大白菜游离小孢子培养中胚胎发生及发育途径

摘要

[目的]观察大白菜离体小孢子培养中的胚胎发生及发育途径.[方法]以大白菜F1代杂交种为试材,采用光学显微镜观察游离小孢子胚胎发生和发育途径.[结果]细胞热激后膨大是胚状体诱导的关键因素.大白菜小孢子诱导成胚有3种途径,小孢子均等分裂途径、小孢子不均等分裂途径和小孢子直接萌发出胚途径.均等分裂途径是在连续的均等分裂以后形成原胚,原胚继续分裂形成球形胚、心形胚、鱼雷形胚和子叶形胚.不均等分裂途径形成的两个细胞中较大的细胞继续分裂最终形成有极性的胚状体.[结论]该研究结果为大白菜小孢子的高频率诱导提供细胞学依据.%[Objective] The aim was to observe embryogenesis and development of isolated microspores in Chinese cabbage.[Method] Chinese cabbage F1 hybrids were used as the experimental materials,and optical microspore was employed to observe the embryogenesis and development of isolated microspores.[Result] Cells swelled after heat shock treatment,which was the critical factor of embryoid induction.Three pathways equal division,unequal division and germination of microspores were discovered to lead to the embryogenesis from isolated microspores after swelling.Microspore could grow directly to embryoid through germination path way.Equally divided microspores formed the original embryos after successive multiple equal divisions.Original embryos could develop into cotyledon-shaped embryos via globular,heart-shaped and torpedo-shaped embryos.The large one of the two cells from unequally divided microspores continued to divide and finally formed a polar embryoid.[Conclusion] The study will provide cytological basis for high induction frequency and embryoid of Chinese cabbage.