Biología

URI permanente para esta colección

https://hdl.handle.net/10669/273

Examinar

Mostrando 1 - 5 de 5

Floral anatomy and evolution of pollination syndromes in Lepanthes and close relatives
(2019-07) Bogarín Chaves, Diego Gerardo; Fernández Campos, Melania; Karremans Lok, Adam Philip; Pupulin, Franco; Smets, Erik; Gravendeel, Barbara
Pleurothallidinae is the largest Neotropical orchid subtribe encompassing >5100 species that are mainly dipteran-pollinated. Various pollination syndromes, targeting hump-backed flies (Phoridae), fungal gnats (Sciaridae), and vinegar flies (Drosophilidae) have been documented in detail for Acianthera, Dracula, Lepanthes, Octomeria, Pleurothallis, and Specklinia, all belonging to different clades. Among them, the highly diverse genus Lepanthes, including about 25% of the species of the Pleurothallidinae, is most closely related to Anathallis, Draconanthes, Frondaria, Lankesteriana, Lepanthopsis, Trichosalpinx, and Zootrophion. Members of this “Lepanthes clade” display high floral divergence and are likely adapted to different pollinators . However, only two pollination studies have been published for the group: one for Lepanthes, pollinated by Bradysia (fungal gnats) and another for Trichosalpinx, pollinated by Forcipomyia (biting midges). Floral traits present in Trichosalpinx, such as purple flowers and a mobile, pubescent lip, evolved to accommodate pollination by biting midges. These traits are also found in other plant species pollinated by biting midges such as Bulbophyllum, Ceropegia spp. (Asclepiadaceae), and Theobroma cacao (Malvaceae). Because some members of the Lepanthes clade exhibit similar floral traits, we hypothesize that pollination by biting midges evolved in these orchids as well. In this study, we discuss the micromorphological and histochemical features of the flowers among some of the members of the Lepanthes clade in order to test the hypothesis on floral convergence in plants pollinated by biting midges and also which other pollination strategies can be inferred from flower anatomy in the sister genera. Based on histochemistry, LM, and SEM we found similar floral secretions such as carbohydrates, proteins, and lipids in different organs of Anathallis, Lankesteriana, and Trichosalpinx, supporting the hypothesis of floral parallelism in these genera. Lepanthopsis with a papillose lip and secretory glenion and Zootrophion with closing flowers and verrucose-papillose inner surface of sepals might employ different pollination systems. This study provides additional micromorphological and histochemical data to support future pollination studies of other members of the Lepanthes clade.
III Congreso Latinoamericano de Equinodermos, Costa Rica
(2017) Alvarado Barrientos, Juan José; Conand, Chantal
The third Latin American Echinoderm Congress was organized in San José, Costa Rica, from 18 to 22 July, at the University of Costa Rica, by the Centro de Investigacion en Ciencas del Mar y Limnologia, and by the Biology School, with the coordination of Juan José Alvarado Barrientos, with the help of a local team and a scientific committee from several countries (México, Spain, Brazil, Ecuador and Argentina). Financial support was offered by Institut Français Amérique centrale and Vicerrectoría de Investigación from the University of Costa Rica which are sincerely thanked. The congress was attended by 74 participants from 13 countries (Spain, USA, Mexico, El Salvador, Costa Rica, Colombia, Ecuador, Chile, Venezuela, Brazil, Uruguay, Argentina and France). There were a total of 93 presentations, 53 oral and 40 posters, with a participation of 37 students (undergraduate and graduate). Four plenary lectures were given: 1) “Recent trends in world sea cucumber fisheries: Captures, markets, management and the problem of the illegal” by Dr Chantal Conand, La Reunion University, France; 2) “Human influence on the population fluctuations of sea urchins: Implications for management of marine ecosystems” by Dr Jose Carlos Hernandez, University of La Laguna, Tenerife, Spain; 3) “Ethical reflections on the use of echinoderms in scientific studies” by Dr Tamara Rubilar, Patagonian National Center, Argentina; and 4) “Molecular studies of echinoderms across the Atlantic-Mediterranean area: From population genetics to gene expression”, by Dr Rocío Pérez Pórtela, University of Miami, United States. The proceeding from this congress will be published in a special issue of the Journal of Tropical Biology in 2017. A week before the congress, three courses were developed and held at the Biology School: 1) “Echinodermata physiology” by Dr Tamara Rubilar; 2) “Experimental design in marine ecology” by Dr Jose Carlos Hernandez; and 3) “Application of molecular markers to ecological and evolutionary studies” by Dr Rocio Perez Portela.
Reproductive biology of Phragmipedium longifolium and floral anatomy associated with pollinators attraction in the genus
(2019) Pupulin, Franco; Díaz Morales, Melissa; Fernández Campos, Melania; Blanco Coto, Mario Alberto; Benavides Acevedo, Miguel Francisco; Sandoval Zapotitla, Estella
Phragmipedium is a genus with 21 species restricted to the tropics and subtropics from Central and South America. As it is a genus capable of producing seeds from both self- and cross-pollinated flowers, it is an ideal group to investigate the components of its reproductive success. In this research some of those components are described in P. longifolium as well as anatomical floral structures possibly related to the attraction of pollinators. To study the reproductive system in P. longifolium, manual self- and cross pollinations were carried out, and seed viability was measured by tetrazolium staining. No significant differences in fruit production between self- and cross-pollinated flowers were found. Higher seed viability was found in the self-pollinated flowers, which indicates that this species is frequently self-pollinated. Sections of the petals of P. humboldtii, P. longifolium, and P. warzewiczianum were stained with toluidine blue in order to identify and characterize anatomical structures possibly involved in the attraction of pollinators. Three kinds of glandular trichomes were observed on the petals of all three species, which are possibly involved in the secretion of fragrances to attract pollinators.
The orchid genomic toolkit
(2018) Gravendeel, Barbara; Bogarín Chaves, Diego Gerardo; Dirks Mulder, Anita; Kusuma Wati, Richa; Pramanik, Dewi
The application of genomic studies to orchids enables increasingly detailed discoveries of the evolution of both species and organs. We discuss different evolutionary questions that can be addressed using such approaches, and indicate optimal sequencing and data-handling solutions for each case. With this article we hope to promote the diversity of genomic research capitalizing the fascinating natural history of orchids that can now even be completed within the timeframe of a single PhD project.
The Pleurothallidinae: extremely high speciation driven by pollination adaptation
(2019) Karremans Lok, Adam Philip; Díaz Morales, Melissa
The generic and subgeneric classification of Pleurothallidinae has traditionally been a hazardous task. The main challenge has been understanding the underlying relationships of the immensely diverse, +5100 accepted species in the subtribe. Species groups that could be easily separated from others by means of specific floral traits have been shown to be non—monophyletic using molecular techniques. Morphological characters related to pollination that have frequently been used to group species, such as anther position and pollinia morphology, have evolved independently in most of the major clades of Pleurothallidinae. Adaptation to specific pollinators is likely to be one of the main drivers for morphological similarity in the reproductive organs of unrelated species. Myophily, or pollination by flies, may be common to members of the subtribe; however, the pollinators of most species and species groups are still unknown. We have compiled a dataset of pleurothallid pollinators by combining pollination reports from the literature and additional unpublished observations and have plotted the occurrence of diverse Diptera families across the Pleurothallidinae phylogeny. As far as we can tell, floral visitors have been documented for only about one fourth of the genera (i.e., Acianthera, Andinia, Dracula, Lepanthes, Echinosepala, Masdevallia, Octomeria, Phloeophila, Pleurothallis, Porroglossum, Specklinia, Stelis, Trichosalpinx, and Teagueia), and just about 2% of all known species belonging to the subtribe. Many of these reports are made for the first time, and most are based on few observations. The number species and genera of Pleurothallidinae for which pollination data are available is far from being enough to allow for an accurate estimation of all the different orchid-insect interactions. A robust DNAvbased phylogeny of the subtribe, however, allows adequate placement of known relationships. Diverse pollination systems employing flies of the families Anthomyiidae, Calliphoridae, Cecidomyiidae, Ceratopogonidae, Chloropidae, Drosophilidae, Keroplatidae, Mycetophilidae, Otitidae, Phoridae, Richardidae, Sarcophagidae, Sciaridae, Tephritidae, and Ulidiidae are found in the subtribe. Most of them are shown to have evolved several times independently, and adaptation to one family or another occurs even among closely related species. Finally, based on the young age of the subtribe in contrast to that of these Diptera families, pollination systems in the Pleurothallidinae are most likely due to the orchid adapting to a preexisting insect/behavior rather than a case of coevolution.

Examinar

Examinando Biología por Tipo "comunicación de congreso"

Resultados por página

Opciones de ordenación