Optimization of Regeneration Process in the Genetic Transformation System of ‘Qihong’ Actinidia chinensis

The effects of different concentrations of plant growth regulator combinations on the callus induction and regeneration of kiwifruit were investigated by using the leaves of aseptic seedlings of Actinidia chinensis ‘Qihong’ kiwifruit as explant, and the best formula of in vitro regeneration system of ‘Qihong’ kiwifruit leaves was screened out. AcALKBH4 overexpression vector was transferred into ‘Qi hong’ kiwifruit by leaf disk method mediated by Agrobacterium tumefaciens, and positive transgenic plants were identified by real-time fluorescence quantitative PCR. We can successfully obtained transgenic plants through this system in a timely manner, which laid a solid foundation for the efficient transformation of kiwifruit. The results showed that adding MS （4.43 mg·L⁻¹）+sucrose （30 g·L⁻¹）+6-BA （2.0 mg·L⁻¹）+NAA （0.5 mg·L⁻¹）+TDZ （1.0 mg·L⁻¹）+agar （8 g·L^-1） was the most beneficial to the callus induction and growth of kiwifruit leaves, and the induction rate was 85.2%. The best condition for ‘Qi hong’ kiwifruit callus in inducing buds was achieved when the medium formulation was MS （4.43 g·L⁻¹）+sucrose （30 g·L⁻¹）+6-BA （1.0 mg·L⁻¹）+NAA （0.1 mg·L⁻¹）+agar （8 g·L⁻¹） after around 5 to 6 weeks culture. The regeneration rate of callus was up to 60.0%. The new buds were cultured and the positive transgenic plants were detected after the leaves grew out. The positive rate was about 25.0%-30.0%.