SOMATIC EMBRYOGENESIS FROM IMMATURE COTYLEDONS OF AN ELITE DARJEELING TEA CLONE

Cotyledons from immature embryos of Camellia sinenis O. Kuntze var. T-78, an elite Darjeeling tea clone, were exposed to various levels of 2,4-D, NAA, IBA, BAP and Kin (1-10 mg/l). While no embryos were formed in MS basal medium without growth regulators, the auxins tried were also inefficient in stimulating primary embryogenesis. Somatic embryos were induced directly on the cotyledonary explants in MS medium with 10 mg/l BAP alone. Somatic embryo formation could be enhanced by addition of 0.5 mg/l IBA and 80 mg/l adenine to 10 mg/l BAP. Embryo conversion was 2-3% in MS medium with or without growth regulators. Almost 20% of somatic embryos converted into whole plants following transfer to B5 medium containing 3 mg/l BAP and 2 mg/l IBA. Embryogenic potential was maintained for over 30 months by secondary embryogenesis through successive generation of embryos. Somatic embryo derived plants were successfully transferred to potted soil at 70% frequency under green house conditions. Morphologically and cytologically (2n = 30) plants are true to type.