Standardization of Protocol for Isolation of High Quality Genomic DNA from Polyphenol and Polysaccharide Containing Pyrus Species

High quality DNA is a prerequisite for several molecular biology applications such as PCR, genomic library construction, endonuclease restriction digestion etc. For plant species like pear, having high polysaccharide and polyphenol, the availabble DNA extraction protocols do not yield good quality DNA. Moreover presence of polysaccharides and polyphenols causes browning of tissues and supernatant even after PVP supplementation. For isolating high quality DNA we optimized a simple and rapid protocol by modifying CTAB procedure through inclusion of 0.1N copper acetate in addition to PVP and several other modifications at different steps during extraction. The isolated DNA was free from polysaccharides, polyphenols, RNA and other contaminants. DNA was easily digestible with endonucleases, suitable for SSR based genetic diversity analysis and long term storage. The average yield of DNA ranged from 0.5 to 1 mg/g of sample. In addition to extraction of DNA, the DNA purification was also accompolished as a part of the protocol and not as a separate one, thus saving the time and labour.