SOMATIC EMBRYOGENESIS FROM STYLES OF DIFFERENT CULTIVARS OF CITRUS LIMON (L) BURM

Plants were regenerated from styles of three cultivars of lemon (Citru s limon (L.) Burm.), 'Monachello', 'Lunario' and 'Femminello Santa Ter esa'. Styles and stigmas were excised from flowers, and cultured on Mu rashige and Skoog (MS) basal medium. Callus formation occurred from th e style base 2 weeks after culture initiation and was significantly (P < 0.001) greater in immature flowers growing on BAP supplemented medi um. Somatic embryos appeared 8 weeks later. The addition of BAP in the culture medium increased significantly (P < 0.01) the embryogenic res ponse of the style, and the best regeneration occurred on MS basal med ium supplemented with 13.3 mu M 6-benzylaminopurine (BAP) and 146 mM s ucrose. Once embryos were transferred to MS medium supplemented with 5 00 mg L(-1) malt extract and 0.27 mu M alpha-naphthaleneacetic acid (N AA), they developed into plantlets. After 5 or 6 months of continuous subculturing, the embryogenic callus became habituated and new embryos were still arising.