Legacy of last millennium timber use on plant cover in Central Europe: Insights from tree rings and pollen.

Throughout history, humans have relied on wood for constructions, tool production or as an energy source. How and to what extent these human activities have impacted plant abundance and composition over a long-term perspective is, however, not well known. To address this knowledge gap, we combined 44,239 precisely dated tree-ring samples from economically and ecologically important tree species (spruce, fir, pine, oak) from historical buildings, and pollen-based plant cover estimates using the REVEALS model from 169 records for a total of 34 1° × 1° grid cells for Central Europe. Building activity and REVEALS estimates were compared for the entire study region (4-15°E, 46-51°N), and for low (<500 m asl) and mid/high elevations (≥500 m asl) in 100-year time windows over the period 1150-1850. Spruce and oak were more widely used in wooden constructions, amounting to 35 % and 32 %, respectively, compared to pine and fir. Besides wood properties and species abundance, tree diameters of harvested individuals, being similar for all four species, were found to be the most crucial criterion for timber selection throughout the last millennium. Regarding land use changes, from the 1150-1250's onwards, forest cover generally decreased due to deforestation until 1850, especially at lower elevations, resulting in a more heterogeneous landscape. The period 1650-1750 marks a distinct change in the environmental history of Central Europe; increasing agriculture and intense forest management practices were introduced to meet the high demands of an increasing population and intensifying industrialization, causing a decrease in palynological diversity, especially at low elevations. Likely the characteristic vegetation structure and composition of contemporary landscapes originated from that period. We further show that land use has impacted vegetation composition and diversity at an increasing speed leading to a general homogenization of landscapes through time, highlighting the limited environmental benefits of even-aged plantation forestry.

Modern pollen dispersal in relation to present vegetation distribution and land use in the Baspa valley, Kinnaur, western Himalayas.

Interpretation of a fossil pollen data for the vegetation and climate reconstruction of any region needs a modern pollen-vegetation analogue for its calibration. We analyzed the surface sediments and moss polsters for the pollen and microcharcoal records to understand the modern pollen-vegetation relationship and human activities in the Baspa Valley, Kinnaur, Himachal Pradesh. Presently, valley is occupied by the arboreal and non-arboreal vegetation of temperate to subalpine habitats and land use activities. The recovered pollen assemblages showed variability in the dispersal behavior of pollen of taxa growing along the valley transect and also captured the signals of human activities over land use. The overall dominance of arboreal pollen in the recovered pollen assemblage corresponds with the dominant growth of conifers and broadleaf tree taxa and represents the valley vegetation at a regional scale. However, the profuse pollen production of a few arboreal taxa and long distance pollen transport from one vegetation zone to other by the strong upthermic valley winds could bias the pollen representation of in-situ vegetation. The high pollen frequency of non-arboreal taxa in the open meadows represents the near vicinity to their plant source. Human activities like fire burning and cultivation by the local population are evident by the recovery of microcharcoal particles and pollen of plants belonging to Cerealia Poaceae, Asteraceae, Amaranthaceae, Polygonaceae, Rosaceae, Juglandaceae, etc. The dataset taken as modern pollen-vegetation analogue is useful to assess past changes in the vegetation and land cover in relation to climate and human factors for future sustenance.

Micrometer insights into Nepeta genus: Pollen micromorphology unveiled.

This study provides a comprehensive pollen micromorphology within the Nepeta genus, revealing intricate details about the pollen grains' structure and characteristics. The findings shed light on the evolutionary and taxonomical aspects of this plant genus, offering valuable insights for botanists and researchers studying Nepeta species. The pollen grains of 18 Nepeta species were studied using scanning electron microscopy (SEM) and light microscopy (LM) in Northern Pakistan. At the microscale, pollen quantitative measurements, qualitative traits, and diverse sculpturing patterns were reported and compared. Significant differences in pollen size, shape, ornamentation, and sculpturing patterns were discovered among the Nepeta species. Our data show that exine sculpturing is quite diverse, with most species exhibiting a reticulate perforate pollen pattern. Nepeta connata, Nepeta discolor, Nepeta elliptica, revealed a distinct bireticulate perforate exine stratification. Hexazonocolpate pollen is the most common. Furthermore, the surface membrane attributes of the colpus varied greatly, ranging from rough, scabrate, psilate, to sinuate patterns. Principal Component Analysis (PCA) was used to discover the key factors influencing pollen diversity. PCA results showed that polar and equatorial diameters, colpi size, and exine thickness were the most influential pollen features between Nepeta species. This study adds to our understanding of pollen morphology in the Nepeta genus, offering information on the vast range of characteristics found in this economically important group. The extensive characterization of pollen features provides useful insights for the categorization and differentiation of Nepeta species, adding to the Lamiaceae micromorphology.

Deductive automated pollen classification in environmental samples via exploratory deep learning and imaging flow cytometry.

Pollen and tracheophyte spores are ubiquitous environmental indicators at local and global scales. Palynology is typically performed manually by microscopic analysis; a specialised and time-consuming task limited in taxonomical precision and sampling frequency, therefore restricting data quality used to inform climate change and pollen forecasting models. We build on the growing work using AI (artificial intelligence) for automated pollen classification to design a flexible network that can deal with the uncertainty of broad-scale environmental applications. We combined imaging flow cytometry with Guided Deep Learning to identify and accurately categorise pollen in environmental samples; here, pollen grains captured within c. 5500 Cal yr BP old lake sediments. Our network discriminates not only pollen included in training libraries to the species level but, depending on the sample, can classify previously unseen pollen to the likely phylogenetic order, family and even genus. Our approach offers valuable insights into the development of a widely transferable, rapid and accurate exploratory tool for pollen classification in 'real-world' environmental samples with improved accuracy over pure deep learning techniques. This work has the potential to revolutionise many aspects of palynology, allowing a more detailed spatial and temporal understanding of pollen in the environment with improved taxonomical resolution.

Valoración de un método de osmoguiado a flores de durazno (Prunus persica) aplicado en abejas Apis mellifera

Diversos estudios demuestran que la inclusión de polinizadores, como las abejas Apis mellifera, generan efectos positivos sobre la productividad de cultivos de durazno (Prunus persica). Esto lleva a probar metodologías que estimulen a las abejas para visitar, con mayor frecuencia, el cultivo de interés, sugiriendo el uso de la técnica de osmoguiado, como herramienta para potencializar el efecto de la polinización. Este estudio valoró un protocolo de osmoguiado, para estimular híbridos africanizados de Apis mellifera, a recolectar polen de flores de durazno, utilizando, como indicador indirecto, el análisis palinológico en muestras de polen. Los tratamientos utilizados fueron con osmoguiado y sin osmoguiado. Cada tratamiento contó con tres colmenas y el periodo de evaluación fue de cinco semanas, coincidiendo con el mayor periodo de floración del durazno. Los resultados evidenciaron que este protocolo no logró estimular a las abejas a visitar la flor de durazno para la búsqueda de polen. La disponibilidad permanente de otras plantas productoras de polen, reportadas previamente como importantes en el aporte de este recurso, pudo influir en la selección de fuentes por parte de las abejas. El polen obtenido provino, principalmente, de plantas de las familias Fabaceae, Asteraceae, Malvaceae y Passifloraceae.

Several studies show that the inclusion of pollinators such as honeybee Apis mellifera generates positive effects in the productivity of peach (Prunus persica) crops. It led to test methodologies that stimulate bees to improve the visit of crops of interest, suggesting the use of the osmoguiding technique, as a tool to potentiate the effect of pollination. This study evaluated an osmoguided protocol to stimulate Africanized hybrids of Apis mellifera to collect pollen from peach flowers, using palynological analysis of pollen samples as an indirect indicator. The treatments used were with osmoguided and without osmoguided. Each treatment had three hives, and the evaluation period was five weeks, coinciding with the peak flowering period of the peach. The results showed that this protocol did not stimulate the bees to visit the peach blossom to search pollen. The permanent availability of other pollen-producing plants, previously reported as significant in the contribution of this resource, could influence bee source selection. The pollen obtained came mainly from plants of the families Fabaceae, Asteraceae, Malvaceae, and Passifloraceae.

Antioxidant, Antimicrobial, and Neurotoxicity (in Sh-Sy5y Cell Lines) Properties of Mg Nanoparticle System (BP@MgNPs) Prepared by Green Synthesis with Bee Pollen.

Due to their distinct characteristics and possible uses in a variety of disciplines, nanoparticles have attracted a lot of attention recently. One area of interest is the synthesis of nanoparticles using natural sources such as bee pollen. The research aims to evaluate the usability of bee pollen extract-based magnesium nanoparticles (MgNPs). First, a palynological study was used to determine the plant source of bee pollen. The nanoparticle was characterized using scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, X-ray diffractometry, and Fourier transform infrared spectroscopy. The results revealed cubic-shaped MgNPs with an average size range of 36-40 nm. Afterward, nanoparticles were evaluated for their antioxidant, antimicrobial, and neurotoxic properties. It was determined that the total antioxidant capacity, phenolic (TPC), flavonoid (TFC) content, DPPH radical scavenging, and antimicrobial activity of the nanoparticles were lower than pollen extract. At the same time, nanoparticles have less toxicity than bee pollen.

Identification of prominent airborne pollen in a city situated in foot-hills of Himalayas, Chandigarh, India.

Pollen allergy is considered one of the important critical thrust areas, as 20-30% of the world population suffers from allergic rhinitis. The increase in global surface temperature directly affects pollen physiological (e.g., pollen production) and morphological parameters and indirectly affects the distribution pattern, the allergenic potential of pollen, and plant species. Therefore, periodic sampling and pollen studies of a region have become necessary to assess the status of change in species and its morphological characteristics of different taxa. The current study is conducted to identify the airborne pollen based on studying their unique and distinctive morphological characters to serve as a reference pollen guide for future research. The airborne pollens were trapped using the Burkard volumetric sampler at three different locations in Chandigarh from 2018 to 2020 and analyzed under Leica DM5500B-Automated Upright Microscope System. The study investigated various pollen features such as shape, size, aperture type, and exine/surface pattern for taxonomic classification of plant groups. The majority of LM-analyzed pollen grains were prolate-spheroidal or oblate, whereas the aperture types were 3-zonocolporate, 3-colpate, and 3-zonocolporate. Exine patterns were predominantly psilate, reticulate, and straite and were easily discernible. Nonetheless, the vast majority of airborne pollen belonging to both arboreal and non-arboreal was quite small and fall into small pollen size classes, i.e., 10-24 µm. The exine pattern was readily apparent and were predominantly psilate, reticulate, and straight. The current study improved the knowledge on airborne pollen biodiversity, which will help to understand the regional distribution, long-range transport, and construct the current status of morphological features of species/taxa.

Combining genome size and pollen morphology data to study species relationships in the genus Daucus (Apiaceae).

BACKGROUND: The genus Daucus (Apiaceae) comprises about 40 wild species and the cultivated carrot, a crop of great economic and nutritional importance. The rich genetic diversity of wild Daucus species makes them a valuable gene pool for carrot improvement breeding programs. Therefore, it is essential to have good knowledge of the genome structure and relationships among wild Daucus species. To broaden such knowledge, in this research, the nuclear DNA content for 14 Daucus accessions and four closely related species was estimated by flow cytometry and their pollen morphology was analyzed by light and scanning electron microscopy (SEM). RESULTS: The flow cytometric analysis showed a 3.2-fold variation in the mean 2C values among Daucus taxa, ranging from 0.999 (D. carota subsp. sativus) to 3.228 pg (D. littoralis). Among the outgroup species, the mean 2C values were 1.775-2.882 pg. The pollen grains of Daucus were tricolporate, mainly prolate or perprolate (rarely) in shape, and mainly medium or small (rarely) in size (21.19-40.38 µm), whereas the outgroup species had tricolporate, perprolate-shaped, and medium-sized (26.01-49.86 µm) pollen grains. In the studied taxa, SEM analysis revealed that exine ornamentation was striate, rugulate, perforate, or the ornamentation pattern was mixed. At the time of shedding, all pollen grains were three-celled, as evidenced by DAPI staining. We also found high positive correlations between the length of the polar axis (P) and the length of the equatorial diameter (E) of pollen grains, as well as between P and P/E. However, when comparing cytogenetic information with palynological data, no significant correlations were observed. CONCLUSIONS: This study complements the information on the nuclear DNA content in Daucus and provides comprehensive knowledge of the pollen morphology of its taxa. These findings may be important in elucidating the taxonomic relationships among Daucus species and can help in the correct identification of gene bank accessions. In a broader view, they could also be meaningful for the interpretation of evolutionary trends in the genus.

Microscopic (LM and SEM) visualization of pollen ultrastructure among honeybee flora from lower Margalla Hills and allied areas.

Microscopic visualization of micro-morphological characters were analyzed using a scanning electron microscopic (SEM) tool, which has proven to be very successful to analyze the pollen surface peculiarities. The significant goal of this research was to perform microscopic examination of pollen of some of the most frequently visited honeybee floral species around apiaries. Micro-morphological characterization of frequented honeybees foraged plants were discussed. A total of 15 species, belonging to 11 different families were identified for the foraging activities of honeybees, namely, Lantana camara, Jatropha integerrima, Helianthus annuus, Tecoma stans, Lagerstroemia indica, Duranta erecta, Cosmos sulphureus, Hymenocollis littoralis, Moringa oleifera, Cestrum nocturnum, Parthenium hysterophorus, Volkameria inermis, Catharanthus roseus, Malvastrum coromandelianum, and Citharexylum spinosum. The microscopic slides were prepared using the acetolysis method, and the qualitative and quantitative features were measured and described using microscopic tools. The pollen type sculpture varies from psilate scabrate to echinate and colpi from tricolpate to tetracolpate. Quantitative parameters such as polar diameter, mesocolpium distance, equatorial dimensions, aperture size, spine diameter, and exine thickness were calculated using IBM SPSS Statistics 20. The exine thickness was measured at its maximum in C. roseus (3.85 µm), whereas it was at its minimum of 0.90 µm in L. indica and D. erecta. Pollen fertility was estimated to be highest in H. annus (88%). The current research validates scanning microscopic features of pollen of the honeybee floral species, which is helpful for the accurate identification and commercializing of honey production to generate revenue for beekeepers through the exploration of bee floral diversity. RESEARCH HIGHLIGHTS: Pollen spectrum examination using microscopic imaging techniques. Variations examined through scanning microscopy in pollen ultrastructure. Micro-morphology has taxonomic value for accurate identification of honeybee flora. Authentication of Honeybee floral species for sustainable beekeeping.

Comparative light and scanning electron microscopic studies of pollen of two marijuana species causing allergies.

Marijuana (Cannabis) belongs to family Cannabaceae. This plant is a great natural source of cannabinoids, which have several medical applications such as it is used for the treatment of anxiety and psychosis, disorders of motility and epilepsy. However, this plant is also notorious for its pollen allergic reactions. Mainly two species, that is, C. sativa L. and C.indica Lam. are involved in allergic reactions. In this study, morpho-palynological studies of both the species were conducted. A number of morphological differences were observed in the both species. C. sativa is tall with narrowed leaves and fibrous stalk plant while C. indica is short, bushier, broad leaves, and having woody stalk plant. Both the species are varied in their pollen characteristics. The polar diameter of C. sativa observed was 7.5 µm and equatorial diameter was 8 µm, and its shape was oblate-spheroidal. C. indica had 7 µm polar diameter, 7.5 µm equatorial diameter but its shape was similar to C. sativa, that is, oblate-spheroidal. About 40%-50% people were affected with both these marijuana species and had symptoms of allergies like dry cough, congestion, itchy eyes, sore throat, nausea, a runny nose, watery eyes, and sneezing. It was concluded that both species' pollen are allergy causing and pollen of both species are different with variations in morphological and allergic symptoms. RESEARCH HIGHLIGHTS: Marijuana has great therapeutic importance but it is also notorious for its pollen allergic reactions. Two species of Marijuana, that is, Cannabis sativa L. and Cannabis indica Lam mainly responsible for these pollen allergies. The present research work focused the morpho palynological analysis of these two Marijuana species through light and scanning electron microscopy.

The comparative palynomorphological studies on Turkish Muscari genera and close relatives (Asparagaceae-scilloideae) with their taxonomic implications.

By this study, the palynomorphological traits of 49 taxa (53 plant samples) of the genus Muscari which has been the main research topic and also its relatives, Pseudomuscari, Hyacinthella and Bellevalia have been studied in details of both using light and scanning electron microscope. In the end of palynologic works, it was suggested the descriptive or symbolized main pollen types to make easier the separation or identification of the species of Muscari and its relative groups. According to this symbolization, the pollen types of species may be changeable as D-shaped, elliptical, triangular, and spindle shaped and all types could be seen in different members of the studied taxonomic groups in this paper. One of the most important findings of the study is that the taxa of the genus Muscari, Hyacinthella and Bellevalia do not show a main difference in terms of pollen structures and especially they exhibit harmony. Therefore, it does not possible to mention about the special pollen shape own to one species but it is possible to see common pollen types for closely related taxa or taxon groups. As a result, it could be commented that there is not evolved the close taxonomical groups within Asparagaceae in terms of pollen shape and morphologies and there is considerably a high suitability in point of theirs germ cells or microspores among them. RESEARCH HIGHLIGHTS: A detailed palynological description is provided for Muscari and close relative genus using scanning electron microscopy (SEM) and light microscopy (LM). Pollen size and sulcus length are been determined as the best informative pollen characters to understand Muscari and other studied species.

Light and scanning electron microscopic characterization of pollen grains of some wetland angiosperms from India.

Pollen grains of 58 wetland species of angiosperms belonging to 17 families, growing in different wetlands of Sub-Himalayan biodiversity hotspots, Northern Bengal and lower Gangetic plains, India were investigated during a 4-year span of 2015-2019. Freshly collected anthers were processed through the acetolysis method and the obtained pollen grains were accurately studied under LM and SEM and properly photographed. Different attributes viz. shape, size, aperture type and exine ornamentation of pollen grains served as consistent features were used for authentic identification of the studied species. To study the phylogeny of pollen grains, characters like polarity, symmetry, aperture and exine sculpturing were found most significant for species segregation. Investigated pollen grains were mostly prolate-spheroidal, spheroidal or triangular, rarely prolate or elongated, exine psilate, granulate, reticulate or microechinate type. Most of the observable aperture of pollen grains of studied species were colporate, colpate and porate, while ulcerate and inaperturate grains were also observed in the studied aquatic members of the families Cyperaceae and Potamogetonaceae. All the gathered data were further statistically analyzed through ANOVA, PCA and Pearson Correlation Matrix to understand the interrelationship among the species. The permanent slides of identified pollen grains were deposited at the herbarium of North Bengal University [NBU] for future references. HIGHLIGHTS: Study of Pollen morphology of 58 wetland species under light & scanning electron microscopy. Unique apertures and exine ornamentation used to understand taxonomic evaluation of studied species. Pollen character supports interrelationship among the studied species. Relationship between exine thickness and the habitat of the wetland plants.

Taxonomic significance of palynological studies for identification of two morphologically similar Malva species.

Pollen studies can assist in distinguishing different plant taxa on the basis of pollen diameter, exine thickness, spines length, spine shape, number of rows of spines between colpi, shape of pollen, P/E ratio, pollen class and aperture type. Light microscopy (LM) and scanning electron microscopy (SEM) was used to compare and differentiate two Malva species on the basis of different pollen characteristics. Pollen in Malva neglecta and Malva parviflora had punctate and subpsilate, and, granulate and verrucate sculpturing between spines respectively. Both species pollen had bulbous spine base, but were more swollen in M. parviflora. M. neglecta had more pollen size, spine length and distance between spine base and spine apex, except spine base and pore diameter. The scatterplot matrix showed a wide variation among sculpturing types and other pollen attributes of both species. In PCA biplot, pore diameter and spine length were linked to M. parviflora while other pollen attributes were clearly linked to M. neglecta, indicating the taxonomic significance of the observed characters. It was concluded that the palynological studies can act as an identification tool and are of great significance in delimiting Malva and different plant taxa. RESEARCH HIGHLIGHTS: Taxonomic identifications is a big problem in morphologically identical Malva neglecta and Malva parviflora. The usefulness of pollen morphology (pollen diameter and exine thickness) and wall ornamentation in identification through light microscopy (LM) and scanning electron microscopy (SEM) was confirmed. Pollen of M. neglecta can be differentiated from M. parviflora by its sculpturing patterns. Spine base and pore diameter of M. parviflora is a taxonomically important feature.

Scanning electron microscopic imaging of palynological metaphors: A case study of family Poaceae taxa.

This study highlighted the taxonomic utilization of palynological metaphors for selected members (53) of family Poaceae. Multiple microscopic technique light and scanning electrons had been employed for detailed analysis. Results reported monad pollen type in all studied 53 members, which showed its limited taxonomic value up to family level. In relation to shape of pollen both polar and equatorial views strikingly differed from each other. Like semi angular pollen observed in Dactyloctenium aegyptium (L.) Wild. whereas round-minutely irregular pollen in Lolium temulentum L. Polar and equatorial diameter also showed variation, that is, Desmostachya bipinnata (L.) Stapf. can be differentiated from Sorghum bicolor (L.) Moench on diameter variation basis. A pore characteristic does not show much qualitative variation; however pore sizes differ species to species. The most frequently scarbate sculpturing was observed in 28 species followed by verrucate. Hence it can be said that pollen shape, polar, and equatorial diameters, pore size, P/E ratio, pore sculpturing are of good taxonomic value and holds a significant position in identification and delimitation of Poaceae taxa.

Palyno-morphological attributes of some selected plant species of family Asteraceae from district Dera Ismail Khan, KPK, Pakistan.

The current study aimed to investigate the palyno-morphological features of Asteraceous species from District Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan. A total of 13 species were collected, pressed, identified, and examined by using light and scanning electron microscopy. Both qualitative and quantitative pollen characters were observed, that is, equatorial and polar diameter, number of pores and colpi, exine thickness, exine sculpturing, pollen shape, and P/E ratio. Pollen shapes observed in studied taxa were spheroidal, suboblate, oblate-spheroidal, and lophate-spheroidal. The aperturation patterns of pollens vary from tricolporate to tetracolporate. The maximum polar and equatorial diameter of 75-100 (87.5 ± 13.6) µm and 87.5-117.5 (102.5 ± 16.4) µm, respectively, was recorded in Echinops echinatus, while minimum polar and equatorial diameter of 20-22.5 (21 ± 1.36) µm and 22.5-25 (23.5 ± 1.36) µm, respectively, was recorded in Aster subulatus. Six types of exine sculpturing patterns were observed; echinate, micro-echinate, echinate-microreticulate, microreticulate, echinate-perforate, and scabrate. Maximum exine thickness of 8.75 µm was recorded in E. echinatus and minimum of 1.25 µm in Launaea mucronata. The pollen morphology has valuable significance in understanding the taxonomy of different plant groups and plays a central role in the correct identification and classification of Asteraceous flora at species, generic, and tribe levels.

Palynomorphological diversity among the Asteraceous honeybee flora: An aid to the correct taxonomic identification using multiple microscopic techniques.

This study aimed to characterize the palynological morphology of melliferous species of family Asteraceae belonged to seven tribes which were categorized into 15 genera and were studied under light and scanning electron microscopy. The pollen grains were acetolyzed, measured, and described qualitatively. Quantitative data were analyzed by descriptive and multivariate statistical analysis. The species were analyzed considering 11 quantitative pollen characteristics. The study revealed that the pollen grains are circular, triangular, angular, semi-angular, quadrangular, pentagonal and hexagonal amb, and 3-colporate or 3-colpate. The size of the pollen is variable among the species, ranged from 56.1 to 23.2 µm. Three pollen types: oblate spheroidal (eight species), prolate spheroidal (six species), and suboblate (two species) were observed. The surface pattern of the exine varies from echinoperforate, echinate, echinate microperforate, fenestrate, echinoperforate reticulate, microreticulate, echinate perforate, tectate, and scabrate. Exine thickness was calculated minimum in Cichorium intybus (2.47 µm) and maximum in Taraxacum campylodes (5.15 µm). A key to studied bee floral species, based on the morphological features of pollen grains, is also provided. The palynomorphological characters here analyzed can be potentially used to correctly identify the Asteraceous honeybee floral species most commonly plants visited by honeybees in the study area.

Implication of light and scanning electron microscopy for pollen morphology of selected taxa of family Asteraceae and Brassicaceae.

The present study was intended to assess pollen morphological attributes of selected Asteraceous and Brassicaceous species from tehsil Esa Khel (Mianwali), Punjab using scanning electron microscopy (SEM) and light microscopy (LM) techniques for its systematic and taxonomic significance for correct identification. Pollen from 12 different species belongs to two plant families from various distributional localities were collected, acetolyzed and measured. Different palynomorphological features were investigated using LM and SEM techniques. In Asteraceous species, three types of pollen (tricolporate, trizonocolporate, and tetracolporate) were observed. Pollen shape was observed prolate-spheroidal in three species while oblate and oblate-spheroidal were detected in Parthenium hysterophorus and Erigeron bonariensis. While sculpturing pattern of exine were echinate, echinate fenestrate, echinate perforate and scabrate echinate. Mesocolpium measurement was calculated maximum for Sonchus oleraceous (16.6 µm). Brassicaceae pollen were circular, lobate, tricolpate and exine show reticulate peculiarities. Whereas dominant shape was oblate-spheroidal followed by prolate-spheroidal and sub-prolate in Lepidium didymum and Sisymbrium irio, respectively. Mesocolpium distance was noted highest in Raphanus raphanistrum (14.4 µm). Exine thickness was noted maximum in Erigeron bonariensis (2.9 µm) in Asteraceous species and in Brassicaceae; Lepedium didymum exine measurement was 2.7 µm. The study showed that pollen micromorphology has important role to accurately identify and classify diverse plants genera belong to different families. Based on these taxonomic palynomorph features, the accurate identification of species from flora of tehsil Esa Khel, Mianwali were elaborated.

Microsporogénesis y micromorfología del polen de la planta Alcea rosea (Malvaceae) / Microsporogenesis and micromorphology of pollen grains of the plant Alcea rosea (Malvaceae)

Resumen Introducción: Los estudios sobre microsporogénesis, micromorfología y estructura de los granos de polen en Malvaceae son escasos. Objetivos: Describir el proceso de microsporogénesis y aspectos micromorfológicos de los granos de polen en A. rosea. Métodos: Se procesaron más de 30 andróforos de acuerdo con los protocolos estándar para incrustar y seccionar en parafina. Las secciones obtenidas se tiñeron con Azul de Safranina-Alcian, las anteras inmaduras y no fijadas se tiñeron con Azul de anilina. Se procesaron secciones de resina adicionales de los andróforos y se tiñeron con azul de toluidina. Se observaron secciones ultrafinas con microscopía electrónica de transmisión (MET). Para la observación con microscopía electrónica de barrido (MEB), el material se fijó y deshidrató en 2,2 dimetoxipropano, luego se secó hasta un punto crítico y se recubrieron con oro. Resultados: las anteras se diferencian de una masa celular en los extremos distales de los filamentos del estambre. La pared de la antera madura presenta una capa externa de células epidérmicas y una capa interna, el endotecio. Las células madre de microesporas se dividen por mitosis y luego experimentan meiosis para formar tétradas. El tapete es inicialmente celular y forma una sola capa de células y luego pierde integridad celular al invadir el lóculo de microsporangio, formando un periplasmodio. Durante la formación de la esporodermis, primero se deposita la exina y luego la intina. Para el momento de la liberación de los granos de polen, el tapete se ha degenerado por completo. Los granos de polen son pantoporados, apolares, con simetría radial, esferoidales, con espinas, báculas, gránulos y microgránulos. El téctum está perforado con fovéoleas dispuestas homogéneamente en toda la superficie y con polenkit. La exina es ancha (5-6 µm) y consta de una endexina gruesa de 3.5 a 4 µm y una ektexina fina (0.6-0.7 µm). La ultraestructura muestra columelas claramente definidas formando el infratéctum. Se aprecian tricomas nectaríferos unicelulares glandulares capitados (TG) cubriendo toda la superficie de los filamentos de los estambres. Conclusiones: La estructura y desarrollo de las anteras sigue los patrones conocidos de las angiospermas. La microsporogénesis simultánea y el depósito centrípeto de la esporodermis se han descrito previamente para Malvaceae.

Abstract Introduction: Studies on microsporogenesis, micromorphology and structure of pollen grains in Malvaceae are scarce. Objectives: To describe the process of microsporogenesis and micromorphological aspects of pollen grains in A. rosea. Methods: Androphores were processed according to standard protocols for sectioning in paraffin. The obtained sections were stained with Safranin-Alcian blue, Aniline blue was used for immature and unfixed anthers and for resin sections of the androphores, Toluidine blue. Ultrathin sections were observed with transmission electron microscopy. For observation with scanning electron microscopy the material was fixed and dehydrated in 2.2 dimethoxypropane, dried to a critical point and coated with gold. Results: Anthers differentiate from a cell mass at the distal ends of the stamen filaments. The wall of the mature anther presents an outer layer of epidermal cells and an inner layer, the endothecium. Microspore mother cells divide by mitosis and then undergo meiosis to form tetrads. The tapetum is initially cellular and forms a single layer of cells and then loses cellular integrity by invading the microsporangium locule, forming a periplasmodia, by the time the pollen grains are released it degenerated. During sporodermis formation, exine is first deposited and then intine. Pollen grains are pantoporate, apolar, with radial symmetry, spheroidal, with spines, bacula, granules and microgranules. Tectum is perforated with foveolae arranged homogeneously over the whole surface and pollenkit is present. Exine is broad and consists of a thick 3.5 to 4 µm endexine and a thin ektexine (0.6-0.7 µm). The ultrastructure shows columellae forming the infratectum. Capitate glandular unicellular nectariferous trichomes covers the whole surface of the stamen filaments. Conclusions: The structure and development of the anthers follows the known patterns for angiosperms. Simultaneous microsporogenesis and centripetal deposit of the sporodermis have been previously described for Malvaceae.

Micromorfología y ultraestructura de las anteras y los granos de polen en diez genotipos élite de Theobroma cacao (Malvaceae) / Micromorphology and ultrastructure of anthers and pollen grains in ten elite genotypes of Theobroma cacao (Malvaceae)

Resumen Introducción: A pesar de que T. cacao es una especie importante a nivel mundial por la producción de cacao, es poco lo que se conoce sobre la micromorfología y estructura de las anteras y los granos de polen. Objetivos: Describir y analizar la estructura y micromorfología de las anteras y los granos de polen de 10 genotipos élite de esta importante especie tropical. Métodos: Se tomaron más de 30 anteras de flores en antesis de los 10 genotipos élite de T. cacao del banco de germoplasma ex situ del Centro de Investigaciones Suiza-Agrosavia (Rionegro, Santander-Colombia). El material se procesó de acuerdo con los protocolos estándar para embeber y seccionar en parafina. Las secciones obtenidas (3 μm) se tiñeron con azul de Safranina-Alcian para discriminar estructuras con paredes primarias y secundarias y polifenoles totales. Además, se usó la técnica PAS-Amidoblack para diferenciar entre polisacáridos estructurales y de reserva, así como proteínas. Para la determinación de esporopolenina y polifenoles se usó la tinción azul de toluidina y finalmente para descripciones adicionales se aplicó la tinción azul alcián-PAS-hematoxilina. Las observaciones se realizaron mediante microscopio fotónico y microscopio de epifluorescencia. Para la observación con microscopía electrónica de barrido (MEB), las anteras con los granos de polen se fijaron y deshidrataron en 2.2 dimetoxipropano, luego se desecaron hasta un punto crítico y finalmente se recubrieron con oro. Resultados: Las anteras son bitecas y están sostenidas por un largo filamento formado por un estrato epidérmico, tejido parenquimatoso y un haz vascular. La dehiscencia ocurre longitudinalmente a través del estomio. La pared de la antera madura está formada por una capa epidérmica monoestratificada, una capa de células endoteliales con engrosamientos fibrilares lignificados y se pueden apreciar restos celulares del tapete y abundantes orbículas recubriendo la cavidad de los microesporangios. Los tejidos epidérmicos y parenquimatosos de las anteras almacenan polifenoles. Las orbículas son generalmente esféricas, psiladas y exhiben las mismas reacciones de tinción y fluorescencia que la exina de los granos de polen. Los granos de polen son mónades, isopolares, pequeños (16-19 µm) con amb circular, esferoidales, tricolpados con colpos medianos o cortos (5-10 µm) con membrana ornamentada, semitectatos, reticulados, heterobrochados, las paredes del retículo ornamentadas o no, con microgránulos de diferente tamaño o escabrados. Los análisis estadísticos mostraron que existen diferencias significativas en el tamaño de los granos de polen (P ˂ 0.05). Se observa que los granos de polen más pequeños son los del genotipo TCS 19 (16.890 µm) y se diferencian del resto de genotipos, y entre estos no se observan diferencias significativas. Solo dos genotipos (SCC 19 y SCA 6) presentaron polenkit y solo uno tiene paredes perforadas (SCA 6). Conclusiones: La estructura y micromorfología de las anteras de T. cacao son similares a las descritas para otras Malvaceae. Así mismo, los granos de polen mostraron variaciones de tamaño, ornamentación de las paredes y del lumen del retículo y presencia de polenkit. Sin embargo, no se observó relación entre las variaciones de los caracteres micromorfológicos analizados en los granos de polen y los modelos de compatibilidad polínica reportados para estos genotipos.

Abstract Introduction: Despite the fact that T. cacao is an important species worldwide for cocoa production, little is known about the micromorphology and structure of anthers and pollen grains. Objectives: To describe and analyze the structure and micromorphology of the anthers and pollen grains of 10 elite genotypes of this important tropical species. Methods: More than 30 anthers of flowers in anthesis were taken of the 10 elite genotypes of T. cacao from the ex situ germplasm bank of the Suiza-Agrosavia Research Center (Rionegro, Santander-Colombia). The anthers with the pollen grains were fixated and processed according to the standard protocols for embedding and sectioning in paraffin. Sections obtained (3 μm thick) were stained with Safranin-Alcian blue to discriminate structures with primary and secondary walls and total polyphenols. Additionally, the samples were also stained with the PAS-Amidoblack technique was used to differentiate between structural and reserve polysaccharides as well as proteins. Toluidine blue staining was used for the determination of sporopollenin and polyphenols and finally Alcian blue-PAS-Hematoxylin staining was applied for additional descriptions. Observations were made using photonic microscopy and epifluorescence microscopy. For observation with scanning electron microscopy (SEM) the anthers with the pollen grains were fixed and dehydrated in 2.2 Dimethoxypropane, then desiccated to critical point and finally coated with gold. Results: The anthers are dithecal and supported by a long filament made up of an epidermal stratum, parenchymal tissue, and a vascular bundle. The dehiscence occurs longitudinally through the stomium. The anther wall is made up of a monostratified epidermal layer, followed by a layer of endothecial cells with lignified fibrillar thickenings, cellular remnants of tapetum and abundant orbicules can be seen covering the cavity of the microsporangia. The epidermal and parenchymal tissues of the anthers are abundant in polyphenols. Orbicules are generally spherical, psilated, and these exhibit the same staining and fluorescence reactions as exine from pollen grains. The pollen grains are monades, isopolar, small (16-19 µm) with circular amb, spheroidal, tricolpate with medium or short colpi (5-10 µm) with sculptured membrane, semitectate, reticulated, heterobrochate, sculptured or non- sculptured walls, with microgranules of different size or scabrate. The statistical analyzes showed that there are significant differences in the size of the pollen grains (P ˂ 0.05). It is observed that the smallest pollen grains are those of the TCS 19 genotype (16.890 µm) and are different from the other genotypes, and among these there are no significant differences. Only two genotypes (SCC 19 and SCA 6) showed pollenkit and only one has perforated walls (SCA 6). Conclusions: The structure and micromorphology of the anthers of T. cacao are similar to those described for other Malvaceae. Likewise, the pollen grains showed variations in size, ornamentation of the sporoderm and the lumen of the reticulum and the presence of pollenkitt. However, no relationship was observed between the micromorphological characters analyzed in the pollen grains and the pollen compatibility models reported for these genotypes.

Identifying the scene of a crime through pollen analysis.

The forensic analysis of pollen involves the comparison of crime scene and reference pollen samples. Successful matches are frequently used to solve time- or location-related crimes. Despite its prospects in criminal investigation, forensic palynology is still underused in casework due to inherent shortcomings such as its limited evidential weighting, scarcity of skilled palynologists dedicated to forensic casework and the laborious nature of analytical procedures. To address these challenges, the current state-of-the-art in forensic palynology is transiting from the traditional light microscopic methods that dominated the early days of palynology to more contemporary approaches like Raman spectroscopy, stable isotope analysis and DNA metabarcoding. The major challenges of these methods, however, include a lack of optimisation to forensic expectations and the unavailability of robust databases to permit accurate data interpretation, and quests to resolve these problems constitute the theme of current research. While reiterating the usefulness of pollen analysis in criminal investigation, this report recommends orthogonal testing as a way of improving the evidential weighting of forensic palynology.