High-frequency shoot multiplication in Artemisia vulgaris L. using thidiazuron

An in vitro propagation system for Artemisia vulgaris L., a traditional medicinal plant, has been developed. The best organogenic response, including adventitious shoot number and elongation, was obtained when hypocotyl segments were cultured onto MS medium supplemented with 4.54 mu M TDZ (N-phenyl-N'-(1,2,3-thidiazolyl) urea). Up to 28 shoots formed per explant for an optimal duration of exposure of 48 days. Regenerated shoots formed roots when subcultured onto a medium containing 8.56 mu M IAA (indole-3-acetic acid). Healthy plantlets were transferred to a garden soil: farmyard soil:sand (2: 1: 1) mixture for acclimatization, which was successful, and subsequent maturity was achieved under greenhouse conditions over a six-month period. The survival rate of the plantlets varied under acclimatization. The regeneration protocol developed in this study provides a basis for germplasm conservation and for further investigation of medicinally active constituents of A. vulgaris. This optimized protocol has been successfully employed for genetic transformation studies in A. vulgaris, which are currently underway in our laboratory.