High-frequency shoot regeneration through transverse thin cell layer culture in Dendrobium Candidum Wall Ex Lindl.

The effects of seed maturity, media type, carbon source, and organic nutrient additives on seed germination, protocorm development, and plant growth of Paphiopedilum villosum var. densissimum Z. J. Liu et S. C. Chen were investigated. Micropropagation frequency was enhanced through the use of 200-day-old seed, Knudson C (KC) medium, and the presence of both glucose and coconut milk in the medium. The effects of various plant growth regulators on the frequency of shoot organogenesis in four Paphiopedilum species were also investigated. Explants of P. villosum var. densissimum and P. insigne (Lindl.) Stein incubated in the presence of 5 mg l -1 6-benzyladenine (BA) with 0.5 mg l -1 a-naphthalene acetic acid (NAA) and 0.2 mg l -1 BA with 0.1 mg l -1 NAA, respectively, showed a twofold increase in the frequency of shoot organogenesis. For explants of P. bellatulum (Rchb. f.) Stein and P. armeniacum S. C. Chen et F. Y. Liu, the combination of 5.5 mg l -1 BA with 0.5 mg l -1 NAA and 4 mg l -1 BA with 0.1 mg l -1 NAA, respectively, resulted in the highest frequencies of shoot organogenesis.

Section: Callus Inductionmentioning

confidence: 91%

In vitro propagation of four threatened Paphiopedilum species (Orchidaceae)

Long

Niemiera

Cheng

et al. 2010

“…Thus, mass propagation of this endangered species via somatic embryogenesis is an important approach for enlarging its population and for genetic reformation. For this purpose, we have established two efficient plant-regeneration systems for the mass propagation of D. candidum through somatic embryogenesis and organogenesis (Zhao et al 2007(Zhao et al , 2008. Based on the experimental system, it is possible to investigate molecular mechanisms involved in somatic embryogenesis in D. candidum.…”

Section: Introductionmentioning

confidence: 99%

Characterization and expression pattern analysis of DcNAC gene in somatic embryos of Dendrobium candidum Wall Ex Lindl.

Zhao

Wang

Sun

2011

Self Cite

The plant-specific ''no apical meristem'' genes are transcription factors that play diverse roles in plant development and stress responses. However, whether the gene family is also involved in somatic embryogenesis remains unknown, and no NAC family genes have been identified from orchid species. Here, we cloned and characterized a new member of NAC family from somatic embryos of Dendrobium candidum. Phylogenetic analysis indicated that DcNAC fell into the NAM subgroup based on similarities in protein sequence. Expression pattern analysis indicated that DcNAC exhibited a specific expression pattern in tissues examined, high levels of DcNAC mRNA was detected in protocorm-like bodies, and predominantly in the shoot apical meristem region as detected by in situ hybrization. Subcellular localization analysis showed that DcNAC protein is restricted in the nucleus through transient expression in Nicotiana benthamiana. Thus, DcNAC is the first NAC family gene isolated from orchid species, and our results provide the foundation for future investigations on the molecular mechanisms of somatic embryogenesis and for genetic improvement of Dendrobium candidum.

“…Dendrobium candidum Wall ex Lindl. is one of the most popular orchids in South and Southeast Asia, and valued for its attractive flowers and medicinal uses (Zhao et al 2007;Shiau et al 2005). Dried stems are used in traditional Chinese or folk medicine as Yin tonic to nourish the stomach, promote secretion of body fluids, prevent the development of cataracts, relieve throat inflammation and fatigue, reduce peripheral vascular obstruction, and enhance immunity (Bao et al 2001).…”

Section: Introductionmentioning

confidence: 99%

Cryopreservation of Dendrobium candidum Wall. ex Lindl. protocorm-like bodies by encapsulation-vitrification

Ming-hua

Senrong

2009

Protocorm-like bodies (PLBs) of Dendrobium candidum Wall. ex Lindl., orchid, were successfully cryopreserved using an encapsulation vitrification method. PLBs were precultured in liquid Murashige and Skoog (MS) medium containing 0.2 mg l -1 a-naphthalene acetic acid and 0.5 mg l -1 6-benzyladenine enriched with 0.75 M sucrose, and grown under continuous light (36 lmol m -2 s -1 ) at 25 ± 1°C for 5 days. PLBs were osmoprotected with a mixture of 2 M glycerol and 1 M sucrose for 80 min at 25°C and dripped in a 0.5 M CaCl 2 solution containing 0.5 M sucrose at 25 ± 1°C and left for 15 min to form Ca-alginate beads (about 4 mm in diameter). Then, these were dehydrated with a plant vitrification solution 2 (PVS 2 ) consisting of 30% (w/v) glycerol, 15% (w/v) ethylene glycol, and 15% (w/v) dimethyl sulfoxide in 0.5 M sucrose, pH 5.8, for 150 min at 0°C. Encapsulated and dehydrated PLBs were plunged directly into liquid nitrogen for 1 h. Cryopreserved PLBs were then rapidly re-warmed in a water bath at 40°C for 3 min and then washed with MS medium containing 1.2 M sucrose for three times at 10 min intervals. Within 60 days, plantlets with the cryopreserved PLBs developed normal shoots and roots, and without any observed morphological abnormalities, were obtained. The survival rate of encapsulated-vitrified PLBs was above 85%. Thus, this encapsulation-vitrification method was deemed promising for cryopreservation of PLBs of D. candidum.