Amount Of Pollen Research Articles

Impulsive simulation model for the dynamics of allergen immunotherapy

This study aims to analyze the effects of allergen immunotherapy, used to treat allergic symptoms such as pollen allergy. Mathematical models are used as a methodological approach to simulate from a system of impulsive differential equations the dynamics of the model. Immunotherapy is based of supplying small amounts of pollen to the patient, which leads to minimizing severe allergic symptoms when patients are subsequently exposed to higher amounts of pollen in the environment. Lymphocyte concentrations are considered state variables, allowing the behavior and efficacy of allergen immunotherapy to be identified. The manuscript proposes a method that allows to model mixed systems. Phenomena that present continuous times in some instants and discrete times in others, these are phenomena that are frequently found in the field of physics. Allergen immunotherapy is most effective when a treatment is created with pollen dose increments in a linear form.

The Role Several Types of Pollinator Insects in Pollination to Improve Fruit Setting in Oil Palm (Elaeis Guineensis) in the Province of Central Sulawesi and North Sulawesi

The several types of insects that are potential as pollinators in oil palm include Chelisoches morio (Dermaptera: Chelisochidae), Elaeidobius kamerunicus (Coleoptera: Curculionidae), and Thrips sp (Thysanoptera: Thripidae). The role of pollinator insects in oil palm plantations has been explored in oil palm plantations in the Provinces of Central Sulawesi and North Sulawesi. This study aims to study the types of insects that have the potential as pollinators in oil palms plants. The sampling method in the field was carried out by purposive sampling with the transec method at the location of oil palm plantations. Observation of pollinating insects was carried out on 120 oil palm trees (60 trees for observing male flowers and 60 trees for observing female flowers). The results showes that the type of insect very significantly affected the amount of pollen carried on its body. Individuals of C. morio can carry a higher amount of pollen 23%, E. kamerunicus 13.16%, ant and thrips 26.32%. This shows that the insect in the formation of quality and quantity of oil palma.

Evaluation of Native and Nonnative Ornamentals as Pollinator Plants in Florida: II. Floral Resource Value

Consumer demand for novel, visually attractive ornamentals has often overshadowed the functional value plants may provide for flower-visiting insects. As native and nonnative species are hybridized for form, color, flowering, and disease resistance, it is important to assess whether some of these alterations influence plant nutrient quality for foraging insect pollinators. A study was conducted to ascertain the resource value of ornamental cultivars compared with their native congeners. The nectar volume and pollen quantity, viability, and protein content of 10 species of popular herbaceous flowering plants, commonly advertised as pollinator-friendly, were evaluated in northcentral Florida. Each genus encompassed a native and nonnative species, apart from pentas. Native species included blanket flower (Gaillardia pulchella), lanceleaf coreopsis (Coreopsis lanceolata), pineland lantana (Lantana depressa), and scarlet sage (Salvia coccinea). Nonnative species included Barbican™ yellow-red ring blanket flower (Gaillardia aristata ‘Gaiz005’), Bloomify™ rose lantana (Lantana camara ‘UF-1011-2’), mysty salvia (Salvia longispicata × farinacea ‘Balsalmysty’), Lucky Star® dark red pentas (Pentas lanceolata ‘PAS1231189’), ruby glow pentas (Pentas lanceolata ‘Ruby glow’) and UpTick™ Gold & Bronze coreopsis (Coreopsis × ‘Baluptgonz’). Floral rewards differed significantly across species. The native scarlet sage exhibited the largest nectar volume per flower in the summer (2.13 ± 0.17 µL), followed by the nonnative mysty salvia (1.26 ± 0.17 µL). In the fall, ruby glow pentas exhibited the largest nectar volume per flower (1.09 ± 0.17 µL) compared with all other ornamentals. The composite flowers of the native and nonnative blanket flower and coreopsis species had the lowest nectar volume per flower regardless of sampling date. Likewise, ruby glow pentas displayed the highest quantity of pollen grains (96.29 ± 0.12) per sample, followed by Lucky star pentas (52.33 ± 0.12), and Barbican blanket flower (50.98 ± 0.12). Pollen viability was similarly high (92% to 98%) among all species, apart from Bloomify rose lantana (20%) and pineland lantana (48%). Pollen protein content was highest in Uptick coreopsis (11.378 ± 1.860 μg/mg dry weight) and Lucky star pentas (10.656 ± 3.726 μg/mg dry weight), followed by lanceleaf coreopsis (7.918 ± 1.793 μg/mg dry weight). These results largely showed that the nonnative ornamentals selected provided resource-rich floral rewards, comparable to native congeners. Still, care should be taken in making similar assessments of other modern floral types.

Pollinator-mediated facilitation alleviates pollen limitation in a plant-hummingbird network.

Facilitation and competition among plants sharing pollinators have contrasting consequences for plant fitness. However, it is unclear whether pollinator-mediated facilitation and competition may affect pollen limitation (potential contribution of pollination to fitness) in pollination networks. Here, we investigated how pollinator sharing affects pollen limitation in a tropical hummingbird-pollinated community marked by facilitation. We employed indices describing how much a plant species potentially affects the pollination of other co-flowering species through shared pollinators (acting degree) and is affected by other co-flowering species (target degree) within the plant-hummingbird network. Since facilitation often increases pollination quantity but not necessarily quality, we expected both indices to be associated with reductions in pollen limitation estimates that depend on pollination quantity (fruit set and seed number) rather than estimates more strictly related to quality (seed weight and germination). We found that both indices were associated with reductions in pollen limitation only for seed weight and germination. Thus, facilitation occurred via qualitative estimates of pollen limitation. Our results suggest that facilitation may enhance plant fitness estimates even if quantitative components of plant fecundity are already saturated. Overall, we showed that pollinator-mediated indirect effects in a multispecies context are important drivers of plant fitness estimates with consequences for coexistence in diverse communities.

Climate change and allergy-related impacts on humans

Abstract Climate change represents a massive threat to global health that could affect many disease factors in the twenty-first century. The influence of a changing climate on allergic disease has generated interest among the public and the scientific community. Climate change is a continuing process that affects allergy, and there are multiple potential consequences of climatic change on plant phenology. Impacts on pollen may be one of the most important consequences of climate change on human health. A growing number of people are contracting allergic diseases caused by pollen. Airborne pollen is one of the common causatives and triggering agents of respiratory allergy in a changing climate. Moreover, allergenic plants grow in soil disturbed by human activities and deforestation with air pollution, and it is impossible to avoid plants that cause allergies because pollen can travel many kilometers on the wind. Weather conditions may alter pollen concentrations. A number of studies have shown that increased CO 2 concentration and atmospheric temperature increase pollen concentration. Hence, most works on the impact of climate change on aeroallergens include its impact on the amount and allergenicity of pollen. It is as yet unknown what complex interactions between pollens, meteorological variables and air pollutants occur as a result of climate change. Considering the effect of climate change on long-term trends in pollen levels and emerging viral infections, it is crucial to report and forecast the associated risk for future human health.

Pollen Allergy in a Changing Planetary Environment.

Airborne pollens are one of the common causative and triggering agents of respiratory allergy in a changing planetary environment. A growing number of people worldwide are contracting allergic diseases caused by pollens. The seasonal variations in pollens have occurred everywhere and the sensitization rate to pollens has increased in children as well as in adults. Moreover, allergenic plants, such as ragweed and Japanese hop, grow in soil damaged by human’s activities and deforestation with air pollution. It is impossible to avoid plants that cause allergies, because pollens can travel many kilometers in the breeze or wind. Hence, it is essential to survey and forecast pollens for the management of pollen allergy. Weather conditions may alter pollen concentrations. A number of studies have shown that increases in CO2 concentration and atmospheric temperature raise pollen concentration. Hence most of the studies on the impact of climate change on aeroallergens must include the amount and allergenicity of pollens. It is yet unknown whether complex interactions with pollens, meteorological variables, and air pollutants in the changing environment. Considering the effect of climate change on the long-term trends in pollen levels and emerging viral infection, it is crucial to forecast and eliminate the associated risk for human health in future and take appropriate measures to reduce it.

Effect of supplementary feeding on morphometry of worker honeybees in Western Himalayan region

Efficient management of bee colonies requires the beekeepers to provide artificial food to the bees when they need it. The need to feed artificial diet depends a lot on the amount of brood in the hive, the amount of stored pollen and nectar, current as well as future nectar and pollen conditions and demands to be placed on the hives. If hives are critically short of pollen and either have a large brood nest or are expanding their brood nest, then the beekeepers need to consider various options available to them for e.g. supplementary feeding, migration of bee colonies to the region rich in flora etc. to avoid a reduction in bee population. Feeding of artificially diet may have positive effect on colony attributes including morphometric characters. It was observed that feeding of diet led to significant increase in some of the morphometric characters like tongue length.

DEVELOPMENT OF THE RECIPE OF WHEAT BREAD WITH THE ADDITION OF BEE POLLEN FROM PHACELIA

Introduction. The use of bee pollen and other biologically active additives in the process of food production makes it possible to enrich them with minerals, vitamins, increase nutrition, replace components with intolerance of the human body, improve taste. The goal of the work. To study the influence of phacelia bee pollen on indicators of quality of wheat bread and compliance of the finished product with national standards. Materials and methods of research. The research was conducted in the training laboratory of the Faculty of Food Technology and Quality Control of Agricultural Products of the National University of Life and Environmental Sciences of Ukraine, Kyiv, (Ukraine) and the Testing Laboratory of Methods of Quality and Safety Assessment of Beekeeping of the National Scientific Center “Institute of beekeeping named after P.I. Prokopovich”. The bee pollen was collected at a private apiary (Selezenivka, Kyiv Oblast, Ukraine). In theoretical studies, the methods of analysis and synthesis of scientific literature were applied using Scopus scientometric databases and the Google Scholar database. Experimental research was carried out in accordance with generally accepted, standard methods, as well as in accordance with the requirements of the national standards of Ukraine. The main stages in the production of bread with the addition of bee pollen, during which various studies of phacelia were carried out, were the preparation of raw materials and auxiliary materials, mixing and processing of dough, baking, cooling and storage. Results of research and discussion. The main stages of the bread production with the addition of phacelia bee pollen were the preparation of raw materials and auxiliary materials, mixing and processing of dough, baking, cooling and storage. Experimental studies were carried out on two specimens with different recipes and a method of treatment of bee pollen – powdery condition; the natural form that remains after the drying process. An organoleptic study using powdered milk, pumpkin seeds and powdered bee pollen in the first sample determined a number of advantages in terms of color, pulp state, taste, and smell. The results of the physico-chemical study of sample 2 revealed an imperfect recipe, and with minor deviations from the process or production modes, it may not meet the requirements for physico-chemical performance. It is believed that the high amount of carbohydrates is due to the large amount of bee pollen in the recipe. The recipe is estimated to have produced a finished product of potentially high biological value that can be used for functional nutrition, but requires further research. In addition, other scientists argue that adding these ingredients to food recipes significantly improves a number of their properties. Conclusions and prospects for further research. Influence of phacelia bee pollen in the composition of the wheat bread recipe on the indicators of quality and compliance of the finished product with national standards has been determined. As a result of the identification of the bee pollen by the number of pollen grains, monoflority was confirmed – 95.4% of pollen grains phacelia tanacetifolia. The main physico-chemical indicators of the finished product: moisture – 42.3%, acidity – 2.7%, porosity of pulp – 75.2%. It has been confirmed that the recipe of sample 1 has high organoleptic and physico-chemical characteristics. Based on the results of the obtained data, prospective studies were determined in revealing the influence on the human body from the consumption of food products with the components of the production or processing of beekeeping products.

Признаки трансформации геосистем при освоении Южного Приморья в средневековье: городище Стеклянуха-2

We analyzed human impact on landscapes on the example of Steklyanukha-2 Medieval fortress, which is a multi-layered archaeological site, and adjacent territories. Buried soils, rampart matrix, cultural layer and surface soils were sampled within the fortress. Along with the material sampled at the site, two sections of the Upper Holocene deposits of the high floodplain of the Steklyanukha River were studied. The results of studying the sporo-pollen spectra and diatoms are presented. The paleo-landscapes during the formation of various archaeological cultures have been restored and the signs of anthropogenic impact on vegetation have been identified. The buried soil in the section of the high floodplain is a natural archive for the environment history during the appearance of the people of the Yankovskaya Culture on this territory. The soil was formed under conditions of decreasing watering in the valley; the age is estimated at more than 2 ka. Oxbow lake deposits had been accumulated from 1.6 to 0.5 ka, when the valley was actively developed in the Middle Ages. Floodplain deposits at the top of the sections indicate that the valley has been heavily watered during the Little Ice Age. Pollen signs of settlements of the lower part of the valley in the Early Iron Age, Mohe and Late Middle Ages were found. Signals of the development of secondary birch and oak forests are identified. Ambrosia and Xanthium pollen, which are reliable evidence of agricultural activity in the valley, was found in the cultural layer and sediments that formed in the Middle Ages. The pollen of plants common in anthropogenically disturbed territories was also found. The study of diatoms in a depression within the fortress confirmed the archaeologists’ assumption that it was used to store water reserves. The pollen spectra from the surface soils in the fortress and the high floodplain reflect the active agricultural development of the nearby river valleys since the second half of the 19th century. The largest amount of pollen of alien and synanthropic plants and weeds, as well as spores of pathogenic fungi (pathogens of soybeans and rice) and fire indicators were found here.

The effect of pollen exposure on consumption behaviors: Evidence from home scanner data

Although seasonal allergies caused by airborne pollen are detrimental to physical and mental health and impair daily activities, their social cost is rarely discussed in the economics literature. Large amounts of airborne pollen can increase healthcare costs, reduce worker productivity, and force people to stay at home, thereby stagnating economic activity. This study uses daily purchase records from scanner data to investigate the effect of pollen exposure on consumption behavior. Exploiting the daily variation in the pollen counts at 120 observation stations in Japan, I find that consumption expenditure decreases by about 2% on days when airborne pollen is unusually high. Estimates using lagged consumption expenditures show that the reduction in consumption due to high pollen exposure lasts for more than a week. Furthermore, estimates using weekly and monthly panel data also indicate a pollen-induced decrease in consumption. This finding suggests that exposure to pollen may reduce total expenditure as opposed to merely delaying spending. It highlights the overlooked economic burden of pollen and seasonal allergies. Hence, urban planning to reduce airborne pollen and health policies to address seasonal allergies are crucial.

Natural conditions of the formation of the monument of Maly Gonbinsky Kordon-2 of the Odintsovo Culture of Altai in the 4th–8th centuries A.D.

The study is aimed at reconstructing the natural and climatic conditions of the Upper Ob River region (south of Western Siberia) in the early Middle Ages (4th–8th centuries A.D.), based on the paleosol data obtained from the fortified settlements of Maly Gonbinsky Kordon-2/11 and Maly Gonbinsky Kordon-2 / 6-3. Settlements are located on the terrace of the right bank of the Ob River. The fortification elements are represented by a horse-shoe-shaped system of a ditch and a rampart, adjacent to the edge of the above-floodplain terrace, inside which there were dwellings and outbuildings. Archaeological investigations of the settlements permitted to study the sediments of the first terrace above the floodplain and to select core samples for palynological analysis. Applica-tion of this method allowed reconstruction of the vegetation during the occupational period of the complex of monuments MGK-2. For interpreting of the actual data, the method of landscape analysis was employed. The need for its application for carrying out paleogeographic reconstructions is warranted by the presence of the relict elements in the morphological structure of the landscapes. To establish their paleogeographic status, within the framework of this study, there was determined the percentage ratio of the amount of pollen and seeds of plants extracted from the deposits of the first above-floodplain terrace, corresponding to the existence of the Odintsovo Culture and belonging to different ecological groups. As the result, the dominance of sparse birch forests and forb dry meadows in the landscape structure of that time was established, whereas the vegetation associations featu-ring pine forests were in the status of progressive elements of the landscape structure. Also, supersedence of birch forb forests by green moss pine forests was revealed. The use of the landscape approach allowed recon-struction of natural conditions of the territory occupied by the complex of fortified settlements of MGK-2. On the basis of the digital elevation model, 3D visualization of the surface of the sediments overlapping the cultural layer of the monuments was rendered, which shows the location of the objects at the lowest elevations of the surface I above the floodplain terrace and the effects of the surface water flow. This necessitated construction of a drai-nage system, the main elements of which might be represented by shallow ditches.

Potential of Impedance Flow Cytometry to Assess the Viability and Quantity of Cannabis sativa L. Pollen.

Over the last decade, efforts to breed new Cannabis sativa L. cultivars with high Cannabidiol (CBD) and other non-psychoactive cannabinoids with low tetrahydrocannabinol (THC) levels have increased. In this context, the identification of the viability and quantity of pollen, which represents the fitness of male gametophytes, to accomplish successful pollination is of high importance. The present study aims to evaluate the potential of impedance flow cytometry (IFC) for the assessment of pollen viability (PV) and total number of pollen cells (TPC) in two phytocannabinoid-rich cannabis genotypes, KANADA (KAN) and A4 treated with two different chemical solutions, silver thiosulfate solution (STS) and gibberellic acid (GA3). Pollen was collected over a period of 8 to 24 days after flowering (DAF) in a greenhouse experiment. Impedance flow cytometry (IFC) technology was used with Cannabis sativa to assess the viability and quantity of pollen. The results showed that the number of flowers per plant was highest at 24 DAF for both genotypes, A4 (317.78) and KAN (189.74). TPC induced by STS was significantly higher compared to GA3 over the collection period of 8 to 24 DAF with the highest mean TPC of 1.54 × 105 at 14 DAF. STS showed significantly higher viability of pollen compared to GA3 in genotype KAN, with the highest PV of 78.18% 11 DAF. Genotype A4 also showed significantly higher PV with STS at 8 (45.66%), 14 (77.88%), 18 (79.37%), and 24 (51.92%) DAF compared to GA3. Furthermore, counting the numbers of flowers did not provide insights into the quality and quantity of pollen; the results showed that PV was highest at 18 DAF with A4; however, the number of flowers per plant was 150.33 at 18 DAF and was thus not the maximum of produced flowers within the experiment. IFC technology successfully estimated the TPC and differentiated between viable and non-viable cells over a period of 8 to 24 DAF in tested genotypes of Cannabis sativa. IFC seems to be an efficient and reliable method to estimate PV, opening new chances for plant breeding and plant production processes in cannabis.

The advantages of being crepuscular for bees: major pollen gain under low competition during the brief twilight period

Abstract The shift in flight activity from daylight to twilight in crepuscular bees is assumed to have evolved to escape competitors, but quantitative confirmation of this hypothesis has never been demonstrated clearly. Pseudobombax longiflorum is a chiropterophilous plant, with flowers presenting large amounts of pollen throughout anthesis, thus attracting not only nocturnal visitors, but also crepuscular and diurnal bees. In this dynamic system, the fraction of pollen that flows to different visitors and the putative role of bees in pollination remain unknown. We analysed floral biology, the frequency of visitors in periods with different light intensities and the rate of pollen removal by each visitor group. A pollinator-exclusion experiment showed that bees were not pollinators of Pseudobombax longiflorum, although they collected > 60% of the pollen from their flowers. Crepuscular bees gained the greatest amount of pollen in the few minutes when they foraged without either nocturnal or diurnal competitors, confirming the advantage of foraging under low light. During the short twilight period, these bees foraged alone and removed 26.5 and 15 times more pollen per minute than nocturnal and diurnal visitors, respectively. Therefore, pollen removal by crepuscular bees is particularly efficient when they forage in the brief period while competitors are absent.

The effect of a novel dietary supplement based on fishery industry waste hydrolysate, essential fatty acids and phytochemicals on honey bee nuclei development

In the late winter or early spring, beekeepers stimulate the colonies to increase the population of bees using different dietary supplements, principally based on carbohydrates and proteins. Honey bees require multiple sources of nectar and pollen to obtain balanced nutrition, so the formulation of effective supplements requires the identification and testing of candidate components, especially at the colony level. In this study, we evaluated the effectiveness of a nutritional supplement (SUP) composed of two important phytochemicals that have been reported to improve honey bee health (abscisic acid (ABA) and p-coumaric acid (CUM)) combined with fish protein hydrolyzate (FPH), and essential omega fatty acids (Ω3/6) in nuclei colonies. We first evaluated the toxicity of SUP compared with the control (sugar syrup) in laboratory bioassays during 96 hours. Then, we tested the effect on the amount of brood, honey, and pollen in bee hives nuclei supplemented with SUP for thirty days. In addition, we quantified and compared the concentration of total proteins in individual honey bees collected at the beginning and at the end of the experiment. The results obtained show that SUP is palatable, nontoxic to Apis mellifera, and significantly increases the amount of open brood and pollen reserves of bee nuclei compared with nuclei feed with sugar syrup. No significant differences were observed, between nuclei feed with SUP and control nuclei, in the amount of honey reserves and total proteins of individual bees. Here, we show the value of a nutritional supplement that combines essential nutritional components and phytochemicals to improve important parameters associated with colony fitness. We expected this nutritional supplement helps beekeepers to develop their colonies in view of the increase of industrial agriculture and the consequent loss of floral resources.

Water availability affects the relationship between pollen intensity and seed production

Seed production can be affected by water availability and also depend on the amount (pollen intensity) and quality of pollen deposited. The way pollen receipt on the stigma translates into seeds produced follows that of a saturating dose–response. Not only can water availability and pollen intensity each influence seed production, these factors could interact in their effects on seed production. Changes to the relationship between seed production and pollen intensity can in turn influence pollinator effectiveness and pollinator-mediated selection. We asked how water availability affected indices of plant fitness (seed set, fruit set and seed mass) and the relationship between pollen intensity and seed production in Phacelia parryi. We conducted a greenhouse experiment where we manipulated water availability (either high- or low-water) to pollen recipient plants and hand-pollinated each plant with a range of pollen intensities. We conducted 703 hand-pollinations on 30 plants. For each hand-pollinated flower we measured pollen deposited, seed production and seed mass. We then generated a piecewise regression of the relationship between pollen intensity and seed production, and determined average effects of water on plant fitness measures. This experiment was paired with a field observational study aimed to document natural variation in pollen deposition. Average seed production per fruit was 21 % higher in the high-watered plants. The relationship between pollen intensity and seed production differed between the two water treatments. Plants under high-water exhibited a wider range in which pollen deposition increased seed production. Average natural pollen intensities fell within different regions of the piecewise regression for low- and high-water plants. Water availability can alter the efficiency by which pollen received is translated into seeds produced. Our greenhouse data suggest that only under certain pollen intensity environments will water availability affect how pollen received is translated into seeds produced.

Foraging Speed of Castor Pollinators

The collected amount of nectar and pollen by the insect pollinators mainly depends upon the time spent on individual flowers referred to as the foraging speed. An experiment conducted at Department of Entomology, CCS Haryana Agricultural University, Hisar, Haryana evaluated the foraging speed of different insect pollinators on flowers of castor Ricinus communis cv. GCH-7 and DCH-177. Apis cerana F. was observed with maximum foraging speed (6.26 sec/flower) followed by Apis mellifera L. (5.12 sec/flower), Apis dorsata F. (4.20 sec/flower), Apis florea F. (3.74 sec/flower). The least foraging speed was observed with Xylocopa iridipennis Lepeletier (2.67 sec/flower). Data taken at different time interval in a day indicated that the peak foraging speed of pollinators is between 10.00-12.00 hr, while the least one was at 16.00-18.00 hr.

Examining the Role of Buzzing Time and Acoustics on Pollen Extraction of Solanum elaeagnifolium.

Buzz pollination is a specialized pollination syndrome that requires vibrational energy to extract concealed pollen grains from poricidal anthers. Although a large body of work has examined the ecology of buzz pollination, whether acoustic properties of buzz pollinators affect pollen extraction is less understood, especially in weeds and invasive species. We examined the pollination biology of Silverleaf nightshade (Solanum elaeagnifolium), a worldwide invasive weed, in its native range in the Lower Rio Grande Valley (LRGV) in south Texas. Over two years, we documented the floral visitors on S. elaeagnifolium, their acoustic parameters (buzzing amplitude, frequency, and duration of buzzing) and estimated the effects of the latter two factors on pollen extraction. We found five major bee genera: Exomalopsis, Halictus, Megachile, Bombus, and Xylocopa, as the most common floral visitors on S. elaeagnifolium in the LRGV. Bee genera varied in their duration of total buzzing time, duration of each visit, and mass. While we did not find any significant differences in buzzing frequency among different genera, an artificial pollen collection experiment using an electric toothbrush showed that the amount of pollen extracted is significantly affected by the duration of buzzing. We conclude that regardless of buzzing frequency, buzzing duration is the most critical factor in pollen removal in this species.

Distinct pollen release dynamics between stamens generate division of labour in pollen flowers of two Pleroma species (Melastomataceae)

Flowers that provide only pollen to pollinators should maximize pollen release for reproduction while minimizing pollen loss through consumption by bees. In flowers that are polymorphic for stamen type, the number of pollen grains produced as well as stamen morphology likely influences pollen release dynamics and favor the division of labor between stamens with different functions. However, few studies have evaluated such predictions. In this study, we tested the “division of labor hypothesis” considering not only the stamen morphology of pollen flowers but also their pollen release dynamics. Stamen morphology as well as the amount and viability of pollen were characterized in two Melastomataceae species, Pleroma granulosum and Pleroma raddianum. Using artificial vibrations, we estimated pollen release dynamics throughout anthesis in the anthers of short and long stamens from flowers of both species. P. granulosum flowers presented low heteranthery (i.e., anthers differed by only about 1 mm in length) and short stamens produced fewer pollen grains in both species. We also found similarly high viability of pollen from all anthers of both species. Although pollen grain release increased in all anthers over the flower´s lifespan, their dynamics were different between the two stamen sets in both species. Anthers of shorter stamens tended to release fewer and proportionally lower quantities of pollen grains at each time interval than anthers of longer stamens. Our study suggests that the number of pollen grains produced, as well as stamen morphology (beyond anther size) may control pollen release dynamics, leading to a division of labor between stamens in these pollen flowers.

CSI Pollen: Diversity of Honey Bee Collected Pollen Studied by Citizen Scientists.

Simple SummaryHoney bee colonies collect pollen from plants as a source of nutrients. Diverse diets comprising pollen from many different plant species are beneficial for honey bee colony health, because they contain a greater diversity of nutrients than monofloral diets of one plant species only. Here, we present the results of the COLOSS “CSI Pollen” study on the diversity of pollen collected by honey bee colonies. In this study, beekeepers acted as citizen scientists sampling and analyzing pollen collected by their own colonies. As a simple measure of diversity, beekeepers determined the number of different colors found in pollen samples that were collected in a coordinated and standardized way. The support of 750 beekeepers allowed the collection of information about almost 18,000 pollen samples from many European countries. We found that the pollen samples consistently comprised approximately six different colors in total, of which four colors were abundant. ‘Urban’ habitats or ‘artificial surfaces’ were associated with higher pollen color diversity. This investigation highlights seasonal- and land-use-related differences in the pollen supply for honey bees, which affects beekeeping and pollinator health. Determining pollen colors is a simple, useful technique for beekeepers to estimate pollen diversity.A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way. Altogether, 750 beekeepers from 28 different regions from 24 countries participated in the two-year study and collected and analyzed almost 18,000 pollen samples. Pollen samples contained approximately six different colors in total throughout the sampling period, of which four colors were abundant. We ran generalized linear mixed models to test for possible effects of diverse factors such as collection, i.e., whether a minimum amount of pollen was collected or not, and habitat type on the number of colors found in pollen samples. To identify habitat effects on pollen diversity, beekeepers’ descriptions of the surrounding landscape and CORINE land cover classes were investigated in two different models, which both showed that both the total number and the rare number of colors in pollen samples were positively affected by ‘urban’ habitats or ‘artificial surfaces’, respectively. This citizen science study underlines the importance of the habitat for pollen diversity for bees and suggests higher diversity in urban areas.

Anatomical Characteristics of Petalized Anther Abortion in Male Sterile Camellia oleifera Plants

Petalized anther abortion is an important characteristic of male sterility in plants. The male sterile plants (HB-21) evincing petalized anther abortion previously discovered in a clone population of the Camellia oleifera cultivar Huashuo by our research group were selected as the experimental material in this study. Using plant microscopy and anatomic methods and given the correspondence between external morphology and internal structure, we studied the anatomic characteristics of petalized anther abortion (with a fertile plant as the control group) in various stages, from flower bud differentiation to anther maturity, in hopes of providing a theoretical basis for research on and applications of male sterile C. oleifera plants, a new method for the selection of male sterile C. oleifera cultivars, and improvements in the yield and quality of C. oleifera. In this study, the development of anthers in C. oleifera was divided into 14 stages. Petalized anther abortion in male sterile plants was mainly initiated in the second stage (the stage of sporogenous cells). Either the petalized upper anther parts did not form pollen sacs, or the entire anthers did not form pollen sacs. The lower parts of some anthers could form deformed pollen sacs and develop, and these anthers could be roughly divided into two types: fully and partially petalized anthers. Abnormal callose and the premature degradation of the tapetum occurred in the pollen sacs formed by partially petalized anthers during the development process, resulting in the absence of inclusions in the pollen grains formed. Small quantities of mature pollen grains withered inward from the germinal furrows, exhibiting obvious abortion characteristics. The relative in vitro germination rate of the pollen produced by the partially petalized anthers of sterile plants was 11.20%, and the relative activity of triphenyltetrazolium chloride was 3.24%, while the fully petalized anthers did not generate pollen grains. Either the petalized anthers in male sterile plants did not produce pollen, or the vitality of the small amounts of pollen produced by sterile plants was very low compared with that of fertile plants. Such male sterile plants could be used to select correct clones and have good prospects for application in production.