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

Abstract

Lycaste aromatica (Graham) Lindl. orchid is known for its outstanding cinnamon aroma, which has caused its illegal and accelerated extraction from its natural habitat. For this reason, procedures were developed for asymbiotic seed germination and seedling development in a gravity immersion bioreactor (GIB) system. Four culture media were tested for in vitro germination: ½ Murashige and Skoog (MS) containing 15 g L−1 sucrose, MS, ½ Knudson C containing 15 g L−1 sucrose, and Knudson C. The efficiency of in vitro culture protocol using semi-solid medium was compared to four immersion frequencies of the GIB system in a liquid medium using 30 mL of ½ MS medium per seedling. Germination began at 8 wk and lasted for 6 wk. The best treatment was ½ MS with 81% seed germination. In 90 d, the GIB did not result in significant effects on most growth parameters, including number of leaves; number of roots and seedling height were not significantly different to those of seedlings developed in the semi-solid medium. However, seedlings developed in the semi-solid medium reported a higher number of shoots (1.6 shoots) and root length (2 cm). The GIB showed the highest photosynthesis rate (0.74 μmol CO2 g−1 s−1). The GIB could be an alternative to develop this species due to its increased photosynthesis and having stomatal function.