Enhancing the germination of fresh seeds of Bowiea volubilis, a widely used bulbous medicinal plant : research in action

We have investigated methods to enhance seed germination of Bowiea volubilis, a widely used medicinal plant. Owing to their hard coat, which inhibits germination, seeds were subjected to mechanical scarification (using sandpaper) and chemical scarification (using concentrated H2SO4 and H2O2) for different lengths of time. The effect of temperature on germination was also investigated. The percentage germination under control conditions (25oC) was only 15% with a mean germination time of 18 days. Scarification with concentrated HlSUBg2l/SUBgSOlSUBg4l/SUBg resulted in 73% germination after 4 days but seeds were then highly susceptible to fungal infestation, resulting in severe loss of young seedlings. Scarification with HlSUBg2l/SUBgOlSUBg2l/SUBg slightly improved the germination rate (30%). The seeds incubated at 20oC resulted in higher germination (90%) than at other temperatures tested, but required a mean germination time of 25 days. In continuous darkness at room temperature, 88% of seeds germinated with a mean germination time of 24 days. Mechanical scarification with sandpaper proved to be the best treatment to enhance germination, which reached 100% within a mean germination time of only 6 days.