Germination of Allanblackia floribunda Seeds: The Effect of Soak Duration in Fluridone on Germination and Seedling Growth

Abstract

Allanblackia seeds contain about 72% white fat (mostly of oleic and stearic acid), with high medicinal and industrial value, but the plant has not been domesticated, so seeds are only gotten from the wild. The demand for seeds of the wild Allanblackia floribunda exceeds supply and efforts to domesticate the plant to increase seed availability have been unsuccessful due to long seed dormancy periods. Soaking scarified seeds from immature fruits in water or fluridone shortened dormancy to less than 3 months, but the effects of different soak durations on germination, dormancy and seedling vigor, are not fully understood. This study aimed to determine the effects of three soak durations (1, 6, and 12 h) in water or fluridone (10 µM or 30 µM) on seed germination and seedling growth. The study was a 3 x 3 factorial experiment arranged in a Completely Randomized Design, using scarified immature seeds. At 16 weeks after treatment, seedlings were transplanted into polypots filled with topsoil and assessed weekly for the effects of treatments on seedling growth (leaf number and plant height). The % germination increased as the duration of soak in water or 10 µM fluridone increased from 1 to 12 h. The tendency to obtain 75-100% germination was higher when seeds were soaked in 10 µM fluridone (i.e., for 6 or 12 h) as compared to soaking in water for up to 12 h. The shortest duration (72 d, i.e., approx. 2.5 months) to achieve >75% germination was when Allanblackia seeds were soaked for 6 h in 10 µM fluridone. Soaking the seeds for 12 h in 10 µM fluridone resulted in 100% germination in 3 months. At transplanting, seedlings from fluridone treated seeds were taller, and had more leaves than those from seeds soaked in water for 1 or 6 h, but the reverse was observed in seedlings from seeds soaked for 12 h in water. However, these effects diminished after 2 weeks, when the seedlings have become established. This study has shown a promising method for achieving rapid and efficient germination of Allanblackia seeds with no noticeable adverse effects on seedling establishment.