Cloning of Casuarina equisetifolia chloroplast ribosomal RNA (rRNA) genes and its application in phylogenetic studies

Chloroplast genes are considered to be highly conserved compared to the nuclear counterparts. This feature has been used extensively in the phylogenic studies of different plant species. In this study, a 3kb sequence consists of 23S rRNA (ribosomal RNA), 4.5SrRNA, ITS 2 (Intergenic Transcribed Spacer 2) and ITS 3 from the chloroplast genome of C. equisetifolia has been amplified using specific primers. The genomic origin of the PCR Amplicon was confirmed by southern hybridization. Multiple alignment with a number of chloroplast sequences showed very high homology with some of the species grouped alongwith Casuarinaceae in the phylogenetic system of classification. In the analysis, C. equisetifolia found to be grouped among the tree species which are closely placed in the classificatory system