in terms of the structure and they secrete fragrant substances.

The research of the anatomy of nectaries of six species from Pomoideae was carried out. The observations concerned the flowers longitudinal sections of the following species: Malus silvestris Mill., Pyrus communis L., P. ussuriensis Maxim., Cydonia oblonga Mill., Chaenomeles japonica Ldl. and Ch. speciosa Nakai. It was stated, that the nectary glands distinguished themselves by the dimension of section surface, thickness of layers, the sizes of glandular and epidermis cells. A considerable difference of external wall thickness among epidermis cells was also observed. The nectaries of the smallest size, consisting of the tiniest cells occurred in Malus silvestris. Whereas, the biggest ones were possessed by Cydonia oblonga. Here the nectaries had maximum section surface, thickness, number of layers and cell dimension. The nectary epidermis of Pyrus was characterized by the thinnest external wall. The Chaenomeles speciosu and Cydonia oblonga, by the thickest one with a massive cuticle layer. The vascular bundles reaching the nectary tissue consisted of phloem and xylem. The positive dependence between the nectary dimension and the abundance of nectar secretion in some species, and the occurence of the opposite tendency in the others is discussed.

We carried out histochemical studies to find the localization of ginsenosides in roots of Panax quinquefolium cultivated in Poland. We performed an anatomical study on the structure and localization of secretory canals on the cross section of 4-year-old American ginseng roots. We observed the occurrence of large secretory canals, mainly in the middle part of the secondary cortex and less in the phloem layer. In our studies, moreover, we demonstrated the production of secretory canals within the periderm layer. After the anatomical study, the 4-year-old ginseng root was divided into periderm, cortex and xylem, and the ginsenosides were extracted from each part of the root. The TLC separation of ginsenosides was performed on silica gel Si60 glass plates with chloroform-methanol-ethyl acetate-water-hexane, 20+22+60+8+4 (v/v) as mobile phase. Quantitative analysis of ginsenosides was performed by using the TLC-densitometric method. Concerning the distribution of ginsenosides in the different anatomical parts of the root of Panax quinquefolium, they were contained in the periderm layer at the highest level.

Similarly to fungal spores and pollen grains, pteridophytic spores can cause allergies in humans. Pteridophyta spore concentrations in the air of Lublin, under the conditions of central-eastern Poland, were first studied over the period 2013–2014. The volumetric method was used in this study. The research showed that that spores of ferns belonging to the following genera: Asplenium, Athyrium, Blechnum, Botrychium, Cystopteris, Dryopteris, Matteuccia, Osmunda, Polypodium and Pteridium, occur in aeroplankton. Spores were recorded in low concentrations and they occurred in a dispersed pattern during the season. They were found to be absent on some days. Among the above-mentioned genera, Dryopteris and Athyrium showed the highest content of spores in aerosol. In both years of the study (2013 and 2014), similar annual spore counts were recorded, respectively 69 and 63. The most spores were identified in August.

The structure of floral nectary surface of Sorbus intermedia in different phases of flower development was examined using scanning electron microscopy. Nectaries in S. intermedia flowers represent a receptacle type. The sculpture of cuticule on nectary epidermis and overlaying cells was described. The differences in the size of striaes on the outer cell wall of epidermis during the flower development were stated. Nectarostomata were situated in small hollows. In the buds, they were closed and not fully developed. During pollen release phase, the outer ledges of the guard cells were better developed than at the beginning of blooming. Depressions on nectary epidermis cell walls were observed in the final phase of blooming.