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AbstractFew data are on bee–plant interactions for the Melipona torrida bee in southern Brazil. This is a native bee vulnerable to extinction that pollinates native plants and produces honey that is especially appreciated by local populations. Aiming to evaluate the floral sources visited by Melipona torrida bee in southern Brazil a palynology investigation on honeys of this bee were carried out. Honeys were extracted each month from March 2020 to November 2021 of hives from two locations of Rio Grande do Sul (Cachoeirinha and Canoas). The 34 samples were analysed with a light microscope. In the honey samples of the Melipona torrida bee were identified 39 pollen types, principally tree plants. Melipona torrida bee visited frequently the plants of Myrcia type, Eucalyptus sp., Schinus terebenthifolia, Mimosa bimucronata, Parapiptadenia rigida, Morus nigra and Solanum sisymbrifolium. The pollen diagram show differences in pollen percentages throughout the year and CONISS grouped the samples in five groups (MT-1–MT-5). Richness of pollen types of samples was low in the months of winter and March and high in the honeys of months of Spring and Summer. The honeys were monofloral and heterofloral, and native plants were more visited than exotic species. The 33 pollen types from honey of Melipona torrida bee from southern Brazil can help in the knowledge of the bee–plant interaction of this native bee and propose appropriate plant management around the hives. [ABSTRACT FROM AUTHOR]

Endemic taxa are critical constituents in the flora of most parts of the world. Recently, most of these taxa have become exposed to extinction. This study aims to increase understanding of four monocot Mediterranean threatened endemic taxa in Egypt (Allium mareoticum Bornm. & Gauba, Bromus aegyptiacus Tausch, Muscari salah-eidii (Täckh. & Boulos) Hosni, Pancratium arabicum Sickenb.) by description of their pollen and seed and authentication of DNA barcoding using rbcL and matK genes. Twenty field visits were conducted from March 2017 till April 2023 including different localities through Mediterranean area for covering the presence of these species. Characterization of pollen grains and seeds were examined using a light (LM) and scanning electron microscopes (SEM). DNA barcoding was carried out for documentation of the four species. Maturase K (matK) and ribulose-bisphosphate carboxylase (rbcL) were used as primers for PCR amplification and gene sequencing. The two genes were successful in identifying Allium mareoticum, Bromus aegyptiacus, and Muscari salah-eidii at the genus level and Pancratium arabicum at both species and genus levels for rbcL marker, and the genus level for matK marker. This study is considered a leading study for new barcodes of (A) mareoticum, (B) aegyptiacus, and M. salah-eidii which were initially made available to the NCBI. [ABSTRACT FROM AUTHOR]

In Sindh province of Pakistan, Date palm growers always use pollens of wild male plants or any other type of male spathes, which are available in the market. That present study was aimed to identify potential male for pollination to obtain better yield. Five male types (viz; M1, M2, M3, M4 and M5) were identified on morphometric basis and pollens of these males were applied on two commercial female varieties i.e., Aseel and Gajar. Maximum results were recorded in Gajar variety with application of M1; weight of single bunch (9.12 kg), yield plant-1 (39.62 kg) at flesh stage, (10.50 g) single fruit weight at flesh stage, (2.03 cm) fruit diameter at flesh stage, (15.99) number of fruits strand-1, (4.68 cm) fruit length at mature fruit dev=elopment stage, (4.35 cm) at flesh stage, (2.32 cm) fruit diameter at mature stage and minimum (1.22 cm) seed stone length. Results regarding the various male type characters depicted that, maximum (31.20 feet) plant height M2, (11.29 inch) frond length M4, (177.43) number of leaflets frond-1 M4, (23.21) number of spines frond-1M1, (6.03feet) trunk diameter of lower plant portion M2, middle (5.70 feet) M4 and upper (5.43 feet) M4, number of spathe male-1 (19.55) M4, the number of flowers 6417.5, 5498.6 and 4620.3 was produced by large, medium, and small spathes respectively by M4. According to results M1 performed better on yield and yield contributing parameters of Gajar as compare to Aseel, hence it is recommended for future as a potential male. As per results, all male types were established diversely in morphometric and reproductive characteristics. [ABSTRACT FROM AUTHOR]

Fragmentary and contradictory evidence prevents a clear understanding of the possible role of the North Pacific Ocean surface on the ice‐sheet evolution. New palynological data encompassing the Pliocene and Pleistocene at Ocean Drilling Program Site 882 in the northwest Pacific document sea‐surface conditions from dinoflagellate cysts in addition to atmospheric trajectories from pollen grains and spores. The comparison of the Site 882 record with that of Site 887 from the northeast Pacific also permits documenting West to East contrasts across the subarctic North Pacific. The dinocyst assemblages at the two sites indicate strong temperature contrasts until 4.2 Ma, with much warmer conditions in the East. From 4.2 to 3.6 Ma, dinocyst assemblages of both sites are characterized by alternated dominance of the extinct taxa Habibacysta tectata and Impagidinium detroitense suggesting homogenous and cool conditions across the subarctic Pacific gyre. A major transition is recorded in the palynological assemblages at Site 882 around 2.7 Ma. It is marked by the highest occurrence of Habibacysta tectata and high percentages of Filisphaera microornata additionally to thermophilic taxa. Dinocyst record indicates high seasonality and warmer surface conditions due to reinforced stratification, which support the hypothesis of high evaporation at the origin of atmospheric moisture supply to high latitudes. During the last 1.2 Ma, the increase of Operculodinium centrocarpum relative to Nematosphaeropsis labyrinthus is tentatively interpreted as a reinforced influence of the subtropical waters. Hence, we suggest that the warm surface ocean fostered the inception and growth of northwestern North American ice‐sheets during the Pliocene and Pleistocene. Key Points: Dinocyst assemblages in the subarctic Pacific record changes in temperature and productivity through the Plio‐PleistoceneThe major transitions reflect halocline onset at 2.7 Ma and a major cooling at 1.7 MaSubarctic ocean temperature and Westerlies migration may have affected northward moisture supply and ice‐sheet growth over North America [ABSTRACT FROM AUTHOR]

Pollen is becoming an increasingly important subject for molecular researchers in genetic engineering, plant breeding, and environmental monitoring. To broaden the scope of these studies, it is essential to develop accessible methods for scientists who are not specialized in palynology. The article presents a simplified technical procedure for preparing pollen grains for scanning electron microscopy (SEM). The protocol is convenient for any molecular laboratory due to its small set of reagents, ease of execution, low cost, does not require special equipment, and takes only one hour to complete. The high penetrating ability of formaldehyde and the final delicate dehydration using hexamethyldisilazane (HMDS) instead of critical point drying allow for sufficient preservation of the architecture of the aperture, which is considered a gateway for the passage of biomolecules. The method was successfully applied to pollen grains of representatives of dicotyledons (beetroot, petunia, radish, tomato and tobacco) and monocotyledons (lily, onion, corn, rye and wheat). Species studied included insect-pollinated (entomophilous) and wind-pollinated (anemophilous) species. A comparative analysis of the sizes of fresh living pollen grains under a light microscope and those prepared for SEM showed some shrinkage. Quantitative analysis of the degree of pollen grain shrinkage showed that this process depends on the initial shape of dry pollen grains, and the number and structure of apertures. The results support the theoretical model of the folding/unfolding pathways of pollen grains. [ABSTRACT FROM AUTHOR]

Egypt is one of the important countries in terms of bee diversity in Northern Africa. The Eastern part of the country has been the subject of several studies over the last decade, especially in comparison to the Western part. In this work, we explore the diversity of solitary bees in the Alexandria Governorate, specifically in the Al Hawaria region (30°57'13" N, 29°40'27" E), based on two years of research conducted in 2021 and 2022. A total of 51 species were identified in the region: 25 species of Apidae, 16 of Megachilidae, 5 of Andrenidae, 4 of Halictidae, and one species of Colletidae. Pollen grain identification from plants and some solitary bee species revealed the creation of reference slides for pollen grains from 32 flowering plant species (both crops and wildflowers) across 19 plant families. The plant family preferences were varied among different bee genera. The most commonly visited plant families were Asteraceae, Brassicaceae, and Fabaceae, which accounted for 58% of the total beeattracting flora. The pollen spectrum from the Xylocopa aestuans (L. 1758) nest consisted of two pollen types, while the nest of Osmia sp. contained a single pollen type. [ABSTRACT FROM AUTHOR]

The main objective of this work is to use convolutional neural networks (CNN) to improve the performance in previous works on their baseline for pollen grain classification, by improving the performance of the following eight popular architectures: InceptionV3, VGG16, VGG19, ResNet50, NASNet, Xception, DenseNet201 and InceptionResNetV2, which are benchmarks on several classification tasks, like on the ImageNet dataset. We use a well-known annotated public image dataset for the Brazilian savanna, called POLLEN73S, composed of 2523 images. Holdout cross-validation is the name of the method used in this work. The experiments carried out showed that DenseNet201 and ResNet50 outperform the other CNNs tested, achieving results of 97.217% and 94.257%, respectively, in terms of accuracy, higher than the existing results, with a difference of 1.517% and 0.257%, respectively. VGG19 is the architecture with the lowest performance, achieving a result of 89.463%. [ABSTRACT FROM AUTHOR]

One of the key factors for sustainability in agricultural systems, particularly, for cultivation of date palms, is the identification of the performance parameters of the pollen grains of male date palms (Phoenix dactylifera L.). This study was carried out to predict the performance parameters of pollen grains using an artificial neural network (ANN) model. The morphological features of spathe length, spathe weight, number of pinnae per leaf, leaf length, leaf width, length of the pinna part, pinna length, pinna width, length of the spathe stem, and spathe width, as well as the concentrations of minerals such as Mg, N, K, P, and Ca in their leaves were used as inputs to the ANN model. For this purpose, we collected the required data from nine male date palms grown in Saudi Arabia. The ANN model utilized in this work included an input layer with 15 parameters, a hidden layer of 30 neurons, and an output layer with 8 neurons. The ANN model was trained with 27 patterns. Seven patterns were utilized for testing purposes. The coefficient of determination (R2) obtained between the observed and predicted performance parameters' values using the testing dataset was 0.902 for the number of strands per spathe, 0.967 for strand length, 0.963 for the number of flowers per strand, 0.941 for the number of flowers per spathe, 0.985 for the weight of pollen grains per spathe, 0.810 for the pollen grains' viability, 0.936 for the pollen grains' length, and 0.992 for the pollen grains' width. The length of the spathe stem had the most critical effect on how the ANN model predicted the values of the dependent variables, i.e., the number of strands per spathe, with a percentage of contribution of 17.66%; the weight of pollen grains per spathe, with 17.85%; the pollen grains' length, with 19.78%, and the pollen grains' width, with a percentage of contribution of 30.59%. Spathe weight had the most critical influence on strand length and pollen grains' viability, with percentages of 26.29% and 14.92%, respectively. Leaf width had the most critical effect on the number of flowers per spathe, with a percentage of 12.55%. The elemental concentration of K in the male date palm leaves had the most critical effect on the number of flowers per strand, with a percentage of 13.98%. It was therefore concluded that using a modeling process with the ANN technique can help estimate the performance parameters of male date palms' pollen grains for different purposes, such as providing a starting point for mathematical analyses associated with the physiological mechanisms of male date palm. Moreover, the outcomes of this research work can be supportive as a practical tool in this field of study. [ABSTRACT FROM AUTHOR]

Abstract Melissopalynological techniques are used in the analysis of pollen grains. However, the adoption of methodologies considering cost-effectiveness, shorter preparation time and lesser toxic procedures for researchers is relevant. Thus, this study aimed to analyze different melissopalynological methodologies in polyfloral honey samples. Three melissopalynological protocols were applied to the samples using alcian blue dye, basic fuchsin, and the traditional acetolysis methodology without dye. After preparing the pollen samples, and analyzing them under an optical microscope, six botanical families were recorded, e.g., Amaranthaceae, Asteraceae, Bignoniaceae, Fabaceae, Malvaceae, and Myrtaceae. The methodologies investigated proved to be efficient for detecting pollen structures and identifying botanical families thereof. The alcian blue dye-based protocol allowed a greater separation and discrimination of pollen grains as compared to the basic fuchsin and acetolysis ones, where pollen conglomerates were often identified. Even though acetolysis has been the most used method in melissopalynological studies, it has been claimed to offer risks to users due to the manipulation of corrosive and toxic solvents (i.e., H2SO4), also being lesser cost-effective and more time-consuming. Thus, considering the cost-effectiveness, the alcian blue dye and basic fuchsin-based methods seem to be preferred, being as efficient as acetolysis for identifying pollen grains.

This study evaluates the engineering properties of various carriers for date palm pollen grains, including Wheat Flour (WF), Wheat Bran (WB), Banana Peels (BP), Male Spathe Flowers (MSF), and Female Bunch Strands (FBS). The focus is on bulk density, repose angle, dynamic coefficient of friction, and terminal velocity. Bulk density ranged from 0.321 to 0.831 g cm-3, with date palm pollen grain (DPP) showing the highest value, suggesting efficient storage but potential flowability issues. Repose angles varied from 24 to 47 degrees; DPP and DPP+FBS (Female bunch strands) had the lowest angles, favoring smooth flow during pollination, while wheat flour (WF) had the highest, indicating resistance and clumping. Friction analysis across different surfaces (acrylic, PVC, aluminum, and stainless steel) highlighted material-surface interactions. Terminal velocity results showed DPP with a balanced value of 0.96 m s-1, while mixtures like DPP+FBS and DPP+BP (banana peels) had low to moderate velocities (0.6 m s-1 and 1.02 m s-1), enhancing dispersion. DPP and its mixtures, especially DPP+FBS, exhibited favorable pollination properties with good flowability and moderate friction, promoting efficient distribution. In contrast, higher friction materials like FBS could hinder application. The study emphasizes the need to select carriers with optimal density, repose angle, and friction to improve pollination efficiency, supporting better agricultural outcomes. Mixtures DPP+FBS and DPP+MSF emerged as the best option, balancing physical, mechanical and aerodynamic characteristics for effective pollination. [ABSTRACT FROM AUTHOR]

The contemporary study examined several wild species of dicotyledons developing in the Samawa Desert in Southern Iraq. The various characteristics of these species' assessment used a light microscope to isolate the species from each other and better utilize their qualities. Based on the collected field samples, four species belonging to the family Asteraceae reached identification, i.e., Aaronsohnia factorovskyi, Anvillea gracinii, Anthemis maritima, and Calendula arvensis. The botanical characteristics, such as shape, size, apertures, pole type, apocolpium, mesocolpium, wall thickness, and exine sculpturing, also gained evaluation in the study. The examined profiles of different species varied greatly, according to the results. The nature of the polarity of the pollen grains determines the pollen grains' polarity, which, in turn, determines the shape of apertures and isopolar to take apertures zono-colporate. The overall shape of the pollen grains, determined by the ratio between the polar axis to the equatorial axis P/E, included prolate spheroidal and oblate spheroidal. By measuring the axis length, the study showed that the species' pollen grains were within a medium range. As for exine sculpturing, the study revealed one type of sculpturing, i.e., echinate in the genera Aaronsohnia factorovskyi, Anvillea gracinii, and Anthemis maritima, while the genus Calendula arvensis was devoid of decorations. [ABSTRACT FROM AUTHOR]

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Copyright of Egyptian Journal of Botany is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Incorporating green chemistry concepts into nanotechnology is an important focus area in nanoscience. The demand for green metal oxide nanoparticle production has grown in recent years. The beneficial effects of using nanoparticles in agriculture have already been established. Here, we highlight some potential antifungal properties of Zizyphus spina leaf extract-derived copper oxide nanoparticles (CuO-Zs-NPs), produced with a spherical shape and defined a 13–30 nm particle size. Three different dosages of CuO-Zs-NPs were utilized and showed promising antifungal efficacy in vitro and in vivo against the selected fungal strain of F. solani causes tomato root rot disease, which was molecularly identified with accession number (OP824846). In vivo results indicated that, for all CuO-Zs-NPs concentrations, a significant reduction in Fusarium root rot disease occurred between 72.0 to 88.6% compared to 80.5% disease severity in the infected control. Although treatments with either the chemical fungicide (Kocide 2000) showed a better disease reduction and incidence with (18.33% and 6.67%) values, respectively, than CuO-Zs-NPs at conc. 50 mg/l, however CuO-Zs-NPs at 250 mg/l conc. showed the highest disease reduction (9.17 ± 2.89%) and lowest disease incidence (4.17 ± 3.80%). On the other hand, CuO-Zs-NPs at varied values elevated the beneficial effects of tomato seedling vigor at the initial stages and plant growth development compared to either treatment with the commercial fungicide or Trichoderma Biocide. Additionally, CuO-Zs-NPs treatments introduced beneficial results for tomato seedling development, with a significant increase in chlorophyll pigments and enzymatic activity for CuO-Zs-NPs treatments. Additionally, treatment with low concentrations of CuO-Zs-NPs led to a rise in the number of mature pollen grains compared to the immature ones. however the data showed that CuO-Zs-NPs have a unique antifungal mechanism against F. solani, they subsequently imply that CuO-Zs-NPs might be a useful environmentally friendly controlling agent for the Fusarium root rot disease that affects tomato plants. Graphical Abstract

Animal pollination is important for more than 75% of agricultural crops, including coffee, whose productivity can increase with adequate pollination. Bees, including many solitary species, are diverse pollinators, with around 85% of them considered more effective than honeybees in pollen transfer. We assessed the coffee plantation and its surrounding vegetation for solitary bee nesting throughout the coffee flowering season and measured their impact on coffee productivity.We installed collection stations with trap nests inside a coffee plantation, on the border and inside the native vegetation in a farm in Diamantina, MG, Brazil. We used 10 weekly monitored replicates at least 1 km apart. We evaluated fruiting by autogamy in relation to natural pollination and used the increase in fruit set from pollinators to calculate the farmer's monetary gain. We recorded bee visits to the exposed flowers during coffee flowering considering both on the edge and inside the coffee plantation. Ripe fruits were dried, counted and weighed.We discovered 132 solitary bee nests outside the plantation, with 54% containing coffee pollen grains, indicating coffee as an essential resource for bees even outside the crop area. More bee visits occurred at the coffee plantation's edge, resulting in increased fruit production, denser fruits, and rounder fruits in that area. Bagged flowers produced consistent seeds in all locations. The farmer could earn an extra US$1736.37 per hectare if the entire area received the same level of pollination contribution from bees as observed at the coffee border.Synthesis and applications. Our study emphasises the key role of pollinators in coffee production and their impact on fruit and seed characteristics. Bee visits were more frequent on border areas, emphasising their reliance on natural nesting sites. Bee‐mediated pollination positively affected fruit traits and self‐pollinated fruits in plantation borders had reduced mass. Solitary bee nesting was primarily observed in native vegetation, underlining its importance for bee populations. Pollen composition in nests varied with proximity to coffee plantations, indicating landscape vegetation influences pollinator foraging. These findings support optimising coffee plantation design by preserving native vegetation to increase coffee yields and conserve biodiversity. [ABSTRACT FROM AUTHOR]

Considering the limited data available on tree species in Uzbekistan, this research aimed to provide new insights. We gathered plant samples from different locations within Samarkand city and thoughtfully selected 15 tree species that represent the country's flora. Using scanning electron microscopy, we conducted comprehensive analyses of pollen morphology, revealing a diverse range of variations in the shapes, dimensions, and surface characteristics displayed by pollen grains. Distinct ornamentations such as micro‐echinate, reticulate, rugulate, gemmate–verrucate, and verrucate–scabrate patterns facilitated the differentiation of species. These scanning electron microscopy findings enhance our comprehension of tree species diversity, adaptation, and ecological roles. In addition, leaf extracts were analyzed using HPLC and GC–MS, revealing a plethora of bioactive compounds, including catechins, chlorogenic acid, vanillic acid, and others. Furthermore, GC–MS analysis revealed the presence of seven key compounds, including 1‐hexadecyne, 2‐chloroethanol, 1,6‐heptadiene, 2‐methyl‐, 5‐bromoadamantan‐2‐one, ethyl 3‐(3‐pyridyl) propenoate, bis (2‐ethylhexyl) phthalate, and quercetin. This study demonstrates the effectiveness of this method in assessing the quality of leaf extracts from tree species by examining both microscopic characteristics and chemical composition. This multifaceted approach has deepened our understanding of the characteristics and chemical compositions of these trees, thus contributing to a more profound appreciation of their ecological significance and potential applications. [ABSTRACT FROM AUTHOR]

Liquidambar L. is a significant constituent of the Cenozoic flora in the Northern Hemisphere. Currently, this genus exhibits a discontinuous distribution across Asia and North America, with the center of diversity being in southeastern Asia. This study presents the first occurrence of Liquidambar in the Oligocene of South China. Fossil sweetgum infructescences, associated pollen, and leaves have been found in the Nanning Basin, Guangxi. A new species, Liquidambar nanningensis sp. nov., is described based on the morphological and anatomical characteristics of three-dimensionally preserved infructescences. The Liquidambar fossils from the Nanning Basin show a combination of features indicative of the former genera of Altingiaceae, Altingia, Liquidambar s. str., and Semiliquidambar. The new occurrence expands the taxonomic and morphological diversity of the Paleogene Liquidambar species in South China. [ABSTRACT FROM AUTHOR]

This study was amied to investigate morphological characteristics of pollen grains and fruits for eleven species belonging to the tribe Brassiceae of cruciferae family, species are: Brassica rapa L, Braasica deflexa Boiss.,Brassica nigra (L.) brassica juncea(L.), Brassica tournefortii Gouan, Brassica oleracea L., sinapis arvensis L., Hirschfeldia incana(L.),Savignya paraflora(Del.),Raphanus sativus L.,Eurca sativa Mill., pollen grains were studied morphologically and all dimentions were recorded. The result of this study showed that most pollen grains are tricolpate,their size varied between small,medium and ornamentation was reticulated. The morphological study of fruits showed a contrast in the ornamentation between reticulate, smooth reticulate and rough reticulate,it’s also varied in color, shape and dimensions. [ABSTRACT FROM AUTHOR]

Pollen micromorphology of nine species of the genus Tulipa (including three subgenera Tulipa, Clusiana, and Eriostemones) and one species from the genus Amana were examined using light microscopy (LM) and scanning electron microscopy (SEM). Moreover, the pollen wall ultrastructure of five selected taxa from the studied species of Tulipa and one species of Amana were examined by transmission electron microscopy (TEM). Pollen micromorphology (especially exine ornamentation, sulcus margin and sulcus membrane ornamentation, operculum ornamentation) and pollen wall ultrastructure (sporoderm thickness, tectum/foot layer ratio, number of intine layers in sulcus membrane region) varied in the studied taxa. A dendrogram of the pollen micromorphological characteristics (obtained from LM and SEM observations) distinguished three pollen types and six subtypes. Amana edulis (subtype A) and Tulipa biebersteiniana (subtype B) were placed in pollen type 1. Tulipa tetraphylla (subgenus Eriostemones) with Tulipa urumiensis and Tulipa kolpakowskiana (subgenus Tulipa) were placed in pollen type 2. Tulipa clusiana (subgenus Clusiana) and Tulipa suaveolens (subgenus Tulipa) belonged to pollen type 3. Information from pollen wall ultrastructure provided better differentiation of these taxa for better taxonomical resolution. Pollen micromorphology along with ultrastructure can be useful for better understanding the systematic affinities of the species in the genus Tulipa and its relation with the genus Amana and for establishing subgenus rank for T. biebersteiniana and T. clusiana. [ABSTRACT FROM AUTHOR]

Diet is an important component of mass-production system of bio-control agents. Thus, using a non-prey diet (such as plant pollen) instead of natural prey could be more cost-effective in mass-production of phytoseiid predatory mites. Therefore, the present study aimed to examine the multigenerational effect of maize, Zea mays L. (Poaceae), pollen diet on life table parameters of Amblyseius swirskii Athias-Henriot and Cydnoseius negevi (Swirski & Amitai) (Acari: Phytoseiidae) reared for one, five and 11 consecutive generations. The predatory mites A. swirskii and C. negevi successfully completed their development on maize pollen for up to 11 generations. In G1, oviposition days, adult longevity, and fecundity showed significantly higher values in the case of C. negevi as compared to A. swirskii. Despite statistically similar oviposition days in the G11, A. swirskii females (44.43 eggs/♀) deposited significantly more eggs than those of C. negevi (40.60 eggs/♀). There were no significant differences in finite rate of increase (λ), intrinsic rate of increase (r), net (R0) and gross (GRR) reproductive rates between the two predatory mites in G1 and G5 (P ≥ 0.05). In G11, individuals of C. negevi had significantly higher values of r (0.181 day-1) and λ (1.198 day-1) compared to those of A. swirskii (r = 0.159 day-1, λ = 1.173 day-1). However, there were no significant differences in R0 and GRR values between A. swirskii (R0 =34.18 offspring, GRR = 39.75 offspring) and C. negevi (R0 = 31.23 offspring, GRR = 35.44 offspring) in G11. In conclusion, maize pollen has a great potential as a suitable and cost-effective diet for developing the mass-production system of A. swirskii and C. negevi on non-prey diets, where the performance of these predators remained to some extent constant across generations. [ABSTRACT FROM AUTHOR]

Nayab, N., and Alam, M.A. 2023. Negative effects of pollen drought stress on floral volatiles, floral nectar, pollinator behavior, and seed production in Ocimum basilicum plants. Tunisian Journal of Plant Protection 18 (2): 41-61.

The nature of pollen grains and karyotype morphology are important bases in the task of clarifying relationships and they are considered to be of significant value in observing the effects of environmental and climatic factors on plants. The investigations of the palynological, as well as karyological and physiological data regarding to M. coralloides, as one of the rarest species of the Armenian flora, were conducted for the first time using light and scanning electronic microscopy. In Armenia the only remaining population of this species is currently located in the Ararat valley salt marshes to the south-east of Ararat town. In the Red Book of Plants of the Republic of Armenia the species M. coralloides is presented in the category EN (Endangered species). Description of the pollen grain and karyotype of the Armenian population of M. coralloides subsp. anatolicum collected from the vicinity of Ararat town are provided in the article. The study of the water regime, transpiration intensity and photosynthesis, as well as plastid pigments were also conducted. Comparative analysis between Armenian and Iranian specimens of the subspecies M. coralloides subsp. anatolicum showed some discrepancies in pollen features, as well as karyological data, which indicate some specificity of the population growing on the territory of Armenia. The diversity and intersections in pollen traits can be attributed to either natural variability within a population (plasticity), or they may be influenced by genetic differences among populations and closely related species. The physiological data highlights specialized adaptations of M. coralloides subsp. anatolicum for managing water resources, reducing transpiration, and performing photosynthesis in the high salinity conditions of the Ararat Plain. This showcases the plant's remarkable resilience and adaptability to its specific ecological niche, emphasizing the interplay between environment and biology.

Pollen is becoming an increasingly important subject for molecular researchers in genetic engineering, plant breeding, and environmental monitoring. To broaden the scope of these studies, it is essential to develop accessible methods for scientists who are not specialized in palynology. The article presents a simplified technical procedure for preparing pollen grains for scanning electron microscopy (SEM). The protocol is convenient for any molecular laboratory due to its small set of reagents, ease of execution, low cost, does not require special equipment, and takes only one hour to complete. The high penetrating ability of formaldehyde and the final delicate dehydration using hexamethyldisilazane (HMDS) instead of critical point drying allow for sufficient preservation of the architecture of the aperture, which is considered a gateway for the passage of biomolecules. The method was successfully applied to pollen grains of representatives of dicotyledons (beetroot, petunia, radish, tomato and tobacco) and monocotyledons (lily, onion, corn, rye and wheat). Species studied included insect-pollinated (entomophilous) and wind-pollinated (anemophilous) species. A comparative analysis of the sizes of fresh living pollen grains under a light microscope and those prepared for SEM showed some shrinkage. Quantitative analysis of the degree of pollen grain shrinkage showed that this process depends on the initial shape of dry pollen grains, and the number and structure of apertures. The results support the theoretical model of the folding/unfolding pathways of pollen grains.

One of the key factors for sustainability in agricultural systems, particularly, for cultivation of date palms, is the identification of the performance parameters of the pollen grains of male date palms (Phoenix dactylifera L.). This study was carried out to predict the performance parameters of pollen grains using an artificial neural network (ANN) model. The morphological features of spathe length, spathe weight, number of pinnae per leaf, leaf length, leaf width, length of the pinna part, pinna length, pinna width, length of the spathe stem, and spathe width, as well as the concentrations of minerals such as Mg, N, K, P, and Ca in their leaves were used as inputs to the ANN model. For this purpose, we collected the required data from nine male date palms grown in Saudi Arabia. The ANN model utilized in this work included an input layer with 15 parameters, a hidden layer of 30 neurons, and an output layer with 8 neurons. The ANN model was trained with 27 patterns. Seven patterns were utilized for testing purposes. The coefficient of determination (R2) obtained between the observed and predicted performance parameters’ values using the testing dataset was 0.902 for the number of strands per spathe, 0.967 for strand length, 0.963 for the number of flowers per strand, 0.941 for the number of flowers per spathe, 0.985 for the weight of pollen grains per spathe, 0.810 for the pollen grains’ viability, 0.936 for the pollen grains’ length, and 0.992 for the pollen grains’ width. The length of the spathe stem had the most critical effect on how the ANN model predicted the values of the dependent variables, i.e., the number of strands per spathe, with a percentage of contribution of 17.66%; the weight of pollen grains per spathe, with 17.85%; the pollen grains’ length, with 19.78%, and the pollen grains’ width, with a percentage of contribution of 30.59%. Spathe weight had the most critical influence on strand length and pollen grains’ viability, with percentages of 26.29% and 14.92%, respectively. Leaf width had the most critical effect on the number of flowers per spathe, with a percentage of 12.55%. The elemental concentration of K in the male date palm leaves had the most critical effect on the number of flowers per strand, with a percentage of 13.98%. It was therefore concluded that using a modeling process with the ANN technique can help estimate the performance parameters of male date palms’ pollen grains for different purposes, such as providing a starting point for mathematical analyses associated with the physiological mechanisms of male date palm. Moreover, the outcomes of this research work can be supportive as a practical tool in this field of study.

Aerobiology is a scientific discipline that focuses on investigating biological particles (bioaerosols) passively transported in the atmosphere, mainly fungal spores and pollen grains. Due to the allergic and pathogenic properties of these particles, aerobiological data is widely used in allergology, plant pathology, and agriculture. In addition, the results of aerobiological monitoring have found applications in biogeography, paleoecology, forestry, veterinary medicine, forensic science, and climate change research, as well as in the assessment of threats to the deterioration of cultural heritage. In this review, the contribution of Polish scientists to the development of worldwide aerobiology is presented. The most important results on the atmospheric dispersion of bioaerosols, spatiotemporal modeling, and novel methods used in aerobiological research are described. Moreover, the cooperation at the national and international levels as part of scientific programs and the perspectives for further development of aerobiology in Poland are discussed.

The new genus Amurodendron with the type species Amurodendronpilosum sp. nov. is described from the Paleocene of the Amur Region (Russian Far East) based on compressions of vegetative shoots and leafy shoots with pollen cones and in situ pollen grains. Leaves are polymorphic. Linear-lanceolate leaves are helically arranged, sometimes distichous, with petiolate long-decurrent bases. The most characteristic feature of the new taxon is the presence of numerous hair-like marginal teeth observed on the linear leaves from leaf base to apex and also on the axis of shoots. Rhomboid scale-like leaves borne at the bases of vegetative shoots and on the axes bearing pollen cones. All leaves are amphistomatic. Stomata of leaves and lower microsporophylls are monocyclic or incompletely amphicyclic and predominantly longitudinally oriented. Pollen cones are ellipsoidal, terminally and laterally arranged; lateral cones arrange alternately or subopposite. Pollen grains are small to medium in size, rounded, with distal papilla, granular ectexine and lamellate endexine. The combination of features of Amurodendronpilosum is indicative of Cupressaceae but distinguishes it from any known extant and fossil conifers of the family. [ABSTRACT FROM AUTHOR]

The failure to treat infectious diseases due to the continual emergence of drug-resistant microbes poses a huge and serious challenge for human health globally. Currently, the discovery and development of natural therapeutic compounds are attracting considerable attention from researchers worldwide. In this project, two types of pollen grains (maize and clover) were evaluated for potential antimicrobial activities. Extracts of both pollen grains were purified using HPLC, which has been shown to have numerous phenolic and flavonoid compounds. Pyro catechol and methyl gallate were detected in high concentrations (1145.56 and 1056.57 µg/mL, respectively) in the maize extract, while caffeic acid, quercetin, and kaempferol (464.73, 393.05, and 390.93 µg/mL, respectively) were among the compounds observed at high concentrations in the clover pollen grains extract. Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Candida albicans were more sensitive to the clover pollen grains extract with inhibition zones of 22 ± 0.2, 18 ± 0.1, 29 ± 0.3, and 42 ± 0.4 mm compared to the size of the inhibitory zones caused by the maize pollen grains extract (19 ± 0.3, 15 ± 0.4, 27 ± 0.1, and 22 ± 0.4 mm, respectively). Moreover, lower MIC values for the clover pollen grains extract were recorded against C. albicans (1.97 ± 0.04 µg/mL), S. aureus (62.5 ± 1.00 µg/mL), and E. coli (62.5 ± 0.07 µg/mL) than the MICs caused by the maize pollen grains extract. The use of a transmission electron microscope revealed that the E. coli that had been treated with the clover pollen grains extract showed changes in its cell walls compared to that treated with the maize pollen grains extract. The clover pollen grains extract exhibited a stronger antioxidant potential, with an IC50 value of 22.18 µg/mL, compared to an IC50 value of 54.85 µg/mL for the maize pollen grains extract, via a DPPH scavenging assay. Regarding anticancer activity, the maize pollen grains extract was revealed to be more effective in terms of inhibiting the human colon cancer cell line HCT-116, with an IC50 value of 67.02 ± 1.37 µg/mL, compared with the observed toxicity caused by the clover extract, with an IC50 value of 75.03 ± 1.02 µg/mL. Overall, the clover pollen grains extract demonstrated potent antibacterial and antioxidant activities, but not anticancer activity, when compared to the maize grains extract. Thus, the current findings related to both types of pollen grains (clover and maize) highlight their potential therapeutic applications for the treatment of certain infectious diseases and malignancies. [ABSTRACT FROM AUTHOR]

Jatropha (Jatropha curcas L.) is a shrub that produces non-food oil and can potentially be used for biodiesel production. An interspecific cross was made between J. curcas and peregrina (J. integerrima) to increase genetic diversity. Interestingly, male sterility was observed in the F2 population. Out of the 445 F2 plants, five, namely, ms-1 to ms-5, exhibited male sterility, characterized by unopened and distorted stamens without pollen. The parental jatropha, peregrina, F1 and F2 had fertile pollen grain rates of 90.61%, 96.39%, 81.46% and 75.39%, respectively. To verify the fertility of the pistils in the male sterile plants, they were pollinated through selfing, opening and hand crossing with fertile pollen. All of the ms lines experienced seed abortion with or without fruit, except for 'ms-5', which produced seed. [ABSTRACT FROM AUTHOR]

Summary: Molecular phylogenetic studies have revealed an entirely holoparasitic Boschniakia–Epifagus clade within Orobanchaceae. Pollen morphology of seven species, four studied for the first time, belonging to five currently recognised genera was studied using both light and scanning electron microscopy. Pollen grains are (2 –) 3 (– 4)-colpate, rarely 3-colporate and inaperturate (reported in Epifagus for the first time); suboblate to prolate (P/E = 0.77 – 1.56) in shape; medium and rarely small-sized: Polar axis = 14.63 – 34.58 µm, Equatorial diameter = 14.63 – 30.59 µm. Colpi are long, medium-length or short, wide or narrow, and acute, obtuse, or with indistinct ends. Exine sculpture is rather diverse: reticulate, microreticulate, rugulate-granulate, granulate-perforate, rugulate-perforate, and granulate. The data obtained demonstrate that pollen grains of the studied taxa are morphologically rather diverse and can, therefore, be distinguished at the levels of genera and species. The diagnostic features include shape and size of pollen grains, length and width of colpi, exine thickness in mesocolpia and apocolpia, and exine sculpture. Palynomorphological data are interpreted within the current phylogenetic framework. An UPGMA dendrogram, based on quantitative characters of the pollen grains, supports the status of Xylanche as a genus. [ABSTRACT FROM AUTHOR]

Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a member of the Juglandaceae family. During spring, pecan trees break their bud dormancy and produce new leaves and flowers. Carbohydrates stored in roots and shoots are thought to support the bloom and early vegetative growth during this time until new leaves start the full photosynthetic activity. Spring freeze is known for its damaging effects on pecan bud and flower growth and development. Pecan shoots with leaves and flowers from five scion-rootstock combinations were collected hours before and after a recent spring freeze (below 0 °C for 6 hours, 21 Apr 2021, Perkins, OK, USA). Morphologies of the leaf, bud, and catkin were visually observed, and the morphologies of the anther and pollen in paraffin sections were investigated by light microscopy. Soluble sugar and starch from bark and wood were analyzed using the anthrone reagent method. The Kanza-Mount showed the maximum damage to terminal leaves, buds, and catkins, whereas Maramec-Colby had the minimum damage only to leaves. Pollen grains were shrunk and reduced in number in the anthers in the protandrous Pawnee scions, whereas no pollen damage was observed in the protogynous Kanza scion. Furthermore, bark soluble sugar levels increased in all the scion-rootstock combinations after the freeze, which may indicate a physiological response to the cold stress. Overall, the extent of spring freeze damage of pecans is affected by the growth stage, types of scion and rootstock, and the scion-rootstock interactions. Furthermore, in addition to low temperature, scion-rootstock interactions also affected the starch and soluble sugar contents in wood and bark tissues. [ABSTRACT FROM AUTHOR]

The nature of pollen grains and karyotype morphology are important bases in the task of clarifying relationships and they are considered to be of significant value in observing the effects of environmental and climatic factors on plants. The investigations of the palynological, as well as karyological and physiological data regarding to M. coralloides, as one of the rarest species of the Armenian flora, were conducted for the first time using light and scanning electronic microscopy. In Armenia the only remaining population of this species is currently located in the Ararat valley salt marshes to the south-east of Ararat town. In the Red Book of Plants of the Republic of Armenia the species M. coralloides is presented in the category EN (Endangered species). Description of the pollen grain and karyotype of the Armenian population of M. coralloides subsp. anatolicum collected from the vicinity of Ararat town are provided in the article. The study of the water regime, transpiration intensity and photosynthesis, as well as plastid pigments were also conducted. Comparative analysis between Armenian and Iranian specimens of the subspecies M. coralloides subsp. anatolicum showed some discrepancies in pollen features, as well as karyological data, which indicate some specificity of the population growing on the territory of Armenia. The diversity and intersections in pollen traits can be attributed to either natural variability within a population (plasticity), or they may be influenced by genetic differences among populations and closely related species. The physiological data highlights specialized adaptations of M. coralloides subsp. anatolicum for managing water resources, reducing transpiration, and performing photosynthesis in the high salinity conditions of the Ararat Plain. This showcases the plant's remarkable resilience and adaptability to its specific ecological niche, emphasizing the interplay between environment and biology. [ABSTRACT FROM AUTHOR]

Simple Summary: The yellow-legged hornet is an invasive species from southeast Asia that has turned the European beekeeping sector upside down. The spread of this species has been advancing in recent years, and today, several European countries are threatened by Vespa velutina. The need to study its behavior is urgent given the increasingly evident economic and environmental impacts. In this regard, there is little information about the feeding habits and the resources it uses during the life cycle. Like other Hymenoptera, hornets require carbohydrates and proteins as their primary nutrients. Sugary secretions such as floral nectar, honeydew, or fruit juices are the main sources of carbohydrates but the protein intake is provided by the consumption of a diverse diet of insects such as the honey bee. There is scarce information on the presence of pollen grains in the gastrointestinal content of larvae other than secondary contamination from hunting. This content could represent the surrounding flora of its habitat that is used as a resource. Therefore, the objective of this study was to describe the main pollen types present in the gastrointestinal system of larvae taken from V. velutina nests. Vespa velutina is an invasive species that exhibits flexible social behavior, which may have contributed to its introduction in several European countries. It is important to understand its behavior in order to combat the effects of its introduction in different areas. This implies knowing the resources that it uses during its biological cycle. Hornets require protein resources taken from insects and organic matter as well as carbohydrates as an energy source to fly and also to forage for food and nest-building materials. The gastrointestinal tract of adults and larvae contains a wide variety of pollen types. The identification of this pollen in larvae collected from nests could offer information about the plant species that V. velutina visits as a foraging place. The main objective of this research was to study the pollen content in the gastrointestinal tract of larvae. Patterns of pollen content and pollen diversity were established according to the nest type, altitude, season, and location in the nest comb. The abundance of pollen types such as Eucalyptus, Castanea, Foeniculum vulgare, Hedera helix, Taraxacum officinale, Echium, or Cytisus pollen type stands out in many of the samples. [ABSTRACT FROM AUTHOR]

The presented research investigated the pollen morphology of endemic Iraqi Hypericum species. The study revealed phenotypic features of pollen grains in the polar and equatorial views and their quantitative and qualitative characteristics. The results showed that the pollen grains of the genus Hypericum were radially symmetrical and isopolar, and their apertures were simple and tricolporate, except the species H. davisii, distinguished as tetracolprate. Dividing the studied species based on pollen grain sizes comprised two groups. Small pollen grains with an average length of the equatorial view ranged between 10-16 µm in H. lysimachioides and H. vermiculare. Medium-sized pollen grains with an average extent between 17-26 µm emerged in the species, i.e., H. retusum, H. triquetrifolium, H. perforatum, H. lydium, H. tetrapterum, H. asperulium, H. scabrum, and H. davisii. Pollen grains, also divided according to the P/E ratio, had two main groups. The pollen grains were subprolate and spherical, with the exine sculpturing examined by a scanning electron microscope (SEM), and isolated into four groups: 1) microreticulate reticulum, including H. asperulium, H. lydium, and H. vermiculare, 2) perforate, i.e., H. retusum, H. scabrum, H. tetrapterum, and H. triquetrifolium, 3) psilate with H. perforatum and H. davisii, 4) and reticulate exine sculpturing in H. lysimachioides, all isolated from the rest of the species. SEM images showed the thickness of exine ranged from 0.5 to 2 µm. The topical study also added H. davisii as a new species with no previous records in Iraq. This pollen study added valuable data for taxonomy and suggested that it should proceed with its first-time registration in Iraq. The pertinent research could provide a taxonomical key for Hypericum species in Iraq. [ABSTRACT FROM AUTHOR]

The main objective of this work is to use convolutional neural networks (CNN) to improve the performance in previous works on their baseline for pollen grain classification, by improving the performance of the following eight popular architectures: InceptionV3, VGG16, VGG19, ResNet50, NASNet, Xception, DenseNet201 and InceptionResNetV2, which are benchmarks on several classification tasks, like on the ImageNet dataset. We use a well-known annotated public image dataset for the Brazilian savanna, called POLLEN73S, composed of 2523 images. Holdout cross-validation is the name of the method used in this work. The experiments carried out showed that DenseNet201 and ResNet50 outperform the other CNNs tested, achieving results of 97.217% and 94.257%, respectively, in terms of accuracy, higher than the existing results, with a difference of 1.517% and 0.257%, respectively. VGG19 is the architecture with the lowest performance, achieving a result of 89.463%.

CRASSULACEAE (orpine or stonecrop family) is a morphologically diverse and systematically complex Angiosperm family with a cosmopolitan distribution. A detailed description of the range of pollen morphological variation within the family has been presented, to resolve the taxonomic confusion between members of this family. palynological investigation of 19 species representing nine genera of Crassulaceae were studied using both light (LM) and scanning electron microscopy (SEM). The aim of the present study was to find out the taxonomic significance of palyno-morphological characteristics in family Crassulaceae. A comparative pollen analysis was accomplished based on pollen size, shape, polar and equatorial views, polar and equatorial diameter ratio (P/E ratio), aperture characters and exine features. Generally, the pollen grains were found to be monad, isopolar, radially symmetric, prolate-spheroidal, subprolate or prolate in equatorial view, triangular, tetragonal, or pentagonal in polar view. There are three different types of apertures encountered in the examined species. These types ranged from tricolporate, tetra- and penta- colporate pollen grains. Clear variation of tectum sculpture pattern was also observed, mostly rugulate/foveolate and rarely striate. According to tectum sculpturing pattern, three major pollen types were recognized: Crassula type, Echeveria type and Kalanchoe type. Based on the overall characteristics of pollen grains, some combinations of pollen morphological characters can reliably delimitate genera, while others are unique to some species. Additionally, based on qualitative pollen morphological characters, an identification key for main pollen types was provided. [ABSTRACT FROM AUTHOR]

Barleria albostellata C.B. Clarke (grey barleria, Acanthaceae) is an indigenous shrub to South Africa and has been relatively understudied. This shrub is a valuable medicinal plant with a wide spectrum of antibacterial and anti-inflammatory activities. Detailed studies on the floral and pollen morphology on B. albostellata are rare. This study was conducted to observe the morphology of the flower and pollen grains using stereomicroscopy and scanning electron microscopy (SEM). Morphological observations showed numerous non-glandular trichomes on the bracteoles and bracts of B. albostellata. Three types of trichomes were identified on these structures: I—unicellular, II—multangulate-dendritic branched non-glandular trichomes, and III—capitate glandular trichomes. A taxonomical description of the floral structures using stereo and SEM micrographs is provided. SEM micrographs revealed the pollen grains as globose tricolporate with a rough honeycomb exine, and small granules inside the lumina. The diameter of the pollen grains was 77.53 ± 5.63 μm, whereas the aperture of these grains was 14.31 ± 0.59 µm. This study provides insight into the floral biology of B. albostellata, and the results presented here will add to the body of knowledge and encourage further research on this species. [ABSTRACT FROM AUTHOR]

Visual classification of pollen grains is crucial for various agricultural applications, particularly for the protection, monitoring, and tracking of flora to preserve the biome and maintain the quality of honey-based products. Traditionally, pollen grain classification has been performed by trained palynologists using a light microscope. Despite their wide range of applications, still tiresome and time-consuming methods are used. Artificial intelligence (AI) can be used to automate the pollen grain classification process. Recently, numerous AI-based techniques for classifying pollen grains have been proposed. However, there is still possibility for performance enhancement including processing time, memory size, and accuracy. In this study, an attention-guided pollen feature aggregation network (APFA-Net) based on deep feature aggregation and channel-wise attention is proposed. Three publicly available datasets, POLLEN73S, POLLEN23E, and Cretan pollen, having a total of 7362 images from 116 distinct pollen types are used for experiments. The proposed method shows F-measure values of 97.37 %, 97.66 %, and 98.39 % with POLLEN73S, POLLEN23E, and Cretan Pollen datasets, respectively. We confirm that our method outperforms existing state-of-the-art methods.

Results of a study of self-pollination in two of Ukrainian flora's threatened species, Gladiolus imbricatus and Iris sibirica (Iridaceae), are presented. To confirm or refute the occurrence of self-pollination in G. imbricatus and I. sibirica, an experiment was conducted on pollen germination on their stigmas. It has been found that in G. imbricatus pollination with autogenous pollen grains on the last day of flowering leads to the growth of pollen tubes in the cases of both hand and natural pollination. However, pollen grains on the stigma of an isolated I. sibirica flower were not detected on the first or last day of flowering, which means the absence of a mechanism of autonomous pollen transfer within the meranthium. Ungerminated pollen grains were also found on the stigma after autogenous hand pollination. It has been experimentally confirmed that in the absence of pollinators at the end of the flowering phase in G. imbricatus, as well as in some other members of the genus, self-pollination and self-fertilization are possible, which contribute to the wellbeing of populations and species. With regard to I. sibirica, it has been found that the autogamous self-incompatibility inherent in this species prevents inbreeding, maintaining heterozygosity in plant populations, allowing plants' better adaptation to different environmental conditions.

Pollen morphology has proven to be particularly informative for elucidating the evolutionary relationships within Asteraceae (or Compositae). However, very few studies have attempted to reconstruct the character states across the family based on pollen data. Here, we mapped pollen characters onto a recent phylogenomic tree of Asteraceae based on new and published observations. We also revised the pollen morphology of selected lineages of the family largely distributed in South America, including living representatives of the oldest fossils of Asteraceae. By mapping the three selected pollen characters onto a recent phylogenomic framework, we detected shifts and trends across the evolution of the family. Our study showed that Asteraceae pollen grains ancestrally possessed microspines and a nonlayered ecaveate exine. The morphology of this reconstructed ancestor agrees with that of the oldest extinct fossil pollen grains assigned to Barnadesieae discovered in late Cretaceous sediments from Antarctica and New Zealand. The presence of a layered sexine with stout columellae characterizes the most recent common ancestor of all Asteraceae, except for the sister clade Barnadesieae. This extinct ancestor also appears to be represented in the fossil record with morphologically related species of Mutisiapollis , distributed in Paleogene sediments across Patagonia, Africa, and Australia. Taken together, our work supports previous studies, indicating that the range of variation in pollen morphology across Asteraceae is wide yet phylogenetically structured. However, pollen characters (and character states) fail to support the unequivocal recognition of the selected monophyletic South American groups. Although preliminary, our results highlight the importance of scoring pollen characters to identify fossil specimens, explore character evolution, and reconstruct ancestral forms. [ABSTRACT FROM AUTHOR]

Premise: Distyly is a condition in which individual plants in a population express two floral morphs, L‐ and S‐morph, characterized by reciprocal placements of anthers and stigmas between morphs. The function of distyly requires that pollinators collect pollen from L‐ and S‐morphs on different parts along their bodies to then deposit it on the stigmas of the opposite morph, known as legitimate pollination. However, different pollinator groups might differ in the ability to transfer pollen legitimately. Methods: We investigated patterns of pollen pickup along the body of different functional groups (hummingbirds and bees) using preserved specimens to analyze their role in the reproductive success of Palicourea rigida. We measured pollen deposition on the body of pollinators, on stigmas, and fruit production after a single visit. Results: Pollen from L‐ and S‐flowers appeared segregated on different body parts of the hummingbird and bee used in the study. S‐pollen was deposited primarily on the proximal regions (near the head), and L‐pollen was placed in the distal regions (tip of the proboscis and bill). Hummingbirds were more efficient at legitimate pollination than bees, particularly to S‐stigmas. However, fruit formation after single visits by both pollinators was similar. Conclusions: The morphology of distylous flowers allows the segregated placement of L‐and S‐pollen on different body parts of the animal specimens used, facilitating the promotion of legitimate pollen transfer, an observation consistent between the two functional pollinator groups. Also, the results show that full fruit set requires more than one visit. [ABSTRACT FROM AUTHOR]

Interactions between species are the driving force behind ecological dynamics within communities. For this reason, community structure has been described as networks of interacting species for over a century. However, the high canopies in forests such as the tropical Amazon pose an additional challenge to understand interactions. The main objective of the present study is to infer the interactions between bees and plants collected in the Carajás National Forest (Eastern Amazon) and its surroundings from the analysis of pollen loads from bee specimens deposited in biological collections and to determine the trophic niches of the evaluated bee species. This study also aims to contribute to the restoration planning of deforested areas in the eastern Amazon by identifying priority plant species that could help in restoring interaction networks. Pollen loads samples were collected from bees deposited in two entomological collections. The samples obtained were prepared according to Erdtman's acetolysis method, and the pollen grains were counted, measured and microphotographed. We found 154 bee-plant interactions. The pollen material identified in the 72 bee samples (51 species; 16 genera) showed 82 pollen types (plant taxa), distributed in 28 families and 54 genera, with 43 fully identified species and three indeterminate pollen types. The amplitudes of the trophic niche indicated that the genera Trigona, Centris and Xylocopa had more diverse diets. This work also emphasizes the importance of understanding the plant species that make up the diets of bees for management, conservation and restoration strategies. [ABSTRACT FROM AUTHOR]

Two Balkan species of the Campanula pyramidalis complex, respectively Campanula montenegrina and Campanula austroadriatica were analyzed based on comparative methodology for their palynomorphological features, and provided the evidence of similarities and differences of palynological features between them. Palynomorphological features of these species were described for the first time. Pollen grains of two species resulted to be triporate with circular pores, isopolar with radial symmetry, spheroidal shape in polar view and wide oval in equatorial one. The exine sculpture of pollen grains appeared echinate in all studied subpopulations, and it was accompanied by spinules in pollen grains of C. austroadriatica and pollen grains of C. montenegrina. The largest sizes of the pollen grains were identified at C. austroadriatica population collected near Perast, for the length of pores were identified at in pollen grains of Shirokë-Zogaj and Petrovac populations and for the width was identified in pollen grains of Shkalla e Tujanit and Kruja Castle populations. As for the exine, it was thicker at pollen grains of C. austroadriatica populations of Shirokë-Zogaj, Petrovac and near Perast localities. The smallest sizes for length of pollen grains and length of pores were found in C. austroadriatica collected at Shirokë-Zogaj, while for the width of pollen grains were found in pollen grains of C. austroadriatica collected in Montenegro populations and C. montenegrina of Albanian localities. The smallest width of pores was observed in pollen grains of C. austroadriatica collected in Petrovac. The exine was thinner in all populations of C. austroadriatica collected in Albanian localities. [ABSTRACT FROM AUTHOR]

Pollen and fungi cause acute respiratory attacks every year around the world. Thunderstorm asthma attacks hospitalized thousands of people in Ahvaz during the first rain meanwhile pollen grains and fungal spores are the strongest reasons for this phenomenon. Therefore, in the current study different types of pollen grains and fungal spores were collected by Burkard pump during autumn and winter of 2016–2017 and 2017–2018. The analysis characterized pollen grains and fungal spores with homogeneous distributions during the sampling periods. A fungal spore called Curvularia genous showed the most significant correlation with daily rainfall. Daily rainfall and Curvularia genous spores reached their peak, simultaneously. During the first rain, it was considerably higher than other days of the study period, especially in contrast with the second and third rainy days. Also, reverse wind direction—blowing from south—during the respiratory outbreaks may reveal the synergistic effect with air pollutants from heavy industries. We concluded that the autumnal respiratory outbreak in Ahvaz might be triggered by a mixture of fungal spores (especially Curvularia genous), industrial air pollutants, and pollen grains of the predominant tree of Ahvaz urban green infrastructure which is Conocarpus erectus.Highlights: A homogeneous distribution for weekly fungal spores integrals during autumn was observed. Reverse wind direction during the event showed the synergistic effects of heavy industries. Simultaneously peak of daily rainfall and fungal spores was observed. Juliflora, Corovularia, and Conocarpus could be posed as bioallergens. [ABSTRACT FROM AUTHOR]

Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a member of the Juglandaceae family. During spring, pecan trees break their bud dormancy and produce new leaves and flowers. Carbohydrates stored in roots and shoots are thought to support the bloom and early vegetative growth during this time until new leaves start the full photosynthetic activity. Spring freeze is known for its damaging effects on pecan bud and flower growth and development. Pecan shoots with leaves and flowers from five scion–rootstock combinations were collected hours before and after a recent spring freeze (below 0 °C for 6 hours, 21 Apr 2021, Perkins, OK, USA). Morphologies of the leaf, bud, and catkin were visually observed, and the morphologies of the anther and pollen in paraffin sections were investigated by light microscopy. Soluble sugar and starch from bark and wood were analyzed using the anthrone reagent method. The Kanza–Mount showed the maximum damage to terminal leaves, buds, and catkins, whereas Maramec–Colby had the minimum damage only to leaves. Pollen grains were shrunk and reduced in number in the anthers in the protandrous Pawnee scions, whereas no pollen damage was observed in the protogynous Kanza scion. Furthermore, bark soluble sugar levels increased in all the scion–rootstock combinations after the freeze, which may indicate a physiological response to the cold stress. Overall, the extent of spring freeze damage of pecans is affected by the growth stage, types of scion and rootstock, and the scion–rootstock interactions. Furthermore, in addition to low temperature, scion–rootstock interactions also affected the starch and soluble sugar contents in wood and bark tissues.

Liquidambar L. is a significant constituent of the Cenozoic flora in the Northern Hemisphere. Currently, this genus exhibits a discontinuous distribution across Asia and North America, with the center of diversity being in southeastern Asia. This study presents the first occurrence of Liquidambar in the Oligocene of South China. Fossil sweetgum infructescences, associated pollen, and leaves have been found in the Nanning Basin, Guangxi. A new species, Liquidambar nanningensis sp. nov., is described based on the morphological and anatomical characteristics of three-dimensionally preserved infructescences. The Liquidambar fossils from the Nanning Basin show a combination of features indicative of the former genera of Altingiaceae, Altingia, Liquidambar s. str., and Semiliquidambar. The new occurrence expands the taxonomic and morphological diversity of the Paleogene Liquidambar species in South China.

ABSTRACT The aim of this study was to identify plant species visited by Apis mellifera L. in honey producing areas with typical Caatinga vegetation in the State of Bahia, as well as morphologically characterize pollen grains of the most representative species. Flowering specimens were collected from both areas, herborized, identified and deposited at the HUNEB herbarium. Analyses of floristic similarities were performed between eleven municipalities close to the study areas. Pollen was collected from all specimens, acetolyzed, measured, statistically analyzed, morphologically described, and photographed in light microscopy. Of the total of species recorded, 67.46 % were regarded as having beekeeping importance, with the richest botanical families being Fabaceae, Malvaceae and Asteraceae. Additionally, 37.5 % of the recorded species were herbs. The analyzed municipalities showed 84 % of floristic similarity. Of the total species recorded with visits by A. mellifera, 25.52 % had their pollen grains already described in the literature as monads, tetrads and polyads; isopolar, apolar and heteropolar; and mostly prolate spheroidal shape. Sizes varied from small to large, and the amb circular was predominant. The exine ornamentation was greatly diversified, varying from psilate to echinate. The obtained data corroborate the palynological knowledge of plants regarded as having beekeeping importance within the Caatinga.