Somatic Embryo Induction and Plantlet Regeneration of Canna × generalis from Immature Zygotic Embryo

Abstract Somatic embryogenesis is a unique method of in vitro regeneration, which can be used in plant reproduction, germplasm conservation, and molecular-assisted breeding. The results showed that the optimum medium for embryogenic callus induction was MS+6 mg L-1 6-BA+1.5 mg L-1 TDZ+0.5 mg·L-1 NAA+30 g·L-1 sucrose +7 g·L-1 agar, and the induction rate was 47.45%. The best somatic differentiation medium was MS+2 mg·L-16-BA+1.5 mg·L-1 TDZ+30g·L-1 sucrose +7g·L-1 agar, and the induction rate of somatic embryos was 54.45%. The optimum medium for embryoid proliferation was MS +6mg·L-1 6-BA + 1 mg·L-1 NAA +0.2mg·L-1 TDZ, and the proliferation rate and the multiplication coefficient reached 46.33% and 7.83, respectively. The mature somatic embryos were put into MS, B5, and 1/2MS medium for seedling culture. T In MS medium, true leaves grew, complete plants were obtained, and the seedling rate was 88.00%. At the same time, the survival rate of transplanting seedlings in the mixed nutrient soil with the ratio of original soil (peat: organic fertilizer: soil) =1:1:1 was as high as 98%. Cytological observation showed that the somatic embryos underwent globular, heart-shaped, torpedo, and cotyledon stages. This study established a tissue culture and regeneration system of C. × generalis with excellent somatic embryos, and provide basic technical support for the large-scale commercial propagation and germplasm resources protection. It will lay a foundation for further research on gene function and breeding new varieties and ideal research materials for the study of somatic embryogenesis mechanism and genetic transformation of C. × generalis.