Leaf anatomical and histological features of Ilex paraguariensis under different in vitro shoot culture system

MROGINSKI, L.; GONZÁLEZ, A.; LUNA, C.; SANSBERRO, P.

PLANT CELL TISSUE AND ORGAN CULTURE

SPRINGER

Año: 2017 vol. 129 p. 457 - 467

0167-6857

Ilex paraguariensis: (Aquifoliaceae) is an evergreen tree traditionally used to prepare a caffeine-rich infusion that has several medicinal properties. The in vitro propagation of this species has been studied as an alternative to conventional methods such as cuttings and seedlings.The in vitro culture environment consists of closed flasks with high relative humidity, reduced gas exchange and low luminosity conditions, which may induce physiological,anatomical and histological disruption in the cultivatedplants. The occurrence of anatomical and histological alterations to the leaves of I. paraguariensis was examined in plants cultivated under greenhouse and different in vitro conditions. The variations in the microclimate inside theculture vessels generated by the different treatments tested affected the anatomy and histology of I. paraguariensis leaves by causing alterations in their architecture, thickness,vascularization and stomatal differentiation. A temporary immersion system was the best treatment for conserving the anatomical and histological features of the leaves.This treatment led to the lowest stomatal index and an extensive system of intercellular spaces that were similarto the characteristics developed under external environment conditions. Consequently, more than 80% of rooted plantlet transferred to pots were successfully rusticated. Plants from temporary immersion had greater photosynthetic rates due to a higher stomatal conductance.