The technique of germinating orchid seeds in vitro has been used since the beginning of the last century. Nevertheless, the available knowledge regarding the nutritional composition of culture media that favor in vitro germination and growth of orchids is still scarce. Cattleya bicolor is a Brazilian threatened orchid species and very little is known about its seed germination and growth in vitro. For that reason, this study aimed at analyzing the influence of the culture medium on the in vitro germination of Cattleya bicolor seeds, on the initial development of its protocorms until they form seedlings, and on seedling growth during the first twelve months of in vitro culture. The results revealed that the Vacin & Went is the ideal culture medium for seed germination and initial seedling development of Cattleya bicolor in vitro. It is recommended that after six months the seedlings be transferred to MS or VW media, since they promote seedling development. They should be kept in one of those media until acclimatization. These results are very important for the optimization of propagation techniques of Brazilian orchid species.
asymbiotic germination; in vitro culture; media culture; orchid
