蓝莓离体叶片胚状体高效发生及其组织学观察

以高灌蓝莓试管苗叶片为外植体、以改良WPM为基本培养基,研究了外源激素TDZ、ZT及其组合对离体叶片胚状体发生的影响,同时也探讨了蔗糖浓度、水解酪蛋白、椰汁等对胚状体发生、丛芽形成的影响.结果表明:不同浓度的外源激素TDZ、ZT及其组合对胚状体的发生频率、丛芽的形成和生长起重要作用;蔗糖浓度对胚状体的发生及丛芽的生长影响较大,而添加有机质则对胚状体的发生及丛芽的生长没有明显影响.适合高灌蓝莓叶片胚状体发生及成苗的培养基为WPM TDZ 0.04 mg/L ZT 0.25～2.0 mg/L 蔗糖20～40 g/L,而培养基WPM ZT 0.5～1.0 mg/L 蔗糖20 g/L适合于丛芽继代生长.组织学观察表明,蓝莓叶片胚状体发生主要起源于叶上表皮细胞和部分叶肉细胞,可能为多细胞起源,历经多细胞原胚、原球胚、梨形胚、心形胚、子叶胚等发育阶段,并能直接发育成苗.

High Efficient Somatic Embryogenesis on Leaf Explants of Blueberry in vitro Culture and Histological Observations

The tube plantlet leaves of blueberry were used as explants to culture in the modified WPM basal medium which contained different kinds of plant hormones, different concentrations of sucrose and organic matter. The effects of different concentrations of two kinds of plant hormones TDZ (thidiazuron,) ZT (zeatin) and their combinations on somatic embryogenesis and crowd shoots growth were studied in vitro culture. Meanwhile, the influences of the concentrations of sucrose (w/v), coconut water (v/v) and casein hydrolysate on somatic embryogenesis and crowd shoots formation were also studied. The results showed that different concentrations of cytokinins TDZ and ZT played an important role in the somatic embryogenesis and crowd shoots growth. The concentration of sucrose had a marked effect on embryoid formation and crowd shoots growth. However, adding organic matter of coconut water and casein hydrolysate had no evident effect on embryoid formation and crowd shoots growth. The optimum medium for somatic embryogenesis is WPM TDZ 0.04 mg/L ZT 0.25~2.0 mg/L sucrose 20~40 g/L while the medium WPM ZT 0.5~1.0 mg/L sucrose 20 g/L was suitable for crowd shoots growth. The results of histological observations indicated that somatic embryos originated from upper epidermis cells and mesophyll cells. The course of somatic embryos development, which included the phases of multicellular proembryo, pear-shaped embryo, globular embryo, heart-shaped embryo and cotyledon-shaped embryo etc., was similar to other plants. Finally, the somatic embryos became crowd shoots and plantlets.