This study is the first comparison of the morphology of pollen grains in ten cultivars of three species of the Taxus,

Torreya nucifera and Cephalotaxus harringtonia var. drupacea genera. The material came from the Botanical

Garden of Adam Mickiewicz University in Poznań, Poland. Each measurement sample consisted of 50 pollen

grains. In total, 750 pollen grains were analyzed. Light and electron scanning microscopy was used for the morphometric

observation and analysis of pollen grains. The pollen grains were inaperturate and classified as small

and medium-sized. They were prolate-spheroidal, subprolate to prolate in shape. The surface of the exine was

microverrucate-orbiculate, perforate in Cephalotaxus harringtonia var. drupacea, granulate-orbiculate, perforate

in all Taxus taxa and granulate-microverrucate-orbiculate, perforate in Torreya. The orbicules were rounded to

oval in surface view, and the size was considerably diversified. The pollen features were insufficient to distinguish

between individual Taxus members – only groups were identified. The values of the coefficient of variability of

three features (LA, SA and LA/SA) were significantly lower than the orbicule diameter. The pollen surface of all

Taxus specimens was similar, so it was not a good identification criterion. The pollen grains of the Taxus taxa

were smaller and had more orbicules than Cephalotaxus and Torreya. Palynological studies provided taxonomic

support for recognition of two different genera of the Cephalotaxaceae and Taxaceae families, which are closely

related.

This paper presents the results of palaeobotanical studies (pollen and plant macrofossil analyses) of the sediments from the profile Michałowo P-3 (Gródek-Michałowo Depression, NE Poland). At this profile the second bed of peat under Holocene peat and the layer of silts and sands was discovered. The pollen succession indicates that they were deposited, with some gaps, from the beginning of Eernian Interglacial to Early Vistulian. The local pollen zones, distinguished in the pollen diagram, correlate with the regional pollen stratigraphy of the Eemian Interglacial, but the pollen record of hornbeam (ES R PAZ) and spruce (E6 R PAZ) regional zones is absent in Michałowo. In the middle part of the Michałowo pine zone (Mi-5 Pinus L PAZ), a cool oscillation of climate is marked by an opening of forests and development of herb plant communities.

The interglacial deposits at Zbójno near Radoszyce (central Poland) was drilled again and reinvestigated by means of pollen analysis. The pollen succession, partly recorded in subaerial sediments with many stratigraphic gaps, treated hitherto as the stratotype of Zbójnian interglacial, does not seem to differ from the Eemian sequence, and may actually be of the Eemian age. This strongly suggests that the term "Zbójno" should be removed from the Polish Pleistocene stratigraphy.

Pollen and palcopedological studies have been carried out in parallel for the Stari Bezradychy sequence of the Upper Pleistocene age. The paleoenvironmental information derived from both sets of data is in general well correlated. The section presents a rather complete sequence of the last interglacial-glacial cycle. It includes eight units of the Ukrainian Stratigraphical Framework of the Pleistocene. Interglacial climatic optimum is registered by pollen succession of the Mikulino (Ecmian) type in the climax forest palcosols of Pryluky-Kaydaky pedocomplcx at the base of the sequence, above the Dnieper Glacial deposits. The coldest and most continental environment is recorded in the youngest loess. The soils of Upper Pryluky, Yytachiv and Dofinivka units are correlated with the Early Glacial and four Plcniglacial interstadials. Multiple environmental variations during the Upper Pleistocene recorded in the Stari Bezradychy sequence arc important for study of global climatic changes and interregional correlation. Tentative correlation with marine isotopic stages is proposed.

Pollen grains of Apiaceae from the profile at Błędowo, Mazovia region, Central Poland were identified. Pollen of this family occurs in higher frequencies in the Late Glacial, the beginning of the Holocene and in the periods under strong human influence. Transfer of pollen of Apiaceae from plants to lake deposits is different for particular species and depends rather on insect activity during the season as well as on the activity of their predators and/or the oscillation of animal populations than the selectivity in insect feeding. Different environmental conditions around the sites, which result in various patterns of transfer agents can cause some difficulties in interpretation of vegetational changes inferred from pollen data.

We used cytological and embryological methods to study reproductive cycle stages in Cerasus fruticosa Pall., Cerasus × eminens (Beck) Buia and Cerasus × mohacsyana (Kárpáti) Janchen from SW Slovakia, focusing on development of the male and female reproductive organs, fertilization processes and embryo formation. We found that reproductive potential was reduced by synergistic effects of negative biotic and abiotic factors. Despite the presence of degenerated, deformed pollen grains and their great variability of shape and size, a sufficient amount of normally developed viable pollen grains developed in anthers of C. fruticosa and C. × mohacsyana. Disturbed microsporogenesis in C. × eminens led to significantly lower production of viable pollen grains. We did not observe serious disturbances during megasporogenesis and megagametogenesis. Lower fruit set was caused by degeneration of ovules as a result of unsuccessful pollination, fertilization failure, or embryo degeneration during its initial development.

Self-incompatibility (SI) is a genetic system that promotes outcrossing by rejecting self-pollen. In the Brassicaceae the SI response is mediated by the pistil S-locus receptor kinase (SRK) and its ligand, pollen Slocus cysteine-rich (SCR) protein. Transfer of SRK-SCR gene pairs to self-fertile Arabidopsis thaliana enabled establishment of robust SI, making this transgenic self-incompatible A. thaliana an excellent platform for SI analysis. Here we report isolation of a novel A. thaliana self-incompatibility mutant, AtC24 SI mutant, induced by heavy-ion beam irradiation. We show that the AtC24 SI mutant exhibits breakdown of SI, with pollen hydration, pollen tube growth and seed set resembling the corresponding processes in wild-type (self-fertile) A. thaliana. Further reciprocal crosses indicated that some perturbed SI factor in the stigmatic cell of the AtC24 SI mutant is responsible for the observed phenotype, while the pollen response remained intact. Our results demonstrate successful application of heavy-ion beam irradiation to induce a novel A. thaliana self-incompatibility mutant useful for SI studies.

Due to the long sedimentation period (about 70 000 y.) and the unique quality of the lake deposits represented by very long, monotonous layers of lacustrine chalk, the sequence at Ossówka is exceptional. We conducted highly-resolved pollen and isotope analysis of the 27-m-long, upper part of the sequence of the lake sediments covering the final stage of the Holsteinian and the early phases of the Saalian Complex (Marine Isotope Stages (MIS) 11–10). In the pollen profile three main forest interstadials (L PAZ O-3, O-5, O-7) and the intervening steppe – tundra stadials (L PAZ O-2, O-4, O-6, O-8) as well as numerous units of lower rank were identified. Interstadials were characterized mainly by the presence of well-established pine forest. Stadials in turn, represented steppe – tundra vegetation with very pronounced continental influences. Also, three clearly established phases of forest fires starting at the beginning of interstadials and gradually disappearing are interesting feature of the sequence. Fires of that scale are very rarely noted in the palynological spectra. The examined sequence is characterized by the high dynamics of changes in the post interglacial part of the profile. It provides, coupled with clear features of the Holsteinian succession and its duration, a reliable correlation with other terrestrial and marine archives.

The Tarnawce I profile, which occurs in the marginal eastern part of the Polish Westem Carpathians, contains loesses representing three last glacial cycles. In this paper we report the results of pollen analysis of the Eemian-Early Glacial pedocomplex and of the Lower plcni-Visrulian loesses with an interstadiał paleosol. The pollen spectra of22 samples were determined. The pollen diagram was divided into 7 local pollen assemblage zones (L PAZ). Interglacial climatic optimum was recorded with the Eemian type of vegetation in the T-4 zone. The coldest conditions occurred during the accumulation of loess, which separates the interglacial and interstadiał soils.

Alluvial and oxbow deposits preserved 18 m above the Skawa River valley floor are related to the Early Vistulian. Pollen analysis of the two mainly terrestrial profiles revealed a boreal forest succession. The age of the deposits is discussed.

The paper presents the results of the research whose aim was to establish the sensitivity degree of Betu/a pendula pollen, seeds and seedlings in the adverse conditions of the zinc-lead waste from "Silesia" Steelworks in Katowice. The pollen and the seeds of the birch (from the dump and unpolluted region - Mirów) were tested by taking into condition: pollen capacity and seeds germination capacity. For the pot cultures metallurgical wastes and the soil from Mirów were placed in plastic boxes. For each kind of seeds a different soil variant was applied: Dump soil, Soil from Mirów, Garden soil (control group), 8 seeds were put into each box (total number of seeds for each variant was 96). The seeds of Betu/a pendula growing on smelter waste dumps had been collected in the vicinity of the dumps. The results of the experiment showed that the soil pollution has a significant impact on generative phase of Betu/a pendula.

The Cao Bang Basin is the northernmost of the basins related to the Cao Bang-Tien Yen Fault Zone in northern Vietnam. The basin is filled with a thick series of continental deposits. However, the exact age of the sedimentary basin infill has been under discussion for a long time. Because of new published data, the authors have decided to revisit this basin. Palynological data has allowed us to assign the Cao Bang Basin infill to the Lower Oligocene PC1 complex of the Shangcun Fm. (southern China). Among the saccate grains of gymnosperms, the domination of Cathaya and Pinus was observed, whereas angiosperms are represented by Carya, Celtis, Hammamelidaceae, Ulmus and also Pterocarya, Quercus, the Castanea–Castanopsis–Lithocarpus group, and the Loranthaceae. Among pteridophytes occur Laevigatosporites, Osmundaceae, and Pteris. The sedimentological features of the Cao Bang Basin are distinct from those of other basins from the Cao Bang-Tien Yen Fault Zone. The basin is filled with a wide variety of clastic deposits, from some of coarse-grained, alluvial-fan origin, through sandy beds of fluvial origin up to fine, organic-rich lacustrine deposits. The coarse-grained lithofacies are built of clasts derived mainly from local sources. The sandstones from the basin equally are submature or immature. They contain a lot of lithoclasts, the composition of which depends on the sample location within the basin. The potential source area is composed of older sedimentary units and of granitic rocks. The geochemical samples studied reflect the geochemical composition of silicic source rocks with only a minor contribution of basic components. The succession that fills the basin is interpreted as a typical fill for relatively long-lasting evolving half-graben or strike-slip basins. Moreover, the basin is partly occupied by a subsequent present-day sedimentary basin of Quaternary age.

The pollen morphology of many collections of taxa of the tribe Nigelleae from the family Ranunculaceae which occur worldwide is presented in this study. A total of 88 specimens from 21 taxa, some of which were recently proposed, belonging to the genera Komaroffia, Garidella, and Nigella of Nigelleae were examined using light microscopy (LM) and scanning electron microscopy (SEM). In the tribe, the pollen type is mostly trizonocolpate, but in many taxa and specimens, both trizonocolpate and non-trizonocolpate types occur together. The pollen grains are small to medium (25–53.75 μm × 20–55 μm) in size and oblate to prolate in shape. The exine pattern at the mesocolpium in all the taxa investigated is similar: micro-echinate in LM and micro-echinate-punctate in SEM. The colpus membrane in Komaroffia and Nigella is micro-echinate in both LM and SEM. In Garidella, it is micro-echinate in LM but echinate (spinulose) in SEM. In this study, multivariate analyses, principal component analysis (PCA), and unweighted pair group method with arithmetic mean (UPGMA), were used to evaluate relationships between the genera and species within the tribe with respect to pollen morphology. PCA results show three main groups in the tribe: Garidella, Komaroffia, and Nigella. Moreover, the UPGMA tree also chiefly supports generic segregation into the smaller genera. An overall synthesis of the pollen characteristics of the three genera is provided and discussed.

Miscanthus ×giganteus Greef et Deu. (Poaceae), a hybrid of Miscanthus sinensis and M. sacchariflorus native to Japan, is an ornamental and a highly lignocellulosic bioenergy crop, cultivated in the European Union as an alternative source of energy. This grass reproduces exclusively vegetatively, by rhizomes or via expensive in vitro micropropagation. The present study was aimed at finding the barriers that prevent sexual seed production, based on detailed embryological analyses of the whole generative cycle, including microsporogenesis, pollen viability, megasporogenesis, female gametophyte development, and embryo and endosperm formation. Sterility of M. ×giganteus results from abnormal development of both male and female gametophytes. Disturbed microsporogenesis (laggard chromosomes, univalents, micronuclei) was further highlighted by low pollen staining. The frequency of stainable pollen ranged from 13.9% to 55.3% depending on the pollen staining test, and no pollen germination was observed either in vitro or in planta. The wide range of pollen sizes (25.5-47.6 μm) clearly indicated unbalanced pollen grain cytology, which evidently affected pollen germination. Only 9.7% of the ovules developed normally. No zygotes nor embryos were found in any analyzed ovules. Sexual reproduction of M. ×giganteus is severely hampered by its allotriploid (2n=3x=57) nature. Hybrid sterility, a strong postzygotic barrier, prevents sexual reproduction and, therefore, seed formation in this taxon.

Poor seed set is a limiting factor in alfalfa breeding, as it slows the selection response. One strategy used to overcome this problem is to search for mutations of inflorescence morphology. Long-peduncle (lp), branched-raceme (br) and top-flowering (tf) inflorescence mutations increase the number of flowers per inflorescence, but they do not improve seed set per flower. Here we assessed pollen tube growth in styles of those inflorescence mutants and we observed embryo and endosperm development in seeds 1 to 16 days after pollination (DAP). The number of pollen tubes penetrating the style and the ovary was similar in all tested mutants and in the reference cultivar Radius. At 2 DAP, fertilized ovules were 2.7-3.9 times less numerous in certain inflorescence mutants than in the short-raceme cv. Radius. Ovule degeneration progressed at 2-4 DAP in all analyzed plants. Most ovules were not properly developed in the control cultivar (62%), nor in the forms with mutated inflorescence morphology (69-86%). The number of seeds per pod was lowest in the tf form despite its having the highest number of ovules per ovary. It appears that the number of ovules per pistil is not a crucial factor in seed set in alfalfa when fertilization efficiency is very low. Both poor fertilization and gradual ovule degeneration were factors causing poor seed set in the investigated alfalfa genotypes.

Based on geochemical and biological investigations of a 6-m-long sediment core, a reconstruction of the environmental conditions in Charzykowskie Lake (northern Poland) is presented. The analyzed sediments consist of fine calcareous detritus gyttja interbedded by lake marl. The results of palynological analysis document the vegetation development around and in the studied lake and confirm the middle and late Holocene age of the sedimentation of the deposits. The identification of 22 taxa of subfossil Cladocera shows the biodiversity of the fauna and reflects the changes in the trophic and water level. The concentrations of various chemical elements suggest the origin of the sediments. Geochemical, including isotope, and biological data, made it possible to reconstruct the environmental conditions, as well as traces of human influence over the last ca. 6,200 years. Four stages of human impact have been documented by the pollen data. The first traces of human groups in the vicinity of Charzykowskie Lake are preserved in sediments from about 4,000 years ago. The human activity is poorly recorded in the Cladocera and in the geochemical compositions of the lake sediments, probably due to the size and depth of the lake and its isolation.

Pollen analysis was performed on 14 profiles of fossil biogenic sediments from different parts of the vast depression near the Wola Starogrodzka village (Central Poland). The results allowed the determination of the time of their accumulation for the period from the end of the Odra Glaciation (Warta Stage, Saalian, MIS-6), through the Eemian Interglacial (MIS-5e), to the first interstadial of the Early Vistulian (Brørup, MIS-5c). In many studied profiles, we noted the incompleteness in the pollen record of the Eemian vegetation succession – hiatuses occur usually in the hornbeam (E5) and/or spruce phase (E6). Moreover, the thickness of the same pollen zone and the development of its palynological record are strongly differentiated between individual profiles, e.g. the hornbeam zone (E5) is contained in an exceptionally thick sediment layer (3.7 m) in the PWS1-19 profile, and the oak zone (E3) in the WH-123 and PWS2-19 profiles (1.0 and 1.2 m, respectively), while in other profiles they are represented only by single pollen spectra. If we only had a single profile with a hiatus and/or a poorly developed pollen record, it would be impossible to reconstruct a complete interglacial succession of vegetation. However, having several such imperfect profiles which complemented each other enabled us to do it.

Pollen morphology of Polygala taxa from the family Polygalaceae in Turkey is presented in this study. Pollen features of 18 species along with one undescribed species in the section Polygala were examined with light and scanning electron microscopy, 11 of which were studied and defined for the first time. Cluster analysis and principal components analysis were conducted to determine informative palynological characters and to discover similarities among the studied taxa. Based on qualitative and quantitative variables in the phenogram, the studied taxa were divided into three major clusters. Multivariate analyses revealed that apocolpium characters, including a psilate apocolpium, the presence of apocolpial lumens with granules and small depressions with psilate or rugulate walls are the most distinct features for discriminating Polygala taxa. Intraspecific variations in some pollen characters, such as the exine pattern and aperture membrane features, are reported for several taxa. Pollen morphological data obtained in the present study are compared with those from previous studies for a number of species, and the results are evaluated. In addition, the aperture number and its probable significance in the Turkish Polygala are considered for some taxa, with emphasis on their known pollination strategies.

Results of a geomorphologic study as well as radiocarbon and pollen analyses of sediments in small basins of the Jasło-Sanok Depression (Western Carpathians) are summarised. Floors of these basins, carved in soft shale-sandstone Krosno Beds, are covered with channel fluvial deposits and oxbow-lake sediments with lake chalk and peat accumulated in the Late Vistulian and Holocene. Since the early Atlantic Phase (ca 8,400–7,900 BP) the apparent acceleration of overbank (flood) deposition intermitting the peat accumulation is observed. The plant succession includes the Late Glacial (pre-Allerød, Allerød and Younger Dryas) with coniferous park forests, through mixed deciduous forests of the Holocene with elm, hazel, oak and lime as well as spruce-elm forests with alder in wetlands, up to present-day hornbeam forests (Tilio-Carpinetum of various types) and extra-zonal Carpathian beech forests (Dentario-Glandulosae- Fagetum). Abies alba (fir) is frequent in both these association types. First evidences of synanthropic plants that prove presence of prehistoric man appeared in the Subboreal Phase. The oldest radiocarbon date 13,550±100 BP (Gd-7355) [16,710–16,085 b2k], from a bottom part of the Humniska section is probably overestimated. This is indicated by palynological data, which suggest attribution of this section to the older Allerød. Small thickness of gravel blanket from the Plenivistulian termination and the beginning of the Late Vistulian, as well as large areas devoid of weathering and solifluction covers indicate that during the Plenivistulian weathering processes and removal of silt-clay material predominated in the basins. In that time the deflation was among important processes, which is proved by deflation troughs, faceted cobbles and thick covers of the Carpathian type of loess. The Besko Basin has pre-Vistulian tectonic foundation, while landforms of its floor are of erosion-degradation origin and formed during the last Scandinavian glaciation. In the Holocene the basin floors were overbuilt with fluvial deposits up to 8 m thick.

The paleoecological research of biogenie sediments sampled in the different lake-mire ecosystems of the ŁęcznaWłodawa Lake District were the basis of studies on hydrological changes during the Late Glacial and Holocene. The lithological differentiation (spatial and temporal) of lacustrine and mire sediments in the studied sites indicates that the hydrological changes were of local nature. The investigations also evidence a specific functioning of the lakes in this region. Lake basins were formed as a result of the ground ice degradation and the transformation of groundwater circulation in the Late Glacial. The total area of lakes in the Lake District was the largest from the Younger Dryas to the Subboreal chronozone. The gradual lowering ofwater level during the early Holocene resulted in the transformation of sedimentation process, and in the development of typologically differentiated mires and lacustrinc-mire complexes

Spitsbergen is the largest island in the Svalbard Archipelago (Norway) that has been permanently populated. The harsh Arctic climate prevents development of large vascular plants such as trees. A two-year aerobiological survey was conducted within the framework of two consecutive polar expeditions (2014 and 2015) in Spitsbergen (Calypsobyen, Bellsund). The air quality was measured continuously from June/July to August using a 7-day volumetric air sampler, Tauber trap and moss specimens. Collected air samples and gravimetric pollen deposits were processed following transfer to sterile laboratory conditions and analyzed with the aid of light microscopy. Days when pine pollen grains were detected in the air were selected for further analysis. Clusters of back-trajectories, computed using the Hybrid Single Particle Lagrangian Integrated Trajectory model in combination with ArcGIS software as well as the Flextra trajectory model, showed the movement of air masses to the sampling location at Hornsund, and thus indicated the likely origin of pollen grains. The GlobCover 2009 and CORINE Land Cover 2012 datasets were employed to establish the distribution of coniferous forests in the areas of interest. Conclusions were drawn based on the analyses of the circulation of air masses, using visualization of global weather conditions forecast to supercomputers. For the first time we have demonstrated that pine pollen grains occurring in pine-free Spitsbergen, could originate from numerous locations, including Scandinavia, Iceland, Siberia and northern Canada. Pollen grains were transported via air masses for distances exceeding ~2000 km. Both air samples and gravimetric pollen deposits revealed the same pattern of Pinus pollen distribution.

The embryology of three polar flowering plants of the family Caryophyllaceae was studied using the methods and techniques of the light, normal and fluorescence microscopes, and the electron microscopes, scanning and transmission. The analyzed species were Colobanthus quitensis of West Antarctic (King George Island, South Shetlands Islands) as well as Cerastium alpinum and Silene involucrata of the Arctic (Spitsbergen, Svalbard). In all evaluated species, flowering responses were adapted to the short Arctic and Australian summer, and adaptations to autogamy and anemogamy were also observed. The microsporangia of the analyzed plants produced small numbers of microspore mother cells that were differentiated into a dozen or dozens of trinucleate pollen grains. The majority of mature pollen grains remained inside microsporangia and germinated in the thecae. The monosporous Polygonum type (the most common type in angiosperms) of embryo sac development was observed in the studied species. The egg apparatus had an egg cell and two synergids with typical polarization. A well-developed filiform apparatus was differentiated in the micropylar end of the synergids. In mature diaspores of the analyzed plants of the family Caryophyllaceae, a large and peripherally located embryo was, in most part, adjacent to perisperm cells filled with reserve substances, whereas the radicle was surrounded by micropylar endosperm composed of a single layer of cells with thick, intensely stained cytoplasm, organelles and reserve substances. The testae of the analyzed plants were characterized by species-specific primary and secondary sculpture, and they contained large amounts of osmophilic material with varied density. Seeds of C. quitensis, C. alpinum and S. involucrata are very small, light and compact shaped.