Abstract: Genetic transformation of Artemisia annua L. with Agrobacteriurn rhizogenes is reported. The strains of Agrobacterium rhizogenes used were: 1. Strain R1000, which harboured the Ri plasmid pRiA4b. 2. Strain R1500, which carried pRiA4b containing a chimaeric neomycin phosph0transferase Ⅱ (NPT-Ⅱ ) gene inserted in the Hind Ⅲ fragment 21 of the TL-DNA. 3. Strain R1601, which was similar to the strain R1500 but into which has been cojugated cosmid pTVK291 containing the part of the vir region from supervirulent Ti plasmid pTiBo542. Hairy roots produced from Artemisia annua transformed with all three strains individually. Transformation frequencies of up to 100% were obtained with the strain R1601, which was higher than with the others. The culture system in vitro of the hairy root transformed by the strain R1601 was established. Results of Southern analysis indicated that all the TL-DNA of Agrobacterium rhizogenes was transferred into the hairy root cells of Artemisia annua. Agropine and mannopine were detected in the extracts of the freshly isolated hairy roots, but not in those which have been cultured for a prolonged time. Cultured hairy roots expressed NPT-Ⅱ enzyme activity which was correlated with the presence of the Ri plasmid TL-DNA and the structural sequence of the NPT- H gene.

Key words: Ri plasmid, Arternisia annua, Hairy root, NPT-Ⅱ gene