Thidiazuron-induced high-frequency shoot proliferation in Cineraria maritima Linn

Cineraria maritima Linn. is an important medicinal plant of known therapeutic value for the treatment of cataract and corneal opacity. An in vitro regeneration protocol has been standardized for large-scale supply of planting material of this otherwise scarce medicinal plant species. The medium for propagation contained MS salts, B 5 vitamins, 30 g l - 1 sucrose and 8.0 g l - 1 agar (designated as MSB medium). Addition of thidiazuron [TDZ: N-phenyl-N'-(1,2,3-thidiazol-5-yl) urea] in the culture medium proved superior to the combined treatments of 6-benzyladenine and α-napthaleneacetic acid. The highest adventitious shoot bud (36 ′ 2.34) induction, per nodal explant used, occurred at 4.54 pM TDZ after 6 weeks of incubation. The number of shoots formed per explant increased significantly upon sub-culture of the responding explants on plant growth regulator-free MSB medium, after 8 weeks of culture initiation. In vitro produced shoots exhibited good rooting response on half strength MSB medium containing 4.92 μM indole 3-butyric acid. After 3 weeks of hardening of plantlets as hydrophonic cultures, almost 95% of 300 rooted plants could be successfully transferred and acclimatized ex vitro under glass-house conditions, followed by their establishment in the field.