Acetolysis Method Research Articles

Blooming calendar and polliniferous plants in Djuanda Great Forest Park, West Java, Indonesia: Implication for beekeeping management

Abstract. Husodo T, Wulandari I, Saputri Y, Kasmara H, Hermawan W, Kusmoro J, Shanida SS, Khairina F, Haydar MRA, Asyraf MN, Febrian RR. 2024. Blooming calendar and polliniferous plants in Djuanda Great Forest Park, West Java, Indonesia: Implication for beekeeping management. Biodiversitas 25: 3216-3229. Information was unavailable regarding the types of pollinator plants and their blooming periods in Djuanda Great Forest Park, West Java, Indonesia. Information about flower blooming seasons was useful for various purposes. These findings will provide a basis for understanding the importance of Apis cerana Fabricius, 1793 in plant pollination and plant species resources for honey bees so that beekeeping practices can be carried out sustainably. The blossoming period of a plant is determined by its blooming period at the time of observation. The blooming period is observed every month in the second and fourth weeks for six months (December 2021-May 2022). Pollen collection was carried out in August 2021 (dry season). Pollen identification was carried out using the acetolysis method, which involves dissolving the non-pollen components of a sample to reveal the pollen grains, thereby enabling accurate identification. An overview of the observation records revealed the presence of 249 plant species from 82 families. The Asteraceae family has the most abundant species richness. Most plants were identified as pollinator plants (30.52%), nectariferous plants (10.04%), and plants that produce both (18.47%). Flowering plants of melliferous plants for honeybees are available throughout the rest of the year, especially from December to May. Therefore, to optimize honey harvesting, it is important to establish multiple colonies during periods of large honey flows. Honeybees may use alternative sugar sources beekeepers provide, such as fruit juice, during nectar scarcity. We would like to know more about the year-round bloom calendar. Sharing knowledge with farmers about the availability of melliferous plants in certain months will empower them to make decisions for sustainable beekeeping.

Larval diet of the carpenter bee Xylocopa (Neoxylocopa) cearensis (Hymenoptera: Apidae: Xylocopini) from the Delta do Parnaíba environmental protection area, Brazil

The genus Xylocopa Latreille, 1802 (Apidae: Xylocopini) Latreille includes efficient pollinating bees that visit a wide range of botanical species. Although several studies have investigated their interactions with plants in dune ecosystems, there is still a limited understanding of these bee communities in coastal environments. This study aimed to characterize the larval diet of Xylocopa (Neoxylocopa) cearensis Ducke, 1910 by analyzing pollen from their nests to assess the presence of specialization or generalization in relation to botanical species. The research was carried out in coastal sandbanks of the Delta do Parnaíba Environmental Protection Area, Tutóia, Maranhão-BR, over a 12-month period. The natural nests were inventoried by active searches and, when possible, transported to the Federal University of Maranhão. Pollen samples were collected from 19 brood cells of 12 nests in total. All the nests were found on branches of Anacardium occidentale L. Using the acetolysis method, 21 types of pollen were recognized, representing 14 botanical families. Three of those types of pollen were considered to be Frequent pollen, Mouriri cearensis Huber (35.44%), Chamaecrista ramosa (Vogel) H. S. Irwin & Barneby (32.80%) and Myrcia multiflora (Lam.) DC (27.05%). Based on these results, X. cearensis can be characterized as a polylectic species that demonstrates adaptability. These floral resources serve as essential protein sources for the nutrition of their brood, highlighting the importance of these plant species in supporting their reproductive success. This study provides useful information that can serve as a reference for future research on other Xylocopa species in similar ecosystems.

Identify The Source of Pollen Feed in Honey and Bee Bread of Tetragonula biroi

This study aims to determine the types of feed pollen consumed by the bee species Tetragonula biroi. The research has the objective of providing information to the public regarding the sources of feed for T. biroi honey bees, which are located in Kuajang Village, Binuang District, Polewali Mandar Regency, West Sulawesi. The research was conducted between February and April 2020. A comparative method was employed to examine the shapes of plant pollen found around the meliponiary in comparison to the shapes of pollen discovered in honey and bee bread. Samples were prepared using the acetolysis method and stained using safranin. The research findings indicate the presence of 23 identified flowering plant species in the vicinity of the meliponiary, along with their identification in bee bread. However, only 12 species were identified in honey. Coconut pollen exhibited the highest percentage, accounting for 44.8% of honey and 38.13% of bee bread, categorizing it as a secondary pollen type.

Potentials of palynotaxa for apicultural entrepreneurships: Implication for conservation and policy

The contemporary global economic meltdown has devastating effect on the economy of most rural people in Africa in general and Nigeria in particular. The frantic search for alternative source of national revenue aside from oil and gas has become imperative for economic emancipation of Nigerians. Knowledge of plants foraged by bees for pollen and nectar becomes a panacea to this challenge. This study analysed the pollen spectrum of four honey samples collected from Southern Nigeria in order to determine the richness of the honey plants in the area, and to highlight the potential of these species in apicultural entrepreneurship in Nigeria for green growth economy, using Shannon-Wiener Diversity Index after a standard acetolysis method. A total number of 39 palynotaxa belonging to 21 plant families and distributed in 39 genera were identified. Fabaceae had the highest plant species (11 species), followed by Euphorbiaceae (5 species). The study revealed that Elaeis guineensis Jacq, Anacardium occidentale L. Diospyros mespiliformis Hochist ex ADC, Alchornea cordifolia (Muell)Arg, Daniella oliveri (Rolfe) Hutch & Dalz, Irvingia wombolu Okafor ex Baill, Treculia africana Decne, Nauclea latifolia Smith and Crossopteryx febrifuga Afzil ex Benth, were the dominant honey plants. The palynotaxa spectrum did not vary greatly in the four samples; however, Shannon diversity index was low to moderate (H= 2.7 -3.1). This baseline information has provided opportunity and amazing potentials for apicultural enterprise in these areas. However, most of these honey plants are rare, threatened and endangered. This calls for urgent conservation strategies by all players. Policy programmes could increase production and productivity of hive products through capacity- building for local populace.

Karakteristik Polen pada Spesies Mangrove di Kawasan Hutan Mangrove Batu Lumbang, Denpasar, Bali

The diversity of mangrove species in an area can be observed through morphological structure, anatomy, as well as palynology. Palynology is a study of pollen that frequently used as a reference to support data in identifying mangrove species. Mangrove areas in Bali have patchy distribution, one of which can be found in the Batu Lumbang area. Batu Lumbang is a mangrove area that is part of the Ngurah Rai Forest Park. Observation of the micromorphological characteristics of pollen in the Batu Lumbang mangrove forest area was carried out through the acetolysis method with modification. Eleven mangrove species were sampled, comprised of Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorhiza, Ceriops tagal, Exoecaria agallocha, Lumnitzera racemosa, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, Sonneratia caseolaris, and Xylocarpus granatum. The results of observations on pollen from eleven species of mangroves show similarities of pollennits, monads. In addition, other pollen characters such as aperture type, pollen shape, and pollen size categories found vary among the samples observed. These characters can also group several species that have the same family or genus. In turns, these can be used as diagnostic character to distinguish one species with another.

Pollen morphology of Ipomoea L. from Garhwal Himalaya, India

Pollen morphology serves as a valuable tool for identification, phylogenetic analysis and evolutionary studies. The present study aims to investigate the pollen morphology of 12 species of the genus Ipomoea L. (a diverse and economically important genus within the family Convolvulaceae) from Garhwal Himalaya, India. Fresh flower buds were collected from the study area and pollen preparation completed using the acetolysis method. The morphology of the pollen grains were examined using light microscopy and scanning electron microscopy. Pollen grains of all the studied species were apolar, spheroidal, pantoporate, subtectate with fine reticulation and echinate, but they differed from one another in their size, number of spines and pores, spine length and spine types. The size of grains ranged from 53.3 to 128.7 μm. Cluster analysis was performed based on pollen characters to show the relationship among the species; a key was prepared and is discussed. The observed variation in pollen morphological traits gives important taxonomic information that is useful for distinguishing Ipomoea species and establishing taxonomic and phylogenetic relationships.

Fluorescence lifetime imaging of sporopollenin: An alternative way to improve taxonomic level of identifying dispersed pollen and spores

Spores/pollen records abundant information of biodiversity, evolution, and climate condition. The exine of spores/pollen is mainly composed of sporopollenin, which is chemically stable over geological time. Morphological study of the exine is a classical method used in palynology. In this study, we developed a fluorescence lifetime imaging (FLIM) method to investigate the numbers and lifetimes of fluorophores in sporopollenin. We used 20 pollen grains of each species to study sporopollenin FLIM. The sporopollenin was purified using the acetolysis method. Laser scanning confocal microscopy (LSCM) was used to study the autofluorescence of sporopollenin. The sporopollenin FLIM of pollen grains collected in different years/geographical populations showed no significant difference. Three fluorophores were estimated in the sporopollenin of all the tested plants, including angiosperms (Oryza sativa and Zea mays, Brassica napus and Arabidopsis thaliana), gymnosperms (Cryptomeria fortune and Metasequoia glyptostroboides), ferns (Lygodium japonicum and Ceratopteris thalictroides), and lycophyte (Lycopodium clavatum). Quantitative analysis demonstrated that the lifetimes of fluorophores varied in different species, showing that FLIM provides additional information to distinguish spores/pollen. Further analysis showed significant differences in sporopollenin fluorescence lifetimes between morphologically similar pollen grains of cultivated crops and their wild relatives of the genera Oryza and Triticum. These results show that sporopollenin FLIM offers a new dimension of information on spores/pollen. This new technique has a big potential to fill a gap for traditional morphological comparison to identify dispersed fossil pollen and spores.

Fenologi Fase Pembungaan dan Perbuahan serta Produksi Polen pada Tanaman Kacang Panjang Kultivar Sabrina

Yardlong beans (Vigna unguiculata subsp. sesquipedalis (L.) Verdc.) is a vegetable source of vitamins and minerals which are quite widely cultivated in Indonesia. Phenology study the phases that occur in a plant that is provides benefits in agriculture, but information on the phenology of legumes crops in Indonesia is still scarce. This study aims to observe the reproductive phenology and pollen production of the yardlong bean cultivar Sabrina. A phenological study was carried on 7 plants to obtain information on the timing and duration of the reproductive period, inflorescence and fruiting phases, peak flowering time, and flower biology. Pollen production was observed in 5 samples of flowers. Pollen microscopic preparations were made using the acetolysis method. The results showed that the flowering and fruiting phases took 21-29 days; including flower initiation phase 7-10 days, small bud phase 1day, large bud phase 1 day, anthesis phase 1-2 days, and fruit development phase 11-15 days. Flower initiation occurred 36 days after planting (DAP), and flower blooming occurred 49 DAP. The peak of flowering occurred at 56-62 DAP. The flowers of the Sabrina cultivar have purplish-white corollas, producing about 276±23.58 pollen/anther.

Stingless bee pollen product from Mount Merapi Slope, Turi Yogyakarta Indonesia

Stingless beekeeping practice (meliponiculture) in Indonesia is known to have an important role in flowering plant pollination outcomes as the stingless bee species is widely distributed across most regions of the country. As a social insect, lebah klaceng (the local name of stingless bee) consists of many species which produces honey, bee pollen, and propolis. It has been found that higher diversity of the collected pollens indicates a higher success of pollination outcomes for different kinds of flowering plants. Thus, the aim of this study is to identify the diversity of collected stingless bee pollens in the meliponiculture practice at the Mount Merapi Slope, Turi, Yogyakarta, Indonesia by observing the pollen characteristics. Acetolysis method was used in the preparation of the collected pollens for identification. The pollens were then observed under a light microscope. The result showed that the stingless bee pollens collected from Mount Merapi Slope were successfully obtained from various flowering plants belonging to 31 families dominated by Arecaceae (46.60%), followed by Asteraceae (6.90%), and Malvaceae (5.70%). It can be concluded that the stingless bee, Tetragonula laeviceps, is a good pollinator insect which supports the successful pollination of up to 31 families of flowering plants found at the Mount Merapi Slope, Turi, Yogyakarta, Indonesia.

Assessment of Morphological, Anatomical and Palynological Variation in the Medicinal Plant Disporopsis longifolia Craib (Asparagaceae) for Botanical Quality Control

Disporopsis longifolia Craib is an Asian medicinal plant belonging to the Asparagaceae family. The plants are well known for their steroidal saponins and phenolic compounds and are traditionally used as tonics for back pain, bellyache, cough, diabetes, asthma, pneumonia and rheumatism. However, they are challenging to identify to species level using morphology. This raises a serious concern for their medicinal applications where botanical quality control is essential. The most appropriate morphological, anatomical and pollen characters for species diagnosis were therefore determined. Synonyms were identified and lectotypification provided. The morphological characters were described from 76 fresh and dried specimens to include a broad range of materials from differing habitats and locations. Paraffin and peeling methods were applied for anatomical studies of leaves and stems and a modified acetolysis method was undertaken for pollen morphology. This paper compares the new character data to published data from other species in the genus, namely D. aspersa, D. fuscopicta, D. jinfushanensis, D. pernyi and D. undulata. This is the first report of such anatomical and pollen morphology characters for D. longifolia. The results provide accurate morphological, anatomical and palynological characters for quality control and are best applied in combination with each other.

Palynological diversity of some species of Coussareeae (Rubiaceae) from the Atlantic Forest, Brazil

Coussareeae is a neotropical tribe with a complex taxonomic history. Several authors considered it very close to the tribe Psychotrieae owing to similarities in their morphological characteristics, such as solitary ovules. The tribe Coussareeae constitutes the largest basal clade of the subfamily Rubioideae, and most of its genera are well represented in Brazil. The tribe is resolved into three suprageneric clades, including the Coccocypselum and Coussarea-Faramea clades, whose representatives are found in Brazil. This study aimed to ascertain whether pollen attributes corroborate the currently proposed phylogeny and systematics of the tribe. For this, pollen grains of 33 species belonging to the Coccocypselum and Coussarea-Faramea clades were analyzed. Specimens were obtained from herbaria, treated by the acetolysis method, measured, photographed, and described using light and scanning electron microscopy. Morphological analysis showed that pollen grains were medium (25–50 µm) or large (50–100 µm) in size; isopolar or apolar; 2-porate, 3-porate, or 3-colporate; and oblate spheroidal, suboblate, prolate spheroidal, or subprolate. Ornamentation varied among clade representatives. Multivariate analysis of quantitative data revealed that pollen diameter, apocolpium side, pore diameter, colpus length, and endoaperture width were the most significant characters. It can be seen from the results that the studied clades are formed by palynologically distinct genera in terms of polarity, aperture type, and ornamentation. Palynology confirms the proposed taxonomic classification.

Methods Employed in the Determining Nectar and Pollen Sources for Bees: A Review of the Global Scenario

Abstract Flowering plants and pollinators are in a mutualistic association, where pollinators collect floral resources and plants receive pollination services. Bees and other pollinators are declining in many parts of the world, and their loss affects the functional composition of fauna, flora, and habitats. Different strategies are being deployed to improve pollinator services, including the management of bees. Sustainable management of a bee species strongly depends on floral resource availability. Therefore, beekeepers need to have adequate knowledge about the surrounding vegetation (especially nectar and pollen sources for the bee species). Diverse methodologies are used around the world to determine floral resources for bees. Field surveys and pollen analysis of honey, corbicular/scopal pollen loads, residual pollens in brood cells, forager’s body surface pollen content, and internal organs (gut, intestine, crop, etc.) were used by the researchers. For pollen identification, most researchers carried out microscopy-based methods. However, pollen DNA-based methods were also used by researchers in recent years. Regarding the morphology-based identification, most researchers processed pollen samples according to Erdtman’s acetolysis method to increase the visibility of diagnostic characteristics of the pollen grains. The method specified by the International Commission for Bee Botany was used to conduct qualitative and quantitative pollen analysis on honey samples. For quantitative pollen load analysis, researchers used numerous techniques that may have been the most effective. Our discussion about the different techniques utilized to determine floral resources of a bee species will be helpful for researchers in selecting a suitable protocol and may assist in developing superior methodologies.

The Pollen Load on Stingless Bees (Apidae: Meliponinae) Foraged in Urban Area

Stingless bees (Apidae: Meliponinae) are eusocial insects that distributed in the tropics and subtropics. Stingless bees are pollinators for various plant species. Foraging activities of worker stingless bees collect pollens, nectar, resin or water as nutrients for individuals and colony needed. This study aimed to measures pollen load and pollen composition carried by four species of stingless bees, i.e., Tetragonula laeviceps, Lepidotrigona terminata, Heterotrigona itama, and Geniotrigona thoracica in urban area at Bogor, Indonesia. Acetolysis method was used for pollens preparation and pollens were counted by using hemacytometer under light microscope embedded with camera. The study showed that the highest pollen load occurred in H. itama (59181 pollen grains), followed by L. terminata (27806 pollen grains), T. laeviceps (20816 pollen grains), and G. thoracica (11775 pollen grains). The number of pollens collected by T. laeviceps, L. terminata, and H. itama positively correlated with body size. Thirteen types of pollen were identified on the body of stingless bees. Pollen composition collected by T. laeviceps were dominated by Chlorantaceae (50%) and Polygonaceae (20%), L. terminata and H. itama were dominated by Asteraceae (70.19% and 62.76%) and Arecaceae (22.87% and 29.65%), while in G. thoracica was dominated by Apocynaceae (53.53%) and Acanthaceae (34.32%). Lepidotrigona terminata and H. itama carried of small pollen-size and G. thoracica carried moderate pollen-size.

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

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

Flora visited by Melipona mondury Smith 1863 (Hymenoptera: Apidae: Meliponini) in a fragment of the Atlantic Forest in the state of Bahia, Brazil

Tropical forests encompass a high diversity of plant species that depend on several pollinator bees, such as Melipona mondury. In the present study, we identified the pollen types in samples of honey, pollen (nest pots) and pollen baskets of M. mondury workers from a meliponary located in the Atlantic Forest of the state of Bahia, north-eastern Brazil. Samples of flowering plants were also collected monthly nearby the meliponary and from trails along the fragment borders. The botanic material was identified and stored as herbarium collections. The samples of honey and pollen from colonies of M. mondury were collected and prepared using the acetolysis method for palynological studies. Using the botanical inventory around the meliponary, palynological slides were prepared and pollen characterised from 43 genera and 46 species within 24 plant families. Asteraceae (23%), Fabaceae (14%), Anacardiaceae (5%), Myrtaceae (5%), and Melastomataceae (4%) were the most common and diverse families around the meliponary. A total of 44 and 54 pollen morphotypes were found in honey and pollen samples, respectively, comprising several plant families, particularly Myrtaceae (15%) and Melastomataceae (10%). The pollen baskets of workers contained 35 pollen morphotypes, with a predominance of Fabaceae-Mimosoideae (16%), Melastomataceae (13%), Sapindaceae (13%), Myrtaceae (10%) and Solanaceae (10%). The flora of the study area proved to be highly diverse and M. mondury utilises a wide variety of plants, albeit with some differences. The conservation of the Atlantic Forest fragments is essential to the maintenance of pollinators such as M. mondury to assure the functionality of local ecosystems.

Pollen micro-morphometry of two endangered species of Rauvolfia L. (Apocynaceae) from the Indo-Gangetic Plains of Central India using LM, CLSM and FESEM

Rauvolfia belongs to the family Apocynaceae and encompasses herbs or shrubs with leaves in whorls of three or four. It is an endangered plant of the tropics and subtropics. We present a preliminary study and analysis of the morphological details of the pollen of two extant species of Rauvolfia (R. serpentina (L.) Benth. ex Kurz and R. tetraphylla L.) from the Ganga Plain using light microscopy (LM), confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM). The critical point drying method (CPD) was adopted to test the pollen size difference from the conventional acetolysis method (ACE). The pollen morphology of R. tetraphylla differs from that of R. serpentina in several specific traits. Its pollen grain is 3-colporate; it is oblate to oblate-spheroidal; sexine is punctate to obscure and mostly as thick as nexine; and a distinct thickening is present around the ectocolpi. The study shows that R. serpentina can be distinguished from R. tetraphylla by its pollen shape, size, sexine ornamentation (particularly the presence and absence of punctae/perforations in the mesocolpial region) and length of the ectocolpi thickening. The pollen shape and aperture number are more or less common features in Rauvolfia spp., but the presence and absence of a punctate pattern at the mesocolpial position marks the primary difference between the two species. The t-test was applied to determine the statistical significance of pollen morphological data of both species. This study provides a source of information for systematic and conservation purposes and provides a baseline to facilitate palynological studies of past vegetation and palaeoenvironments.

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

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

Pollen morphology of some species in family Amaranthaceae from Thailand

Abstract. Saensouk S, Saensouk P. 2021. Pollen morphology of some species in family Amaranthaceae from Thailand. Biodiversitas 23: 601-611. The aim of this study was to study the pollen morphology of 14 species, eight genera from the family Amaranthaceae in Thailand by the applied acetolysis method and it was taken under light and scanning electron microcopies. All pollen grains had monad, radial symmetry and apolar. The pollens in this study can be divided into several groups based on shape, size, aperture, mesoporia, the character of aperture, and exine sculpturing. The sizes of the pollen can be divided into three groups, i.e., very small pollen group, small pollen group, and medium pollen group. The shapes of the pollen can be divided into three groups, i.e., spheroidal, pentagon, and dodecahedric. Exine sculpturing can be divided into three groups, i.e., granular, macrogranular, and microspine. The pollen in this study can be divided into five groups based on the character of the aperture, i.e., aperture with convex circular-like shape, aperture with deeply collapsed circular-like shape, aperture with collapsed circular-like shape, aperture with collapsed pentagon-like shape, and 6-angular element or hexagon-like shape. The pollen in this study can be divided into three groups based on the mesoporia, i.e., mesoporia broadly flat, mesoporia moderately and broadly vaulted, and mesoporia narrow and highly vaulted. The number of apertures was found to be between 12-54 apertures per pollen. The aperture diameters of Amaranthaceae pollen in this study ranged from 0.5-5 µm. The exine thickness of the pollen in this study was 1.12±0.04 - 2.14±0.31 µm. The pollen character of this study can be divided into eight types, i.e., Achyranthes-type, Alternanthera-type, Amaranthus-type, Celosia-type, Cyathula-type, Gomphrena-type, Ouret-type, and Psilotrichum-type. The pollen characteristic of Alternanthera pungens Kunth, A. Sessilis (L.) R. BR., Amaranthus blitum subsp. oleraceus (L.) Costea, Cyathula prostrate (L.) Blume., Ouret sanguinolenta (L.) Kuntze, and Psilotrichum ferrugineum (Roxb.) Voigt were reported for the first time.

Pollen profile of bee pollen from semiarid Northeastern Brazil

The Northeastern Brazil has xerical vegetation with different biomes. Its botanical heterogeneity represents shelter for diverse fauna. The region is rich in bees, which demand the resources offered by the plants, and provide pollination services. Bee pollen has been used as a beneficial food source for humans due to its high nutritional content and being a natural antioxidant. Pollen analysis can determine the plant species visited by bees, using them as the source of pollen supply. This study aimed to identify the main pollen types present in the pollen collected by Apis mellifera in the Northeastern Brazil and to define its botanical affinity. Commercial bee pollen samples produced in the region were treated by acetolysis method, mounted on slides, and the frequency of occurrence was estimated for each type of pollen. It was possible to distinguish 113 pollen types belonging to 35 botanical families, distributed in 92 genera. Fabaceae and Asteraceae were the families that most contributed to pollen types. Pollen types of Cocos nucifera and Myrcia were found in more than 50% of the samples. The families Arecaceae and Fabaceae showed high beekeeping potential. There is a striking similarity between the pollen samples from the states of Pernambuco and Rio Grande Norte.

Importance of palynology in the taxonomy of Piptolepis Sch.Bip. (Asteraceae: Lychnophorinae), a genus endemic to Brazil.

Lychnophorinae comprises 19 genera and 117 species. Its representatives are found mostly in the rocky grasslands ("campos rupestres") of Minas Gerais, Bahia, and Goiás States, Brazil. This study presents a palynological investigation of 10 species belonging to the genus Piptolepis, endemic to the rocky grasslands of the Espinhaço Mountains, in Minas Gerais State. The plant material used in this investigation was obtained from specimens deposited in Brazilian herbaria. Pollen grains were processed by the acetolysis method, measured, described, and photomicrographed in light microscopy and scanning electron microscopy. Morphological observations revealed Piptolepis pollen to be large, prolate spheroidal in most species, 3-colporate, ectoapertures long, sexine subechinolophate or sublophate. Endoapertures vary from almost circular, lalongate or lalongate, with a median constriction observed only in three species. Three types of spines were identified: prostrate and disorganized, elongated and narrow, and conical, erect, apex acute in the other species. This first palynological study of Piptolepis species allowed the separation of representatives of the genus using pollen keys. The most significant characters were pollen shape, ornamentation, endoaperture, and presence of median constriction in the endoaperture. The findings presented here do not support the infrageneric classification of Piptolepis, as pollen characters were not unique to any section.