Induction of Green Globular Bodies and Plantlet Regeneration in Adiantum trapeziforme

The green globular body is a unique, organized tissue that emerges from explants in pteridophyte tissue cultures. This article describes the first comprehensive study of in vitro regeneration of Adiantum trapeziforme via green globular bodies. Green globular bodies were induced on the rhizomes of sterile sporophytes of Adiantum trapeziforme. The green globular bodies were used as explants for additional proliferation and regeneration. The study evaluated the concentrations of basal salts, sucrose, tryptone, and plant growth regulators. The results showed that the presence of 6-benzyladenine inhibited the proliferation and regeneration of green globular bodies, whereas while increasing the concentration of α-naphthaleneacetic acid to 5 mg·L⁻¹ led to the highest proliferation and drastically impeded the development of green globular bodies. Hyponex No. 1 fertilizer, especially at 3 g·L⁻¹, with a proliferation rate up to 8.8 times, was a better salt source than Murashige and Skoog medium. In the sucrose concentration test, 30 g·L⁻¹ sucrose resulted in the highest proliferation rate. Furthermore, medium with a higher tryptone concentration inhibited the proliferation of green globular bodies. Green globular body differentiation medium containing 2 g·L⁻¹ Hyponex, 30 g·L⁻¹ sucrose, 2 g·L⁻¹ tryptone, and pH 5.8 resulted in the highest bud induction rate, averaging 18.6 buds. Paraffin sections were examined to observe the development of green globular bodies induced by the rhizome. In the soil containing perlite, 100% of regenerated shoots successfully formed roots during acclimation.