40 research outputs found

    A literature review of the pollination strategies and breeding systems in Oncidiinae orchids

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    Oncidiinae is an exclusively Neotropical orchid subtribe with about 1600 described species and an impressive array of vegetative and floral morphological adaptations. We present the results of a literature survey on the pollination strategies and breeding systems of this orchid subtribe. The flowers are pollinated by a wide range of insects (mostly bees) and, sometimes, hummingbirds. Several genera reward their pollinators with floral resources such as oils, nectar or perfumes. Whereas pollination by oil-gathering bees likely evolved several times within Oncidiinae, exclusive pollination by perfume-gathering male Euglossine bees is likely restricted to a set of closely-related genera. Pollination by food or sexual deception is also present within the subtribe. Up to date, the pollen-vectors of the 92 species of Oncidiinae studied so far are as follows: 84.7 % are pollinated by bees, 6.5 % by wasps, 4.3 % by hummingbirds, 3.2 % by butterflies and 3.2 % by flies. Oncidiinae orchids are preferentially self-incompatible (69.4 % of the species studied so far), some may also present protandry as a mechanism to promote cross-pollination. Fruiting success is generally low. The rate of visitation with subsequent pollination is low, in general, which contributes to the low reproductive success of this plant group

    Synopsis of Dorstenia (Moraceae) in Rio Grande do Sul, Southern Brazil

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    A taxonomic synopsis of Dorstenia (Moraceae) in Rio Grande do Sul (RS), Southern Brazil, is presented. Three species were recorded: D. brasiliensis, D. carautae, a new record for the state of RS, and D. tenuis. All species are described and illustrated through detailed photos of living specimens. A taxonomic key to separate the species, as well as details on distribution, overall phenology, habitat, conservation status and ecology are presented

    Unveiling the germination requirements for Cereus hildmannianus (Cactaceae), a potential new crop from southern and southeastern Brazil

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    Cereus hildmannianus K. Schum is a columnar cactus native to South and Southeast Brazil. The cultivation of this species seems justifiable for several reasons: its fruits are spineless and edible; it is not threatened with extinction; it naturally occurs in Pampa and Atlantic Forest under non-xeric conditions that may be unsuitable for the cultivation of other tropical cacti; and the plants are pollinator-dependent and so should benefit from native pollinators. This study aimed to test seed germination of C. hildmannianus with samples collected at three different localities in southern Brazil, as a necessary step preceding any attempts of management and domestication. Seeds were exposed to temperatures of 20° C, 25° C, 30° C and room temperature. The germinability, average germination time and synchronization index were calculated. All samples showed higher germinability at 20° C and 25° C. Seeds from Caçapava do Sul and Santiago showed significant variation in the synchronization index at 25° C and 30° C, respectively. Seeds from Porto Alegre had maximum germinability, indicating greater vigor. Our results show that the seeds of C. hildmannianus germinate well and thrive within a wide range of temperatures and that cultivation of the species from seed-raised plants should not be problematic

    Taxonomic notes on Lyroglossa and Pteroglossa (Orchidaceae: Spiranthinae) : two new generic records for the flora of Rio Grande do Sul

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    Lyroglossa and Pteroglossa (Orchidaceae: Spiranthinae) are first recorded for Rio Grande do Sul. Descriptions, illustrations, taxonomic notes and distribution are presented. We also provide an artificial key to distinguish the genera of the “Stenorrhynchos Clade” reported so far in Rio Grande do Sul

    O gênero Elleanthus C. Presl (Orchidaceae: Sobraliaeae) no Rio Grande do Sul, Brasil

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    Elleanthus embraces about 106 species distributed in tropical and subtropical regions of the Americas. This contribution deals with this genus in Rio Grande do Sul State, Southern Brazil, therefore contributing to the knowledge of its orchid flora. This work is based in both, literature and the analysis of herbarium vouchers. Only one species was recorded: Elleanthus brasiliensis Rchb. f., which dwells as epiphyte or rupicolous in forests within the Atlantic Rain Forest Biome. This contribution does also present the synonymies, description, illustrations, photos, geographic distribution as well as comments on habitat and Natural History for this taxon.Elleanthus abrange, aproximadamente, 106 espécies distribuídas, principalmente, nas regiões tropicais e subtropicais das Américas. O presente trabalho trata do estudo taxonômico deste gênero no Rio Grande do Sul, contribuindo, portanto, para o conhecimento da flora do estado. Este trabalho baseou-se em revisão bibliográfica bem como na análise de espécimes de herbário. Uma única espécie ocorre no estado do Rio Grande do Sul: Elleanthus brasiliensis Rchb. f., que cresce naturalmente como epífita ou rupícola, em formações florestais inseridas no Bioma Mata Atlântica. O trabalho apresenta também as sinonímias, descrição, ilustrações, fotos, distribuição geográfica, hábitat e comentários adicionais para este táxon

    O gênero Eulophia R. Brown ex Lindl. (Orchidaceae: Eulophinae) no Rio Grande do Sul, Brasil

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    The genus Eulophia (Orchidaceae: Eulophiinae) in Rio Grande do Sul State, Brazil). Eulophia embraces about 200 species distributed in tropical and subtropical regions of Africa, Madagascar and the Americas. The present work deals with the taxonomic study of this genus in Rio Grande do Sul State, Southern Brazil, therefore contributing to the knowledge of its orchid flora. This work is based in both, literature and the analysis of herbarium specimen. Only one specie was found in the State: Eulophia alta (L.) Fawcet & Rendle, which grows in open and swampy areas within the Atlantic Rain Forest Biome. This work does also present the synonymies, description, illustrations, geographic distribution as well as comments on habitat and Natural History for this taxon.Eulophia abrange aproximadamente 200 espécies distribuídas principalmente nas regiões tropicais e subtropicais da África, Madagascar e das Américas. O presente trabalho trata do estudo taxonômico deste gênero no Rio Grande do Sul, contribuindo, portanto, para o conhecimento da flora do Estado. Este estudo baseou-se em revisão bibliográfica bem como na análise de espécimes de herbário. Uma única espécie ocorre no Estado: Eulophia alta (L.) Fawcet & Rendle, que cresce naturalmente em áreas abertas e brejosas dentro do Bioma Mata Atlântica. O trabalho apresenta também as sinonímias, descrição, ilustrações, distribuição geográfica, hábitat e comentários adicionais para este táxon

    Floral features, pollination biology and breeding system of Chloraea membranacea Lindl. (Orchidaceae: Chloraeinae)

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    Background and Aims: The pollination biology of very few Chloraeinae orchids has been studied to date, and most of these studies have focused on breeding systems and fruiting success. Chloraea membranacea Lindl. is one of the few non-Andean species in this group, and the aim of the present contribution is to elucidate the pollination biology, functional floral morphology and breeding system in native populations of this species from Argentina (Buenos Aires) and Brazil (Rio Grande do Sul State). Methods:Floral features were examined using light microscopy, and scanning and transmission electron microscopy. The breeding system was studied by means of controlled pollinations applied to plants, either bagged in the field or cultivated in a glasshouse. Pollination observations were made on natural populations, and pollinator behaviour was recorded by means of photography and video.Key ResultsBoth Argentinean and Brazilian plants were very consistent regarding all studied features. Flowers are nectarless but scented and anatomical analysis indicates that the dark, clavate projections on the adaxial labellar surface are osmophores (scent-producing glands). The plants are self-compatible but pollinator-dependent. The fruit-set obtained through cross-pollination and manual self-pollination was almost identical. The main pollinators are male and female Halictidae bees that withdraw the pollinarium when leaving the flower. Remarkably, the bees tend to visit more than one flower per inflorescence, thus promoting self-pollination (geitonogamy). Fruiting success in Brazilian plants reached 60·78 in 2010 and 46 in 2011. Some pollinarium-laden female bees were observed transferring pollen from the carried pollinarium to their hind legs. The use of pollen by pollinators is a rare record for Orchidaceae in general.ConclusionsChloraea membrancea is pollinated by deceit. Together, self-compatibility, pollinarium texture, pollinator abundance and behaviour may account for the observed high fruiting success. It is suggested that a reappraisal and re-analysis of important flower features in Chloraeinae orchids is necessary.Fil: Sanguinetti, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Buzatto, Cristiano Roberto. Universidade Federal do Rio Grande do Sul; BrasilFil: Pedron, Marcelo. Universidade Federal do Rio Grande do Sul; BrasilFil: Davies, Kevin L.. Cardiff University; Reino UnidoFil: Ferreira, Pedro Maria De Abreu. Universidade Federal do Rio Grande do Sul; BrasilFil: Maldonado, Sara Beatriz. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Singer, Rodrigo Bustos. Universidade Federal do Rio Grande do Sul; Brasi

    Study of acute toxicity and investigation of the presence of β-N-methylamino-L-alanine in the Gunnera manicata L. a species native to Southern Brazil

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    Gunnera (Gunneraceae) forma uma complexa associação com a cianobactéria Nostoc puctiforme L. A simbiose Gunnera-Nostoc é a única relatada envolvendo uma angiosperma e, em decorrência desta, ocorre a formação da neurotoxina β-N-metilamino-L-alanina (BMAA). No sul do Brasil, encontra-se a espécie G. manicata L., da qual não constam, na literatura científica, estudos fitoquímicos, farmacológicos e toxicológicos. Assim, o presente estudo avaliou a toxicidade aguda e a presença da neurotoxina BMAA em extratos aquosos de G. manicata. O ensaio de toxicidade aguda foi realizado com extrato aquoso das raízes de G. manicata na concentração de 2000 mg/kg, administrado em dose única via oral em ratos Wistar. Letalidade foi observada diariamente durante 14 dias pós-tratamento. Após a eutanásia, a massa relativa dos órgãos foi analisada por ANOVA de uma via e investigou-se a presença de alterações macroscópicas. A análise do BMAA por CG/EM envolveu uma etapa preliminar de derivatização, já a análise por ESI-EM/EM foi realizada por infusão direta. O presente estudo demonstrou a ausência da neurotoxina nas amostras de G. manicata analisadas bem como a ausência de toxicidade aguda no extrato aquoso das raízes. Esses dados demonstram alta margem de segurança dos extratos testados.Gunnera (Gunneraceae) forms a complex association with the cyanobacterium Nostoc puctiforme L. Gunnera-Nostoc symbiosis is the only one reported involving a flowering plant, and results in the formation of the neurotoxic amino acid β-N-methylamino-L-alanine (BMAA). The species Gunnera manicata L., for which phytochemical, pharmacological and toxicological studies are lacking, is found in Southern Brazil. Therefore, acute toxicity and the presence of neurotoxic amino acid were investigated in aqueous extracts of G. manicata. The acute toxicity test was conducted by administering aqueous root extract of G. manicata at a concentration of 2000 mg/kg in a single dose orally to Wistar rats. Lethality was monitored daily for 14 days after treatment. The relative mass of organs was analyzed by one-way ANOVA and macroscopic changes were investigated. The analysis of BMAA, a procedure performed by GC/MS, involved a preliminary derivatization step. The ESI-MS/MS analysis was done by direct infusion. The present study demonstrated absence of neurotoxin in the samples of G. manicata analyzed and absence of acute toxicity in aqueous root extracts. These data confirm that extracts from the roots of G. manicata have a high margin of drug safety

    Pollination and breeding system in two sympatric Fuchsia (Onagraceae) species at the Parque Nacional do Itatiaia (Brazil): Hummingbirds, insects and facultative self-pollination

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    Fuchsia regia and F. campos-portoi (Onagraceae) belong to section Quelusia; a group native to the Patagonian, Southern and South eastern Brazilian regions. To date, no studies coupling detailed pollinator observations and breeding system experiments have been published for these species. Studies were performed at the Parque Nacional do Itatiaia (Rio de Janeiro), in altitudes ranging from 1300 to 2790 meters a.s.l. The flowers are nectariferous and protogynous. Yet, both species are self-compatible and facultatively autogamous, since more than 43% of the intact flowers undergo delayed self-pollination. Hummingbirds (four species), Acroceridae flies and bees (Apis mellifera and Bombus brasiliensis), in that order of importance, were recorded as pollinators of F. regia. In F. campos-portoi, bees of B. brasiliensis were the most frequent pollinators, followed by hummingbirds (three species). Experimental crosses between the two species yielded no fruits, in spite of their sharing of pollinators and of the existence of hybrids mentioned in literatur

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
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