Somatic embryogenesis (SE) is a developmental process during which plant somatic cells, under suitable conditions, produce embryogenic cells that develop into somatic embryos (se). SE is the most important method for plant propagation in vitro, having both fundamental and applicative significance. SE can be induced from different tissues and organs, but when se are used as explants, the process is recognized as secondary or cyclic SE. We induced secondary SE in Centaurium erythraea by application of 2,4-dichlorophenoxyacetic acid (2,4-D) and N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU). A medium containing 0.1 mgL⁻¹ 2,4-D and 0.25 mgL⁻¹ CPPU was optimal in terms of the number of primary SE explants forming se, the number of well-developed se per explant, and morphological appearance of the obtained se. These concentrations allowed SE to progress through three cycles, whereas at higher concentrations of 0.2 mgL⁻¹ 2,4-D and 0.5 mgL⁻¹ CPPU, only two cycles were achieved. Histological analysis revealed that secondary se are formed both directly and indirectly. Secondary SE readily germinated and converted into plantlets. Induction of cyclic SE contributes to the conservation efforts of this endangered medicinal plant and expands the spectrum of in vitro developmental pathways described in centaury—an emerging model in developmental biology.

中文翻译：

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半人马座红细胞的次生体细胞胚发生

体细胞胚发生（SE）是一个发育过程，在此过程中，植物体细胞在合适的条件下会产生可发育为体胚（se）的胚发生细胞。SE是植物体外繁殖的最重要方法，具有基础和应用意义。SE可以从不同的组织和器官中诱导出来，但是当将se用作外植体时，该过程被认为是继发性SE或环状SE。我们通过应用2,4-二氯苯氧基乙酸（2,4-D）和N-（2-氯-4-吡啶基）-N'-苯基脲（CPPU）诱导了在半人马座中的继发性SE 。含有0.1 mgL ^-1 2,4-D和0.25 mgL ^-1的培养基从形成se的主要SE外植体的数量，每个外植体成熟的se的数量以及获得的se的形态外观方面来看，CPPU是最佳的。这些浓度允许SE进行三个循环，而在0.2mgL ^-1的2，4-D和0.5mgL ^-1的CPPU的较高浓度下，仅实现了两个循环。组织学分析表明，二次SE直接和间接形成。次生SE容易发芽并转化为幼苗。环状SE的诱导有助于这种濒临灭绝的药用植物的保护工作，并扩大了在世纪中所描述的体外发育途径的谱图，该方法是发育生物学中的新兴模型。