Search

Background: Plants and bees have coevolved throughout geological time, establishing a mutualistic relationship that results in feeding/resource obtention by bees and the reproductive success of angiosperms. Questions and Hypotheses: What is the floristic composition of the vegetation visited by bees in the Caatinga? How are pollen grains from Caatinga bee plant species characterized? Do pollen grains of bee plant species present characters that could be associated with the pollination process? Studied species: We studied the pollen grains of 45 bee plant species belonging to 41 genera and 23 angiosperm families. Among the studied species, 37 % are endemic to Brazil, and eight species are endemic to the Caatinga biome. Study site and dates: Apiary within the Caatinga biome, in the State of Bahia, Brazil. Climate warm semiarid. Fieldwork was carried out between August 2016 and June 2017. Methods: Plants in bloom and being visited by Apis mellifera were collected during biweekly field expeditions, herborized, identified, and deposited at the HUNEB herbarium. Pollen grains were acetolyzed, characterized, and microphotographed under light microscopy. Results: Forty-five bee plants were collected and classified according to field observations and specialized literature. Pollen morphology was variable, and nine species had their pollen morphology described for the first time. The apertures of the studied pollen grains were mainly tricolporate (44 %), pantoporate (15 %), and inaperturate (13 %), and exine ornamentation was mainly (micro)reticulate (46 %) and (micro)echinate (33 %). Conclusions: Our results suggest that bee plants present a set of palynological characters that may favor entomophily. Translate stop Translate stop

Deidamioides, one of the four subgenera proposed for the genus Passiflora, is distributed in South and Central America, with its species, until now having been grouped in five sections: Deidamioide...

This study aims to expand knowledge of the pollen morphology of Passifloraceae and contribute to the taxonomic delimitation of the group by morphologically characterizing pollen grains of species that occur in the Brazilian state of Bahia. Thirty-six species occur in the state, one of the genus Mitostemma (M. glaziovii) and 35 of the genus Passiflora. Pollen samples were acetolysed, measured, and described using light and scanning electron microscopy. The results group the studied species into four pollen types based mainly on aperture type and number, opercular variation, and the presence/absence of ornamentation elements inside the lumina of the reticulum: Pollen type I - species belonging to the subgenera Astrophea and Deidamioides; pollen type II - subgenus Decaloba; pollen type III - subgenus Passiflora; and pollen type IV - M. glaziovii, with pollen characteristics that separate it from the other species analyzed. The results reinforce the recognition of three subgenera of Passiflora. Morphopalynologically the species have very similar pollen types except for those of the subgenus Deidamioides, which are quite diverse and thus included in another pollen type. The results reveal the importance of pollen grains for the taxonomic study of Passifloraceae.

The pollen grains of 15 species belonging to five genera (Ceiba Mill., Eriotheca Schott & Endl., Pachira Aubl., Pseudobombax Dugand, and Rhodognaphalopsis A. Robyns) of the subfamily Bombacoideae (Malvaceae s.l.) were acetolysed, measured, described and photomicrographed under light microscopy and scanning and transmission electron microscopy, in order to characterize the pollen morphology of species of the subfamily occurring in Brazil. The pollen characters studied were size, shape, exine constitution, and apertural type. Pollen grains were medium to large-sized and isopolar with a (sub)circular and (sub)triangular amb with flat, convex or concave sides; oblate to suboblate; 3(-4)-colp(or)ate or 4-5(-6)-colporate, planaperturate, sinuaperturate; equatorial calottes different or not; exine tectate or semitectate, perforate and microreticulate with or without supratectal spines. The results confirm the eurypalynous nature of the group with variation among the studied genera being mainly in the exine pattern.

Made available in DSpace on 2022-04-29T08:30:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 We analyzed the pollen morphology of 13 Brazilian native species of Malvaceae s.l. from forest fragments of Cerrado belonging to nine genera [Bastardiopsis (K. Schum.) Hassl., Byttneria Loefl., Ceiba Mill., Eriotheca Schott & Endl., Guazuma Adans., Helicteres L., Heliocarpus L., Luehea Willd. and Pseudobombax Dugand] in search for characters that can expand the knowledge on the pollen morphology of species of the family that occur in areas of fragments. The pollen grains were acetolyzed, measured, described and photographed under light microscopy and scanning electron microscopy. The species studied were grouped into two pollen types based mainly on the type of aperture [simple aperture (3-porate or 4-colpate) and compound aperture (3-pororate or 3-colporate)], and the quantitative data were analyzed using descriptive and multivariate statistics. Details of apertures (planaperturate, angulaperturate, type of endoaperture, costa, aspis and atrium) and exine ornamentation (verrucate, microreticulate, microreticulate-echinate, reticulate and bireticulate) contributed as secondary data to the segregation of species in an artificial pollen key. The metric characters examined by multivariate analysis allow the distinction of groups of species, based on the length of the apertures and the diameters of the pollen grains. Our results allow the identification among genera and species of Malvaceae s.l. in Brazilian forest fragments. Programa de Pós-Graduação em Biologia Comparada Faculdade de Filosofia Ciências e Letras Universidade de São Paulo (USP), SP Programa de Pós-Graduação em Biodiversidade Vegetal Departamento de Educação Universidade do Estado da Bahia (UEB) Campus VII, BA Departamento de Biologia Aplicada à Agropecuária Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), SP Departamento de Biologia Aplicada à Agropecuária Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (UNESP), SP

This study aimed to identify the pollen types of 11 honey samples produced in apiaries of two cities in the State of Bahia, Brazil: Antônio Gonçalves (five samples) and Campo Formoso (six samples); to verify richness and diversity from each apiary and to compare the similarity among them. The samples were obtained from beekeepers according to the period of production and availability. The palynological analysis of these samples followed the standard procedures of melissopalynology with the use of acetolysis. The pollen types occurring in the honey samples were identified and at least 1,000 pollen grains per sample were counted to determine the frequency classes and the frequency of occurrence. Overall, 147 pollen types were detected, of which 143 are distributed in 35 botanical families. The most representative families concerning the number of pollen types were: Fabaceae (33), Asteraceae (18), Euphorbiaceae (11), Anacardiaceae and Malvaceae (09 types each), Rubiaceae (08) and Myrtaceae (07). The average value of pollen types per sample was 28.18. The genus that contributed the most was Mimosa L. (Fabaceae) with eight pollen types detected. The wealth of pollen types found revealed important information about the local flora which is explored by Apis mellifera. Therefore, it becomes an important tool to assist in the preservation and propagation of these plants and, consequently, increasing honey production.

Waltheria encompasses about 60 species distributed in Brazil and Mexico. To improve the palynology of the genus, we analyzed 14 species occurring in the Brazilian State of Bahia. Pollen grains were acetolyzed and examined using light microscopy and scanning electron microscopy. Non-acetolyzed pollen grains were viewed by transmission electron microscopy. The results revealed two general pollen types based on exine ornamentation, such as reticulate and echinate, which are distinct with regard to (1) size and shape, (2) apertural type and number, (3) relative length of ectoapertures, and (4) thickening of the nexine compared to the sexine. An ultrastructural analysis of the pollen wall revealed a continuous foot layer and a compact and discontinuous endexine in most cases. The sexine consisted of heterogeneous columellae, which support a perforated semitectum (echinate type) or the semitectum was composed of perforations and muri-shaped thickening (reticulate type). These results confirm a high degree of pollen dimorphism in Waltheria associated with heterostyly.

This study dealt with six species of Acalyphoideae and 18 species of Euphorbioideae occurring in the Caatinga ecoregion, with emphasis on endemic species. Pollen samples were obtained from herbarium specimens and were acetolysed and analysed via light and scanning electron microscopy. The pollen of three genera of Acalyphoideae was medium to large, 3-colporate or 3-colpate, with an echinate-perforate exine that was reticulate, bireticulate, and microreticulate. The six genera of Euphorbioideae studied exhibited pollen grains that were small, medium and large; 3-colporate with margines; and an exine with microreticulate, microreticulate-rugulate, microreticulate-caveate, and reticulate ornamentation. The pollen characteristics were more variable in the Acalyphoideae compared to the relatively homogeneous Euphorbioideae. This study provides new data and interpretations of the pollen morphology of two subfamilies of the Euphorbiaceae of the Caatinga ecoregion in Brazil.

RESUMO A morfologia polínica de 17 táxons de Convolvulaceae [Bonamia agrostopolis, Evolvulus (nove espécies) - Tribo Cresseae) e Jacquemontia (sete espécies) - Tribo Jacquemontieae)] foi descrita sob microscopia de luz (ML) e microscopia eletrônica de varredura (MEV) com objetivo de contribuir com a palinologia e taxonomia do grupo. O material polinífero foi retirado de anteras e/ou botões florais de exsicatas de herbários, acetolisado, analisado quantitativa e qualitativamente sob ML e MEV, descrito e ilustrado. Os dados aqui apresentados sobre a morfologia polínica das espécies de Bonamia, Evolvulus e Jacquemontia estudadas evidenciaram que B. agrostopolis apresenta grãos de pólen médios, isopolares, microequinados, granulados e o tipo apertural 3-colpado, presente na maioria das espécies estudadas de Jacquemontia. Por outro lado, as espécies de Evolvulus, J. gracillima e J. pentanthos compreendem o mesmo tipo polínico, caracterizado pelos grãos de pólen esferoidais, pantocolpados e microequinados. As demais espécies de Jacquemontia caracterizaram-se pelos grãos de pólen com forma variando de subprolata a prolata-esferoidal, zonocolpados e exina microequinada em todas as espécies, com grânulos, perfurações e microrretículo em algumas espécies. Observou-se aqui uma indefinição dos tipos polínicos que delimitam Cresseae e Jacquemontieae, visto que há afinidades palinológicas entre espécies das duas tribos. As espécies de Evolvulus formam um grupo estenopolínico. No entanto, o presente estudo apresenta descrições palinológicas inéditas para nove espécies, contribuindo para a ampliação dos dados palinológicos e confirmando o carácter euripolínico de Convolvulaceae.

Crotonoideae is a subfamily of Euphorbiaceae, a plant family that is characterized by the presence of laticifers and pollen grains with Croton pattern exine. We analysed 48 species of Crotonoideae from Seasonally Dry Tropical Forests within Caatinga vegetation aiming to contribute to the pollen morphology of this subfamily, focusing on endemics to these forests. Pollen samples were obtained from specimens of the herbarium. Pollen grains were acetolyzed, measured, photographed and described using light and scanning electron microscopy methods. Three pollen types and seven subtypes were recognized based on aperture type, polarity, shape, size and details of the exine sculpture. The exine ornamentation and the type and number of apertures are the most important characteristics for recognizing genera in Crotonoideae. Inaperturate pollen grains with surface pila plicate were observed in representatives of Croton and Jatropha; 4–8 pantoporate pollen grains and a 3-colpate one with psilate pila were observed in Cnidoscolus, and 10–22 pantoporate pollen grains with rugulate pila were observed in Manihot. Due to the high diversity of Crotonoideae pollen morphology, we highlighted its eurypalynous properties, in addition to its taxonomic relevance, for the identification of groups.

Melochia L. species are morphologically characterized by a pentacarpelar gynoecium with free papillose styles at the apex, whereas some are connate. The genus comprises about 60 species, with 22 occurring in Brazil. We analyzed pollen grains from 12 heterostylous species occurring in the State of Bahia to contribute to the palynology of the Melochia Group, including Melochia betonicifolia A. St.-Hil., M. caracasana Jacq., M. chamaedrys A. St.-Hil., M. hirsuta Cav., M. illicoides K. Schum., M. parvifolia Kunth, M. pilosa (Mill.) Fawc. & Rendle, M. pyramidata L., M. spicata (L.) Fryxell, M. splendens A. St.-Hil. & Naudin, M. tomentosa L., and M. villosa Fawc. & Rendle. Pollen grains were provided from specimens deposited at the CEPEC, HUEFS, and SP herbaria. The floral morphs of all specimens had been previously studied with a stereomicroscope. Acetolyzed pollen grains were investigated by light microscopy, and non-acetolyzed pollen grains were observed by scanning and transmission electron microscopy. It was confirmed in two pollen types of the two floral morphs: (1) the longistylous morph was characterized as medium sized; prolate spheroidal; 3-colporate, with ectoapertures comparatively larger, endoaperture lalongate; reticulate-perforate; exine ultrastructure with nexine differentiated into endexine and a foot layer (M. pyramidata) or undifferentiated (M. betonicifolia); a 4-stratified sexine may also occur; (2) the brevistylous morph showed medium to large-sized pollen grains; oblate spheroidal; 3(4)-colporate, ectoaperture short, endoaperture lalongate; microechinate and echinate; semitectum perforate and microreticulate-rugulate (M. betonicifolia); M. pyramidata wall ultrastructure with nexine showing “internal foramina.” Pollen dimorphism was confirmed in the genus due to heterostyly. The type and number of apertures were not as useful as exine ornamentation to characterize and distinguish the pollen grains.

The palynology of the following 16 species of Rubiaceae, from Brejinho das Amestistas, was investigated: Coccocypselum hirsutum Bartl. ex DC., Cordiera rigida Kuntze, Coutarea hexandra K.Schum., Declieuxia fruticosa Kuntze, Diodella apiculata (Willd. ex Roem. & Schult.) Delprete, D. radula (Willd. ex Roem. & Schult.) Delprete, D. teres Small., Emmeorhiza umbellata K.Schum., Leptoscela ruellioides Hook. f., Mitracarpus baturitensis Sucre., Mitracarpus villosus Cham. & Schltdl., Palicourea rigida Kunth, Psyllocarpus asparagoides Mart., Richardia grandiflora Steud., Staelia aurea K. Schum., and Staelia galioides DC. The pollen grains were acetolysed to and their morphological characters were analyzed using light and scanning electron microscopy. They varied in size from small to large; were suboblate to subprolate; inaperturate (P. rigida), colpate and colporate in the remaining species, with an aperture number that varied from three to several. The exines were microreticulate in most species, reticulate (C. hirsutum, C. rigida and P. rigida), bireticulate (D. fruticosa), microechinate-perforated (C. hexandra), echinate-granulate (R. grandiflora), echinate-granulate-perforate (D. apiculata and D. teres), and psilate (P. asparagoides). Based on the results, palynological data can be used to distinguish these species. Rubiaceae foi representada na flora de Brejinho das Ametistas por dezesseis espécies, as quais foram tratadas palinologicamente no presente estudo: Coccocypselum hirsutum Bartl. ex DC., Cordiera rigida Kuntze, Coutarea hexandra K.Schum., Declieuxia fruticosa Kuntze, Diodella apiculata (Willd. ex Roem. & Schult.) Delprete, D. radula (Willd. ex Roem. & Schult.) Delprete, D. teres Small., Emmeorhiza umbellata K.Schum., Leptoscela ruellioides Hook. f., Mitracarpus baturitensis Sucre., Mitracarpus villosus Cham. & Schltdl., Palicourea rigida Kunth, Psyllocarpus asparagoides Mart., Richardia grandiflora Steud., Staelia aurea K. Schum., Staelia galioides DC. Para análise sob microscopia de luz e eletrônica de varredura, os grãos de pólen foram acetolisados, mensurados, descritos, foto e eletromicrografados. Os grãos de pólen variaram de pequenos a grandes; suboblatos a subprolatos. Inaperturados em P. rigida, colpados, e colporados na maioria das espécies, com número de aberturas variável de três a várias. Exina predominantemente microrreticulada entre as espécies, sendo reticulada (C. hirsutum, C. rigida, P. rigida), birreticulada (D. fruticosa), microequinada-perfurada (C. hexandra), equinado-granulada (R. grandiflora), equinado-granulado-perfurada (D. apiculata e D. teres), e psilada (P. asparagoides). Os resultados mostraram que as espécies são palinologicamente distintas.

RESUMO O estudo da morfologia polínica das espécies das tribos Ipomoeeae e Merremieae (Convolvulaceae) tem como finalidade contribuir com a ampliação do conhecimento palinológico dos táxons estudados e subsidiar a taxonomia do grupo. Foram examinados os grãos de pólen de 10 espécies de Ipomoea, uma de Turbina (tribo Ipomoeeae) e quatro de Merremia (tribo Merremieae) ocorrentes na flora de Brejinho das Ametistas, Caetité, BA, Brasil. Os grãos de pólen foram acetolisados, mensurados, descritos e ilustrados sob microscopia de luz (ML) e eletrônica de varredura (MEV). Mediante a análise da morfologia polínica dos táxons estudados, foi possível confirmar o caráter euripolínico do grupo e reconhecer dois tipos polínicos com base no tipo apertural e na ornamentação da exina: Tipo 1. grãos de pólen pantoporados, equinados; Tipo 2. grãos de pólen 3-6-colpados, microequinados, granulados. ABSTRACT This pollen morphology study of species of the tribes Ipomoeeae and Merremieae (Convolvulaceae) aims to contribute to the knowledge of palynology of the taxa studied and to the taxonomy of the group. Ten species of Ipomoea, one of Turbina (Ipomoeeae tribe), and four species of Merremia (Merremieae tribe) occurring in the flora of the Brejinho das Ametistas, Caetité, Bahia State, Brazil were examined. The pollen grains were acetolysed, measured, described, and illustrated under light microscopy (LM) and scanning electron (SEM) microscopy. By analyzing the pollen morphology of the taxa studied, it was possible to confirm the euripollinic character of the group and to recognize two pollen types based upon the apertural type and the exine ornamentation: 1) pantoporate, echinate pollen grain; 2) 3-6-colpate, microechinate, granulate pollen grain.