Somatic embryogenesis in Rosa chinensis cv. 'Old Blush'

Rose is one of the most widely used ornamental flowers in the world. However, the low induction rates for most rose somatic embryos means that it is difficult to use somatic embryos for genetic transformation. In order to improve the induction rate of somatic embryos to improve the genetic transformation efficiency, this study investigated the effects of explant type, plant growth regulator concentration, calli status, medium conversion time, and medium tilt on the growth of rose somatic embryos. The results showed that Rosa chinensis cv. 'Old Blush' leaflets could induce normal embryogenic calli, but petioles could not. When the 2,4-dichlorophenoxyacetic acid concentration was 13.57 mu M, the calli induction rate was the highest in the embryo proliferation medium supplemented with 2.32 mu M kinetin, and white and reddish-brown translucent calli were the main type of embryogenic calli induced. As the culture time in embryo proliferation medium was extended, the relative induction rate for secondary embryos and multicotyledon secondary embryos gradually increased when transferred to embryo maturation medium, but the induction rate for somatic embryos decreased. Placing the embryo maturation medium at an angle of 45 degrees had little effect on the general induction rate for somatic embryos. The germination buds produced by the somatic embryos with two cotyledons showed the fastest germination and greatest survival rates. The results of this experiment will help improve somatic embryo regeneration rates and can be used to explore new regeneration methods. They also lay the foundation for further optimization of the somatic embryo genetic transformation system. Extend the embryogenic calli culture time to produce secondary embryos and the secondary embryos germinate normally.

Automated summary

This study investigates the factors affecting the growth of rose somatic embryos and identifies key factors that can improve the induction rate and efficiency of somatic embryo regeneration.