Abstract

DNA extraction is difficult in a variety of plants because of the presence of metabolites that interfere with DNA isolation procedures and downstream applications such as DNA restriction, amplification, and cloning. Here we describe a modified procedure based on the hexadecyltrimethylammonium bromide (CTAB) method to isolate DNA from tissues containing high levels of polysaccharides. The procedure is applicable to both dry and fresh leaves of Pennisetum glaucum. This modified CTAB (2%) protocol include the use of 1.4 M NaCl, 1% polyvinylpyrrolidone (PVP), 1% β-mercaptoethanol and 100% ethanol in the extraction as well as reducing the centrifugation times during the separation and precipitation of the DNA. This method solved the problems of DNA degradation, contamination, and low yield due to binding and/or coprecipitation with starches and polysaccharides. The isolated DNA proved amenable to PCR amplification and restriction digestion. The technique is fast, reproducible, and can be applied for SSR-PCR markers identification.

Key words: Pennisetum glaucum, genomic DNA isolation, leaves.