Somatic embryogenesis and organogenesis in peanut: The role of thidiazuronand N-6-benzylaminopurine in the induction of plant morphogenesis

Intact peanut (Arachis hypogaea L.) seeds, incubated on media containing N- 6-benzylaminopurine (BAP) or thidiazuron (TDZ) exhibited de novo regenerati on at the hypocotyledonary notch region. Regeneration was observed when see ds were cultured on either TDZ or BAP but the optimal level of media supple mentation was 10 mu mol.L-1 for TDZ and 50 mu mol.L-1 for BAP. Light micros copic observations revealed that the regenerants induced by TDZ were somati c embryos while those induced by BAP were shoots. An alternative approach o f exposing the seeds to TDZ was through vacuum infiltration followed by cul ture on basal media but BAP did not induce regeneration by this method. Alt hough TDZ has often been classified as a synthetic cytokinin, our results c learly demonstrate that seedlings treated with TDZ undergo a different morp hological route of development than that induced by purine cytokinins.