Dendrobuim friedericksianum Rchb. f. is native orchid found in the Eastern region of Thailand, especially Chanthaburi Province. Recently, the decreasing rate of natural breeding has resulted in decreasing number of orchids, which leads to a much higher risk of extinction in the forest of Chanthaburi Province. The study on in vitro preservation was a means of conservation of the genetic diversity of this orchid strain. This study consisted of two experiments. The first experiment was the in vitro preservation of seed and protocorm of D. friedericksianum Rchb. f. in liquid nitrogen. The second experiment was to study the effect of supplementation of sucrose, mannitol and sorbitol on Modified Vacin and Went (1949) media at various concentrations Z0, 2, 4, 6, 8 and 10%) on slow growth of this orchid strain. The experiments were conducted at the plant tissue culture laboratory, Faculty of Agricultural Technology, Rambhai Barni Rajabhat University.
