Initially, the small and densely stained meristematic cells (most of them were less than 20 - 30 µm in diameter) were
originated from the epidermal cell layers (Fig. 2A). Generally, the somatic embryos (SEs) developed after several layers of meristematic cells were formed (Fig. 2B). Developing embryos were composed of small embryonic cells, and these cells also had densely stained cytoplasm (Fig. 2C). The both adaxial sides and abaxial sides of leaf explants developed meristematic cells, and these meristematic cells further proliferated and became nodular masses containing embryogenic cells (Fig. 2E). Subsequently, these embryogenic masses developed somatic embryos from their outer cell layers (Fig. 2F).