In vitro germination and development of “Canelita” (Lycaste aromatica (Graham) Lindl.) in gravity immersion bioreactors

Abstract

The orchid Lycaste aromatica (Graham) Lindl. is known for its outstanding cinnamon aroma, which has caused its illegal extraction from its natural habitat. For this reason, procedures were developed for the asymbiotic seeds germination and seedlings development in a gravity immersion bioreactor (GIB) system. Four culture media were tested for in vitro germination: ½ Murashige and Skoog (MS), MS, ½ Knudson C 15 g L− 1 sucrose, Knudson C. The efficiency of the in vitro culture protocol using the semi-solid medium was compared and with four immersion frequencies of the GIB system in a liquid medium, using 30 mL of ½ MS medium per seedling. Germination began at eight weeks and lasted for six weeks. The best treatment was ½ MS with 161 germinated seeds. In 90 days, the cultures in bioreactors reached significant differences in the number of leaves (10 leaves), number of roots (4.7 roots), and seedling height (5.4 cm). However, the seedlings developed in the semi-solid medium reported a higher number of shoots (1.6 shoots) and root length (2 cm); furthermore, the bioreactor culture showed the highest photosynthesis rate (0.74 µmol CO2 g− 1 s− 1). The culture system in bioreactors is an excellent alternative to develop this species because it increases photosynthesis and the size of the seedlings, which favor their acclimatization.