Scientific Study from the year 2016 in the subject Biology - Micro- and Molecular Biology, grade: 1.5, Mar Augusthinose College, language: English, abstract: Citrus, one of the major genes of Rutaceae family and most economically important fruit tree and widely cultivated throughout the country. The Citrus have high nutritional value and medicinal value. The three varieties obtained from various districts in Kerala were used in this study. The phylogenetics is the study of the evolutionary relationships among different species which have common ancestor. These relationships are shown in the form of phylogenetic trees composed of branches which indicate the descendents and nodes which represent the most recent common ancestors. In order to assess the phylogenetic relationships among the 6 samples belongs to the 3 Citrus species (Citrus aurantifolia, Citrus maxima, Citrus limon) a chloroplast gene rbcL and matK was successfully amplified and sequenced. For this study DNA was extracted by using CTAB method. This extracted DNA was analysed by spectrophotometry method for checking purity of DNA.The samples were gel electrophoresed by 1% agarose gel electrophoresis at 80 volts. After electrophoresis the gel is examined in gel documentation system. The DNA band was observed under UV light looking florescent Orangish red colour. The extracted DNA was amplified by PCR method and PCR sample was applied for electrophoresis for checking DNA bands. PCR sample were purified sent for sequencing. Sequences obtained were subjected to editing and alignment using ClustalW programme of Bio Edit and phylogenetic analysis was performed using MEGA software. High similarity observed between selected verities. The locally collected gene sequence-based phylogeny presented here provides support for the early studies of speciation within the Rutaceae. An understanding of the main phylogenetic relationships between Citrus species will help to fine-tune the taxonomy of Rutaceae.