Efficient callus induction and a temperature condition for flowering and seed setting in kenaf <i>Hibiscus cannabinus</i>

Kenaf, Hibiscus cannabinus, is a fiber-enriched plant belonging to Malvaceae and is an important fiber crop. The features of kenaf of being fast-growing and fiber-enriched suggest the potential for the use of kenaf in biomass and materials. Here, we modified procedures for regeneration from kenaf explants in order to establish efficient genetic modification for improving the property of kenaf as a material. We tested several tissues of kenaf seedlings for callus induction and subsequent shoot regeneration by supplying several combinations of plant growth factors. We show the cotyledons to be the best tissue for efficient callus induction, and the rate for callus induction reached ∼98% on an improved callus inducing medium. We also show the efficient regeneration of kenaf from cotyledon-derived calli achieved by shoot induction on a shoot-inducing medium. We also achieved seed setting of the regenerated kanaf plants under a regulated growth condition in a chamber. Our efficient regeneration method and seed setting condition will enable the production of stably transformed kenaf that can improve the properties of kenaf as a material.