Morpho-histological characterization of the somatic embryogenesis in guava (Psidium guajava L.) cv. Red Dwarf Cuban EEA-1840

Due to the scarce information on the morphological and histological characterization of the somatic embryogenesis (EmbS) of guava, it was proposed to study these aspects on embryogenic callus (EC) in the induction, EC and somatic embryos (ES) in the multiplication and ES in the maturation and germination. The EmbS was performed following the protocols of Vilchez et al. (2002), Vilchez et al. (2004) and Vilchez and Albany (2015). The histological study revealed that ES was indirect and low frequency, showing an intermediate callus phase prior to the formation of differentiated embryogenic structures from the epidermal and sub-epidermal tissues of the immature zygotic embryo. In the multiplication, two types of proliferating tissues were evidenced, one formed by a meristematic tissue and another located at the base of the ES differentiated in torpedo-elongated and cotyledon. During the maturation, ES showed a well-differentiated incipient vascular tissue and in the germination they were characterized by having "pear-shaped" similar to other dicotyledonous woody angiosperms.