ABSTRACT
Molecular Systematics provides a solid conceptual basis for the evolutionary history of organisms. Most genes in chloroplast genome are essentially single copy. The most characteristic feature of the chloroplast genome is the presence of two regions that encode the same genes, but in opposite directions. It is one of the most variable intergenic spacers present in the chloroplast genome of angiosperms. Introns and spacers of Chloroplast DNA (cpDNA) have been widely used but substitution rates are often too low to distinguish closely related species. Mitochondrial genome carries several genes and is maternally inherited. In contrast to cpDNA sequences, mitochondrial DNA has been employed much less frequently in plant systematics due to a high degree of intramolecular recombination and a low rate of base pair substitution. DNA sequence data basically refers to the sequence of nucleotide: Adenine, Thymine, Cytosine, and Guanine in a particular stretch of DNA of a given taxon.
