In vitro propagation and regeneration of an industrial plant kenaf (Hibiscus cannabinus L.)

The present study report a protocol for the efficient in vitro propagation of kenaf (Hibiscus cannabinus L., an industrial crop having high cellulosic fiber content) on hormone free MS medium using the shoot apex and nodal explants. Shoot tips and nodes were isolated from 15 days old seedlings cultivated on MS medium. Different combinations and concentrations of auxin/cytokinin were used and added to the MS medium to assess the shoot and root induction of theses explants. Several subcultures were drived in order to enhance the multiplication rate. Healthy and well developed in vitro propagated shoots were transferred for acclimatization under greenhouse conditions in pots filled with different substrates (sand + compost or perlite). Our results showed that shoots could elongate and root within 4-6 weeks on MS basal medium without any callus formation. However, addition of growth regulators to the MS medium leaded to a decrease in shoot and root induction rates. Indeed, the highest shoot regeneration frequency (90.5%) was obtained on MS control medium. Elongated shoots were transferred onto the same hormone free MS medium using five subcultures where the multiplication rate reached the highest value (3.66) at the fifth and last step. The in vitro rooted plantlets were acclimatized in greenhouse and successfully transplanted to natural conditions with 70% survival.