Protocol for asymbiotic germination and initial protocorm development of Brazilian Cerrado native orchids

Abstract Due to the extractivism Orchidaceae presents high vulnerability, needing measures for the conservation of its species. The aim of this study was to determine a protocol for germination and initial protocorm development of Cattleya nobilior, Cattleya lundii and Brassavola tuberculata for seed disinfestation and the use of culture media. Seeds were disinfested in 0.8% NaClO solution by 5 min or 15 min, receiving or not triple-wash. They were then sowing in MS, 1/2 MS, K or VW culture media. Subsequently, they were transferred to growth room with controlled temperature and photoperiod. The percentage of germination and initial development of the species studied were evaluated 45 days after sowing. For all species, the seeds disinfested by 5 min and submitted to the triple-wash showed higher germination percentage. Thus, is recommended the use of the 5 min disinfestation time, followed by the practice of triple-wash and sowing in 1/2 MS medium, for the germination and in vitro initial establishment of C. nobilior and B. tuberculata (%G = 100 and 72.8% and seedlings in stages 3 and 2, respectively). For C. lundii, sowing should be done in KC medium, with 5 min disinfestation and triple-wash (%G = 95.8% and seedlings in stage 2).