Genetic transformation of Alstroemeria using particle bombardment

Transgenic plants were obtained after particle bombardment of embryogenic c allus derived from stem segments of two tetraploid Alstroemeria genotypes w ith plasmids containing different selection/reporter genes. Firstly, a plas mid containing a firefly luciferase reporter gene driven by the maize ubiqu itin promoter (Ubi1), was bombarded into both friable embryogenic callus an d proembryos. Transient and stable expression of luciferase was visually de tected by a luminometer. This selection method is non-destructive and can b e applied over the whole developmental process from callus to embryo and pl antlet. Molecular proof of transformation was obtained both by PCR analysis and Southern hybridization. Secondly, a plasmid containing the bar gene to gether with an uidA gene coding for beta-glucuronidase both driven by the U bi1 promoter was bombarded into proembryos. The transgenic callus was effec tively selected from the callus clumps four months after bombardment on a m edium containing 5 mg/l phosphinotricin (PPT). Selection by PPT was efficie nt and labour-saving. Stable expression of GUS was confirmed by the histoch emical staining assay and molecular proof was obtained by PCR analysis.