Effects of temperature, gibberellic acid, and KNO3 treatments on seed germination of the wild plant Maesa japonica

We investigated the morphological characteristics of Maesa japonica seeds and the optimal conditions for germination. The seeds were exalbuminous, and their length and width were 0.85 +/- 0.09 mm and 0.77 +/- 0.05 mm, respectively. We tested germination at 15, 20, 25, 30 and 35 degrees C; the optimum temperature for germination was 30 degrees C (64% germination). To test the effects of gibberellic acid (GA(3)) and KNO3 on germination, the seeds were soaked in solutions containing 0, 0.2, 0.5, 1.0, 1.5 or 2.0 g GA(3) L-1 or 0, 0.05, 0.10, 0.20 or 0.50 g KNO3 L-1 before sowing for germination. KNO3 treatment increased germination percentage and speed. Soaking in GA(3) concentrations over 1.0 g L-1 stimulated 100% germination after 13 days. A presoaking treatment that combined 1.0 g GA(3) L-1 and 0.2 g KNO3 L-1 promoted germination speed and shortened the time in which half of the seeds germinated. Overall, we determined that the best method for germination of Maesa japonica seeds was pre-soaking in 1.0 g GA(3) L-1 and 0.2 g KNO3 L-1 at 4 degrees C in the dark for 24 hours, followed by incubation at 25-30 degrees C in a 16-hour light, 8-hour dark cycle for 10 days.