Optimization of genomic DNA extraction from fresh and dry leaves of large cardamom (<i style="mso-bidi-font-style:normal">Amomum subulatum</i> Roxb.) for diversity analysis

Abstract

<i style="mso-bidi-font-style:normal">Amomum subulatum</i> Roxb., the great Indian, Nepal or large cardamom, is a highly valued spice of family Zingiberaceae. Its seeds have similar properties as those of true cardamom. Tremendous variability also exists within the species. During molecular characterization of its germplasms, genomic DNA extraction protocols posed certain limitations as they yielded brownish yellow, sticky and highly viscous DNA due to the presence of polyphenols and polysaccharides. In the present study, we report a simple protocol for isolation of high mol wt DNA through a CTAB (hexadecyl trimethyl ammonium bromide) extraction method, in which a combined strategy of poly vinyl pyrrolidone (PVP), 2-mercaptoethanol and sodium metabisulfite as well as higher concentration of NaCl was devised for removing polyphenols and polysaccharides. The procedure was applicable for both fresh and dry leaf tissues and yielded good quality genomic DNA, which was free from contamination and colour. The DNA so isolated was successfully used for diversity analysis of large cardamom using different inter simple sequence repeats (ISSR) molecular markers.