Somatic embryogenesis offers many benefits for clonal propagation in large-scale plant production of conifers. A key rate-limiting step is the conversion from early-stage somatic embryos in pro-embryogenic masses (PEMs) to the maturation stage. Immature embryos in PEMs are present at different developmental stages, where some are unable to respond to the maturation treatment, thus limiting yields of mature embryos. Synchronization of early somatic embryo development in PEMs could greatly improve subsequent yields of mature embryos. A temporary immersion bioreactor designed for Norway spruce (Picea abies (L.) H.Karst.) was used in this study. Through a specific system for dispersion, connected tissue of PEMs, composed of immature embryos grown in liquid medium in the temporary immersion bioreactors or on solid medium as a control, was dispersed and redistributed in a more uniform spatial arrangement. It was demonstrated that development of mature embryos could be significantly stimulated by dispersion, compared to controls, in both medium types. Synchronization of maturation was evaluated by a statistical approach. The present study shows that the yield of mature embryos from dispersed PEMs was three to five times higher than that from non-dispersed controls in three of four cell lines of Norway spruce tested, both in bioreactors and on solid medium.

中文翻译：

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挪威云杉 (Picea abies (L.) H.Karst.) 体细胞胚胎在临时浸入式生物反应器中的改进和同步成熟。

体细胞胚胎发生为针叶树大规模植物生产中的克隆繁殖提供了许多好处。一个关键的限速步骤是从前胚胎发生团（PEM）中的早期体细胞胚胎向成熟阶段的转化。PEM 中的未成熟胚胎存在于不同的发育阶段，其中一些无法对成熟处理做出反应，从而限制了成熟胚胎的产量。PEM 中早期体细胞胚胎发育的同步可以极大地提高成熟胚胎的后续产量。本研究使用了为挪威云杉（Picea abies (L.) H.Karst.）设计的临时浸入式生物反应器。通过特定的分散系统，由在临时浸入式生物反应器的液体培养基或作为对照的固体培养基上生长的未成熟胚胎组成的PEMs的连接组织被分散并以更均匀的空间排列重新分布。结果表明，与对照相比，在两种培养基类型中分散可以显着刺激成熟胚胎的发育。通过统计方法评估成熟的同步性。本研究表明，在生物反应器和固体培养基上测试的挪威云杉细胞系中的四分之三中，分散的 PEM 成熟胚胎的产量比非分散对照的成熟胚胎产量高出三到五倍。