Analysis for Molecular Distinction in the Chloroplast DNA Sequences of Gymnospora montana (Celastraceae) and Belanites aegyptiaca (Balanitaceae) from Semi-arid Area

Gymnospora montana (Celastraceae) and Belanites aegyptiaca  (Balanitaceae) showed marked similarity in  their cpDNA sequences. Therefore, its detail analysis of cpDNA sequences is performed for codon use bias and its index, relative synonymous codon use value (RSCU), effective number of codons (ENC), GC content of the gene and frequencies of the nucleotides G+C at various positions in synonymous codon were calculated and compared it with Tribulus terresties. Length of the gene and ENC showed close relationship which suggest that longer genes has less codon bias. The codons for leucine, isoleucine and serine were most abundant in the studied plant species. The correlation analysis suggested that codon usage patterns in both cp genomes appear due to the different forces; natural selection, mutation pressure, GC content of gene and protein length.   Their role in gene evolution process is discussed