Genetic diversity and comparative study of genomic DNA extraction protocols in Tamarix L. species

Abstract

The genus Tamarix consists of about 54 species that mainly grow in saline areas of deserts and semi-deserts. This genus is chemically characterized by the presence of tannins, flavonoids, anthocyanins and essential oils which interfere with the extraction of pure genomic DNA. Thus it is necessary to optimize extraction protocols to minimize the influence of these compounds to the lowest level. The present study compares the efficiency of five different approaches to extract total genomic DNA in Tamarix species, showing significant differences in the extracted DNA contents and quality,by using Kit (DNP TM Kit), CTAB DNA extraction method by Murray and Thompson, Sahu et al., Nalini et al. and Bi et al., for the extraction of DNA from Tamarix species. Our results showed significant differences in DNA contents between these five methods. The quantity and quality of extracted genomic DNA were checked by the spectrophotometer, Nano-Drop and and agarose gel electrophoresis analysis. Finally, a PCR-based method was also applied to verify the amplification efficiency for two molecular markers (ITS and ISSR).. In the present study, the genetic diversity of 96 Tamarix individuals species and 8 populations were studied using 10 ISSR markerswhile for nrDNA ITS 8 species samples were used. The method of Nalini et al., provided best results (207 ng/μL) in terms of quantity and quality ofDNA. Our results proposed that this method could be effective for plants with the same polysaccharides, proteins and polyphenols components. The advantage of this method is simple and fast as it does not involve time consuming steps such as incubation at higher temperatures, and also do not requires expensive chemicals such as proteinase K, liquid nitrogen. ,. The success of this method in obtaining high-quality genomic DNA has been demonstrated in the Tamarix species group and the reliability of this method has been discussed.