Shoot organogenesis and plant regeneration in Begonia coptidifolia

Abstract

An efficient regeneration protocol was established for a rare plant species, Begonia coptidifolia. Using leaf explants, adventitious shoots were induced on Murashige and Skoog (MS) basal medium using various concentrations (1.0–10.0 mM) of three cytokinins, 6-benzyladenine (BA), thidiazuron (TDZ) and kinetin (KIN). However, adventitious shoots could not be induced on MS medium supplemented with auxins [α-naphthaleneacetic acid (NAA) or 2,4-dichlorophenoxyacetic acid (2,4-D)] tested in the 1.0–10.0 mM range. The highest number of shoots per explant (31.2) was induced on MS medium with 5.0 mM BA and 1.0 mM NAA. Although roots were induced in ½MS medium free of plant growth regulators, the time to form roots was shorter in the 0.5 mM IBA, 0.5 mM IAA and 0.5 mM NAA treatments. Following acclimatization, over 95% of plantlets survived in a substrate of sand and humus (1:1, v/v). Over 200 plantlets were reintroduced to their natural habit, and over 50% of plants survived after one year.