STUDIES ON ANTIBIOTICS SENSITIVITY AND GENETIC TRANSFORMATION OF Actinidia latifolia

Effects of antibiotics on in vitro regeneration and organogenesis from leaf explants of Actinidia latifolia were studied.Genetic transformation calli of A.latifolia were generated after co-cultivation of leaf segments with Agrobacterium tumefaciens strain.Successful transformation was confirmed by histochemical analysis of gus activity in kanamycin-resistant calli and leaves.Results showed that cefotaxime is superior to carbenicillin for shoot differentiation.When cefotaxime concentration was 300mg·L~(-1),shoot differentiation rate and mean number of shoots per explant both reached the highest levels,100% and 9.76 shoots/explant.However,a negative effect on in vitro rooting of regenerated shoots by higher cefotaxime concentrations(≥200mg·L~(-1)) was also seen.Carbenicillin had no marked influence on rooting.In the treatments of different combinations or alone of kanamycin and carbenicillin on rooting,carbenicillin had no marked influence on rooting but kanamycin inhibited markedly rooting.With the increase of kanamycin concentration,the rooting rate decreased sharply.Rooting was completely inhibited on the media containing 50mg·L~(-1) kanamycin.It was considered that for A.latifolia 300mg·L~(-1) cefotaxime was suitabie for elimination of Agrobacterium tumefaciens during transgenic shoot induction;20mg·L~(-1) kanamycin was useful in the selection of transgenic versus false-positive shoots;during rooting phase kanamycin concentration should be controlled under 50mg·L~(-1),and carbenicillin substitute for cefotaxime to elimination of Agrobacterium facilitated rooting.This study had determined the type and concentration of antibiotics in Agrobacterium-mediated transformation of A.latifolia,and laid a good foundation for germplasm improvement through genetic engineering.