Somatic embryogenesis processes and changes in endogenous hormone content of Cinnamomum camphora L.

Abstract

Abstract Immature zygotic embryos of the camphor tree were used as explants, under dark conditions, the somatic embryos induction rate (68.75%) was the highest when the immature zygotic embryos were 6 mm in size. And using sucrose as a carbon source was more conducive to the induction of somatic embryos. The highest cotyledon embryos proliferation rate (36.67%) appeared in the combination of 1.2 mg/L 6-BA + 0.2 mg/L IBA + 8.0 mg/L GA3, and the highest cotyledon embryos germination rate (20%) appeared at 2.4 mg/L 6-BA + 0.4 mg/L IBA + 4.0 mg/L GA3. Changes of endogenous hormone content and radio of various types of embryogenic cultures were clearly diverse: IAA and ABA were always at higher levels, and the highest values of GA3 (0.31 ng·g-1) and ZT (0.09 ng·g-1) appeared in SEG explant, and ZT was only detected in SEG explant, it is speculated that appropriately increasing the content of endogenous ZT or the concentration of exogenous cytokinin may help to induce germination of somatic embryos. The highest values of ABA/IAA (8.46) occurred in SEG explant, followed by SE explant (2.83), which was initially thought to be related to the development and germination of somatic embryos. The highest values of ABA/GA3(180.00) were found in SE explant, followed by YC explant (69.50), which indicated that a higher ratio was beneficial to the normal development of somatic embryos.