Comparative analysis of DNA extracted from mature leaves of rubber tree and application for seventeen tropical plant species for PCR amplification

Rubber tree is the main source of natural rubber and is the most important economic member of the Hevea genus. Polysaccharides and polyphenols in mature leaf can reduce the success of DNA extraction and downstream applications. This makes the isolation of high quality and molecular weight DNA from mature leaves of rubber tree challenging. The DNA yield and purity obtained using eight methods involving use of cetyltrimethylammonium bromide, SDS, and two commercial kits were compared. The modified procedure from Moreira & Oliveira (2011) consistently yields approximately 34 μg of high-quality amplifiable DNA with as little as 0.05 g fresh weight of mature leaf tissue of rubber tree. The key changes in the procedure were (1) a short grinding of leaf powder in mortar with extraction buffer after blending the leaf tissue in the presence of liquid nitrogen; (2) the optimization of the ratio of tissue (weight) to buffer (volume); (3) CTAB was added only once and (4) reduction in the incubation time of the macerated tissue in an extraction buffer including RNase A at 65 °C for 15 minutes. The procedure was also applicable to seventeen other tropical plant species. This helped to avoid the limitation of plant materials and could provide total DNA for further molecular studies.