Plant regeneration from protocorm callus of V. planifolia. a. Protocorm-like structure (PLS) from seed on germination medium; bar = 1.5 mm. b. Embryogenic callus from PLS after transfer to callus induction medium; bar = 1 mm. c. Embryogenic/organogenic callus mass showing nodular compact structure (dashed arrow) and pale green zone (arrow) after 30 days of culture on A4 medium (i.e. CA4 d30 callus); bar = 750 μm. d. CA4 d90 callus with poorly-differentiated green structures (arrow); bar = 3 mm. e. CA4 d120 callus exhibiting poorly-differentiated green structures (black arrows); necrotic area can be seen (white arrow); bar = 2.5 mm. f. Protocorm - like body (PLB) in early stage of development with emerging shoot primordia (arrows) in 30-day-old embryogenic/organogenic callus on A10 medium (i.e. CA10 d30 callus); bar = 1 mm. g. CA10 d60 callus showing PLBs formed from shoot primordia; bar = 350 μm. h. CA10 d90 callusexhibiting cluster of PLBs and rooting; bar = 3.5 mm. i. CA10 d120 callusexhibiting PLB - derived plantlets; bar = 8.5 mm. j. Rooted plantlet on A5 medium 15 days after subculture; bar = 6.5 mm.