Background : Saliva miltiorrhiza is a perennial medicinal crop of Lamiaceae and has been reported to have various functionalities such as improvement of cardiovascular function and antihypertensive. However, domestic cultivation technique in Korea has not been established yet. Seed production system is required to increase propagation efficiency and to establish breeding basis for stable production. This experiment was carried out to determine the optimal date of the S. miltiorrhiza.
Methods and Results : S. miltiorrhiza was seeded in April of 2017 and 2018. The seeds were harvested at 5-day intervals based on the flowering period of 2018. Number of peduncles, flowers, and seeds were investigated at each period. And germination rate was also investigated. The optimum seed harvest time was estimated by relationship between the seed production and days after flowering period (DAF) or cumulative temperature. The flowering rate and amount of seed of 2-years plant was higher than 1-year plant. As DAF increased, number of flowers, fertility rate, and the amount of seeds increased. At 20 DAF, 1-year, and 2-years plant respectively produced 2.2 g and 25.2 g of seed. Seed production (SP) and DAF or accumulated temperature (AT) had a quadratic relation, SP (g) = -0.1052DAF2 + 3.7396DAF - 12.347 (R2 = 0.828) and SP (g) = -0.0002AC2 + 0.1727AC - 9.146 (R2 = 0.853). The maximum amount of seed was estimated to be 20.9 g at 17.8 DAF or 21.3 g at 353℃. The seed germination rate was increased until 20 DAF with 62.0%. The amount of seed and germination rate were decreased at 25 DAF.
Conclusion : The seeds of S. miltiorrhiza can be produced the highest amount with high viability on the 18th day after flowering period in 2-years after planting.