松柏类植物体细胞胚胎发生的研究进展

松柏类植物的体细胞胚胎发生既是繁育的一种手段，又是研究胚胎发育过程中结构、生理和分子事件的一种重要的模式系统。整个体细胞胚胎发生过程主要包括3个步骤：胚性组织的诱导和增殖、体细胞胚的成熟以及体细胞胚的萌发和转换。过去为了提高胚胎发育过程所做的努力主要都集中在胚的成熟阶段，这是因为一直认为能否成功再生的关键在于胚发育成熟阶段的处理。然而，在过去几年里,结合生理生化以及分子生物学的研究发现，胚胎发生的早期阶段对于完成整个发育过程也是至关重要的，早期阶段培养条件的优化可以显著提高培养过程中体细胞胚的数量和质量。此外，萌发过程培养条件的调节对于提高成熟体细胞胚的萌发率和转换率也很重要。因此，这些新的研究成果对于改善松柏类植物体细胞胚胎发生中的胚的诱导率和转换率低的现象具有重要的意义。

Recent Advances in Conifer Somatic Embryogenesis

Somatic embryogenesis of coniferous species is used both as a means of propagation and as a valuable model system for investigating the structural, physiological, and molecular events occurring during embryo development. The whole embryogenesis is composed of three steps: induction and proliferation of embryogenic tissue, somatic embryo maturation, and somatic embryo germination and conversion. In past, attempts for improving the whole embryogenesis procedure were made almost during the maturation stage, because of the assumption that successful regeneration would be related to treatments provided during the development of the embryos. However, in the last several years, studies demonstrated that the early events in embryogenesis were also crucial for the completion of the overall embryogenic program, implemented by physiological, biochemical, and molecular studies. Manipulation of the culture conditions early in the process can increase both number and quality of the embryos. Furthermore, adjusting the medium can also enhance germination and conversion frequencies of somatic embryos matured. These new findings are important for improving induction and conversion frequencies in conifer somatic embryogenesis.