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Podcasts Videos
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BEYOND THE
 CJBG
Plants and theater
 Plants and theater
 The CJBG's Versailles
 planters move to the
 Théâtre de l'Orangerie
 July 2- September 27
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Post Facebook THE GARDEN'S  SECRETS
Amazing new blooms to discover in the Rockeries
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NEWS
Radio Cité
 Radio Cité - Podcast
 End of confinement and
 presentation of the
 exhibition "The rise of
 invasive neophytes",  with director, Pierre-
 André Loizeau
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Radio Lac
 Radio Lac - Podcast
 Introduction to the CJBG
 and to some invasive
 species, with director
 Pierre-André Loizeau
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Cult.ge
 Cult.ge
 Presentation of the
 exhibition "The rise of
 invasive neophytes",  with director, Pierre-
 André Loizeau
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Plan Biodiversité 2020-2023
 The 2020-2023 Biodi-
 versity Plan approuved
 by the State Council.
 The CJBG greatly
 contributed to the
 objectives' definition
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Tribune de Genève 06.06.2020
 La Tribune de Genève
 Learn more about
 invasive exotic plants
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Agro-environmental networks
 Genève Grandeur
 Nature
 Agro-environmental
 networks
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THE HESPERIDES'
 TREASURE
Symboles & Sentiments
Interactive & multimedia
 fiction !

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Opening Hours
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Carl von Martius Exhibition
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EVENTS
This summer rhymes with concerts!
This summer rhymes with concerts!
Live from the CJBG's lawn!
Every Wednesday and Friday
From July 6 to August 28
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EXHIBITIONS
Botanica - invasive neophytes
The MeteoSuisse blog:
Botanica 2020
Until October 18
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Carl von Martius Exhibition
Carl von Martius: discovering tropical biodiversity
In the CJBG Library
Until Decembre 24th
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FAMILY ACTIVITIES
Hors-murs bibliothèque - Martius
The Library heads outside
Come and learn more about Martius!
August 12 and 19 from noon to 4pm
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Extraordinary Trails
The extraordinary Trails
A new historical fiction
Join the adventure HERE!
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Botany Cultural Trail
The "Botany" Cultural Trail
To discover the botany in Geneva since the 18th century
The visit begins HERE!
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REOPENING
Bon Retour Chez Nous
WELCOME BACK !
Learn more HERE...
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GUIDED TOURS
GUIDED TOURS
All guided tours are cancelled until further notice. Thank you for your understanding.
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VISIT THE GREENHOUSES
tropical greenhouse
Presentation of the tropical greenhouse (run time: 1'30)
For your safety, please follow the instructions in effect
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ombrage

Conservatoire et Jardin botaniques de la Ville de Genève


WelcomeScientific ActivitiesResearch programmes
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Systematics and evolution of neotropical Gesneriaceae

The main goal of our research is to inventory and classify the taxons pertaining to the Gesneriaceae family in order to understand the origin of their diversity, focusing our interest on the neotropical lineages that belong to the subfamily Gesnerioideae. This monophyletic group includes some 1050 species that occur in different biomes of tropical America (i.e. Brazilian Atlantic Forest, Andes, Amazonia). These species display an astonishing diversity in morphology and ecology, as in the case of adaptations to pollination by hummingbirds, bats, bees or habitats that can be epiphytic, saxicolous or terrestrial. Our research follows three main axes: - Inventories and Floras Geographic distribution, morphology and ecological data are compiled from field trips, herbaria studies, mainly in Brazil. These data allow the production of check-lists, red-lists or floristic treatments at local, regional, country or continent levels. During this process, new species are recognized, leading to their formal description and publication. - Systematics The phylogenetic relationships between species are investigated through DNA sequences analysis, from nuclear and plastidic genomes. These analyses were focused on different neotropical lineages, i.e. Sinningieae (85 spp.), Gloxinieae (167 spp.), Sphaerorrhizeae (4 spp.), Episcieae (477 spp.). Results of these analyses allow us to propose new classifications for these groups and to understand the evolution of selected morphological characters. - Origin and radiation processes The history and the radiation processes of Gesneriaceae are studied by combining phylogenetical results with species distribution and ecology data. We focused on Brazilian clades for which we rely on an exhaustive sampling along with many data on the species biology like the tribe Sinningieae or the genera Codonanthe/Nematanthus. For these groups we infer the biogeographic history of the lineages and evaluate the importance of geographical and ecological factors within the radiation processes, as well as the role of plants-pollinators relationships vs. floral diversification. In addition, the molecular bases for evolutionary transitions in some phenotypes like the flower color are also investigated.

The tribe Sinningieae comprises some 85 species mostly occurring in the Brazilian Atlantic Forest Biome; a few taxa are found in other biomes in Brazil or elsewhere in Tropical America. The monograph will deal with an exhaustive treatment of the taxa, including identifications keys, full descriptions, distribution maps, illustrations and discussions about ecological and morphological aspects. The data are mainly obtained from investigations in European and North or South American herbaria, along with material and information provided by a network of numerous scientists and plant growers established since the early 1980’s. Field trips are regularly done in order to obtain missing or incomplete data. Besides herbarium sheets, fertile part are fixed in alcohol, leaf tissues are desiccated for future DNA analyses. Cuttings or other vegetative parts are gathered in order to introduce them in cultivation in Brazil (long term collaboration with Mauro Peixoto in São Paulo) or in the Geneva Conservatoire et Jardin Botaniques greenhouses, in accordance with national and international rules and legal procedures.

This project put together geographic, morphological and ecological data obtained in the field and during herbaria investigations. Results are organized for treatments in various ongoing Brazilian state or local floras. In this process, new species are recognized and formal publication is done, often in collaboration with Brazilian students at bachelor, master, PhD or post-doc levels.

This project aims to produce a systematic revision of the tribe Sinningieae (85 spp. mainly in Brazil), which includes the genera Sinningia, Paliavana, et Vanhouttea. Previous phylogenetic analyses have shown that Paliavana et Vanhouttea are not monophyletic and embedded within Sinningia (Perret et al. 2003). In order to get a better resolution of the relationships within Sinningieae, two additional molecular markers (ITS et rps16) will be added to the existing data and a morphological matrix will be produced. The six newly described species of Sinningia will be included in these analyses. Our goal is to get a robust phylogenetic tree for the group that will serve as a basis to redefine the generic boundaries in the tribe and to better understand its striking diversification. PERRET, M., A. CHAUTEMS, R. SPICHIGER, G. KITE, AND V. SAVOLAINEN. 2003. Systematics and evolution of tribe Sinningieae (Gesneriaceae): evidence from phylogenetic analyses of six plastid DNA regions and nuclear ncpGS. American Journal of Botany 90: 445-460.

Systematics of the tribe Gloxinieae s.l. has been extensively revised on the basis of recent molecular and morphological studies (Roalson et al 2005a, 2005b). These works have shown the non-monophyly of several genera (e.g., Gloxinia) and the segregated position of Gloxinia sarmentiana, now included in the new tribe Sphaerorrhizeae. In collaboration with Dr. Andrea O. Araujo, we proposed to continue these efforts through a detailed analysis of the Brazilian taxa (21 species; Araujo 2007). A phylogenetic analysis of these species will performed using several molecular markers (matK, trnL-trnF, rps16, rpl16, atpB-rbcL ncpGS, ITS). Results of this analysis will be used to better define generic and species boundaries for these Brazilian taxa and their relationships within the Neotropical Gesneriaceae.

This project aims to produce a systematic revision of the genera Codonanthe (18 spp.) and Nematanthus (32 spp.) that belong to the tribe Episcieae (Gesneriaceae). The genus Nematanthus is endemic to the Brazilian Atlantic forest, whereas the Codonanthe also occur at low altitude in northern South America and Central America. Species of these genera are all epiphytic plants displaying either hummingbird flowers (in Nematanthus) or bee flowers (in Codonanthe). Preliminary results suggest that these two genera belong to a single clade and that Codonanthe is likely paraphyletic. To verify these hypothesis, we will further evaluate phylogenetic relationships within this groups based on a three molecular markers (trnL-trnF, rps16 et ITS) and an exhaustive species sampling. This phylogenetic framework will be used as a basis for a new generic arrangement in the group and to better understand the evolution of certain floral traits such as pollination syndrome and resupination.

Understanding the origin and causes of diversification is a major challenge in biology. Recent phylogenetic methods allowing to test the association between shift in diversification rates and a particular evolutionary event have opened new perspective towards the understanding of the factors that trigger radiations. In plants, the researches have focused primarily on potential « key traits » mainly linked to floral morphology and dispersal mode, whereas more recent study stress the importance of dispersal events in new geographic areas. Beyond the identification of lineage attributes, evolution of geographical distributions and ecological differentiation within clades may also influence diversification rates through their effect on speciation and species coexistence. These correlates of plant radiations and their impact on diversification are the focus of this proposal.
The main goal of this project is to understand the processes that contribute to the origin and maintenance of biodiversity in the sub-family Gesnerioideae, a monophyletic group of 1050 species endemic to the Neotropics. This study group may be particularly appropriate to study the evolution of plant diversity in the Neotropics since its radiation took place in various biomes of tropical America and was accompanied by extensive ecological and phenotypic diversification. To achieve this goal, we will assemble available DNA sequences and complement molecular and taxonomic sampling in selected groups to produce a global phylogenetic tree for the Gesnerioideae with a complete species sampling in several lineages. Plant tissue for additional sequencing will be collected during two field trips in Brazil and Peru, and by visiting various herbaria and living collections. Based on this historical framework, we will reconstruct the evolution of geographical distribution and morphological innovations (e.g., hummingbird pollination, epiphytism, fleshy fruit) and evaluate their impact on diversification rates. To explore the relative role of geographic and ecologic factors in promoting speciation and species maintenance in the different Gesnerioideae lineages, we will collect detailed information on species distribution, local environmental conditions and climatic tolerance in targeted clades. These data will be used to evaluate the importance of geographical isolation and ecological shifts in speciation by comparing sister species and to characterize how geographical and ecological space is occupied during radiation by inferring the evolution of niche characteristics. Results from this project may contribute to identify general patterns in the relationships between species diversification, species distribution and the evolution of ecological disparity within plant radiations in the Neotropics.