FACTORS AFFECTING BULBLET GROWTH OF Lilium sp. — AN UPSCALE MODELING OF EXPLANT PLACEMENT IN VITRO

In vitro culture techniques of lily bulbscales, evolved as an alternative to conventional methods for bulblet multiplication of lilies. In the technique, explants play a vital role, so the objective of this study was to establish an upscale model of lily bulb scale explant placement on culture medium to assess the influence on the regeneration and organogenesis process to influence the uniformity and increase bulblets size and to gain more information in relation to the rapid bulblet production in vitro. Hence, lily cultivar Stargazer bulb scale explants with adaxial surface deep (T₁), vascular tissue deep (T₂), and fully submerged (T₃) placement were cultured for 90 days on solid and in liquid culture media. In the results, vascular tissue deep explant placement (T₂) led to rapid regeneration (within two weeks), leaf and root formation (within four weeks), and bulblet appearance (within six weeks), and higher fresh weight of bulblets. Lily bulb scale explants subjected to adaxial surface deep (T₁) placement on culture medium in vitro had slower progress in regeneration and organogenesis, and explants subjected to fully submerged placement (T₃) failed to regenerate. In view of that, explant placement in or on the medium, chlorophyll content in the explant tissues and CO₂ within the glass vessel affect lily bulb scale explant regeneration and organogenesis in vitro.