In vitro Symbiotic Seed Germination of Dendrobium formosum Roxb. ex Lindl.

Abstract

Most studies on orchid symbiotic seed germination involve with terrestrial and temperate orchids. There are few reports on association between epiphytic or tropical orchid species and symbiotic seed germination. This study was to determine the effect of mycorrhizal fungi on Dendrobium formosum symbiotic seed germination in vitro. Five mycorrhizal fungi isolated from D. formosum roots, were identified as genera Ceratobasidium (DFRN02), Cylindrocarpon (DFRN01 and DFRN03) and Epacris (DFRN04 and DFRN05). All fungal species were cultured into D. formosum seeds which were collected from provinces of Ranong and Chumphon in 2011-2012.,whilst on group of seeds were treated without fungal (control). After 3 months sowing, seeds of all treatments germinated over 60%. The germination (%) of DFRN02 treatment was significantly higher than other groups after 4 months sowing, followed by treatments of DFRN04, DFRN05 and DFRN01 respectively. The results indicates that Ceratobasidium sp. (DFRN02) can be a potential mycorrhizal fungus for D. formosum symbiotic seed germination and therefore for the conservation of this threatened orchid.