Leaf-derived organogenesis in vitro for mass propagation of lisianthus (Eustoma grandiflorum (Raf.) Shinn

Lisianthus (Eustoma grandiflorum (Raf.) Shinn) is an important ornamental commodity in South-East Asia. However, mass propagation of the plant at a commercial scale to satisfy market demands is faced by limited availability of high quality and uniform seedlings as planting material. Using different regeneration media and leaf explants for callus induction, regeneration, proliferation, root formation and acclimatization were studied. High callus induction and adventitious shoot formation were possible from leaf explants of E. grandiflorum 'White Lavender' cultured on Murashige and Skoog (MS) medium supplemented with 3.0 mg/l thidiazuron (TDZ) and 0.3 mg/l α-naphthalene acetic acid (NAA), but high quality shoots (8.0) was established on MS medium containing 0.5 mg/l N^sup 6^-benzyladenine (BA) and 0.002 mg/l NAA. In the same medium, adventitious shoots could be multiplied up to the fourth subculture at a rate of 1.74 which decreased to a 1.57 multiplication rate in subsequent subcultures. Shoots rooted easily on MS medium containing 0.1 mg/l BA and 0.02 mg/l NAA with 3.9 roots per shoot. The plantlets, which were successfully acclimatized in a mixture of burned-rice husk and organic manure (1:1, v/v) with 90% survival, grew well after repotting.