AGROBACTERIUM-MEDIATED TRANSFORMATION OF HIERACIUM-AURANTIACUM

An Agrobacterium-mediated transformation system, based on the neomycin phosphotransferase II (NPTII) gene, is described for the apomictic pl ant Hieracium aurantiacum. Integration of foreign DNA was confirmed by Southern analysis and its expression demonstrated by assaying for NPT II enzymatic activity. NPTII activity, which confers kanamycin resista nce, was inherited by clonal seedlings of transformed plants. Growth o f untransformed seedlings was inhibited by 20 mg/L kanamycin, while tr ansformants continued to grow at 300 mg/L. The clarity of the response , together with the convenience of screening at the seedling stage, ma kes kanamycin resistance a valuable tool for quantifying reproductive mechanisms in facultatively apomictic plants of this species.