Comparison of conventional and temporary immersion systems on micropropagation (multiplication phase) of ''.

The aim of this study was to improve the quality of the micropropagated Haw. plants cultured in temporary immersion bioreactors (TIS) comparing them with those produced through conventional semisolid-solid tissue culture system (SS). The Recipient for Automated Temporary Immersion (RITA) bioreactor was used as TIS in this work. The effect of different culture conditions, such as explants density, genotype, and duration of the incubation stages, were analyzed. The growth and morphological parameters measured for the in vitro cultured plants were: plant height, number of new leaves, number of shoots/explants, growth index (GI), dry mass content, and water content. In all experiments, it was observed that plantlets cultivated in the TIS grew larger than those cultivated in SS. Analyzing all the parameters used in this study, the results showed that RITA bioreactor generates a better shoot production and a better GI when using 20 plantlets per container. The number of shoots increased with time of culture (60 days) in both systems. However, the shoots and plantlets cultivated in TIS grew bigger and showed better quality (did not present necrosis in the leaves) than the ones cultured in SS. This study provides experimental evidence that the application of TIS for micropropagation of is a viable option for the production of high-quality shoots for reforestation purposes.