Micropropagation of Syngonanthus elegantulus

Abstract

The species Syngonanthus elegantulus Ruhland is an important native plant used as cut flowers, but extractive exploration has caused the endangered status of this plant. Therefore, the objective of this study was to establish a protocol of the micropropagation of S. elegantulus. To this end, seed germination was tested in media containing different concentrations of WPM salts. For plantlet establishment, MS and WPM media were evaluated with 50 and 100% of the salt concentrations. Different the sucrose levels in the WPM medium were also evaluated. For multiplication, the plantlets were inoculated in WPM media with 0.0, 0.5, 1.0, 2.0 and 4.0 mg L-1 TDZ and 0.0, 0.5 and 1.0 mg L-1 NAA in all possible combinations. The pre-acclimatization effect was tested in the plantlets using the following substrates: sand, PlantmaxTM and vermiculite. The concentration of the medium did not influence the percentage of germination, but the germination speed index was inversely proportional to the nutrient addition to the culture medium. The best medium for plantlet establishment was WPM at the original salt concentration plus 17 g L-1 sucrose. The addition of 0.5 and 1.0 mg L-1 NAA is recommended for callus induction. The highest number of shoots was obtained in the presence of 1.0 mg L-1 TDZ or the combination of 1.0 mg L-1 TDZ with 0.5 mg L-1 NAA. S. elegantulus presented higher survival when acclimatized directly in sand.