DIRECT AND INDIRECT ORGANOGENESIS FROM LEAF EXPLANTS OF LISIANTHUS [Eustoma grandiflorum (Raf.) Shinn.]

Abstract

A highly efficient protocol for the regeneration of plantlets of lisianthus (cut flowers plant) was established via direct and indirect organogenesis induced from leaves explants. In direct pathway, a reliable strategy for mass propagation of shoots was devised after testing several concentrations of BA with Murashige and Skoog (MS) media, it was confirmed that the use of MS medium supplemented with 2 or 3 mg.L-1 produced the highest average number of shoots (13.8 and 14.2 respectively). The shoots were easily rooted on MS medium containing 2 mg.L-1 of indole-3-acetic acid (IAA) and high percentage of survival rate (80%) was achieved. In the second pathway (indirect organogenesis), leaves explants were cultured on MS medium supplemented with NAA at 0,3, and 4 mg.L-1 for callus induction. Results appeared the maximum formation of callus 11.2 mm (in diameter) was recorded on a medium containing 4mg.L-1. Shoots proliferation was achieved using MS medium enriched with GA3 at 0.5 mg.L-1 +BA at 1.5 mg.L-1 as it was vigorous and produced the highest average of shoot numbers (23) and shoot length (3.6 mm) on callus tissue but hyper hydric shoots were observed. The root formation was occurred on MS medium devoid of growth regulators. Based on the results of our experiments, the direct pathway protocol should be useful for the rapid propagation of lisianthus plant, as good quality and quantity of shoots proliferation were obtained as well as it produced healthy plants that could still live in the field to produce one of the most beautiful cut flowers in the world.

Keywords: Propagation, Lisianthus plant, Callus tissue, organogenesis.