Somatic Embryogenesis And Cytological Observation Of Picea Mongolica

In this study,utilized immature zygotic embryos and mature zygotic embryos of P.mongolica as explants,in order to study the influences of different basic medium,hormone combinations and strains on the induction of embryogenic callus proliferation and somatic embryo differentiation.Finally,establish and optimize the systems of somatic embryos of P.mongolica.The results as followed:1.The optimal conditions for inducing embryogenic callus based on immature zygotic embryos of P.mongolica including the best combination of hormone containing 1.2?1.8mg/L 6-BA and 1.8?2.7mg/L 2,4-D,and the embryogenic callus induction rate could be up to 74.00%.The most appropriate time is in around August 5th,and the embryogenic callus induction rate up to 67.70%.The embryogenic callus induction rates of different strains with a minimum of 15.91%and a maximum 77.50%,and the induction rate is positively correlate with full seed ratio(r=0.865,P=0.006).The optimal conditions for inducing embryogenic callus of mature zygotic embryos of P.mongolica including LM + 6-BA 2.0 mg/L +1.0 mg/L KT + 4.0 mg/L 2,4-D in primary culture,and 1/2LM +1.0 mg/L 6-BA + mg/L KT 0.5 + 2.0 mg/L 2,4-D in the stage of subculture,the other treatments did not induce embryogenic callus.2.The optimal hormone combinations of embryogenic callus including 0.8 mg/L 6-BA and 0.8?1.6 mg/L 2,4-D,and the 2,4-D has better results compared to 6-BA in the process of callus proliferation with high proliferation multiple is up to 7.24 times.3.The optimal culture systems of somatic embryo differentiations and maturations of P.mongolica including 1/2LM + 22.5 mg/L ABA + 45g/L PEG4000,and the highest number of somatic embryos differentiation was 362/g,the number of malformed embryos was 108/g,and the rate of malformed embryos is 29.83%.In addition,K-81 strain has the highest number of somatic embryos with 573.4/g,the number of malformed embryos is 151/g,and the abnormal embryo rate was 26.33%.4.The histological observation of somatic embryogenesis and development of P.mongolica indicated that oval or elongated embryogenic cells and the embryonal-suspensor mass which had apical meristem and suspensor cells in the tail formed the embryogenic callus.In the process of mature development,early proembryo,globular embryo,early embryo and cotyledon embryo were observed.