Temperature and light requirements for seed germination and seedling growth of two medicinal Hyacinthaceae species

Abstract

The effects of temperature and light on seed germination of two medicinal plant species Albuca pachychlamys and Drimia robusta were investigated. Temperatures of 25°C and alternating 25/20°C had a significant (P < 0.05) effect on seed germination of A. pachychlamys, resulting in 100% germination under 16:8h light/dark conditions. The highest percentage germination was recorded at a constant temperature of 20°C (87%) and alternating temperatures of 25/20°C (90%) for D. robusta. The seeds of A. pachychlamys exhibited significantly (P < 0.05) higher germination (100%) under constant dark conditions, compared to 87.5% germination under constant light. In D. robusta, the opposite effect was observed with 93% germination recorded under constant light and 80% in the dark. Different temperatures influenced the seedling survival and growth of both the species. Seedling survival of A. pachychlamys at 25°C was low (68%) but seedlings had significantly (P < 0.05) more roots as well as a higher total seedling and bulb mass compared to seedlings grown at other temperatures. More (82%) D. robusta seedlings survived at 25°C and their growth was significantly (P < 0.05) higher than at other temperatures examined.

South African Journal of Botany 2005, 71(3&4): 349–353