Objective: To study the relationship between plant growth and accumulation of active ingredients in Salvia miltiorrhiza.
Method: Transplants of S. miltiorrhiza were sampled at 20 day intervals. At each stage, the growth of seedling and root system was recorded and the contents of tanshinone II (A) and salvia acid were measured.
Result and conclusion: This study showed that the rapid growth stage of the root system lags behind that of the seedling system, but the growing period of root system lasts longer. The quantitative change of roots reveals a double "S" curve; two rapid growth stages emerge during 30 - 70 days and 140 - 200 days after the seedlings were transplanted. The content of salvia acid reaches the highest level during 140 - 180 days, whereas the content of tanshinone peaks during 100 - 120 days.