Abstract Detail

Recent Topics Posters

LLerena Gordillo , Silvia Alejandra [1], Segovia, Claudia [2], Salinas Aponte, Natalia [3], Jadán Guerrero, Mónica Beatriz [4], Oliveira, Luiz [5].

Molecular phylogenetics and phylogeography of Ecuadorian Cedrela (Meliaceae) based on chloroplast DNA and nuclear internal transcribed spacer (ITS) data.

The genus Cedrela is native to continental Ecuador with four species: C. odorata, C. montana, C. fissilis and C. nebulosa. In the last decade, selective logging has extremely reduced populations of these species and, as a consequence, substantial genetic degradation has occurred. Currently, C. odorata and C. nebulosa are considered vulnerable species, and C. fissilis is an endangered timber tree species. Accurate technical information is needed in order to understand better the interactions between past geographical and climate events and evolutionary history to carry on effective conservation. In this context, the phylogenetic relationships and the phylogeographic structure in populations of Ecuadorian Cedrela were estimated using sequence data from chloroplast spacer regions (trnT-trnL, trnS-trnG, and psbB-psbF) and nuclear internal transcribed spacers (ITS). Bayesian phylogenetic analysis using both ITS and cpDNA data revealed that C. montana is monophyletic. Phylogenetic relationships between C. odorata and C. fissilis remain unclear because their populations grouped in the same clade. Two lineages were found for C. odorata that correspond to populations located in separate geographic regions. Samples from the Central Coast Region and the Insular Region, which show a dry climate, grouped in the same lineage. The other lineage is composed of samples from the North Coast Region and the Amazon Region, which have a humid climate. These results suggest possible incipient speciation and/or subspecies status of different populations. In fact, these subclades were grouped into two ribogroups. The estimated date of divergence for C. montana clade and C. odorata/C. fissilis clade was the Late Pliocene-Early Pleistocene, and the vicariant event that occurred at that time was the orogeny of the Cordillera de los Andes (some 4.5 to 3.5 mA), which could have prevented gene flow between C. montana and C. odorata and between the two lineages of C. odorata (include C. fissilis), thus producing allopatric speciation by vicariance. These shifts in vegetation were intensified during the Pleistocene by cycles of alternating cool–dry and warm–wet climates. This phylogenetic and phylogeographic knowledge about Cedrela contributes greatly to the development of future strategies to preserve the genetic diversity of these species.

Broader Impacts:

1 - Escuela Politecnica del Ejercito, Departamento de Ciencias de la Vida, Sangolqui, PI, Ecuador
2 - University of Florida, Florida Museum of Natural History, Dickinson Hall, Gainesville, FL, 32611, USA
3 - Oregon State University, Horticulture, Corvallis, OR, USA
4 - Escuela Politécnica del Ejército, Biotecnología, Av. Del Progreso S-N, vía Amaguaña, Quito, Pichincha, 593, ECU
5 - Federal University of Viçosa, Biochemistry And Molecular Biology, Av. P. H. Rolfs S/n, Viçosa (MG), 36570-000, Brazil

Keywords:
Cedrela
Phylogeography
Ecuador
Internal transcribed spacer
chloroplast genes.

Presentation Type: Recent Topics Poster
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PRT015
Abstract ID:1304
Candidate for Awards:None