IN VITRO PRESERVATION OF THE ‎EGYPTIAN ENDEMIC SILENE ‎SCHIMPERIANA BOISS. PLANT VIA ‎ENCAPSULATION

Abstract

ilene schimperiana (Caryophyllaceae) is an endemic plant of Saint Katherine Protectorate, Sinai, Egypt. This genus has various medicinal properties. Due to over exploitation, S. schimperiana is at risk of extinction at the vulnerable stage in Egypt. Therefore, its conservation is important. An efficient protocol for S. schimperiana synthetic seeds production was developed in the present study. Shoot tips and nodal segments obtained from in vitro proliferated shoots were encapsulated in calcium alginate beads for medium term conservation and germplasm exchange. Encapsulated propagules were stored for five months at 4°C in three different matrixes of calcium alginate; water, Murashige and Skoog (MS) medium and MS medium containing 3% sucrose. The most efficient gel complex for formation of identical beads was 3% Na-alginate and 100 mM CaCl2.2H2O. The optimum temperature for storage was 4°C with 100% viability during the period of five months of storage with all tested alginate matrix compositions. However, the matrix containing MS medium with 3% sucrose was the best for the encapsulated propagules. The regrowth frequency of encapsulated propagules and mean number of shoots were decreased by increasing in storage duration. Rooting was achieved on ¼ MS medium supplemented with 1.0 mg L-1 indole-3-butyric acid (IBA) and 2 mg L-1 α-naphthalene acetic acid (NAA). About 90% of regenerated plantlets were successfully acclimatized under greenhouse conditions. This method can be successfully applied for in vitro preservation of S. schimperiana propagules for five months at 4°C to conserve this valuable plant.