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In vitro culture of Lilium longiflorum pollen grains was carried out to determine the role of manganese in pollen germination and pollen tube growth. Pollen germination was adversely affected by the presence of manganese (>10−8 M), whereas low concentrations (10−12–10−10 M) stimulated the process. Manganese caused morphological anomalies during tube growth, characterized by irregular pollen tube thickening and swollen tips. The main effect was the anomalous cell wall formation at the tip, in which the presence of several organelles reduced the number of secretory vesicles. A loose network of fibrillar material and spherical aggregates, mostly in the tip region, was detected, and this material was progressively loosened into the surrounding medium. As a response to potential toxicity, the excess manganese was isolated in vacuoles, which formed an internal barrier against penetration of manganese to the tip area. Elevated manganese concentrations might affect plant reproduction, resulting in anomalies in gamete development. Consequently, the loss in genetic diversity and decreased fruit set ultimately lower yield. [ABSTRACT FROM AUTHOR]

In terms of flowering ecology, Pulsatilla flowers are classified as "pollen flowers" producing inconsiderable amounts of nectar. The aim of this study was to assess the length of the flowering period in Pulsatilla slavica and P. vulgaris and to investigate the structure of the epidermis of the perianth and generative elements of their flowers. Special focus was placed on the structure of hairs and the distribution of stomata. The weight of nectar released by the flowers of the two Pulsatilla species and the content of sugars in the nectar was also evaluated. In SE Poland, both species flowered for similar periods between the second half of April and the first half of May. The flower life-span of both was determined to be 9-14 days. The lower part of each sepal was observed to be covered by long hairs having cellulose-pectin cell walls of varying thickness. Hairs present on the pistil style are thinner; they may provide some protection against cold and can play a role of a secondary pollen presenter for insects. The bowl-shaped structure of the perianth and the nature of the adaxial surface of the sepal epidermis may facilitate reflection of sunlight into the inner parts of the flower, which may contribute to an elevation of the intraflower temperature. This is particularly important for the functionality of the ovary. The surface of the hairs was seen to be covered by a cuticle ensuring water impermeability. Flowers are visited by honeybees, bumblebees, butterflies, and ants, for which nectar and pollen are the main attractants. Ants, which are regarded as illegitimate flower visitors, were found to cause damage to the androecium. The number of fruits produced in the flowers of both Pulsatilla species was lower than 50% of the number of pistils. [ABSTRACT FROM AUTHOR]

Pollen and nectar produced by flowers of species from the genus Salix are an important source of food for various insect groups in early spring. Most willows are entomophilous species; however, substantial amounts of airborne Salix pollen can be noted. The aim of the study was to evaluate the content of pollen of this taxon in the air of Lublin (central-east Poland) in 2001-2016 and to identify the period of its greatest availability to insects. In 2015, we compared the course of the Salix pollen season in Lublin (51°14'37" N; 22°32'25" E) and in the Roztoczański National Park (50°34'57" N; 23°04'24" E), Poland. We found that the date of the pollen season onset fluctuated greatly between March 16 and April 17. The greatest availability of Salix pollen to insects was noted from the end of the first 10-day-period of April to the first 10-day-period of May. The mean annual sum of airborne Salix pollen grains was 833. In Lublin, Salix pollen accounted for ca. 1.25% of the total airborne pollen content of different plant taxa. The investigations have demonstrated a 2-year cycle of Salix pollen abundance. The comparison of the pollen seasons in Lublin and in the Roztoczański National Park indicates that considerably greater amounts of pollen occur in the urban area than in the air of the Roztoczański National Park. [ABSTRACT FROM AUTHOR]

Many plant species respond to the climate change reported in the recent decades, which is confirmed by the results of phenological and aerobiological investigations. This paper presents characteristics of the pollen seasons of Acer spp. revealed by aerobiological analyses performed with the volumetric method in Lublin, Poland in 2001-2015. Additionally, phenological observations of flowering of four Acer species, i.e., A. negundo, A. platanoides, A. campestre, and A. pseudoplatanus, were carried out in 2011-2012. The results indicate a slight upward trend in the annual totals of Acer pollen grains. Over the last 10 years, the annual totals of Acer pollen grains have increased in comparison to the previous 5-year period. Acceleration of the onset of pollen seasons and the dates of peak days was noted. The comparison of the pollen seasons and flowering phenology of four Acer species indicates that A. negundo and A. platanoides produce the highest concentrations of pollen grains, whereas the pollen of A. campestre and A. pseudoplatanus accounts for a significantly lower proportion of the pollen content in the air of Lublin. [ABSTRACT FROM AUTHOR]

In Poland Galanthus nivalis L. is partially protected. The flowers of this species are one of the first sources of nectar and pollen for insects from February to April. The aim of this study was to present the flowering biology as well as the topography, anatomical, and ultrastructural features of the floral nectary. The flower lifespan, the breeding system, and the mass of pollen and nectar produced by the flowers were determined. Examination of the nectary structure was performed using light, fluorescence, scanning and transmission electron microscopy. The flower of G. nivalis lives for about 30 days. The stamens and pistils mature simultaneously and during this time nectar is secreted. The anthers of one flower produced the large amount of pollen (4 mg). The breeding system of G. nivalis was found to be characterized by partial self-compatibility, outcrossing, and xenogamy. The nectary is located at the top of the inferior ovary. The nectary epidermal cells are characterized by striated cuticular ornamentation. Initially, the secreted nectar formed vesicle-like protuberances under the cuticle. The epidermal and parenchymal cells contain numerous plastids, mitochondria, dictyosomes, ER cisterns, and vesicles fused with the plasmalemma, which indicates granulocrine nectar secretion. [ABSTRACT FROM AUTHOR]

The study compared the occurrence of airborne pollen of 7 arboreal taxa (Corylus, Alnus, Cupressaceae/Taxaceae, Populus, Fraxinus, Betula and Carpinus) during the period 2007-2009 from two sites in Lublin city, SE Poland. The sites differed in the character of building development and surrounding vegetation. Pollen monitoring was conducted by the volumetric method using two Hirst-type samplers. Daily and intradiurnal pollen counts were determined. For all the taxa, Spearman's test revealed statistically significant positive correlations between daily pollen fluctuations at two sites. Nevertheless, the Mann-Whitney U-test showed differences for Cupressaceae/Taxaceae, Fraxinus, Populus and Corylus between sites. The intradiurnal pattern of pollen concentration was characterized by high variation. Cupressaceae/Taxaceae and Populus, clearly differed in hourly pollen concentrations at both sites. Moreover, in the case of Betula and Alnus it was shown that a part of pollen recorded in Lublin can originate from long-distance transport. High pollen concentrations can be expected at different hours of the day. The lowest average pollen concentrations at both sites were found during morning hours at 5 and 6 a.m. Based on the obtained results, it can be concluded that data from a single pollen-sampling device are not representative of some taxa in the particular districts of the city. Average data obtained from at least two pollen samplers could provide optimum results. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agrobotanica is the property of Polish Botanical Society / Polskie Towarzystwo Botaniczne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agrobotanica is the property of Polish Botanical Society / Polskie Towarzystwo Botaniczne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Agrobotanica is the property of Polish Botanical Society / Polskie Towarzystwo Botaniczne and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the presence of secondary metabolites exhibiting pharmacological activity, the flowers of Rosa rugosa Thunb. have found application in traditional and folk medicine. The essential oil obtained from them is also considered to be a phytoncide. The morphological and anatomical characters of glandular trichomes located on the sepals of R. rugosa were studied by light and scanning electron microscopy. Using histochemical tests, the type of secretion produced in the trichomes was determined and its contents were compared with the secretion produced by the papillae on the petals. It was found that multicellular glandular trichomes, having the features of colleters, and non-glandular trichomes were located on the abaxial epidermis, while only non-glandular trichomes were situated on the adaxial epidermis. The stalk cells of the glandular trichomes are arranged in multiple rows, whereas the epidermal cells of the head are arranged radially. The capitate trichomes were classified into two types: short and long trichomes. The largest density of glandular trichomes was recorded in the basal abaxial epidermis and in the middle part of the sepals. During the initial stages of bud development, the glandular hairs were green colored, whereas in the next development stages they changed the color to red. The histochemical tests used allowed us to find that the trichomes on the sepals and the papille on the petals produced lipid substances, polyphenols, tannins, and flavonoids. Sesquiterpenes were found only in the secretion of the glandular hairs on the sepals. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Euphrasia stricta D. Wolff ex J. F. Lehm. (Orobanchaceae) is a representative of plants that are widely used in folk medicine, phytomedicine, and homeopathy. The medicinal raw material derived from the drug eyebright is applied primarily in treatment of ophthalmic diseases. The investigations of trichomes in drug eyebright (Euphrasia stricta D. Wolff ex J. F. Lehm) were conducted in 2010-2011. Using light microscopy and scanning electron microscopy, their location and morphological and anatomical features were identified. Three types of non-glandular trichomes were found: short unicellular, long 1-2 celled, and long 2-celled with wall ornamentation. Additionally, 7 types of glandular trichomes were found; these included: unicellular clavate, 2-3-celled clavate, capitate with a unicellular head and a 3-celled stalk, capitate with a unicellular head and a 2-celled stalk, capitate with a 2-celled head, conical papillae, and ribbon-like trichomes with wall thickening. [ABSTRACT FROM AUTHOR]

Aesculus hippocastanum L. is an ornamental tree appreciated for its beautiful flowers and leaves. The flowers of this species contain secondary metabolites exhibiting pharmacological activity. They also produce essential oils and coloured "nectar guides", which enable insects to reach nectar and pollen. The aim of the study was to investigate the types and characteristics of chestnut flower trichomes, which may contain biologically active substances. The analyses were performed using light, fluorescence, and scanning electron microscopy. Three types of trichomes were found on the sepals and the surface of the ovary, whereas the corolla petals exhibited two types of hairs and papillae. The hairs differ in terms of their length and number of cells. The perianth and pistil had no capitate hairs, whereas the ovary exhibited the presence of colleters. Histochemical assays revealed that all the types of trichomes and papillae contained lipids or essential oils; hence, they can be classified as glandular structures. The "nectar guides" were characterised by higher density of secretory hairs than that on the rest of the petal surface, which implies that these petal fragments may emit stronger fragrance. [ABSTRACT FROM AUTHOR]

Many plants develop in the petal epidermis papillae emitting essential oils. In species of the genus Allium, papillae occur in the ovary epidermis. The aim of this study was to determine the structure of papillae in Allium karataviense Regel and to perform histochemical tests that would allow the components of their secretion to be investigated, mainly the presence of essential oils. Examination was performed using light and scanning electron microscopy. It was found that in conical papillae, with a height of about 83 μm, there were large cell nuclei, a thick outer wall with a layer of striated cuticle, and a varying degree of cell vacuolation, depending on the age of the ovary. Using histochemical reactions, we demonstrated neutral lipids, acid lipids and pectins to occur in the papillae. Neutral lipids are characteristic of essential oils. [ABSTRACT FROM AUTHOR]

In Europe Ambrosia is included in invasive species. Its pollen contains very strong allergens that can be the cause of pollinosis at the turn of summer and autumn. The aim of the present study was to compare Ambrosia pollen concentrations in the air of Lublin and Lviv and to analyse the effect of weather conditions on Ambrosia pollen content in the air. The study was carried out in 2011 and 2012. In Lublin the volumetric method was applied using a Lanzoni VPPS 2000 trap, whereas in Lviv the gravimetric method was applied using a Durham trap. To make the results comparable, the data obtained by the gravimetric method were properly counted and expressed as the number of pollen grains per 1 m³ of air. This research shows that the Ambrosia pollen season started about a month earlier in Lviv and lasted longer than in Lublin. In Lviv ragweed pollen was recorded from the beginning of July, while in Lublin from the second week of August. The pollen season in both cities ended on different days of October. The seasonal peaks in both years and the annual pollen count in 2011 were much higher in Lublin than in Lviv. In both cities air temperature was the most important meteorological factor affecting pollen concentrations. During the pollen season in Lublin, the wind was predominantly from NE and E directions, whereas in Lviv from N and SE. [ABSTRACT FROM AUTHOR]

The present study investigated the size and structure of the nectaries in flowers of marrow -- Cucurbita pepo convar. giromontiina cv. 'Weiser Busch'. The diameter and thickness of nectariferous layer were compared in female and male flowers of this taxon. The micromorphology as well as the anatomical and ultrastructural characters of the nectary from the female flower were observed using light, scanning and transmission electron microscopy. The density and size of stomata of the nectary epidermis from both types of flowers were examined using light microscopy. The nectaries in female flowers were found to have a larger size than in male flowers. The stomata occurring in the nectary epidermis of both types of flowers have a similar size and density. We observed that nectar was released onto the surface of the nectary not only via the stomata, but also through the walls of the epidermal cells. In TEM examination, large nuclei, different-shaped plastids, ER tubules, dictyosomes, and ribosomes were observed in the nectariferous tissue cells. A large number of mitochondria accompanying the plastids were found in the parenchyma cells of the nectary. The degradation of the nectary parenchyma cells in the flowers living for about 6 hours was asynchronous. [ABSTRACT FROM AUTHOR]

The content of Aesculus pollen in aeroplankton of Lublin, located in central-eastern Poland, was studied during the period 2001-2012. The volumetric method was used for the study. The following parameters were determined: start, end, and duration of the pollen season, days of maximum concentration, and total annual pollen counts. Correlation coefficients were calculated between the start of the pollen season and meteorological parameters. The study showed that during the period 2007-2012 the onset of the Aesculus pollen season occurred on average 4 days earlier than in the years 2001-2006. The total annual pollen counts were in the range of 53-271, with an average number of 117. The average pollen counts did not differ significantly in the first and second year of a 6-year period of the study. The analysis of the correlation coefficients showed that there were significant positive correlations only between the season start date and minimum temperature of the first decade of May. The highest Aesculus pollen concentration occurred between 6 and 22 May. The flowers of A. hippocastanum demonstrate an ambophilous pollination strategy due to partial insect and wind pollination. [ABSTRACT FROM AUTHOR]

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 demonstrated 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. Fragrant 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. [ABSTRACT FROM AUTHOR]

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 x 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. [ABSTRACT FROM AUTHOR]