ABSTRACT. The objectives of this research were to improve the efficiency of
regeneration and establish optimal condition for transformation of Vanda lilacina
Teijsm & Binn. The new Dogashima (ND) medium supplemented with 1% potato
extract was suitable for seed germination. Experiments were performed to determine
the effect of plant growth regulators on the number of shoots. It was found that the
shoot number per protocorm was 6 when cultured on ND medium supplemented with
1 mg/l napthalene acetic acid and 5 mg/l benzylaminopurine. The protocorm
regeneration was completely inhibited by hygromycin at 9 mg/l. Agrobacterium
tumefaciens strain LBA 4404 (pCAMBIA1305.1) was used to establish a
transformation protocol. The plasmid pCAMBIA containing antisense ACC oxidase,
ȕ- glucuronidase (GUS) and hygromycin resistant (hpt) genes, was used.
Co-cultivation of the protocorms with Agrobacterium LBA 4404 led to numerous
positive GUS staining. Successful transformation of antisense ACC oxidase into
V. lilacina was veri¿ ed by GUS assay. The GUS assay revealed the GUS activity
while PCR method indicated the integration of DNA.