秦艽(Gentiana macrophylla Pall.)离体培养再生过程中体细胞胚的发生(简报)

本文以秦艽叶片和茎段作为外植体,通过离体培养对秦艽植株再生途径进行研究。愈伤组织在添加2mg/L 2,4-D和0.5mg/L BA的MS培养基上诱导,两周内可出现愈伤组织。愈伤组织在相同激素配比并附加500mg/L LH的MS培养基上继代。愈伤组织的分化在添加有0.1mg/L 2,4-D和0.5mg/L BA的MB培养基上进行。通过显微观测,疑似体细胞胚可以在叶片和茎段的愈伤组织上产生。形态学和组织学的分析进一步证实了秦艽离体再生过程中体细胞胚发生的现象。体细胞胚和合子胚一样,也经历球形、心形、鱼雷和子叶胚等发育时期。相对独立的结构说明秦艽的体细胞胚可能是单细胞来源。体细胞胚在愈伤组织的表面和内部都有出现。在本实验中,体细胞胚发生途径是在秦艽愈伤组织形成后观察到的唯一再生途径。

SOMATIC EMBRYOGENESIS PATHWAY FOR PLANT REGENERATION IN QINJIAO (GENTIANA MACROPHYLLA PALL .)

Qinjiao (Gentiana macrophylla Pall.) is a perennial herbage native to northwestern China. It has been taken as a kind of Chinese herbs for more than one thousand years. The major secondary metabolite named as gentiopicroside accounts for 8% of the dry weight of roots. It has been used for medical purpose in the treatment with rheumatism, osteoarthritis, inflammatory or ulceration. Conventionally, Qinjiao is propagated by seeds, but the seeds should be planted in one year after harvesting and the germination rate is extremely low. These confine its spread by seeds after year-round storage. Therefore, plant regeneration from somatic cells will be an ideal way for its propagation. Plant regeneration from somatic cell can be divided into two ways: somatic embryogenesis and organogenesis. Similar to zygotic embryo, somatic embryo has a bipolar structure with both shoot and root poles. Somatic embryogenesis also goes through the same key stages as globular-, heart-, torpedo- and cotyledon-stages Somatic embryogenesis was first observed in carrot callus cells more than 45 years ago. Since then, plant regeneration via somatic embryogenesis has been studied in many important species. Though the plant regeneration of Qinjiao has been previously studied, there is no investigation of somatic embryogenesis reported in this plant. Therefore, the aim of our experiment is to confirm the somatic embryogenesis pathway of plant regeneration in Qinjiao.