Produção de frutos e germinação das sementes de Anemopaegma chamberlaynii Bur. & K. Schum. (Bignoniaceae) - Um registro de poliembrionia)

A register of polyembryony) - The fruit set under natural conditions and the seed germination of Anemopaegma chamberlaynii Bur. & K. Schum. were studied in Maricá (Rio de Janeiro State) sand dunes “restinga vegetation”. The species demonstrates a low fruit / flower ratio (4.86%) but a high seed / ovule ratio. The seeds display anemocoric dispersion. Germination assays showed that recently collected seeds have higher rates of germination (79.3%). Polyembryony was recorded for the first time for the genus Anemopaegma. Seedlings were not found in the natural habitat.No presente trabalho foi estudada a produção de frutos em condições naturais e a germinação das sementes de Anemopaegma chamberlaynii Bur. & K. Schum. na restinga de Maricá, Rio de Janeiro. A espécie apresenta índice baixo de formação de frutos (4,86%). As sementes têm dispersão anemocórica. Os ensaios de germinação revelaram que sementes recém liberadas apresentam alto índice de germinação (79,3%). Registra-se pela primeira vez poliembrionia para o gênero Anemopaegma. Não foram observadas plântulas da espécie no habitat natural

A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing

Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management. Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org. Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Biologia floral e polinização de Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae) Floral and pollination biology of Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae)

O trabalho aborda a biologia floral, a atividade forrageira dos visitantes florais (polinizadores e pilhadores), os eventos fenológicos e o sistema de reprodução de Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae), em área de vegetação de restinga, município de Maricá, Rio de Janeiro, no período 1997 a 2000. A espécie estudada tem flores com antese diurna, lilases, tubulosas, hermafroditas, odoríferas e oferecem néctar como recurso floral. O néctar é secretado por um disco localizado na base do gineceu e é acumulado em câmara nectarífera. Os grãos de pólen são liberados gradativamente, prolongando-se a fase de doação de pólen. As abelhas Euglossa cordata Linnaeus, Centris analis Fabricius e C. tarsata Smith são os polinizadores da espécie. Destaca-se pilhagem primária de néctar, por abelhas, e secundária, por borboletas e beija-flor. A espécie é auto-incompatível, apresentando baixos índices de formação de frutos em condições naturais (Frutos/Flores = 12,2%). Foi registrado padrão de floração "cornucópia", entre os meses de dezembro a março (estação quente/chuvosa), com pico em janeiro. As sementes são anemocóricas e liberadas gradativamente na estação fria e seca.<br>This work deals with the floral biology, the foraging activities of floral visitors (pollinators and robbers), phenology and reproductive system of Arrabidaea conjugata (Vell.) Mart. (Bignoniaceae) in the "restinga" of Maricá, Rio de Janeiro, Brazil, from 1997 to 2000. The flowers display daytime anthesis and last only one day. These attractive pink flowers are tubular, hermaphroditic, odoriferous and produce nectar as the floral reward. The nectar is secreted by a nectariferous disk concealed within a chamber. The pollen grains are gradually released throughout anthesis, extending the pollen presentation phase. The bees Euglossa cordata Linnaeus, Centris analis Fabricius and C. tarsata Smith are the pollinator species. Primary and secondary nectar pilferage by several bees, butterflies and a hummingbird is found in A. conjugata. The species is self-incompatible and has low fruit set (Fruit/Flower = 12.2%). Flowering of A. conjugata lasts from December to March (hot, rainy season) with a peak in January. The seeds are anemocoric and dispersal peaks in the cold, dry season