| The system of somatic embryogenesis in Catalpa fargesii Bur. f. duclouxii (Dode) Gilmour was established with comprehensive application of solid and liquid culturing methods.The best medium and conditions were chosen for somatic embryogenesis and plantlets originated from somatic embryos were cultured; the origins and processes of somatic embryogenesis and development had been primarily acknowledged during the anatomical observation. Physiological and biochemical characteristics and the dynamic of protein metabolism during the processes of the development of SE were analyzed. Furthermore, the physiological and molecular mechanism was evaluated further. The main results as follows :1. The cotyledons of seedlings in C. fargesii f. duclouxi was cultured on the medium of 1/2MS+6-BA2.00mg·L-1 +NAA 0.10 mg·L-1 to induce somatic embryos directly.The system of somatic embryogenesis was directly established. The cotyledons and the axis of seedlings in C. fargesii f. duclouxi was cultured on the medium of N6+NAA0.10mg·L-1+ 6-BA2.00 mg·L-1 or 1/2MS+TDZ0.50mg·L-1 to induce callus. Then the embryogenic callus was cultured on the medium of 1/2MS+1.00mg·L-16-BA +0.01mg·L-1NAA + Inositol 500mg·L-1 to induce somatic embryos indirectly. The plantlets developed from embryoid were transplanted and domesticated, thus the syetem of somatic embryogenesis was established indirectly.2. Somatic embryos can be induced from the internal and external of callus. Somatic embryo was originated from single cell, and then developed to multicellular proembryo, globular embryo, heart-shaped embryo, torpedo-shaped embryo, cotyledon embryo in sequence. There is obvious reproductive isolation between the embryos and the peripheral tissue. There were obvious physical and chemical variations between different types of callus and somatic embryos, and the variations of physical and chemical properties were related to the vitrification of somatic embryos and the development of deformed plantlet.3. The metabolism of protein in callus was relatively weak, while that in the midstage embryos, the matured embryos ? and the matured embryosⅡwere vigorous. The results of two-dimensional electrophoresis of protein showed great variance between 4 kinds of material which included the mixture of little callus and the early-stage embryos, the midstage embryos, matured embryos ? and matured embryosⅡ. There were 341 proteins expressed in the 4 stages in total. The relative molecular weight was in the range of 15.1kD to 85.0kD. The isoelectric point was in the range of 4.47 to 6.92. There were 79,200,102 and 191 proteins expressed in the 4 stages respectively, and 40,65,30 and 36 proteins specially expressed in the 4 kinds of material respectively. The other proteins expression changed along with the development of somatic embryos.
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