Pollen Collection Research Articles

Evidence for recent climate change and carbon dioxide influence on plant based aero-allergens in the Northern Hemisphere

BACKGROUND AND AIM: Recent and projected assessments of climate change and carbon dioxide may influence plant based aero-allergen characteristics related to pollen load and pollen seasonality METHODS: Characterization and quantification of allergenic plant species related to growth, phenology and allergenicity in the context of rising temperatures and increased carbon dioxide. Methodologies include chamber and open-air assessments of pollen collection, ELISA and historical records. RESULTS:Integration of historical and experimental results from controlled chambers to open-air facilities indicate recent (since the 1970s) and projected changes (to 2100) in climate and CO2, are increasing allergen seasonality and pollen amounts. In addition there is evidence indicating that carbon dioxide per se may increase exine allergen concentration. CONCLUSIONS:These data overall, show a net influence of recent and projected increases in carbon dioxide and global surface temperatures on temporal aspects of aero-allergen exposure, including pollen load, and potential changes in allergenicity. Such changes have significant health consequences for those in the general population who suffer from seasonal allergic rhinitis and asthma. KEYWORDS: aeroallergens, climate change, carbon dioxide, pollen

Modern honey bees disrupt the pollination of an ancient gymnosperm, Gnetum luofuense.

Bees belong to modern groups of pollinators, which originated concurrently with new angiosperms (flowering plants), and might have contributed to the global gymnosperm-to-angiosperm turnover in the mid-Cretaceous (125 to 90 million years ago (Ma); Cardinal & Danforth 2013, Peris et al. 2017). Understanding the role that bees played in this turnover requires an exploration of angiosperm-bee associations as well as an understanding of the potential early interactions between gymnosperms and bees. Because bees are effective pollen collectors that depend on pollen for protein, and the unisexual gymnosperms produce numerous male strobili with plenty of exposed pollen, bees might have collected pollen from coexisting gymnosperm species to meet their nutritional needs (Saunders 2017). However, the gymnosperm-bee interactions from the fossil record and their ecological and evolutionary consequences, if ever exist, are still unknown.

Not all about the buzz: licking, a new foraging behavior of bees in tomato flowers

Bees that visit flowers of open tomato crops were identified, their pollen collection behavior in the flowers was analyzed, and a new behavior was described. It was evaluated whether improved fruit quality results from additional pollination performed by bees and whether Paratrigona lineata (Lepeletier, 1836) and Apis mellifera L., 1758 are effective pollinators of tomatoes. The pollination experiments in the study were carried out on 2 commercial tomato fields located in the Triângulo Mineiro region (Southeastern Brazil). During the study, the licking was observed and described, a new bee behavior to collect pollen that results in fruit formation. A total of 1036 bees belonging to 14 species were sampled. Paratrigona lineata was the most abundant species (63%), followed by A. mellifera (26%) and Exomalopsis spp. (7%). The other species together accounted for the remaining 4%. In general, additional pollination performed by bees in flowers free for visitation (control group) generated fruits that were larger and heavier, with more seeds. Fruits originating from flowers of the single visit tests with P. lineata and A. mellifera showed, respectively, 30.4% and 20.9% more seeds when compared to tomatoes from bee exclusion treatments. Our results reinforce the importance of pollination services provided by bees in tomato crops and provide evidence that species that do not perform buzz pollination, such as P. lineata and A. mellifera, do act as pollinators of this crop.

Keep trees for bees: Pollen collection by Osmia bicornis along the urbanization gradient

Development of urban agglomerations and the intensification of agriculture profoundly affect bees’ food resources, hence ecosystem services such as pollination. A solitary bee, Osmia bicornis (syn. O. rufa), is an effective springtime pollinator of crops, decorative and wild plants. However, it is largely unknown if this species is conservative or plastic in pollen collection in different environments. New breedings of O. bicornis were established in localizations qualified as urban (90 % of built-up infrastructure), suburban (55–65 %), and rural (up to 20 %). From each nest randomly chosen samples of unused pollen provisions were collected and analysed. Moreover, literature databases of food composition of O. bicornis was compiled to show overall tendencies in the choice of plant type, habitat, as well as pollen coating and size. Our field study showed that in the less human-modified environment O. bicornis collected higher diversity of pollen types to build its provision, compared to more urban areas (Simpson diversity index was 3.7 in rural, 2.8 in suburban and 2.2 in urban sites). Literature review showed that bees repeatedly collected pollen from commonly available trees like oaks, maples, horse chestnut and elms. Field data also revealed that the use of tree pollen was especially common in urban sites while bees from suburban and rural sites included pollen of herbaceous plants and shrubs. Neither the shape nor the size of the pollen mattered to bee foraging choices. However, bees frequently used pollen dispersed by wind in urban sites. The main conclusion is that polylectic bees opportunistically collect pollen of plants present in the environment and number of plant taxa may be limiting factor for studied bees. The welfare of O. bicornis requires planting trees such as oaks, willows, maples, and representatives from Rosaceae family, and it is especially advisable in urban sites where herbaceous flowering plants are less common than in urban and suburban areas. Hence, keeping even singular trees may complement the bee food base in urbanized areas.

Three options are better than two: compensatory nature of different pollination modes in <i>Salix caprea</i> L.

Mixed pollination systems have been reported for many angiosperms. Here, we report on a dioecious willow, Salix caprea L., which employs three pollination modes, namely pollination by wind, nocturnal moths, and diurnal bees. In four field populations of S. caprea in Germany, we addressed the following questions: (a) How are the pollination modes affected by local mate availability? (b) What is the contribution of each pollination mode to seed set? (c) How does flower opening time affect pollination? We compared seed set among seven pollination treatments (wind pollination, diurnal pollination, nocturnal pollination, natural pollination, apomictic reproduction, daytime/night-time artificial pollination). Pollen limitation was observed across populations. On the other hand, limitations in mate availability affected the pollination modes differently. Insect pollination outperformed wind pollination in situations where nearby males were few or all positioned in the same direction from the females. The contribution of nocturnal moths was lower than that of the other pollen vectors. However, moth pollination worked complementarily with bee pollination in compensating for the lack of wind pollination. Furthermore, we found that the onset of flower anthesis peaked at sunset, and that cold night temperatures had no negative effect on seed set or pollen viability. Thus, nocturnal anthesis and prior pollination by moths may minimize male fitness loss due to pollen collection and grooming by bees. We suggest that S. caprea maximizes its fitness by combining multiple pollination modes that work in different environmental conditions, while optimizing the anthesis so that more pollen would be delivered to stigmas.

A bee's eye view of remarkable floral colour patterns in the south-west Australian biodiversity hotspot revealed by false colour photography.

Colour pattern is a key cue of bee attraction selectively driving the appeal of pollinators. It comprises the main colour of the flower with extra fine patterns, indicating a reward focal point such as nectar, nectaries, pollen, stamens and floral guides. Such advertising of floral traits guides visitation by the insects, ensuring precision in pollen gathering and deposition. The study, focused in the Southwest Australian Floristic Region, aimed to spot bee colour patterns that are usual and unusual, missing, accomplished by mimicry of pollen and anthers, and overlapping between mimic-model species in floral mimicry cases. Floral colour patterns were examined by false colour photography in 55 flower species of multiple highly diverse natural plant communities in south-west Australia. False colour photography is a method to transform a UV photograph and a colour photograph into a false colour photograph based on the trichromatic vision of bees. This method is particularly effective for rapid screening of large numbers of flowers for the presence of fine-scale bee-sensitive structures and surface roughness that are not detectable using standard spectrophotometry. Bee- and bird-pollinated flowers showed the expected but also some remarkable and unusual previously undetected floral colour pattern syndromes. Typical colour patterns include cases of pollen and flower mimicry and UV-absorbing targets. Among the atypical floral colour patterns are unusual white and UV-reflecting flowers of bee-pollinated plants, bicoloured floral guides, consistently occurring in Fabaceae spp., and flowers displaying a selective attractiveness to birds only. In the orchid genera (Diuris and Thelymitra) that employ floral mimicry of model species, we revealed a surprising mimicry phenomenon of anthers mimicked in turn by model species. The study demonstrates the applicability of 'bee view' colour imaging for deciphering pollinator cues in a biodiverse flora with potential to be applied to other eco regions. The technique provides an exciting opportunity for indexing floral traits on a biome scale to establish pollination drivers of ecological and evolutionary relevance.

Complementary Contribution of Wild Bumblebees and Managed Honeybee to the Pollination Niche of an Introduced Blueberry Crop.

Simple SummaryBlueberry is a crop that is increasing globally, both in terms of yield and extent, mostly thanks to the recent introduction of North American blueberry in the temperate areas of Europe, Asia, and South America. As blueberry depends largely on insects for pollination, farmers in these expansion areas face the challenge of adapting this crop to unexpected pollinator species, whose traits and features may not entirely fit the pollination needs of the introduced crop. Here we study the abundance, the behaviour, and the response to environmental conditions of different managed and wild native pollinators of blueberry in northern Spain. Our findings suggest the dominant role of native wild bumblebees and managed honeybee as suppliers of pollination service. Honeybee and bumblebees differed in both when and where they occurred, in how they responded to environmental conditions, and in how they behaved as an effective pollinator. The role of bumblebees and honeybee as blueberry pollinators thus seems complementary and additive. These results encourage the preservation of populations of native wild bees in order to ensure the effective management of introduced blueberry crops.The entomophilous pollination niche (abundance, phenotypic traits, foraging behaviours and environmental tolerances of insect pollinators) helps to understand and better manage crop pollination. We apply this niche approach to assess how an entomophilous crop (blueberry, Vaccinium ashei) can be expanded into new territories (i.e., northern Spain) far from their original area of domestication (North America). Insect visits to blueberry flowers were monitored in a plantation on 12 different days, at 8 different times during day and covering various weather conditions. Abundance, visitation rate, pollen gathering behaviour, and frequency of inter-plant and inter-row movements were recorded. The pollinator assemblage was basically composed of one managed honeybee species (50.8% of visits) and three native bumblebee species (48.3%). There was a marked pattern of seasonal segregation throughout bloom, with bumblebees dominating the early bloom and honeybee the late bloom. Pollinators also segregated along gradients of daily temperature and relative humidity. Finally, the two pollinator types differed in foraging behaviour, with bumblebees having a visitation rate double that of honeybee, collecting pollen more frequently and changing plant and row more frequently. The spatio-temporal and functional complementarity between honeybee and bumblebees suggested here encourages the consideration of an integrated crop pollination strategy for blueberries, based on the concurrence of both wild and managed bees.

Global patterns in bumble bee pollen collection show phylogenetic conservation of diet.

Bumble bees (Bombus) are a group of eusocial bees with a strongly generalised feeding pattern, collecting pollen from many different botanical families. Though predominantly generalists, some bumble bee species seem to have restricted dietary choices. It is unclear whether restricted diets in bumble bees are inherent or a function of local conditions due to a lack of data for many species across different regions. The objective of this study was to determine whether bumble bee species displayed specific patterns of pollen collection, and whether patterns were influenced by phylogenetic relatedness or tongue length, a trait known to be associated with structuring floral visitation. Bumble bee pollen collection patterns were quantified from 4,132 pollen loads taken from 58 bumble bee species, representing 24% of the pollen-collecting diversity of this genus. Phylogenetic trait mapping showed a conserved pattern of dietary dissimilarity across species, but not for dietary breadth. Dietary dissimilarity was driven by collection of Fabaceae, with the most similar species collecting around 50%-60% of their diet from this botanical family. The proportion of the diet collected from Fabaceae also showed a conserved phylogenetic signal. Greater collection of Fabaceae was associated with longer tongue lengths, with shorter tongued species focusing on alternative botanical families. However, this result was largely driven by phylogenetic relatedness, not tongue length per se. These results demonstrate that, though generalists, bumble bees are still subject to dietary restrictions that constrain their foraging choices. These dietary constraints have implications for their persistence should their core resources decline in abundance.

Nocturnal and diurnal pollination in Copaifera coriacea, a dominant species in sand dunes of the Middle São Francisco River Basin, Northeastern Brazil

Background and aims – Copaifera coriacea, a species in the resin-producing clade Detarioideae (Leguminosae), is an endemic and abundant species found in sand dunes in Brazilian Caatinga domain vegetation – a Quaternary paleodesert. We investigated floral traits and aspects of pollination biology, focusing on the pollination system of C. coriacea. Material and methods – Anthesis duration, stigma receptivity, pollen viability, nectar concentration, and the presence of osmophores and pigments reflecting UV light were assessed. Floral visitors were classified as potential pollinators, occasional pollinators or thieves, based on the time and foraging behaviour and resource collected. Pollination effectiveness were assessed for potential pollinators by the detection of pollen tubes on the stigma or stylar canal by epifluorescence microscopy.Key results – The species has white and small flowers, with anthesis beginning in the dark (ca 00:30) and the flowers are completely opened approximately 3 h later, when a sweet odour is perceptible. The onset of stigma receptivity and pollen grain viability occurs only after the completion of flower opening, and a concentrated nectar is available during the day. The presence of pollen tubes confirmed the efficiency of the main insects in the transfer of pollen. Conclusion – Our result demonstrates that C. coriacea has a generalist pollination system mediated mainly by two distinct guilds of insect pollinators: moths (nocturnal, searching for nectar) and bees (diurnal, pollen collectors). This finding can provide more information about diversification in the genus Copaifera.

Trade-off mitigation: a conceptual framework for understanding floral adaptation in multispecies interactions.

ABSTRACTExplanations of floral adaptation to diverse pollinator faunas have often invoked visitor‐mediated trade‐offs in which no intermediate, generalized floral phenotype is optimal for pollination success, i.e. fitness valleys are created. In such cases, plant species are expected to specialize on particular groups of flower visitors. Contrary to this expectation, it is commonly observed that flowers interact with various groups of visitors, while at the same time maintaining distinct phenotypes among ecotypes, subspecies, or congeners. This apparent paradox may be due to a gap in our understanding of how visitor‐mediated trade‐offs could affect floral adaptation. Here we provide a conceptual framework for analysing visitor‐mediated trade‐offs with the hope of stimulating empirical and theoretical studies to fill this gap. We propose two types of visitor‐mediated trade‐offs to address negative correlations among fitness contributions of different visitors: visitor‐mediated phenotypic trade‐offs (phenotypic trade‐offs) and visitor‐mediated opportunity trade‐offs (opportunity trade‐offs). Phenotypic trade‐offs occur when different groups of visitors impose conflicting selection pressures on a floral trait. By contrast, opportunity trade‐offs emerge only when some visitors’ actions (e.g. pollen collection) remove opportunities for fitness contribution by more beneficial visitors. Previous studies have observed disruptive selection due to phenotypic trade‐offs less often than expected. In addition to existing explanations, we propose that some flowers have achieved ‘adaptive generalization’ by evolving features to avoid or eliminate the fitness valleys that phenotypic trade‐offs tend to produce. The literature suggests a variety of pathways to such ‘trade‐off mitigation’. Trade‐off mitigation may also evolve as an adaptation to opportunity trade‐offs. We argue that active exclusion, or floral specialization, can be viewed as a trade‐off mitigation, occurring only when flowers cannot otherwise avoid strong opportunity trade‐offs. These considerations suggest that an evolutionary strategy for trade‐off mitigation is achieved often by acquiring novel combinations of traits. Thus, phenotypic diversification of flowers through convergent evolution of certain trait combinations may have been enhanced not only through adaptive specialization for particular visitors, but also through adaptive generalization for particular visitor communities. Explorations of how visitor‐mediated trade‐offs explain the recurrent patterns of floral phenotypes may help reconcile the long‐lasting controversy on the validity of pollination syndromes.

Safe sex: ant defense does not interfere with pollination in passion flowers

Ant defense against floral enemies incurs a two-fold ant-pollinator conflict, both via pollinator deterrence and nectar or pollen collection by non-pollinating protective ants. Some ant-plants have physical barriers whereas others produce ant-repellent chemicals to avoid ant visitation to flowers and subsequent pollination interference. Passiflora coccinea is a hummingbird-pollinated myrmecophilous plant in which floral enemy repellence occurs without limiting ant access to open flowers. To test the hypothesis that ant activity is restricted within flowers to prevent contact with anthers, we compared ant defense response between reproductive (anthers and stigmas) and non-reproductive (bracts, corona and perianth) floral structures by combining an observational survey with an experimental approach. A few insect species were found to visit flowers without providing pollination service, mostly pollen-collecting bees and nectar-thieving butterflies landing on petals. Ants always attacked floral visitors that landed on non-reproductive structures, but they never attacked insects visiting reproductive structures as ants never accessed anthers. Our results suggest that the differential ant defense response is an adaptative process to prevent ant-pollinator conflict. The eventual mechanism that regulates this process could be closely linked to the corona of filaments that protects nectar chambers, simultaneously restricting ant access to nectar and pollen.

Тhe influence of the removal bee pollen with the pollen catcher on the flight activity and behaviour of the bees-polen collectors

The possibility of demonstration of the productivity potential of the bee families depends directly on the level of provision of protein feed. In this regard, the study of the bees behavior that is connected to harvesting and processing of protein food is important for both biology and practical beekeeping. The presented work provides some data of experimental studies of the influence of the removal of the bee pollen on the flight activity of bees. The study of the ethological features that enhance the increase of collection, harvesting and processing of the protein feed was conducted. With this purpose the studies were conducted to elucidate the factors that induce collection of the protein feed -bee pollen by bees and its harvesting in the nest of the bee family in the form of the bee bread. The factors that influence the increase of the collection of the protein feed by bees were researched on experimental and control bee families- analogues. Throughout the studies it was identified that the bees with medium strength were the most active in collecting the pollen. The removal of the bee pollen with pollen catchers decreases the raising of brood by bee families, but doesn’t result in their significant weakening. With the enlargement of the area of the open brood the collection of the pollen by bees increases. In order to obtain the saleable bee pollen the strong bee families should be kept on the apiary. The bees-collectors of the protein feed have the individual features of collecting the bee pollen. With the removal of thbrood from the nest the activity the bees that flew out decreased. When adding the open brood the activity increased. On the contrary, with supply of the bee pollen to the nest, the pollen collecting activity decreases and adding the carbohydrates has no effect. The removal of the bee pollen with the pollen catcher from the bee families increases the flight activity which in turn leads to obtaining more bee pollen on the apiaries and pollination of additional quantity of entomophilous plants. In order to obtain the saleable bee pollen the strong families should be kept on the apiary and the removal should be conducted in the morning and day hours. Key words: bee family, Ukrainian steppe breed, pollen, bee pollen, bee bread, pollen catcher, flight activity of bees.

The bioenergy crop Sorghum bicolor is a relevant pollen source for honey bees (Apis mellifera)

AbstractAbundance and diversity of pollinating insects are decreasing. Intensification of agricultural bioenergy production is presumed to accelerate the decline of pollinators. Sorghum (Sorghum bicolor L. Moench) is a promising bioenergy crop. Enhanced dual‐purpose type cultivars have been developed and tested for suitability for bioenergy cropping in Germany. Sorghum is assumed to be a nutritional resource for pollen‐collecting insects. To evaluate this assumption, we studied the foraging strategy of A. mellifera colonies, which were migrated to sorghum fields in Germany. The bee hives were equipped with bottom fixed pollen traps. The pollen loads of the colonies contained variable shares of sorghum pollen ranging between approx. 10% and 50% (weight/weight). Sorghum pollen occurred frequently in more than 50% of all pollen samples. Experimental mini colonies were placed in plots which were grown with two varieties of sorghum, phacelia (Phacelia tanacetifolia), maize (Zea mays) and a control plot without any vegetation. All plots were encased with flight tents. Significant effects of the crop were found for the productivity parameters brood rearing and pollen collection. The sorghum and maize variants performed significantly better than the controls but significantly poorer than phacelia (p < 0.05). The parameters number of dead bees and colony sizes were not affected by the crops (p < 0.05). Pollen of sorghum is a valuable food for bees which supports nursing of bee brood, but its availability proved to be inferior to phacelia as the pollen shedding of sorghum lasted a considerably shorter time. Pollen collection by honeybees did not negatively affect seed yield of sorghum in any case. Under unfavourable weather conditions, flower visiting bees enhanced seed yield of sorghum.

Fragile queen mole rats

Development Honey bees are social animals, with populations consisting of castes of siblings with defined divisions of labor and matching phenotypes. Drones, queens, and workers have specific jobs within the hive for reproduction, rearing the brood, or gathering pollen and nectar. The Damaraland mole rat ( Fukomys damarensis ) is similarly social. Groups of mole rats consist of a single breeding pair and their offspring, which divide the labor of locating food, burrowing, nest building, and caring for offspring. Knowing that, similar to honey bees, mole rats show phenotypic differences depending on caste, Johnston et al. investigated the molecular basis for these transformations. If a female mole rat is experimentally induced to become a breeding “queen,” her vertebral column lengthens. The authors found that transitions in breeding status were accompanied by skeletal gene-regulatory changes that endowed major skeletal remodeling. In addition to a lengthening of the lumbar vertebrae, gene expression analysis indicated increased bone resorption and changes in estrogen levels in queens that reduced long bone growth and femur density. These morphological costs are thus a trade-off between fertility and bone fragility. eLife 10 , e65760 (2021).

Enhancing flowering plant functional richness improves wild bee diversity in vineyard inter-rows in different floral kingdoms.

Wild bees are threatened by multiple interacting stressors, such as habitat loss, land use change, parasites, and pathogens. However, vineyards with vegetated inter‐rows can offer high floral resources within viticultural landscapes and provide foraging and nesting habitats for wild bees. Here, we assess how vineyard management regimes (organic vs. conventional; inter‐row vegetation management) and landscape composition determine the inter‐row plant and wild bee assemblages, as well as how these variables relate to functional traits in 24 Austrian and 10 South African vineyards. Vineyards had either permanent vegetation cover in untilled inter‐rows or temporary vegetation cover in infrequently tilled inter‐rows. Proportion of seminatural habitats (e.g., fallows, grassland, field margins) and woody structures (e.g., woodlots, single trees, tree rows) were used as proxies for landscape composition and mapped within 500‐m radius around the study vineyards. Organic vineyard management increased functional richness (FRic) of wild bees and flowering plants, with woody structures marginally increasing species richness and FRic of wild bees. Wild bee and floral traits were differently associated across the countries. In Austria, several bee traits (e.g., lecty, pollen collection type, proboscis length) were associated with flower color and symmetry, while in South African vineyards, only bees’ proboscis length was positively correlated with floral traits characteristic of Asteraceae flowers (e.g., ray–disk morphology, yellow colors). Solitary bee species in Austria benefitted from infrequent tillage, while ground nesting species preferred inter‐rows with undisturbed soils. Higher proportions of woody structures in surrounding landscapes resulted in less solitary and corbiculate bees in Austria, but more aboveground nesting species in South Africa. In both countries, associations between FRic of wild bees and flowering plants were positive both in organic and in conventional vineyards. We recommend the use of diverse cover crop seed mixtures to enhance plant flowering diversity in inter‐rows, to increase wild bee richness in viticultural landscapes.

Pollen management and controlled pollination in Eucalyptus urophylla

The genus Eucalyptus has shown great potential for the establishment of commercial forest plantations, it is one of the most widely planted worldwide, it is planted in different regions of the planet, which indicates its ability to adapt to various environmental conditions. Eucalyptus urophylla is a species of this genus that adapts to tropical and subtropical regions, in suitable sites it can achieve high growth rates. It is one of the species with the most research in breeding programs in the world, mainly due to its capacity to hybridize naturally, since it generates populations with high genetic diversity, coupled with its ability to reproduce asexually. In Mexico, the breeding programs for Eucalyptus urophylla are in the initial phase, although plantations are already managed under clonal silviculture, controlled crossing are just beginning, so pollen management and crossing techniques are the most important activities in these programs. Since there is currently no information about the management of pollen for Eucalyptus urophylla in Mexico, the aim of this paper is to show a methodology based on the information documented in other parts of the world and the recent experience acquired in the collection and management of pollen, as well as the controlled pollination techniques recently employed in the breeding programs of Eucalyptus urophylla in southeastern Mexico.

Optimized Protocol for In Vitro Pollen Germination in Yam (Dioscorea spp.).

Yam (Dioscorea spp.) plants are mostly dioecious and sometimes monoecious. Low, irregular, and asynchronous flowering of the genotypes are critical problems in yam breeding. Selecting suitable pollen parents and preserving yam pollen for future use are potential means of controlling these constraints and optimizing hybridization practice in yam breeding programs. However, implementing such procedures requires a robust protocol for pollen collection and viability testing to monitor pollen quality in the field and in storage. This study, therefore, aimed at optimizing the pollen germination assessment protocol for yam. The standard medium composition was stepwisely modified, the optimal growth condition was tested, and in vivo predictions were made. This study showed that the differences in yam pollen germination percentage are primarily linked to the genotype and growing conditions (i.e., medium viscosity, incubation temperature, and time to use) rather than the medium composition. The inclusion of polyethylene glycol (PEG) in the culture medium caused 67–75% inhibition of germination in D. alata. Although the in vivo fertilization was dependent on female parents, the in vitro germination test predicted the percentage fruit set at 25.2–79.7% and 26.4–59.7% accuracy for D. rotundata and D. alata genotypes, respectively. This study provides a reliable in vitro yam pollen germination protocol to support pollen management and preservation efforts in yam breeding.

Вплив умов медозбору на продукування бджолами маточного молочка

Goal. To study the biological potential for the production of the royal jelly by bees in the conditions of supportive and intensive honey harvest. Methods. Laboratory — for the determination of royal jelly mass, zootechnical — for the accounting the number of queen larvae in the bee families, ethological — for the determination of the orientation of bees in the area near the hive hole, and statistical — for biometric processing of experimental data. For the first time in the production of beekeeping products, a comparative analysis of obtaining the royal jelly was made for maintaining an intensive honey harvest. The production of the royal jelly was based on the technological process of artificial growth of the queens, which is interrupted after 72 hours after grafting larvae. Families for the reception of larvae were formed by a method of incomplete desertion. Incomplete desertion of the bee family meant that the bee queen was not completely isolated from a bee family. For that purpose, the bee family was divided in half with a solid diaphragm with the Hahnemann lattice, which isolated the queen bee. For the flight of the bees-collectors of nectar and bee pollen, only the entrance in the section with the queen bee was left open. In the research process, they applied the method of the use of bee families for producing the royal jelly simultaneously with the collection of nectar and pollen by bees in conditions of relatively small supportive and intensive honey harvest. Results. The technological method of formation and use of families-growers during the obtaining the royal jelly, which significantly reduced labor costs and funds for its production has been developed and tested. Conclusions. In the conditions of supporting honey harvest, the positive effect of bringing nectar to the reception of larvae in the nests of families was revealed. In various types of honey harvest (maintenance and intensive) for the production of royal jelly using the method of incomplete desertion, it is possible to use bee families of Ukrainian and Carpathian breeds. It was a slight advantage of the bee families of the Ukrainian steppe breed over the bee families of the Carpathian breed for the production of royal jelly.

Beebread consumption by honey bees is fast: results of a six-week field study

Due to their foraging behavior, honey bees interact with the landscape. As a result, honey bees and their brood will be exposed to pesticides through nectar and pollen entering the hive. Although these pathways seem rather straightforward, there are several steps between the entry of nectar and pollen and its consumption by the colony. One of the aspects involved here is the time between collection and consumption of pollen in the hive. This is of importance for the actual exposure of nurse bees and larvae to pesticides in pollen. Although lab and short-term field studies indicated that bees prefer to consume freshly stored pollen, this has to our knowledge not been verified in a long-term field study under realistic environmental and apiculturist conditions. To study pollen consumption dynamics, influx and consumption were recorded at 3 or 4 day intervals over a six-week period in two colonies. It was demonstrated that throughout the experimental period, beebread consumption was high in the first 3 to 5 days after collection, over which approximately 70% was consumed. The remaining 30% was consumed within a 2 to 3 week period. Pollen consumption is swift and indicates that only limited time is available for potential degradation processes. As actual data on degradation of pesticides in stored pollen are not available, a justified worse case assumption would be that the actual exposure concentrations consumed by the nurse bees and larvae are the same as the concentrations in collected pollen.

Pollen storage of coconut dwarf accession Chowghat Orange Dwarf at low temperature

Pollen collection and storage assume importance in hybridization programs in coconut. Development of an effective short-term storage method for coconut pollen ensures availability of pollen for coconut breeding throughout the year. In the present study, pollen collected from dwarf coconut cultivar Chowghat Orange Dwarf (COD), using standardized extraction procedures, was utilized for studying their storage behaviour under four different low-temperature regimes, i.e. 4ºC, -20ºC, -45ºC and -196ºC along with control at room temperature. Data on pollen germination percentage and pollen tube lengths were collected based on in vitro procedures at four different storage intervals (1st day, 14th day, 30th day and 60th day) to identify best short-term storage temperature. Germination percentage of pollen gradually reduced with duration of storage in all treatments but in case of pollen, which was stored at room temperature (control, i.e. 28±2ºC), viability decreased drastically and became nil within two weeks. Results revealed that higher germination percentage (38.82%) and pollen tube length (535.9 μm) were observed at -196ºC followed by -45ºC (31.77%, 400.73 μm) and -20ºC (30.82%, 282.89 μm) after a storage period of eight weeks. This study shows that desiccated pollen grains can be successfully stored at -45ºC for its utilization in breeding programmes besides long term storage at -196ºC.