Abstract
Tobacco (Nicotiana tabacum L.) plants are known to present high levels of secondary metabolites that increase with the plant age. Molecular biology techniques like restriction enzyme digestion and PCR, requires as pre-requisite the isolation of genomic DNA of suitable purity, good quality and with low levels of contaminants. Several methods to isolate pure and intact tobacco DNA for molecular research purposes have been developed. In this work, a combination between a tobacco seed germination technique using gibberellic acid and a fast and simple genomic DNA extraction method from 14-days old tobacco seedlings to reduce the secondary metabolites levels in the final samples was presented. Ten tobacco genotypes were used to evaluate this method. The DNA concentrations were in a range between 0.73 μg/μL to 1.47 μg/μL for Habana-2000 cv. and Criollo cv., respectively. The absorbance ratios values to determine DNA quality were acceptable. This method allows the obtaining of high molecular weight DNA suitable for digestion with restriction enzymes, EcoRI and BamHI. Tobacco seedlings DNA in a short period of time, in a simple way and with a low cost, was obtained with this extraction method.