Abstract:This experiment was studied on the effect of different selection methods and selection treatments on resistant protocorm-like bodies (PLBs),the selection and examination of transgenic plant regeneration in Dendrobium spp.The results showed that:(1)The method of retarding selection with the gradual enhancement of kanamycin (Km) concentration and selecting treatments with cutting under low Km after sterilizating PLBs mediated by Agrobacterium tumefaciens strain LBA4404 with antisense ACS gene and gus gene was optimal.The rate of transgenic resistant PLBs was up to 14.97%.(2)The multiplication of resistant PLBs was cultured on medium with gradual reduction of Km concentration and cutting under low Km concentration.The rate was 1.15 and the growth of PLBs was the best.(3)The differential rate of resistant PLBs cultured on the 1/2 MS medium supplemented with 0.5 mg/L 6-BA was 73.85%,13 resistant plantlets rooted on the 1/2 MS medium supplemented with 1.0 mg/L NAA and 50.0 mg/L Km and 100.0 mg/L Cefotaxime (Cef),the transgenic rate was 12.15%.(4)GUS histochemical assay and PCR assays proved that the T-DNA containing antisense ACS gene was integrated into the genome of these resistant plantlets.There was no morphological difference between transgenic plantlets and no-transgenic plantlets.Three transgenic plantlets transferred after 2 months were survival.