Background and Objective: Medicinal plants are widely used in Thailand, so seed production cannot meet demand. Often these plants have seed dormancy and this delays seed germination. Therefore, if there is a way to stimulate the germination rate of medicinal seeds faster, it will increase the production of those plants. The objective of this research was to find suitable methods to stimulate seed germination for three medicinal plants. Materials and Methods: There were three species of medicinal plants used: Paniculata (Andrographis paniculata (Burm. f.) Wall. ex Nees), black sesame (Sesamum indicum L.) and okra (Abelmoschus esculentus (L.) Moench.). Seeds were treated with four methods: Control, hydropriming, osmopriming and auxin hormone for 12 hrs before sowing. Seeds were monitored until they germinated and the results were recorded and analyzed. The experiments were performed using a Completely Randomized Design (CRD) with four replicates of 10 seeds. Results: For the paniculata Phichit 4-4 cultivar it was found that hydropriming by soaking in water at 25°C, osmopriming and auxin treatments resulted in increased germination indexes (GI). For the Phitsanulok 5-4 cultivar, soaking in water at 40°C reduced the days to emergence (DTE). Black sesame seeds, UB-2 cultivar, it was found that hydropriming and osmopriming treatments increased the GI. For UB-2, B-15-3-1 and B-15-2-1 cultivars, mean germination time (MGT) was reduced when soaked in water at 25°C and under osmopriming. For the B-15-1-3 cultivar, osmopriming, soaking seeds in water at 60°C and IAA at 20 and 60 mg increased the GI. The okra Maneemaejo cultivar soaked seeds in water at 60°C increased the GI and for the No. 49 cultivar, it decreased under IAA 20 mg. Conclusion: For paniculata, every seed priming treatment increased the germination index in the Phichit 4-4 cultivar, while soaking sesame seeds in Potassium Nitrate (KNO3) had a positive effect on the germination index and mean germination time in all four cultivars. In addition, for okra, both Maneemaejo and No. 49 cultivars, a low concentration of IAA resulted in reduced MGT.
Sumalee Chookhampaeng, Suphannika Juntho, Priyaphat Hongsawong and Chowwalit Chookhampaeng, 2023. Effects of Seed Priming for Accelerating Germination of Paniculata, Black Sesame and Okra Seeds. Asian Journal of Plant Sciences, 22: 458-464.