In cork oak (Quercus suber L.), recurrent embryogenesis is produced in vitro through autoembryony without exogenous plant growth regulators (PGRs); secondary embryos appear on the embryo axis but seldom on cotyledons. Focusing mainly on the histological origin of neoformations, we investigated the influence of the embryo axis and exogenous PGRs on the embryogenic potential of somatic embryo cotyledons. Isolated cotyledons of somatic embryos became necrotic when cultured on PGR‐free medium but gave secondary embryos when cultured on media containing benzyladenine and naphthaleneacetic acid. Cotyledons of cork oak somatic embryos are competent to give embryogenic responses. Isolated cotyledons without a petiole showed a lower percentage of embryogenic response than did those with a petiole. In petioles, somatic embryos arose from inner parenchyma tissues following a multicellular budding pattern. Joined to the embryo axis, cotyledons did not show morphogenic responses when cultured on PGR‐free medium but revealed budlike and phylloid formations when cultured on medium with PGRs. The different morphogenic behavior displayed by somatic cotyledons indicates an influence of the embryo axis and indicates a relationship between organogenic and embryogenic regeneration pathways.

中文翻译：

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Quercus suberL 体细胞胚胎子叶器官发生和胚胎发生反应的组织学。

在软木橡木 (Quercus suber L.) 中，通过自体胚胎在体外产生反复胚胎发生，无需外源植物生长调节剂 (PGR)；次生胚出现在胚轴上，但很少出现在子叶上。主要关注新形成的组织学起源，我们研究了胚胎轴和外源 PGR 对体细胞胚胎子叶胚胎发生潜力的影响。分离的体细胞胚子叶在不含 PGR 的培养基上培养时会坏死，但在含有苄基腺嘌呤和萘乙酸的培养基上培养时会产生次级胚。软木橡木体细胞胚胎的子叶能够产生胚胎发生反应。与有叶柄的子叶相比，没有叶柄的分离子叶显示出较低的胚胎发生反应百分比。在叶柄中，体细胞胚胎按照多细胞出芽模式从内部薄壁组织中产生。连接到胚轴，子叶在无 PGR 培养基上培养时没有表现出形态发生反应，但在有 PGR 的培养基上培养时显示出芽状和叶状形成。体细胞子叶所表现出的不同形态发生行为表明胚胎轴的影响以及器官发生和胚胎发生再生途径之间的关系。