Plant Regeneration in Glycine clandestina Wendl. from Explants of Cultured Cotyledons

The ability of nodal shoot segments regenerated in vitro to form plantlets under culture conditions has been investigated in Glycine clandestina, a wild relative of cultivated soybean (Glycine max). The nodal shoot segments (NSSs) were excised from in vitro regenerated shoots which differentiated from the cultured cotyledons on B5 medium supplemented with IBA (0.05 mg/l) and BAP (3.0 mg/l). Plant regeneration from NSSs occurred through direct multiple shoot as well as via callus formation on B5 medium with different levels of IBA (0.005 to 0.05 mg/l) and BAP (1 to 10 mg/l). Clumps of the regenerated shoot segments were further subcultured on B5 medium with IBA (0.005 mg/l) and BAP (1.0 mg/l) for continuous shoot proliferation. Plants can be obtained from shoot buds when transferred to low levels of IBA and BAP. It was found that on this medium new shoot buds were also differentiated while small shoot buds elongated into shoots without any loss of morphogenic potential for more than six years. The differentiated shoots were rooted on hormone-free B5 medium containing 6% sucrose. This approach of plant regeneration can be applied to improve the soybeans through transformation by Agrobacterium as well as particle bombardment.