In Vitro Growth Optimization and Acclimatization Techniques for Cattleya cernua (Lindl.)

Orchids exhibit remarkable diversity in terms of form, color, and fragrance, and are highly valued for their ornamental potential. In the Brazilian Cerrado, several native epiphytic species, including Cattleya cernua (Lindl.), are increasingly threatened by habitat loss and uncontrolled wild harvesting, leading to significant genetic erosion. In this context, conservation strategies and the development of optimized in vitro culture protocols are essential for preserving these species. This study optimized in vitro growth and established an acclimatization protocol for C. cernua by evaluating the effects of salt and sucrose concentrations, plant flour supplementation, and substrate types and fertilizer levels on acclimatization performance. Results indicated that the MS medium at 25% supplemented with 10 g L−1 sucrose promoted the greatest shoot growth, number of leaves, and pseudobulb formation. The addition of cashew nut flour at 10 g L−1 significantly enhanced both shoot and root development, increasing leaf and root numbers compared to other treatments. Data showed that coconut fiber, even without fertilization, supported high survival rates and robust plant growth. Collectively, these findings demonstrate that the in vitro growth of Cattleya cernua is most effectively achieved using MS medium at 25% strength supplemented with 10 g L−1 sucrose and 10 g L−1 cashew flour, followed by acclimatization in coconut fiber without additional fertilization. This protocol represents an efficient, sustainable strategy for propagating and conserving this native Cerrado orchid species.