Organogenesis and regeneration from pigmented callus in Camellia sinensis (L.) O. Kuntze cv. Nandadevi, an elite Darjeeling tea clone

Abstract

Organogenesis and regeneration of adventitious shoots from stem callus in Camellia sinensis ev. Nandadevi was affected by explant type, nature of calli lines established and cytokinin type used. Callus cultures were established from three types of explants viz., stem epidermal layers (E 1), transversely cut stem segments (E 2) and longitudinally cut stripped stem segments (E 3), cultured on half strength Murashige and Skoog's media containing 3 mg/l benzyladenine (BA), 3 mg/l BA, 50 mg/l adenine sulphate (M 2). 3 mg/l Zn and 50 mg/l adenine sulphate (M 3). Two calli lines were established from the three types of explants in M 1, M 2 and M 3 medium i.e., friable green (FG) or compact green (CG), after 3 weeks of culture. Regeneration was achieved only in CG calli derived from E 2 and E 3 but not E 1 explants, when such calli turned heterogenous with respect to pigmentation on subculture to basal medium containing BA (1–10 mg/l). Callus derived from E 2 explants showed a higher regeneration frequency (90%) in basal medium with 5 mg/l BA. The maximum number of shoot buds obtained was 22.5±0.5 g calli within 4 weeks of culture. Shoots proliferated on basal medium containing 1 mg/l BA and 5 mg/l GA 3. 37.2 ± 0.3 microshoots/g calli could be excised after 4 weeks and microshoots (3–4 cms) rooted on 1 4 basal media containing 6 mg/l lBA.