A reliable DNA extraction protocol for the medicinal plant Chrysobalanus icaco (Chrysobalanaceae), a recalcitrant species

The evaluation of genetic variability is essential to support the conservation of economically important plant species such as Chrysobalanus icaco, a medicinal plant. In Brazil, this species occurs in endangered sandbank areas along the Atlantic coast raising considerable concern over C. icaco diversity conservation. Therefore, research in population structure is needed and can be carried out using single-nucleotide polymorphisms. The aim of this study was to optimize high-quality DNA extraction based on the CTAB method. Two standardized protocols were used. DNA was extracted only when SDS was added to the extraction buffer, resulting in 700 ng of DNA per sample of leaf tissue (250 mg). However, the use of metal beads combined with proteinase K resulted in 2000 ng of purified DNA per sample (50 mg). This protocol proved advantageous in terms of efficiency and the absence of phenol, allowing high-quality DNA to be obtained from C. icaco leaf tissues.