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Members of the Loranthaceae family are considered parasitic, and mistletoe negatively affects the growth and productivity of host trees. Loranthaceae has several complicated taxonomic issues. Six species of Loranthaceae grow naturally in Saudi Arabia, but these species have not been well studied. The aim of this work was to evaluate the importance of morpho-palynological characters as a taxonomic tool in the identification of Loranthaceae species growing in Saudi Arabia. The discriminatory power of these characteristics was evaluated using different statistical analysis methods. The descriptive characteristics of pollen polar and equatorial views and colpus type are useful for describing the species, and the presence of three colpus patterns was detected among the study samples: syn-(3)-, demisyn-(3)-, and zono-(3)-colpate. The quantitative characteristics, specifically, the equatorial diameter and P/E ratio, are the most useful and can be used to classify species within clusters based on their affiliation with genera, species, and subtribes Emelianthinae and Tapinanthinae. This study confirmed that pollen grain characteristics can be used as a taxonomical tool to identify Loranthaceae species. This information will aid in determining parasitic species that infect trees and could be useful for strengthening efforts in weed management.

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Introducción: No conocemos estudios sobre la microsporogénesis de la planta de cacao, y poco se sabe sobre la ultraestructura de sus granos de polen. Objetivo: Describir la microsporogénesis y ultraestructura de los granos de polen en T. cacao. Métodos: Procesamos más de 30 flores para cada etapa floral, teñidas con Safranina-Azul Alcian, PAS-Amidoblack y Lacmoid. Para la microscopía de transmisión procesamos las muestras en resina y las teñimos con azul de toluidina. Para microscopía electrónica de barrido, fijamos y deshidratamos en 2.2-dimetoxipropano, secamos hasta un punto crítico y recubrimos con oro. Resultados: Anteras diferenciadas por una masa celular en los extremos distales a los filamentos estaminales. Durante el desarrollo la pared de las anteras presenta varios estratos celulares y al madurar se reducen a la epidermis y al endotecio. Las células madre de microsporas se dividen por meiosis para formar tétradas. El tapete es secretor e intacto hasta que se liberan los granos, para luego degenerar. Los granos de polen son isopolares, esferoidales, pequeños, tricolpados. La ultraestructura presenta una esporodermis semitectada, con ornamentación reticulada, y un retículo heterobrochado con el muri sin ornamentación. La exina se deposita antes que la intina. Los orbículos son individuales, lisos y de tamaño variado. Hay abundante polenkit en el tectum y entre las columelas. La intina es delgada, pero se desarrolla ampliamente en las áreas del colpo, formando una intina interna compacta y una intina externa inusual con una apariencia columelada. Conclusión: La estructura y el desarrollo de las anteras siguen el patrón de las angiospermas. La microsporogénesis simultánea y la deposición centrípeta de la esporodermis se conocen de Malvaceae, pero los caracteres de la intina son nuevos para la familia.

Introduction: We know of no studies on the microsporogenesis of the cocoa plant, and little is known about the ultrastructure of its pollen grains. Objective: To describe microsporogenesis and ultrastructure of pollen grains in T. cacao. Methods: We processed over 30 flowers for each floral stage and stained with Safranin-Alcian Blue, PAS-Amidoblack and Lacmoid. For transmission microscopy we processed samples on resin and stained with toluidine blue. For scanning electron microscopy, we fixed and dehydrated in 2.2-dimethoxypropane, critically dried and coated with gold. Results: Anthers differentiated by a cellular mass at the ends distal to the staminal filaments. During development, the anther wall has several cellular layers reduced, at maturity, to the epidermis and endothecium. Microspore mother cells divide by meiosis to form tetrads. The tapetum is secretory and intact until the grains are released, to later degenerate. Pollen grains are isopolar, spheroidal, small, tricolpate. Ultrastructure has a semi-tectate sporodermis, with reticulate ornamentation, and heterobrochated reticulum with the muri without ornamentation. Exine is deposited before intine. The orbicles are individual, smooth, and varied in size. There is abundant pollenkitt on the tectum and between the columellae. The intine is thin, but develops widely in the colpus areas, forming a compact internal intine and an unusual external intine with a columellated appearance. Conclusion: Anther structure and development follows the angiosperm pattern. Simultaneous microsporogenesis and centripetal deposition of the sporodermis are known from Malvaceae, but intine characters are novel for the family.

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Although bat guano deposits have been proven to be excellent environmental archives for paleoecological and paleoclimate studies, the development of a standardized method specially catering to pollen extraction has received no attention so far. In general, the processing procedure is quite similar among published studies, but adjustments must be made regarding the proportion of organic and particulate matter in the guano deposit. In this study, we present step-by-step optimized sample processing methods for pollen analysis. These procedures first apply a chemical treatment for the removal of siliceous and organic material, followed by a sieving step to remove the remaining inorganic matter from those samples with high detrital content. Overall, our methods can efficiently remove particulate matter and improve the quality of the final residue, resulting in cleaner slides and better visualization of pollen and spores.•Remove humic acid and organic material with Potassium hydroxide.•Remove inorganic matter with hydrofluoric acid and sieving.•Concentrate and store the pollen residues in glycerin.

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Most paleoecological investigations use different biotic or abiotic proxies for climate and environmental reconstructions. Although fossil pollen is one of the most used biological proxies, Non-Pollen Palynomorphs (NPPs), especially fungal spores and tissues, have an underestimated potential to infer local and regional climate dynamics. This dataset describes the most common Non-pollen palynomorphs of fungal origin from mangrove sediments in the Caribbean Sea, southeastern Mexico. A detailed descriptive Atlas is presented, with light micrographs taken from routine pollen slides in paleoecological reconstructions. Microphotographs were included to facilitate their identification. A total of 59 spores, 4 tissues, 2 hyphae, and 11 unidentified fungal palynomorphs are described.

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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.

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This review explores the evolution of extant South American tropical biomes, focusing on when and why they developed. Tropical vegetation experienced a radical transformation from being dominated by non-angiosperms at the onset of the Cretaceous to full angiosperm dominance nowadays. Cretaceous tropical biomes do not have extant equivalents; lowland forests, dominated mainly by gymnosperms and ferns, lacked a closed canopy. This condition was radically transformed following the massive extinction event at the Cretaceous-Paleogene boundary. The extant lowland tropical rainforests first developed at the onset of the Cenozoic with a multistratified forest, an angiosperm-dominated closed canopy, and the dominance of the main families of the tropics including legumes. Cenozoic rainforest diversity has increased during global warming and decreased during global cooling. Tropical dry forests emerged at least by the late Eocene, whereas other Neotropical biomes including tropical savannas, montane forests, páramo/puna, and xerophytic forest are much younger, greatly expanding during the late Neogene, probably at the onset of the Quaternary, at the expense of the rainforest.

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Criminal cases are studied from several disciplines to link a suspect with a criminal act. In this case, a man was reported missing in a coastal area in Buenos Aires Province, Argentina. The victim's relatives pointed to a possible suspect, and the local police carried out the investigation. We contributed to this research by applying palynological and mycological techniques. Palynomorphs and fungal spores offer valuable trace evidence, as they can be easily transferred between objects and crime scenes due to their minute size and persist on them for a long time. The victim was found 25 days later, lying on sandy soil, which partially covered the body, 35 km from where the suspect was arrested. Comparative samples were collected from the crime scene and the suspect's home and belongings (clothes, footwear, and seized vehicle). The palynological associations obtained from the crime scene and the defendant's belongings were dominated by diatoms and acritarchs (Acantomorphitae), all elements of marine origin, and a high CFU number of Bipolaris cynodontis, which allowed the defendant's clothing to be related to the place of corpse discovery. Soil from the defendant's home had an entirely continental composition, and the fungal biota was characteristic of prairie areas which were different from those of the crime scene.

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Predictions of the effects of modern Relative Sea-Level (RSL) rise on mangroves should be based on decadal-millennial mangrove dynamics and the particularities of each depositional environment under past RSL changes. This work identified inland and seaward mangrove migrations along the Ceará-Mirim estuary (Rio Grande do Norte, northeastern Brazil) during the mid-late Holocene and Anthropocene based on sedimentary features, palynological, and geochemical (δ13C, δ15N, C/N) data integrated with spatial-temporal analysis based on satellite images. The data indicated three phases for the mangrove development: (1°) mangrove expansion on tidal flats with estuarine organic matter between >4420 and ~2870 cal yrs BP, under the influence of the mid-Holocene sea-level highstand; (2°) mangrove contraction with an increased contribution of C3 terrestrial plants between ~2870 and ~84 cal yrs BP due to an RSL fall, and (3°) mangrove expansion onto the highest tidal flats since ~84 cal yr BP due to a relative sea-level rise. However, significant mangrove areas were converted to fish farming before 1984 CE. Spatial-temporal analysis also indicated a mangrove expansion since 1984 CE due to mangrove recolonization of shrimp farming areas previously deforested for pisciculture. This work mainly evidenced a trend of mangrove expansion due to RSL rise preceding the effects of anthropogenic emissions of CO2 in the atmosphere and the resilience of these forests in the face of anthropogenic interventions.

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Diatom and pollen references such as atlases and identification keys are remarkably rare from the Gulf Coast region of the United States. This dataset describes modern and fossil diatom and pollen from Galveston Bay, Texas to Cedar Keys Florida, USA. An illustrated and descriptive atlas of diatom and pollen was compiled from original data to facilitate the identification of microfossil in sediments. For diatom atlas, we include light micrographs and detailed descriptions of a total of 32 diatom species, including 9 marine diatom species, 18 estuarine diatom species, and 5 freshwater diatom species. For pollen atlas, we include light micrographs and descriptions of a total of 28 pollen and non-pollen palynomorphs, including 3 mangrove taxa, 12 upland (tree and shrub) taxa, and 10 herbaceous taxa. The diatom atlas is referenced from LSU Global Change and Coastal Paleoecology Laboratory's light micrographs collection. The pollen and diatom datasets are associated with research articles by Yao et al. [1,2].

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Promoting neglected and underutilized crop species is a possible solution to deal with the complex challenges of global food security. Chayote is a Neglected and Underutilized Cucurbit Species (NUCuS), which is recognized as a fruit vegetable in Latin America and is widely grown in Asia and Africa. However, basic biological knowledge about the crop is insufficient in scientific sources, especially outside of its center of origin. In this study, limited observations on reproductive characters were conducted, differentiating accessions from Mexico, Japan, and Myanmar. Cytological evaluation among Mexican and Japanese accessions showed that the relative nuclear DNA content is 1.55 ± 0.05 pg, the estimated genome size is 1511 at 2C/Mbp, and the observed mitotic chromosomal number is 2n = 28. The genetic diversity of 21 chayote accessions was also examined using six microsatellite markers. A global low genetic heterozygosity (Ho = 0.286 and He = 0.408) and three genetic groups were detected. The results established the basis to provide insights into chayote arrival history in Asia by looking at the crop's reproductive morphology, cytology, and genetic diversity status outside its origin center. This could help in developing sustainable utilization and conservation programs for chayote.

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Pollen references such as atlas and identification keys are remarkably rare from the Atlantic coasts of south Brazil. This dataset describes modern and fossil pollen from São Francisco do Sul Bay in the state of Santa Catarina, south Brazil. An illustrated and descriptive atlas of pollen was compiled from original and published data to facilitate the identification of various pollen taxa in sediments. We include light micrographs and descriptions of a total of 60 pollen taxa, including 3 mangrove taxa, 27 coastal woodland (restinga) taxa, and 15 rainforest taxa, and 15 herbaceous taxa. This dataset is associated with a published research article by Rodrigues et al. (2022) - Rodrigues, E., Cohen, M.C.L., Pessenda, L.C.R., França, M.C., Magalhães, E. and Yao, Q., 2022. Poleward mangrove expansion in South America coincides with MCA and CWP: A diatom, pollen, and organic geochemistry study. Quaternary Science Reviews, 288, p.107598.

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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.

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Tsunamis and hurricanes are two earth surface processes that can dramatically impact coastal landforms and ecosystems. This study uses a combination of palynological, grain-size, X-ray fluorescence, and loss-on-ignition analyses, short-lived isotopic and radiocarbon dating, and statistical analysis to differentiate the tsunami and hurricane deposits, establish a Late-Holocene record of extreme events, and document the landscape and vegetation transformation in response to disturbance events and environmental changes from a small coastal lagoon in Baja California, Mexico. Prior to ~530 cal yr BP, Playa Los Cocos was occupied by a short-hydroperiod tidal marsh bounded by desert vegetation on the surrounding hillslopes. At ~530 cal yr BP, a tsunami created a backbarrier lagoon and introduced mangrove propagules from other coastal localities, and the lagoonal environment and substrates also provided suitable habitats for red mangroves to proliferate. Once established, red mangrove populations rapidly expanded until ~180 cal yr BP, when modern human activities diminished the mangrove forest in our study area. Overall, the multi-proxy dataset revealed four hurricane events at ~770, ~600, ~280, and ~0 cal yr BP, and one tsunami event at ~530 cal yr BP. The hurricane deposits were preserved in the form of fluvial and slope-wash deposits characterized by low organic and water contents, low concentration of marine elements, and high concentration of terrestrial elements. The tsunami run-up deposits are characterized by abundant broken and intact sea shells, high content of carbonate and marine elements, low concentration of terrestrial elements, and sharp basal contact with the underlying sediments. The tsunami backwash deposits are characterized by a mixed physical and chemical signature resembling both marine and terrestrial sediments. Results also suggest that both hurricanes and tsunamis can help propagule dispersal and create suitable coastal habitats favorable for the spread and proliferation of mangroves in a desert coastal environment.

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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.

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Taxonomic resolution is a major challenge in palynology, largely limiting the ecological and evolutionary interpretations possible with deep-time fossil pollen data. We present an approach for fossil pollen analysis that uses optical superresolution microscopy and machine learning to create a quantitative and higher throughput workflow for producing palynological identifications and hypotheses of biological affinity. We developed three convolutional neural network (CNN) classification models: maximum projection (MPM), multislice (MSM), and fused (FM). We trained the models on the pollen of 16 genera of the legume tribe Amherstieae, and then used these models to constrain the biological classifications of 48 fossil Striatopollis specimens from the Paleocene, Eocene, and Miocene of western Africa and northern South America. All models achieved average accuracies of 83 to 90% in the classification of the extant genera, and the majority of fossil identifications (86%) showed consensus among at least two of the three models. Our fossil identifications support the paleobiogeographic hypothesis that Amherstieae originated in Paleocene Africa and dispersed to South America during the Paleocene-Eocene Thermal Maximum (56 Ma). They also raise the possibility that at least three Amherstieae genera (Crudia, Berlinia, and Anthonotha) may have diverged earlier in the Cenozoic than predicted by molecular phylogenies.

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Bombus atratus Franklin is a widely distributed bumblebee of South America. In Colombia, this species is recognized for its ability to adapt to highly disturbed habitats. However, knowledge of its ecology is poorly known, in particular conditions to ensure the long-term conservation of its populations. Identification of pollen resources is an important issue that could be used as a tool to manage and conserve bumblebees. In tropical areas, rainfall patterns could affect floral phenology and therefore the availability of pollen resources. Considering this, the present work aimed to establish the effect of extreme weather conditions (El Niño) in pollen availability, use of pollinic sources, and gyne production in B. atratus colonies. We reared and located 14 B. atratus colonies in a suburban area during a dry season (ENSO "El Niño") and a rainy season (ENSO "La Niña"). We registered time to gyne production and numbers of gynes produced per colony. We extracted pollen samples to establish both its floral origin and its relative abundance. We measured floral offer for each season. The data of pollen use per colony were utilized to perform Bipartite networks. We analyzed the production of gynes and pollen use per season with correlation models and generalized linear models. Colonies of the rainy season produced more gynes and faster. The floral diversity and offer were higher during the rainy season. Successful colonies used specific pollen sources in two seasons, independently of the floral offer. Extreme dry season affected development of B. atratus colonies.

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When honey bees (Apis mellifera) feed on flowers, they extend their proboscis to absorb the nectar, i.e. they perform the proboscis extension response (PER). The presence of pollen and/or nectar can be associated with odors, colors or visual patterns, which allows honey bees to recognize food sources in the environment. Honey bees can associate similar, though different, stimuli with the presence of food; i.e. honey bees discriminate and generalize among stimuli. Here, we evaluated generalization among pollen scents from six different plant species. Experiments were based on the PER conditioning protocol over two phases: (1) conditioning, in which honey bees associated the scent of each pollen type with sucrose, and (2) test, in which honey bees were presented with a novel scent, to evaluate generalization. Generalization was evinced by honey bees extending their proboscis to a novel scent. The level of PER increased over the course of the conditioning phase for all pollen scents. Honey bees generalized pollen from Pyracantha coccinea and from Hypochaeris radicata These two plants have different amounts of protein and are not taxonomically related. We observed that the flowering period influences the olfactory perceptual similarity and we suggest that both pollen types may share volatile compounds that play key roles in perception. Our results highlight the importance of analyzing the implications of the generalization between pollen types of different nutritional quality. Such studies could provide valuable information for beekeepers and agricultural producers, as the generalization of a higher quality pollen can benefit hive development, and increase pollination and honey production.

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Passifloraceae shows a huge variability of pollen wall characteristics, most still little described. Passiflora is the largest genus with about 580 species with tropical distribution. Few studies in palynological approaches have described the intine layer which can fill existent gaps. Passiflora L. present four subgenera, from which Passiflora, Astrophea, and Decaloba were described in this study. The pollen wall variations were poorly studied, with the objective of describing the morphological and histochemical structure of Passiflora sporoderm that occurs in South America, aims to supply more pollen wall characters in some contexts. Besides the inference of evolutive trends, we described the number of apertures, type, reticule, and variations of the morphology and sporoderm and we related them with possible evolutive trends for the group. As a result, the pollen grains were not far from the patterns found by the literature, with exceptions. The species of the subgenus Passiflora have fused colpi, varying from 6 to 12 colpi, with type 2-reticulate exine. The species of the subgenus Astrophea have colporus and the species of Decaloba varied as the type of aperture, in which a new type of exine to be considered was found: the type 3. The subgenus Passiflora showed the thickest intine, slim endexine, and absent foot layer. While the species that belong to the other subgenera present a slim intine, the endexine is thick and the foot layer is continuous, among other variable characteristics. The size of the pollen grain seems to be related to the thickness of the intine, and consequently, related to possible pollinators. Through the cluster analysis, we reinforce the affinity of the species to its respective subgenus. To conclude, the analysis of the ultrastructure of the sporoderm and external morphology would be useful for an almost complete interpretation of the variations occurring in the genus, giving more information that the subgenus Passiflora is apomorphic when compared to the other two. The pollen wall characters should be considered on the interpretation of natural history, as well as the phylogenetic relationships of the family, mainly in the Passiflora genus, that has a large number of species distributed across the Neotropical regions.

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There is often the risk of confusing pollen grains with helminth eggs from archaeological sites. Thousands to millions of pollen grains can be recovered from archaeological burial sediments that represent past ritual, medication and environment. Some pollen grain types can be similar to parasite eggs. Such a confusion is represented by the diagnosis of enterobiasis in ancient Iran. The authors of this study confused a joint-pine (Ephedra spp.) pollen grain with a pinworm egg. This paper describes the specific Ephedra pollen morphology that can be confused with pinworm eggs.

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Abstract Stingless bees are located in the tropic areas, and produced a sweet natural substance called pot honey, with different properties and uses. Recently, most studies are focused on characterizing them, in order to contribute to their knowledge and the establishment of quality laws. Thus physicochemical, acceptance and palynological studies were performed in stingless bee honeys from Soconusco, Chiapas, in order to learn and contribute to their knowledge in the Tropics. Nine honey samples were collected from Melipona solani (Ms), M. beecheii (Mb) and Scaptotrigona mexicana (Sm) in different meliponaries. Our results registered physicochemical values that ranged as follow; pH 2.8-4.8, electrical conductivity (EC) 114-1211 μS/cm, free acidity 24-100 meq/kg, aw 59-71 g/100g, moisture 35-38 %, color 0.13-0.75 Pfund scale, reducing sugars 47-71 %, hidroxymethylfurfural (HMF) not determined - 2.72 mg/100g, and diastase activity 1.92-11.22 DN. On the other hand, the principal component analysis (PCA) of physicochemical values showed that 86.9 % of the total variability between species was explained by the following parameters aw, moisture, free acidity, color, pH, sugars and EC. Sm honeys were associated (PCA) with a higher water content, free acidity and darker colors, while Melipona honeys with a sweeter taste and a lower diastase activity; thus honeys could be grouped by genera. The acceptance test showed that 78 % of honeys were preferred, being the SmCa sample in the category "I likely dislike" due to the bitter taste (disapproved by consumers). The melisopalynological results showed that M. beecheii honeys are monofloral with a 45 % of Fabaceae pollen, while Melipona solani and Scaptotrigona mexicana honeys are multi or polyfloral with diferent pollen types; Fabaceae, Melastomataceae, Malvaceae and Asteraceae. From this complementary study we can asume that it is necessary to implicate researchers with producers, so they could have accesss to stingless bee honey analysis and to help them to improve meliponaries management by identifying and introducing stingless bee flora.(AU)

Resumen En las regiones tropicales se ubican las abejas sin aguijón, las cuales producen una sustancia dulce denominada miel de cántaro con propiedades y usos diferentes a los de las abejas melíferas (Apis mellifera). Actualmente, se han desarrollado diversos trabajos enfocados a su caracterización, con la finalidad de contribuir con su conocimiento y el establecimiento de estándares de calidad. En este estudio se realizaron estudios fisicoquímicos, de aceptación y palinológicos en mieles de abejas sin aguijón de Soconusco, Chiapas. Se recolectaron nueve muestras de miel de las siguientes especies: Melipona solani (Ms), M. beecheii (Mb) y Scaptotrigona mexicana (Sm) en diferentes meliponarios. Nuestros resultados registraron valores fisicoquímicos que variaron de la siguiente manera: pH 2.8-4.8, conductividad eléctrica (CE) 114-1 211 μS/cm, acidez libre 24-100 meq/kg, aw 59-71 g/100 g, humedad 35-38 %, color 0.13-0.75 escala Pfund, azúcares reductores 47-71 %, hidroximetilfurfural (HMF) no determinado - 2.72 mg/100 g, y actividad de la días-tasa 1.92-11.22 ND. Por otro lado, el análisis del componente principal (PCA) de los valores fisicoquímicos mostró que el 86.9 % de la variabilidad total entre las especies se explica por los siguientes parámetros: aw, humedad, acidez libre, color, pH, azúcares y CE. Las mieles de Sm (PCA) se asociaron con un mayor contenido de agua, acidez libre y colores más oscuros, mientras que las mieles de Melipona con un sabor más dulce y una actividad de días-tasa más baja; por lo tanto, las mieles podrían agruparse por géneros. La prueba de aceptación mostró que el 78 % de las mieles eran preferidas, siendo la muestra de SmCa en la categoría "Probablemente no me gusta" debido al sabor amargo (desaprobado por los consumidores). Los resultados melisopalinológicos mostraron que las mieles de M. beecheii son monoflorales con un 45 % de polen de Fabaceae, mientras que las mieles de M. solani y S. mexicana son multi o poliflorales con diferentes tipos de polen: Fabaceae, Melastomataceae, Malvaceae y Asteraceae. De este estudio complementario observamos que se requiere poner en contacto a investigadores y productores, para que el acceso a los análisis de las mieles de abejas sin aguijón sea posible, y así mismo se pueda ayudar con el mejoramiento del manejo de los melionarios al momento de identificar e introducir la flora preferida por las abejas sin aguijón.(AU)

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