Somatic Embryogenesis from Embryogenic Leaf Callus of Tea (Camellia sinensis (L.) Kuntze

Abstract

The aim of this study was to produce somatic embryos indirectly from embryogenic leaf callus of tea (Camellia sinensis (L.) Kuntze). Primary embryogenic colli (friable colli, 16 weeks after culture of in vitro leaf segments) were first cultured on Murashige and Skoog (MS) medium containing Benzyl Aminopurine (BAP) (3 mg/l) and Napthalene Acitic Acid (NAA) (0.1 mg/l) and maintained for 4 weeks. Primary colli were then transferred to half and full strength MS media containing BAP and NAA in combination with Abscisic Acid (ABA) (0-1.0 mg/l) to select the suitable second medium. MS medium supplemented with BAP (1.0 mg/l) and NAA (0.1 mg/l) was found to be the second best medium for somatic embryogenesis. Further work was done to select the optimum culture duration for maintaining primary calli on first and second media for efficient somatic embryogenesis. It was noted that the production of somatic embryos was relatively high (8.3%), but the size of embryos was very small (1 mm long) when the primary calli were kept for 8 weeks on the second medium after maintaining them on the first medium for 8 weeks. Meanwhile, 2 mm long somatic embryos were obtained from the primary calli cultured directly on the second medium without maintaining them on the first medium. Rates of somatic embryogenesis were not significant in both patterns of culture periods. Protocol developed on indirect somatic embryogenesis will be useful in order to achieve new somatic variants from seedling explants and also to use in transformation work.