Conservation of Dendrobium cruentum Rchb. f.

Conservation of plant genetic resources plays an important role to protect endangered species from genetic loss. In case of native Thai orchid species, Dendrobium cruentum Rchb. f. faces extinction problem because of various factors including over collection, deforestation, and climate change. Therefore, conservation of this species is needed. In this study, the different conservation aspects including natural growth habitat observation, seed germination, and long-term conservation by cryopreservation are described. From the experiment, observation of D. cruentum Rchb. f. natural habitat in Ko Phra Thong in Phangnga province of Thailand was done, and it was found that the optimum environment for D. cruentum Rchb. f. growth is in swamp forest as an epiphyte. In addition, specific host trees for this species were observed in Melaleuca cajuputi and Syzygium gratum. The quality of D. cruentum Rchb. f. seed is potentially affected by a number of standard practices associated with attempts to maximize growth in vitro by using seeds from 16-week-old capsule and cultured on modified VW agar medium to reach 80.6% seed germination. However, the long-term conservation was determined by using different cryopreservation techniques including encapsulation-vitrification, encapsulation-dehydration, V cryo-plate, and D cryo-plate with the same dehydration time at 60 min. The cryopreservation results showed that the highest seed germination by D cryo-plate technique was at 57.8%.