Propagation of Endangered Thermopsis turcica Tan, Vural & Küçüködük Using Conventional and In Vitro Techniques

Abstract

This report deals with the successful clonal propagation of endangered T. turcica using rhizome cuttings and epicotyl explants. Rhizome cuttings were treated with \alpha-naphthaleneacetic acid (NAA) or indole-3-butyric acid (IBA) before planting for vegetative multiplication. Rhizome cuttings pretreated with NAA (10 mg/L) were both rooted and sprouted (66.6 percent) after 100 days. Application of NAA induced callus and adventitious root formation in epicotyl explants and 6-benzyladenine (BA) induced production of microshoots. Low levels of NAA (0.5-1 \muM) together with BA promoted shoot initiation and development. The highest regeneration rate (86.6 percent), with a mean number of shoots (3.05) and a mean length of shoots (2.3 cm) per epicotyl, was achieved at 10 µM BA and 0.5 \muM NAA. About 83 percent of in vitro regenerated shoots rooted on a ½ Murashige and Skoog (MS) medium supplemented with 0.3 \muM NAA. In vitro plantlets were morphologically normal and a uniform chromosome complement of 2n = 18 was detected in root tips. The study demonstrated that both conventional and in vitro techniques could be useful for large scale multiplication and propagation of this endangered plant species.