Comparison of DNA extraction methods in medicinal Plant Peganum harmala L.

The identification of genetic, morphological and ecological characteristics of plants is essential for the economic and health exploitation of plant products and the extraction of a high quality DNA is one of the ways. However, DNA extraction with good quality and high efficiency from plant tissues is difficult due to the presence of hard polysaccharide cell wall, pigments and some secondary metabolites. It is noteworthy, secondary metabolites which usually cause medicinal properties, may also prevent the extraction of DNA of appropriate quality and quantity. Although, the basis for DNA extraction is the same, due to the diversity of components of different tissue, the same method cannot be used to extract DNA from all plant species. A more desirable method not only provides the right DNA in terms of quantity and quality, but also is low cost and without the need for advanced laboratory equipment. In this study, five DNA extraction methods, including CTAB (Doyl & Doyl), its two modified methods, the modified Murray and Thompson method, and the kit Gene All were compared in both fresh and dried leaves of P. harmala. The quantity and quality of the isolated DNAs were evaluated using spectrophotometry and agarose gel electrophoresis. The suitability of obtained DNAs for molecular studies was evaluated by PCR of ITS fragments in the nuclear ribosomal DNA and trnL-F region in the chloroplast genome. Based on the findings, the changes in the main CTAB method, such as the elimination of beta-mercaptoethanol or ammonium acetate, had no negative effect on the quantity or quality of the extracted DNA or PCR results. The PCR of ITS fragments and trnL-F region was successfully performed in all DNAs obtained from both fresh and dried leaves of P. harmala. Therefore, in the case of P. harmala, all the studied methods can provide DNA suitable for PCR studies.

کلیدواژه ها:

PCR ، CTAB ، Murray and Thompson ، Secondary metabolites ، P. harmala