From the callus cell cultures of Kava established by the above methods, it was possible to regenerate viable Kava plants by first promoting shoot organogenesis from the callus cells and then allowing these microshoots to establish roots in culture. Shoot morphogenesis was achieved with the Kava growth medium modified to contain 1.0 mg/l benzyladenine (BA). The cytokinin and microshoots were then transferred to a medium free of plant growth regulator (Fig. 8.6(A, B)). In contrast, we found that a medium with a higher auxin ratio with respect to cytokinin caused spontaneous rhizogenesis of callus cultures (data not shown). From the shoot cultures it was then possible to obtain intact regenerated Kava plants in culture that remained viable following acclimatization and then transfer to a commercial soil-free potting medium (Fig. 8.6(C)). We have allowed the regenerated plants to grow in the greenhouse, and currently our first set of regenerated Kava plants are over 2 feet tall and demonstrate a growth habit similar to Kava plants propagated via cuttings (Fig. 8.7). Moreover, these plants produce kavapyrones in a similar manner to the in vivo plants from which explants were initially generated (Kobayashi et al. 2003).
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