Effect of temperature, light and storage on seed germination of Salvia plebeia R.Br., Leonurus japonicus Houtt., Mosla scabra (Thunb.) C.Y.Wu & H.W.Li and Perilla frutescens (L.) Britton

Understanding seed storage and germination ecophysiology is important for cultivation and for ex situ conservation of economically important species. Here we investigated the germination of four economically important plant species from the subtropical area of southeast China in relation to different environmental parameters. The seeds were subjected to different alternating temperatures (5/10 °C, 10/20 °C, 20/30 °C, 25/35 °C and 35/40 °C) and photoperiods (12 h light/12 h darkness and 24 h darkness). We also tested the effects of dry-storage on germination of selected species. The germination of all the species varied significantly with the temperature of incubation. The germination of L. japonicus and S. plebeia was highest under warm conditions, at 25/35 °C and 20/30 °C, respectively. However, seeds of M. scabra and P. frutescens showed the highest germination at 10/20 °C and the lowest at 35/40 °C, respectively. Exposure to 12 h of light enhanced the germination in all species (germination reached between 19 % and 87 %). Seed germination percentages of all the species were significantly enhanced by storage time, although the extent was species-specific. This study established a successful approach for optimizing seed germination of different species of Lamiaceae that could be utilize for their large scale production.