Improvements in shoot apex regeneration of two fiber crops: cotton and kenaf

Cotton (Gossypium hirsutum L.) and kenaf ( Hibiscus cannabinus L.) belong to the Malvaceae family, and both are used as sources of fibers. Shoot apices from vigorous seedlings aseptically germinated from 3 different cultivars of both cotton and kenaf were used in this study. The cotton and kenaf shoot apex size was between 2–3 mm containing the meristem, unexpanded leaves, and a small portion of the cotyledon. Shoot apices were placed on 18 different media comparing full and 1/2 strength Murashige and Skoog (1962) plus vitamins, and combinations of 0, 0.1, and 1 mg l^-1 of naphthaleneacetic acid and 6-benzyladenine (BA). The shoot apices of both crops developed successfully without intervening callus formation, and no significant differences among cultivars were found. An average of 58% of the cotton shoot apices initiated shoot and rooted in full strength Murashige and Skoog (1962) plus vitamins in 6 weeks. For kenaf, an average of 92% of shoot apices initiated shoot and rooted in full strength Murashige and Skoog plus vitamins and 0.1 mg l^-1 BA in 3 weeks. All regenerated plants of both crops were phenotypically normal and set seeds. This revised version was published online in June 2006 with corrections to the Cover Date.