Seed Germination of Scabiosa stellata (Caprifoliaceae), a Potential Medicinal Plant

Increasing seed germination of native medicinal plant species is fundamental to improving conservation and restoration practices, especially for threatened ecosystems. However, the seeds of some species exhibit poor germination, limiting propagation and large-scale distribution. In this study, the effect of temperature on seed germination of a medicinal plant Scabiosa stellata was investigated in vitro. Germination of S. stellata was tested at constant temperatures of 10, 20, 25, 30 and 40 °C, coupled with total darkness. The seeds enclosed by achenes were cultured in Petri dishes (0.8% agar water) with 7 replicates of 10 seeds, for 15 days of incubation. The germination kinetics were determined according to the final germination percentage (FGP), the mean germination time (MGT), the seedling survival percentage (SS) and the seedling total length (STL). Temperatures had a significant effect (p< 0.001) on all parameters studied. Germination kinetics indicated that S. stellata seeds were non-dormant. The average seed germination percentage relative to temperatures ranged from 31.4% (30 °C) to 94.2% (25 °C). The temperature of 25 °C was found to be very suitable with 94.2% FGP, 5.37 days of MGT and 7.82 cm of STL, while the temperature of 20 °C optimally improved germination with 58.5% of FGP. In addition, a significant 62.8% reduction in FGP was observed at 30 °C temperature compared to 25 °C. No germination was observed at 10 °C and 40 °C over a period of 15 days. Analysis also revealed that a period of 10 days after sowing seeds is suitable for final germination counts in S. stellata seeds. An overview of the establishment of S. stellata seedlings over a 30-day period in pots is also presented. Germination of seeds of S. stellata is epigeal type.