Optimization of Somatic Embryo Regeneration of <i>Larix olgensis</i> Through Multiple Media

Abstract

To establish a stable and efficient  Larix olgensis  somatic embryo regeneration system. In this study, immature zygotic embryos of  Larix olgensis  were used as explant materials for embryogenic callus induction, and embryogenic callus with good growth were selected to induce somatic embryo formation by liquid medium A, semi-solid medium B, and solid medium C. The callus induction medium is S medium+2,4-D 1.0 mg/L + 6-BA 0.5 mg/L + KT 0.3 mg/L, sucrose 20 g/L, agar 3 g/L; the subculture medium is S medium+2, 4-D 0.15 mg/L + 6-BA 0.05 mg/L + KT 0.05 mg/L, sucrose 30 g/L, agar 6 g/L. Mature medium A is S medium + PEG4000 100 g/L + ABA 15 mg/L + AgNO 3  10 mg/L, sucrose 45 g/L liquid medium. Mature medium B and C are mature medium A supplemented with 2 g/L and 10 g/L agar, respectively. The maturation time of this method is about 32 days, the synchronization rate is 78.0%, and the proportion of somatic embryos in normal morphology is 83.0%. Somatic embryo formation efficiency in normal morphology can reach 223.0 embryos/g embryogenic callus, somatic embryo germination rate can reach 47.2%. Compared with a single maturation medium, the maturation time is shortened, somatic embryo generation is more synchronized, and high somatic embryo yield and quality are improved. It provides a way for the commercialization of somatic embryo regeneration of  Larix olgensis , brings great convenience to large-scale breeding and reproduction, physiological and biochemical research, and genetic modification, and has great practical application value.