Identificación molecular del género Caucaea (Orchidaceae) mediante el sistema Barcode y análisis químico de los aromas florales

Abstract

The Orchidaceae family is considered one of the largest families in the world in addition to its economic, ornamental and ecological importance. Caucaea is a genus of epiphytic orchids that is distributed in Ecuador, Colombia and Venezuela above 2500 m.s.n.m, 23 species are recognized, of which only 9 have been accepted, so there is currently no correct classification and description of this genus. We collected 98 samples from different orchids and private collections for molecular identification using the BARCODE system, extracted DNA from the plant tissue, followed by the amplification of a segment of the matK gene by the conventional PCR method for subsequent sequencing using the Sanger method. automated and finally establish the phylogeny using Mega 7 software. In the phylogenetic tree, the species were grouped in 9 clades, showing the level of divergence of the matK gene and the possibility of defining new species present in Ecuador, for which it is suggested to investigate new regions of chloroplastic and nuclear DNA. A map of distribution of the species was elaborated establishing the correlation of the data with the phylogenetic information, it was determined that the points of diversification of the Caucaea genus are located in the south zone of Ecuador and it presents 3 biological corridors. In addition, the chemical analysis of the floral aromas was carried out by means of gas chromatography coupled to mass spectrometry (GC-MS) of the species that were in flowering, detecting a total of 95 chemical compounds.