Standardization of Extraction of DNA from Silica-Gel Dried Leaf Sample of Garcinia Indica (Thouars) Choisy ^†

Abstract

Garcinia indica, commonly known as Kokum, is a vulnerable species and endemic to Western Ghats. The fruits are commercially important and have multifarious uses. Genetic variation within the species is studied using DNA finger printing for its commercial exploitation. Extraction of DNA from Garcinia indica is challenging due to the presence of high level of secondary metabolites, such as polyphenols and flavonoids. The present study focuses on extraction and estimation of DNA from silica gel-dried leaves. Leaf samples were collected from two different regions of Western Ghats viz., Kukke Subramanya (n = 4) and Karwar (n = 6). The leaf samples were stored in silica gel during transportation to the laboratory, dried well in silica gel, and later stored at −20 °C for long-term storage. The DNA was extracted with 4% Cetyl trimethyl ammonium bromide (CTAB). The concentration of polyvinyl pyrrolidone (PVP) and β–mercaptoethanol was modified in extraction buffer to reduce the interference of secondary metabolites. The determination of quality and quantity of DNA are essential for amplification of DNA in PCR. The DNA obtained showed absorbance ratio (A260/280) between 1.6–1.9 indicating the good quality of DNA and the quantity varied from 111.8–297.9 ng/μL in the silica gel dried samples. In the present investigation, the modified method of extraction of DNA found to be best method for obtaining good quality and quantity of DNA from the silica gel dried leaves of Garcinia indica.