Stasolla Claudio
Department of Plant Science, University of Manitoba, Winnipeg, Canada.
Methods Mol Biol. 2006;318:87-99. doi: 10.1385/1-59259-959-1:087.
Generation of somatic embryos in spruce is achieved through the execution of five steps designated as: (1) induction of embryogenic tissue, (2) maintenance of embryogenic tissue, (3) embryo development, (4) embryo maturation, and (5) conversion into plants. Depending on species and genotypes within the same species, each step must be optimized for obtaining maximum results. In general, embryogenic tissue is generated from immature and mature zygotic embryos and maintained in either liquid or solid conditions in the presence of plant growth regulators auxin and cytokinin. Initiation of embryo development in suspension cultured is induced by removal of plant growth regulators, whereas continuation of development and completion of maturation require applications of abscisic acid and imposition of a desiccation period. Both treatments are needed for conferring morphological and physiological maturation to the embryos. Mature somatic embryos are germinated in the absence of plant regulators and embryo conversion (i.e., formation of a functional shoot and root, occurs after a few weeks in culture).
（1）胚性组织的诱导；（2）胚性组织的维持；（3）胚的发育；（4）胚的成熟；（5）转化为植株。根据物种以及同一物种内的基因型不同，必须对每个步骤进行优化以获得最佳结果。一般来说，胚性组织由未成熟和成熟的合子胚产生，并在植物生长调节剂生长素和细胞分裂素存在的情况下，在液体或固体条件下维持。悬浮培养中胚发育的起始是通过去除植物生长调节剂来诱导的，而发育的持续和成熟的完成则需要施加脱落酸并经历一个干燥期。这两种处理对于使胚获得形态和生理成熟都是必需的。成熟的体细胞胚在没有植物调节剂的情况下萌发，胚的转化（即形成功能性的芽和根）在培养几周后发生。
