In vitro leaf anatomy, ex vitro photosynthetic behaviors and growth of Ilex paraguariensis plants obtained from temporary immersion systems

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

Montreal

Congreso; Plant Biology 2010; 2010

American Society of Plant Biologists and Canadian Society of Plant Physiologists.

In vitro established nodal segments of Ilex paraguariensis St. Hil. were subcultured in semisolid (agar) medium, continuous stationary liquid medium (polyurethane bridges) and temporary immersion system (TIS) for 4 weeks. Comparisons of leaf anatomy were made between regenerated leaves from the different system of micropropagation and those originated from plant growing under greenhouse conditions. The evaluation of ex vitro photosynthetic behaviors and growth was made between plantlets obtained by TIS and conventional rooting of softwood cuttings. Shoot in TIS produced thicker leaf due to an increase of spongy parenchyma and lower stomatal frequency than did those in semisolid and continuous liquid medium. The anatomic performance of leaf from TIS was similar to that one grown in greenhouse. During ex vitro acclimatization, plants from TIS had substantial higher photosynthetic rates than plants obtained by rooting of softwood cuttings in a nursery. Although, the rise of photosynthetic rate was accompanied by an increment of transpiration in detriment of the WUE, this fact did not affect the ex vitro survival. The results obtained in the present study confirm the potential use of temporal immersion system for the massive production of I. paraguariensis plants with anatomical and physiological features similar to those obtained by conventional propagation.