Development of an effective propagation protocol for <i>Osbeckia octandra</i> (L.) DC. (Heen Bovitiya)

Abstract

Effective multiplication technique for mass propagation of Osbeckia octandra (L.) DC, an endemic species to Sri Lanka with potential values as an ornamental flowering plant was investigated. Production of planting materials was evaluated using seeds, conventional vegetative propagation and tissue culture techniques. Effect of substrate on in-vivo seed germination and effect of Gibberellic acid (GA3) on seed germination under in-vivo and in- vitro conditions were investigated. Survival rates of in-vitro germinated seedlings were tested with three different acclimatization environments. Rooting performances of cuttings were evaluated by using both softwood and semi-hardwood cuttings treated with Indole-3-butyric acid (IBA). Effect of shoot multiplication of plant under in-vitro conditions was investigated by establishing nodal cultures. The substrate containing sand: soil at 1:1 ratio was found as the best for seed germination. There was no effect of GA3 on seed germination and a higher (P<0.05) number of seedlings (61.27%) could be obtained by the seeds under in-vitro conditions. Use of non-sterilized growing medium (sand : soil - 1:1) in a polythene sleeve arranged as a single propagator was the most cost effective way of acclimatizing in-vitro grown plants, and use of semi-hardwood cuttings with an initial dip in 500 mg L-1 IBA solution for 10 minutes was the most effective method for rapid plant multiplication. A successful shoot production was achieved by culturing single nodes on full strength Murashige and Skoog medium supplemented with 0.1 mg L-1 Benzyl-aminopurine under in-vitro conditions.