Somatic embryogenesis from styles of different cultivars of Citrus limon (L.) Burm

Plants were regenerated from styles of three cultivars of lemon (Citrus limon (L.) Burm.), 'Monachello', 'Lunario' and 'Femminello Santa Teresa'. Styles and stigmas were excised from flowers, and cultured on Murashige and Skoog (MS) basal medium. Callus formation occurred from the style base 2 weeks after culture initiation and was significantly (P < 0.001) greater in immature flowers growing on BAP supplemented medium. Somatic embryos appeared 8 weeks later. The addition of BAP in the culture medium increased significantly (P < 0.01) the embryogenic response of the style, and the best regeneration occurred on MS basal medium supplemented with 13.3 mu M 6-benzylaminopurine (BAP) and 146 mM sucrose. Once embryos were transferred to MS medium supplemented with 500 mg L(-1) malt extract and 0.27 mu M alpha-naphthaleneacetic acid (NAA), they developed into plantlets. After 5 or 6 months of continuous subculturing, the embryogenic callus became habituated and new embryos were still arising.