【摘要】 为了诱导大蒜外植体形成体细胞胚、明确大蒜体细胞胚发生过程及不同阶段的形态解剖学特征，以大蒜品种‘二水早’为材料，探讨不同外植体和植物生长调节剂对大蒜胚性愈伤组织诱导和体细胞胚成熟萌发的影响，观察大蒜体细胞胚发生过程中形态、组织和超微结构变化。结果表明：大蒜花序轴、鳞茎盘和发芽叶基胚性愈伤组织诱导最适宜的2,4-D质量浓度分别为3.0、2.0、2.0和3.0 mg/L,诱导率分别为82.22%、89.21%、82.52%和83.40%。在2,4-D 0.25 mg/L+6-BA 0.5 mg/L条件下，体细胞胚的萌发系数最高，达35.56个/g。以花序轴为外植体，依据形态和组织学特征，可将体细胞胚发生早期过程划分为外植体、愈伤组织、初期胚性愈伤组织、后期胚性愈伤组织和球形胚5个阶段：外植体-花序轴顶端形成一层半透明的物质，表面不光滑，为愈伤组织，组成愈伤组织的细胞为典型的薄壁细胞。在愈伤组织局部形成明显的表面光滑的颗粒状突起，为初期胚性愈伤组织，解剖学观察发现薄壁细胞中产生了胚性细胞团。当颗粒状突起几乎完全覆盖外植体，表明形成大量胚性愈伤组织，为后期胚性愈伤组织，其由大量胚性细胞组成。球形胚为表面光滑、半透明的球状组织，组成球形胚的细胞呈分生细胞状态。由大蒜体细胞胚萌发形成的植株，培养90 d后可形成试管鳞茎，将其播种在由草炭、珍珠岩、蛭石按2∶1∶1体积比配制的复合基质中，试管鳞茎的出芽率为70.73%,试管鳞茎苗的成活率达96.55%。更多还原

【Abstract】 The aim of this study is to induce garlic explants to form somatic embryos and clarify the process of garlic somatic embryogenesis, along with its morphological and anatomical characteristics at different stages.Using garlic variety ‘Ershuizao’ as research material, this study investigated the effects of different explants and plant growth regulators on the induction of embryogenic callus and the maturation and germination of somatic embryos.Moreover, morphological, histological and ultrastructural changes during garlic somatic embryogenesis were observed.The results showed that the optimum concentrations of 2,4-D for the induction of garlic inflorescence axis, bulb disc and sprout leaf base embryogenic callus were 3.0,2.0,2.0/3.0 mg/L with the induction rates of 82.22%, 89.21%,82.52% and 83.40%,respectively.Under the condition of 0.25 mg/L 2,4-D+0.5 mg/L 6-BA,the germination coefficient of somatic embryos was the highest, reaching 35.56 embryos per gram.Taking inflorescence axis as explant, the early process of somatic embryogenesis was divided into five stages.The five stages included explant, callus, primary embryogenic callus, late embryogenic callus and globular embryo according to the morphological and histological characteristics.A layer of translucent material was formed at the top of the explant-inflorescence axis with unsmmooth surface, which was callus.The cells that made up the callus were typical parenchyma cells.In the local callus, there were obvious granular protrusions with smooth surface, which was primary embryogenic callus.Anatomical observation showed that embryogenic cell mass was produced in parenchyma cells.When the granular protrusions almost completely covered the explant, it indicated the formation of a large amount of embryogenic callus.This was late embryogenic callus, which was composed of many embryogenic cells.The globular embryo was spherical tissue with smooth and translucent surface, and the cells that made up the globular embryo was in a state of meristem cell.The plantlet germinated from garlic somatic embryo could form bulblet after 90 days’ culture.They were sown in a composite matrix composed of peat, perlite and vermiculite with a volume ratio of 2∶1∶1.The germination rate of bulblets was 70.73%,and the survival rate of bulblets seedlings was 96.55%.This study laid a foundation for the construction of a high-efficiency culture system of garlic plantlets in vitro by somatic embryogenesis and enriched the morphological and anatomical knowledge of plant somatic embryogenesis.更多还原