防风悬浮培养中的体细胞胚发生

SOMATIC EMBRYOGENESIS IN CELL SUSPENSION CULTURE OF SAPOSHNIKOVIA DIVARICATA

将防风（Ｓａｐｏｓｈｎｉｋｏｖｉａ ｄｉｖａｒｉｃａｔａ （Ｔｕｒｃｚ．） Ｓｃｈｉｓｃｈｋ．）试管苗幼根接种在含０．５ ｍ ｇ／Ｌ ２，４－Ｄ 的ＭＳ培养基上诱导出愈伤组织，继而在含１０％ 椰子乳和０．５ ｍ ｇ／Ｌ ２，４－Ｄ的ＭＳ液体培养基中振荡分散建立了细胞悬浮物。至胚性细胞团产生后转至无激素培养基中形成体细胞胚。观察了从单细胞直到球形胚发生的显微及超微结构的变化。在胚性细胞团阶段细胞内出现周质内质网，它的出现可能与细胞团向原胚过渡时的特殊代谢相联系。从单细胞至原胚各阶段细胞内均含有圆球体，到原胚时数量大增，而且其中央电子致密的基质变小变浅，周边部分扩大并更加透明，暗示圆球体在胚胎发生早期起着贮藏蛋白或脂蛋白的作用，后来消耗于原胚的建成而衍生为脂滴。球形胚阶段，在很多细胞的液泡中出现团块状的液泡蛋白。此外还观察到。

Calli of Saposhnikovia divaricata (Turcz.) Schischk.were induced from the roots of test tube seedlings cultured on MS medium containing 0.5 mg/L 2,4 D.Cell suspension was established by shaking the calli in liquid medium of the same components supplemented with 10% coconut milk.After the formation of embryogenic clusters, 2,4 D was omitted promoting the transformation of the embryogenic clusters to somatic embryos.Micro and submicroscopic structural changes during the single cell to globular embryonic stage were observed.It was noticed that cortical endoplasmic reticulum appeared in the cells at the stage of embryogenic clump formation but was absent in other stages.Perhaps this was related to the metabolic specification leading to embryo formation.Spherosomes were observed of embryogenesis but remarkably increased in number at proglobular embryo stage.Meanwhile,the central electric dense matrix became progressively smaller and paler, while the outer part became enlarged and more transparent.This implied that the spherosomes took part in the storage of proteins or lipidproteins in the early stages of embryogenesis and transformation to lipid drops when the proteins were exhausted in the development of embryo, vacuolar protein bodies could be risualized in many cells in the proglobular embryo stage.This together with the existance and changes of spherosomes was similar to that observed in Peucedanum terebinthaceum. Further studies are meritted to approach, whether these are general phenomena in Umbelliferae.This work also revealed that the aggregation of single cells in suspension culture stimulated the initiation of embryogenesis. Calli of Saposhnikovia divaricata (Turcz.) Schischk.were induced from the roots of test tube seedlings cultured on MS medium containing 0.5 mg/L 2,4 D.Cell suspension was established by shaking the calli in liquid medium of the same components supplemented with 10% coconut milk.After the formation of embryogenic clusters, 2,4 D was omitted promoting the transformation of the embryogenic clusters to somatic embryos.Micro and submicroscopic structural changes during the single cell to globular embryonic stage were observed.It was noticed that cortical endoplasmic reticulum appeared in the cells at the stage of embryogenic clump formation but was absent in other stages.Perhaps this was related to the metabolic specification leading to embryo formation.Spherosomes were observed of embryogenesis but remarkably increased in number at proglobular embryo stage.Meanwhile,the central electric dense matrix became progressively smaller and paler, while the outer part became enlarged and more transparent.This implied that the spherosomes took part in the storage of proteins or lipidproteins in the early stages of embryogenesis and transformation to lipid drops when the proteins were exhausted in the development of embryo, vacuolar protein bodies could be risualized in many cells in the proglobular embryo stage.This together with the existance and changes of spherosomes was similar to that observed in Peucedanum terebinthaceum. Further studies are meritted to approach, whether these are general phenomena in Umbelliferae.This work also revealed that the aggregation of single cells in suspension culture stimulated the initiation of embryogenesis. Saposhnikovia divaricata (Turcz.) Schischk.were induced from the roots of test tube seedlings cultured on MS medium containing 0.5 mg/L 2,4 D.Cell suspension was established by shaking the calli in liquid medium of the same components supplemented with 10% coconut milk.After the formation of embryogenic clusters, 2,4 D was omitted promoting the transformation of the embryogenic clusters to somatic embryos.Micro and submicroscopic structural changes during the single cell to globular embryonic stage were observed.It was noticed that cortical endoplasmic reticulum appeared in the cells at the stage of embryogenic clump formation but was absent in other stages.Perhaps this was related to the metabolic specification leading to embryo formation.Spherosom