Optimization of annealing temperature of 20 RAPDs used to detect polymorphism in java tea ( Orthosiphon stamineus Benth.)

Orthosiphon stamineus Benth. is commonly known as misai kucing or java tea. Since centuries ago, people believed that there are only two varieties of java tea available on land which is basically based on colour of the flower, white and purple flower especifically in Malaysia as one of the origin centre of java tea. This fact leads to genetic diversity study of this plant on molecular level. This research used RAPD markers to study the polymorphism in java tea. Before used as molecular marker, the annealing temperatures must be optimized. Some ranges of annealing temperatures were tried. The PCR products were stained by using ethidium bromide (EtBr) and separated using 1% standard agarose gel electrophoresis. The bands were then visualized using a Biorad® UV transilluminator. Amplification patterns were obtained when annealing temperatures ranged between 33.0° C to 40.0 °C. Amplification bands can be seen in 19 primers. The optimized annealing temperatures and selected primers will be used in further study of genetic diversity of 0. stamineus.