Germination Conditions of Artemisia dubia Seeds for Factory Cultivation

Abstract

This study was conducted to determine the optimal temperature and light conditions for the germination rate, energy, and vigor of Artemisia dubia to enable the plant’s cultivation in a factory system for year-round growth and harvest. Seeds of A. dubia were obtained at the cultivation site (Hampyeong) over a 3-year period and were stored at either low temperature (3°C) or room temperature, and germination experiments were conducted under controlled growth conditions. Seeds were immersed in 15 mL of distilled water in filter paper-lined Petri dishes, and germination was monitored over the next 8 days. We observed that the percentage germination was highest at 30°C (97.7%), followed by that at 25°C (97.5%) and 20°C (94.5%). Whereas differences in percentage germination at 25°C and 30°C were found to be non-significant, germination at these temperatures was found to be significantly higher than that at 20°C. The germination energy determined 3 days after sowing at 20, 25, and 30°C was 0%, 33.4%, and 93.7%, respectively, thereby further indicating that 30°C is the optimum temperature for A. dubia seed germination. In the low-temperature dormancy breaking experiment, we detected no statistically significant difference between the 3-month seed vernalization and non-treatment groups, thereby indicating that supplemental dormancy breaking treatment is unnecessary. In experiments investigating seed longevity, in which the germination vigor of seeds was determined when stored at room temperature (25-27°C) for 1-3 years, we recorded a germination vigor of 1.4% after storage for 3 years, thus indicating the extremely low viability of these seeds. By contrast, the seeds stored for 2 years and 1 year were characterized by vigor of 88% and 97%, respectively. On the basis of these observations, we performed a germination energy experiment on seeds stored for 1 year at room temperature (2527°C) or low temperature (3°C). We detected a significant difference in the percentage germination of seeds subjected to room temperature and low-temperature treatments (83.7% and 95.6%, respectively), thereby indicating that germination viability can be enhanced by optimizing the storage conditions. However, we observed no significant difference between the germination of seeds subjected to light and dark treatments, with high germination vigor being observed under both conditions. Thus, illumination does not appear to be an essential factor for the germination of A. dubia seeds. Additional key words: Asteraceae, light treatment, seed storage, seed vernalization, wormwood