Cultura de tecidos e conservação in vitro de Passiflora foetida L.

Abstract

The genus Passiflora occurs mainly in tropical regions, and Brazil is na important diversity Center. Passiflora foetida L. is a wild species with ornamental and medicinal potential. The goal of this work was the establishment of tissue culture systems and cryopreservation for P. foetida. Stem explants were excised from primary cultures obtained from plantlets derived from in vitro germination. Nodal and internodal segments were inoculated on MSM medium supplemented with different concentrations of NAA, PIC, TDZ and BAP, used alone or in combination with NAA, and maintained in the presence or absence of light. The production of shoots, calluses and adventitious roots was observed, according to the type and concentration of growth regulator and the culture condition. Plant production occurred via direct and indirect organogenesis in response to BAP, whereas the formation of non-morphogenic calluses was observed from both explants in response to PIC. The production of adventitious roots occurred in response to NAA. In the view of root production on solid medium, internodal segments were inoculated on liquid medium supplemented with different auxins and maintained under continuous immersion or on filter-paper bridges. The highest root multiplication rate was observed from internodes maintained on filter-paper bridge in response to NAA. Root segments excised from primary cultures were also used aiming at shoot production and root multiplication. However, we only observed buds formation, without shoot development. In addition, proliferation capacity of root segments inoculated on medium supplemented with NAA was lower than the observed from internodes cultivated at the same conditions. In this work, we also tested different cryopreservation protocols for shoot tips of P. foetida through vitrification and encapsulation-vitrification. Post-freezing recovery was only observed from encapsulated explants which were exposed to the vitrification solution PVS2 for 120 minutes. In the view of the medicinal potential described for P. foetida, the different culture systems developed in this work will provide sources of material for the evaluation of distinct biological activities.