Application of fourier transform infrared (FT-IR) spectroscopy for rapid screening of mutant lines in Panax ginseng

Abstract

Panax ginseng Meyer, an important pharmaceutical herb that is extensively cultivated in Japan, China and Korea. Ginseng has been used as a medicine for over 2000 years in these oriental regions. However its use has been rapidly expanding in Western countries as the demand for complementary and alternative medicine rises (Shim et al. 2009). Saponins are glycosylated triterpenes, referred to ginsenoside, have been especially noted as active compounds contributing to the various efficacy of ginseng. In the present study adventitious roots of P.ginseng were treated by different dosages of gamma irradiation zero being non-irradiated, 10Gy, 30Gy, 50Gy and 70Gy, grown in hormone free MS modified medium at 23±20C dark condition for 7 days. The effects of gamma radiation on adventitious root was done by checking the remaining survived roots after 5 weeks of exposure. Total 137 mutagenized ginseng lines including wild type survived after gamma irradiation. Hence out of 137 mutant lines corresponding to the three wild-type lines and only 81 (10Gy), 39 (30Gy) mutagenized lines were selected for FT-IR analysis. An efficient selection system has been established that is suitable to quantify the contents of ginsenoside in ginseng mutant lines using Fourier transform infrared (FT-IR) spectroscopy in junction with multivariate analysis. The quantitative prediction modeling of ginsenoside content from mutant ginseng lines was established using partial least square regression algorithms (PLS-DA) from FT-IR spectra data and ginsenoside contents measured by HPLC analysis. The correlation coefficient (R2) for ginsenoside Re+Rg1, Rb1, Rb2, Rc, Rd and total ginsenoside contents between predicted and estimated values measured by linear regression analysis was R=0.99, respectively. The ginsenoside contents prediction modeling could be used as an efficient tool for selection of elite mutant lines with high ginsenoside contents in mutation breeding of P.ginseng.