The Caatinga biome occupies some 12% of the Brazilian territory, which is present in at least nine states. The species that constitute its biodiversity have the potential to be used as natural resources, among them are approximately 700 species of the genus Croton. As an example of this potential, the Croton linearifolius specie is used by local communities as a natural insecticide. Associated with the economic potential of the Caatinga species, one must stress the risk of extinction or genetic erosion due to the growing deforestation of natural areas of this biome. These factors make it relevant in genetic studies in order to guide conservation strategies. Considering the lack of molecular studies involving C. linearifolius, we compared the efficiency of six protocols for genomic DNA extraction previously described in literature. The DNA extraction buffers [based on the use of Cetyl trimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), mannitol and sorbitol] were different in their efficiency to obtaining the genomic DNA of C. linearifloius. In general, protocols using CTAB buffer were more efficient. The use of liquid nitrogen in the maceration process was also evaluated and its use was considered a no necessary factor in obtaining DNA in adequate quantity and quality for PCR platform procedures.

mate leaves can be stored on silica gel or in CTAB buffer for up to 90 days at room temperature without reduction in DNA quality. Samples stored in CTAB buffer can be refrigerated at 4ºC to minimize oxidation of phenolic compounds. The improved methods for sample storage and DNA extraction with CTAB maintain quantity and integrity for conducting molecular studies of mate.