Seed germination and in vitro propagation of Piliostigma thonningii – an important medicinal plant

Abstract

Piliostigma thonningii is a multipurpose tree of high priority for conservation in Nigeria. Almost all its parts are used in traditional medicine and its seeds are a good source of antioxidant micronutrients,
rich in crude protein and carbohydrate. Its seeds are however dormant and the plant is uncultivated. Seed germination and in vitro regeneration experiments were carried out on P. thonningii. Seed dormancy was successfully broken by physical and chemical scarification using concentrated sulphuric acid for 15 min with 91.7 ± 4.01 and 95.0 ± 2.24% germination, respectively. The seed dormancy was due mainly to the hard seed-coat. Callus production was observed in both cotyledon and hypocotyl explants cultured in auxin-supplemented Murashige and Skoog (MS) medium. Explant orientation on the medium and the position from which the explant is taken affected callus production. Complete plantlet was regenerated from the hypocotyl-derived callus in medium containing auxin only.