Micropropagation of Campomanesia xanthocarpa O. Berg (Myrtaceae), a medicinal tree from the Brazilian Atlantic Forest

Key message Our study shows for the first time a complete guabiroba micropropagation system with acclimatized plants. BA was the best plant growth regulator for multiplication and IBA for rooting. Campomanesia xanthocarpa O. Berg (Myrtaceae), popularly known as guabiroba, is a woody species native to Brazil, important for its potential as a medicinal plant and fruit tree. For the first time, this study shows a complete system of micropropagation for this species. For this, nodal segments with two axillary buds each were used as starting material. Plant Preservative Mixture™ (0.1%) added to culture media was efficient in controlling contamination throughout the culture process. Two formulations of culture medium were compared for in vitro establishment. 2-Isopentenyladenine, 6-benzyladenine, kinetin and zeatin were tested during the multiplication step. Woody plant medium (WPM) was appropriate for all culture steps and, during the multiplication process, 2.2 µM BA induced the best numbers of new shoots per explant during three subcultures (3.0–3.5 per month). For rooting of microcuttings, a rate of 53% was reached in the WPM supplemented with 4.9 µM indol-3-butyric acid. A plastic box containing a mixture of commercial substrate and vermiculite (1:1 v/v) was used for plantlet acclimatization, allowing 52% of survival after two months. In conclusion, a complete micropropagation protocol was developed providing healthy plants. Further studies are needed to improve multiplication and survival rates.