Accumulation of saponins in the callus of Psammosilene tunicoides, a rare and endangered medicinal plant

Psammosilene tunicoides W. C. Wu et C. Y. Wu is a rare and endangered herb species with medicinal value, endemic to the South-Western region of China. In this paper, we mainly studied the growth and saponin accumulation in the callus of P. tunicoides for the purpose of improving its callus culture. The results showed that MS with trait of high macronutrients concentration was better for the growth and saponin accumulation of callus compared to B5. With a supplement of 1500-2500 lx illumination for 8 h under 24°C,it brought about the fast growth and high content of saponin in callus. In the range of 22 to 28°C, fast growth and saponin accumulation were observed with a rise of culture temperature, however, the growth of callus was suppressed as the temperature was over 26°C. The suitable initial pH of media proved to be 5.8 facilitating the growth of callus, and less or more than that would inhibit the growth of callus. The results obtained here were helpful for solving the problem of P. tunicoides resources through tissue culture.