Extraction of genomic DNA is necessary for many applications in molecular genetics and it is difficult in forest tree species due to presence of high amount of secondary metabolites polyphenols, poly-terpenes in mature forest trees than the annual crops, shrubs and flowering plants. DNA isolation from the routine protocol is quite expensive due to use of highly priced chemicals such as proteinase K used as a protein degradable enzyme. In this study, we optimized the modified DNA extraction protocol developed for eighteen forest tree species (mature dried and fresh leaf tissues), Santalum album, Melia dubia, Bambusa balcooa, Tectona grandis, Dalbargia latifolia, Pterocarpus santalinus, Aquilaria malaccensis, Nothapodytes nimmoniana, Pongamia pinnata, Terminalia catappa, Swietinia macrophylla, Bambusa vulgaris, Bambusa Guadua, Diospyrous ebenum, Bamboosa brandisii, Madhuca indica, Garcinia indica and Garcinia gummigatta without proteinase K enzyme. DNA purified with this modified method resulted in the DNA extraction at much reduced cost. DNA obtained by this method was found an average of 19.47 mu g /sample of DNA for selected species with a purity level of 1.87. The extracted DNA from all the selected species was successfully amplified using microsatellite markers (rbcL and Actin), confirming the absence of hidden and strong proteins as PCR inhibitors. This alternative method for isolating DNA from different tree leaf samples would facilitate cost effective molecular work and therefore is more economical when compared to other protocols.
