Marcos da Costa Dórea

Palynological Origin, Phenolic Content, and Antioxidant Properties of Honeybee-Collected Pollen from Bahia, Brazil

The aim of this study was to determine the palynological origin, phenolic and flavonoid content, and antioxidant properties of twenty-five samples of bee pollen harvested during a nine-month period (February–November) from the Canavieiras municipality (northeastern Brazil). Of the 25 samples analyzed, only two (February 01 and 02) were heterofloral. The predominant pollens in the samples analyzed during that month were: Cecropia, Eucalyptus, Elaeis, Mimosa pudica, Eupatorium, and Scoparia. Ethyl acetate fractions were analyzed by HPLC-DAD. The flavonoids isoquercetin, myricetin, tricetin, quercetin, luteolin, selagin, kaempferol, and isorhamnetin were detected. The flavonoid present in all 22 samples was isolated and identified as isorhamnetin 3-O-β-neohesperidoside. The total phenolic contents determined using the Folin-Ciocalteu reagent ranged from 41.5 to 213.2 mg GAE/g. Antioxidant activities based on the 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis 3-ethylbenzothiozoline-6-sulfonic acid (ABTS), and Fe2+ ion chelating activity assays were observed for all extracts, and correlated with the total phenolic content.

Pollen residues in nests of Centris tarsata Smith (Hymenoptera, Apidae, Centridini) in a tropical semiarid area in NE Brazil

Pollen sources used by Centris tarsata bees were identified in an area of “caatinga” vegetation (Canudos Biological Station) in NE Bahia, NE Brazil, by analyzing the pollen residues encountered in the nests. The analysis of the pollen residues was performed by pulverizing the sediments used to construct the cells, followed by the application of the acetolysis method. Thirty-one pollen types were identified belonging to 13 botanical families (in associations of from 4 to 15 distinct pollen types per nest), indicating which plants were used by the bees to feed their offspring. The plant families most represented were Leguminosae and Malpighiaceae, while the pollen types most frequently found were Chamaecrista ramosa (46.5%), Senna rizzinii (19.7%), and Solanum paniculatum (19.6%). The identification of the pollen types and information about the resources offered by the plants indicated that many species were visited as nectar sources rather than as pollen or oil sources by C. tarsata.ZusammenfassungBienen der Gattung Centris sind potentielle Bestäuber von Kulturpflanzen in Brasilien und verschiedene Untersuchungen weisen bereits auf die Bedeutung dieser Bienen als Bestäuber verschiedener Pflanzenfamilien, einschließlich kommerzieller Früchte hin. Wenig ist allerdings darüber bekannt, welche floralen Ressourcen für den Erhalt der Populationen notwendig sind. Anhand der Analyse von Pollenresten im sandigen Substrat der Nistzellen dieser solitären Bienen untersuchten wir die von C. tarsata genutzten Pollen-, Öl- und Nektarquellen in einer Region mit nativer Vegetation in einer Halbtrockenregion im Nordosten Brasiliens, der Caatinga. Pollenkörner wurden quantifiziert, um die Bedeutung der verschiedenen Pflanzenarten für die Bienen abschätzen zu können. Hierzu wurden monatlich Nistfallen eingesammelt, so dass aus den Nestern (n = 13) nach dem Schlupf der Imagines die Pollenreste chemisch herausgelöst werden konnten. Pro Probe wurden sieben Mikrospopiepräparate erstellt. Die quantitative Analyse basierte auf jeweils 1000 Pollenkörnern. Wir identifizierten 31 verschiedene Pollentypen, wobei die von Chamaecrista ramosa, Senna rizzinii, Solanum paniculatum und Byrsonima vacciniifolia die größten Häufigkeiten aufwiesen (Tab. I) und damit vermutlich die wichtigsten Pollenquellen für C. tarsata in dieser Region darstellen. In geringen mittleren Häufigkeiten (<0,01 %) waren 11 Pollentypen vertreten, und 16 Pollentypen wiesen Häufigkeiten von 0,01 % bis 10 % auf, darunter Byrsonima vacciniifolia. Neun Arten der lokalen Flora im Pollenspektrum des Materials aus C. tarsata Nestern stellen vermutlich die Hauptpollenquellen dieser Bienen in der Caatinga dar. Die Mehrzahl der Pollentypen stellte weniger als 1 % des aus den Nestern gewonnen Pollenmaterials dar (Tab. II). Drei Malpighiaceen-Arten und eine Krameriacee konnten wir als Ölquellen von C. tarsata identifizieren. Wir konnten zeigen, dass Pollenanalysen in Nestmaterial interessante Ergebnisse liefern können. Eine Verbindung dieser Methode mit einer Sammelstrategie von Bienen an einzelnen Pflanzenarten sollte es dementsprechend ermöglichen, dass wir unser Wissen über die Nutzung floraler Ressourcen erweitern und daraus angemessene Strategien zum Erhalt und Nutzung von Centris-Arten als Bestäuber entwickeln können.

Botanical profile of bee pollen from the southern coastal region of Bahia, Brazil

This paper aims to identify the botanical origin of pollen loads collected by Apis mellifera L. in Canavieiras municipality, Bahia state. It provides a list of polliniferous plant species from the Atlantic Forest biome that are important for the development of regional apiculture. Using the acetolysis method, 35 bee-pollen samples were analyzed qualitatively and quantitatively. Results showed that pollen types Elaeis (23.99%), Mimosa pudica (22.78%) and Cecropia (13.68%) were the most abundant among the samples. These also showed the highest relative frequencies of the material studied and were important pollen sources for bees in the study area.

A study of pollen residues in nests of Centris trigonoides Lepeletier (Hymenoptera, Apidae, Centridini) in the Caatinga vegetation, Bahia, Brazil

Abstract Pollen sources used by Centris trigonoides bees were identifıed in an area of the Caatinga vegetation by analysing the pollen residues encountered in their nests. Twenty-eight pollen types were identifıed, and the most frequently found were Chamaecrista ramosa (46.45%; Leguminosae-Caesalpinioideae), Solanum paniculatum (16.65%; Solanaceae) and Zornia echinocarpa (10.27%; Leguminosae-Papilionoideae). The identifıcation of the pollen types and information about the resources offered by the plants indicated that many species were visited as nectar sources rather than as pollen or oil sources by Centris trigonoides.

Piresia palmula: A New Species of Herbaceous Bamboo (Poaceae, Olyreae) Endemic to the Atlantic Rainforest, Southern Bahia, Brazil

Abstract Piresia is a low growing perennial grass in the tribe Olyreae (Poaceae, Bambusoideae). It differs from other herbaceous bamboos in having dimorphic culms: aerial ones bear broad and flat leaf blades at the top and rarely develop an inflorescence, and decumbent ones usually bear reduced leaves or bladeless leaf sheaths, with inflorescences that are raceme-like, few-flowered, and often hidden under the litter. Four species are accepted in this genus, and a fifth one is described and illustrated herein, Piresia palmula. This new species resembles P. leptophylla in having narrow leaf blades, but differs in the number of aerial culms, texture of leaf blades, and in the number and size of inflorescences on both aerial and decumbent culms. Both species are associated with rainforest remnants, but display distinct patterns of geographic distribution and environmental conditions. Piresia leptophylla occurs in northern South America and northeastern Brazil (Bahia to Paraíba), often in sandy soils, especially in “Restinga” forests, whereas the new species is known only from Michelins Ecological Reserve, in southern Bahia, growing on rocky substrate in a humid environment. For these reasons it is considered as CR (critically endangered) according to IUCN criteria.

Panicoideae (Poaceae) em remanescentes florestais do sul da Bahia: aspectos taxonômicos e ecológicos

Resumo Esse trabalho consiste no levantamento das especies de Panicoideae (Poaceae) em remanescentes de Mata Atlântica no sul do estado da Bahia. As coletas foram realizadas entre os anos de 2007 e 2010, concentrando-se nos bordos e no interior dos tres maiores remanescentes florestais da Reserva Ecologica da Michelin (Mata da Vila 5, Pancada Grande e Pacange). Foram confirmadas 24 especies em 11 generos, sendo Ichnanthus P. Beauv. e Paspalum L. os mais representativos, com cinco e oito especies, respectivamente. Uma chave de identificacao para generos e especies e apresentada, assim como descricoes, ilustracoes e dados ecologicos, contribuindo para o conhecimento das especies florestais de Poaceae do Brasil. Palavras-chave : Gramineae , floristica, Mata Atlântica. Panicoideae (Poaceae) from forest remnants at the Southern Bahia: taxonomic and ecological aspects Abstract We present a floristic survey of Panicoideae (Poaceae) in remnants of Atlantic Forest in Southern Bahia State, Brazil, in the Michelin Ecological Reserve. Collections were made from 2007 to 2010, focusing on the borders and interior of the three major forest fragments (Vila 5, Pancada Grande and Pacange). Twenty four species in 11 genera were found, being Ichnanthus P. Beauv. and Paspalum L. the most representative, with five and eight species, respectively. An identification key to genera and species is presented, as well as descriptions, illustrations and ecological data, increasing the knowledge on Poaceae from Brazilian forests. Key words : Gramineae , floristic survey, Atlantic Forest.

Reproductive traits related to anemophily and insect visitors in two species of Poaceae from the Brazilian Atlantic rainforest

The floral biologies of two grass species occurring in the Brazilian Atlantic Forest, Bahia were examined to determine whether the morphological characteristics of their synflorescences, spikelets, and pollen grains were compatible with those expected for anemophily, and whether there was any biotic assistance in their pollination. Both Lasiacis ligulata Hitchc. & Chase (Panicoideae) and Olyra latifolia L. (Bambusoideae) have herbaceous habits, paniculate synflorescences, bifloral and unifloral spikelets, inconspicuous flowers, with pollen offered as a resource. L. ligulata is a homogamous species, while O. latifolia is protogynous. Their pollens are only available in the morning; the pollen grains of L. ligulata and O. latifolia are ornamented and contain starch, but without pollenkitt or lipids. Both species are visited by flies (Cecidomyiidae), beetles (Chrysomelidae), and ants (Brachymyrmex sp.) that possibly can aid in liberating pollen grains. The present study brings new data concerning the floral biology and anemophily of herbaceous Poaceae in the Brazilian Atlantic Rainforest, suggesting the insect-assisted anemophily in L. ligulata.