Induction Of Somatic Embryos In Abelia×Grandiflora

In this paper, young leaves and stems from three varieties of Abelia×grandiflora were used as explants, we first studied the induction process of somatic embryos, cytological observation and the physiological index, providing a theoretical basis for establishing highly-efficient system and understanding the mechanism of somatic embryogenesis of Abelia×grandiflora. The results were as follows:1. Effects on different varieties to induce callus were studied, indicated that'Francis Mason'was better than'Edward Goucher'and'Dwarf White', but the differences were not significant. Cytomorphology research also showed that the structure of the embryogenic cells of the three varieties was greatly similar.2. Young leaves were best explants for inducing of somatic embryos of Abelia×grandiflora.3. The best medium for inducing callus of leaf and stem was MS+3.5mg/L 2,4-D+0.2mg/L NAA+1.0mg/L KT+0.05mg/L TDZ and MS+1.5mg/L 2,4-D+0.5mg/L NAA+0.5mg/L KT+0.1mg/L TDZ; and the appropriate medium for proliferating embryogenic callus was MS+1.0mg/L 6-BA+1.0mg/L KT+0.1mg/L NAA和MS+0.1mg/L 6-BA+0.1mg/L KT+0.1mg/L NAA, with inositol 100mg/L, casein hydrolysate 200mg/L, 15g/L sucrose, pH value 5.8, and 30 days darkness culture in 25℃.4. In the stage of callus induction, 2,4-D was very effective growth hormone, the effect of NAA was less than 2,4-D. Cytokinin was also not obvious, but it's an integral part in the proliferation stage. In order to avoid browning of cultures, 6-BA concentration should be controlled at 1.0mg/L, KT and TDZ was both not obvious. ABA could inhibit the growth of abnormal embryos, the appropriate range of ABA concentration was 0.5～1.0 mg/L.5. In the stage of suspension culture, embryogenic calli cultured in the liquid MS medium without hormones could grow the plenty of root-like, in the liquid medium MS+1.0mg/L 6-BA+30g/Lsucrose, they could induce some bud-like without roots and browning.6. Anatomic structures showed that the cells of embryonic calli with large nuclei were small, arranged tightly and regularly, while the cells of non-embryonic calli were contrary to them. Somatic embryogenesis mostly derived from embryonic cell of endogenous origin, and developed through nest-like multicellular proembryo, globular embryo, heart-shape embryo and torpedo-shape embryo.7. Soluble protein content and SOD activity reached their peak value in the stage of globular, providing the premise and material basis for the somatic embryogenesis and further development. Change of soluble sugar content was closely related to transition of somatic embryo. The accumulation of them provided the energy for the somatic embryo differentiation and development in the stage of embryogenic callus and heart-shaped.