SEED GERMINATION OF POTENTIAL WILD ORNAMENTAL PLANTS NATIVE TO KOREA IN RESPONSE TO CHILLED-WATER STRATIFICATION, GA 3, AND GERMINATION TEMPERATURE

Abstract

This study was conducted to investigate the effect of chilled-water stratification, Gibberellic acid (GA(3)), and germination temperature on improving seed germination of Cimicifuga heracleifolia Komarov and Clematis serratifolia Rehder (Ranunculaceae), and Aster maackii Regel and Saussurea calcicola Nakai (Asteraceae), which are native to South Korea. These species are conventionally propagated by seeds, however improving their germination (%) will help in their preservation and utilization as ornamental and/or medicinal plants since their germination is slow and difficult. Seed pre-treatment applied before sowing was different durations of chilled-water stratification for either 0 or 40 days, followed by soaking for 24 h in a 0, 15, or 30 mg l(-1) GA(3) solution. Then the seeds were incubated at 15 or 25 degrees C, with an 80% relative humidity, in dark. Compared with 0 day of chilled-water treatment, the final germination percentage (FGP), days to 25% and 50% of germination of the final germination ratio (T-25 and T-50), germination rate index (GRI), and mean daily germination (MDG) of the seeds treated for 40 days with chilled-water stratification were significantly increased in C. heracleifolia, C. serratifolia, and A. maackii. Moreover, germination was observed in both A. maackii and S. calcicola before the termination of 40-days of chilled-water stratification. The GA(3) had a significant positive effect on FGP, T-50, GRI, and MDG of S. calcicola, but not in C. heracleifolia, C. serratifolia, and A. maackii. The highest and lowest FGP were 62.0% and 1.3% in C. heracleifolia, 10.7% and 0.0% in C. serratifolia, 46.3% and 8.7% in A. maackii, and 69.3% and 40.0% in S. calcicola, respectively.