Efecto del tiempo en la degradación del ADN en muestras colectadas en el bosque húmedo tropical

Abstract

Molecular data now has a wide range of applications. DNA sequences are used in disciplines such as ethnobotany, conservation, archaeology, systematics, forestry, and ecology in projects ranging from supporting the formulation of conservation strategies to managing the global biodiversity crisis, to systematic studies, to generating genetic mechanisms for plant breeders, and in the field of genetic diversity (Spooner & Ruess, 2014). Many factors influence the success of DNA extraction. For example, by the age of the specimen in herbarium samples, the drying conditions, the way the sample is stored, or the interaction of the sample with chemicals is highly dependent on the method of preservation of the plant tissue, with DNA quality being very high in freeze-dried and even silica-dried tissues and contrastingly low in tissues taken from collections (Neubig et al. 2014). Concerning the influence of climatic factors on plant tissue collection and subsequent DNA extraction, Pabón (2022) evaluated the purity and concentration of DNA extracted from more than 3,000 plant specimens from seven life zones in Colombia. A direct relationship was found between altitude and the DNA concentration obtained, demonstrating that quality is affected and that taking the portion of plant tissue for extraction simultaneously with the botanical specimen is necessary. However, the lack of knowledge of the time elapsed between collecting the specimen and placing the tissue in silica gel did not allow her to affirm that this is a determining factor. Therefore, in this project, extractions of tissues collected in the Tropical Rainforest of the Centro Experimental Amazónico - CEA located in Mocoa (Putumayo) were carried out, following the modified Ivanova (2008) protocol, and the concentrations obtained simultaneously or at different times, taking the specimen and taking the tissue in silica gel were compared, finding that the time elapsed proved to be important, but not significant with the degradation of DNA, measured through its concentration. As an uncontrolled environmental factor, humidity contributed positively to quality DNA extraction by preventing immediate wilting of the tissues and slowing down the production of secondary metabolites, which are diverse in botanical families and act as inhibitors of DNA extraction.