Protocol for Isolation of Genomic Dna from Dry and Fresh Leaves of Vigna Species Suitable for Rapd and Restriction Digestion

A simple and efficient protocol for isolating genomic DNA from fresh and dry leaves of Vigna aconitifolia and V. trilobata was developed. It involves a modified CTAB procedure using 3% CTAB, 4% -mercaptoethanol, 2 M NaCl and 5% PVP. The extraction was carried out at 70°C. A slight increase in the concentrations of these chemical components and temperature helped in the removal of secondary metabolites and polysaccharides from the DNA preparation. The quantity and purity of isolated DNA was higher when compared with DNA extracted by the methods of Dellaporta et al. (1983) and Doyle and Doyle (1990) [9, 13]. The DNA yield ranged from 45 -55 μg per g of leave samples and it was 1.25 times greater in dried than fresh samples. The DNA samples were found suitable for analysis with restriction enzyme digestion and randomamplification of polymorphic DNA (RAPD).