Catharanthus roseus (L.) G. Don is a common ornamental crop worldwide due to its high tolerance to drought and heat. The researches on Agrobacterium-mediated transformation of C. roseus are few, and mostly focus on the production of secondary metabolites in roots. Furthermore, the organogenesis from callus to plantlet is frequently unstable which limits the study on entire plant, especially on flowering. The objective of this study is to evaluate the in planta transformation survival rate in different explants and Agrobacterium strains. C. roseus ‘Cora XDR White’ seeds were cultivated in vitro till the cotyledon expanded. Plantlets and cotyledonary nodes were respectively inoculated with two Agrobacterium strains, GV3101 or LBA4404 harboring the binary vector pHEE401E. Explants were co-cultivated in 1/2 MS medium for three days. After washing with sterile water and cefotaxime, the explants were first placed in a medium containing cefotaxime, then were transferred to a same medium that was further added hygromycin. During the elimination and selection, each cotyledonary node turned brown. In the process of subculture, necrotic parts were removed. Result showed that the survival rate of plantlets was 5% in GV3101 treatment. However, LBA4404 ones eventually got brown.
