title: In vitro propagation and reintroduction of the endangered Renanthera imschootiana Rolfe.
abstract: Renanthera imschootiana Rolfe is an endangered tropical epiphytic orchid that is threatened with extinction due to over-collection and the loss of suitable habitats. In vitro propagation is a useful way to mass produce plants for re-establishment in the wild and for commercial propagation. Seeds collected 150 days after pollination (DAP) were the optimum stage for in vitro culture. Seed germination reached 93.1% on quarter-strength MS (i.e., MS containing a quarter of macro- and micronutrients) medium containing 0.5 mg l(-1) α-naphthaleneacetic acid (NAA), 20% coconut water (CW), 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 1.0 g l(-1) activated charcoal (AC). Quarter-strength MS medium supplemented with 1.0 mg l(-1) BA, 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 10 g l(-1) sucrose and 20% CW was suitable for the sub-culture of protocorm-like bodies (PLBs) in which the PLB proliferation ratio was 2.88. Quarter-strength MS medium containing 1.0 mg l(-1) NAA, 1.0 g l(-1) peptone, 100 g l(-1) banana homogenate (BH), and 1.0 g l(-1) AC was suitable for plantlet formation and 95.67% of plantlets developed from PLBs within 60 days of culture. Hyponex N016 medium supplemented with 0.5 mg l(-1) NAA, 1.0 g l(-1) peptone, 20 g l(-1) sucrose, 150 g l(-1) BH, and 1.0 g l(-1) AC was suitable for the in vitro growth of plantlets about 2-cm in height. Plantlets 3-cm in height or taller were transplanted to Chilean sphagnum moss, and 95% of plantlets survived after 60 days in a greenhouse. Three hundred transplanted of seedlings 360-days old were reintroduced into three natural habitats. Highest percentage survival (79.67%) was observed in Yuanjiang Nature Reserve two years after reintroduction, followed by Huolu Mountain forest park (71.33%). This protocol is an efficient means for the large-scale propagation and in vitro and in vivo germplasm conservation of R. imschootiana.
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Kunlin
authors.initials: K
authors.lastname: Wu
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Songjun
authors.initials: S
authors.lastname: Zeng
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Danni
authors.initials: D
authors.lastname: Lin
authors.affiliation: Kagawa-ken, Japan.
authors.forename: Jaime A
authors.initials: JA
authors.lastname: Teixeira da Silva
authors.affiliation: Flower Research Institute of Guangxi Academy of Agricultural Sciences, Nanning, China.
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Bu
authors.affiliation: Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Jianxia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of South China Agricultural Plant Molecular Analysis and Gene Improvement, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Duan
mesh_terms: D003470:Culture Media / Q000737:chemistry; D046508:Culture Techniques; D056727:Endangered Species; D018525:Germination; D029595:Orchidaceae / Q000254:growth & development*; D010641:Phenotype; D036226:Seedlings / Q000254:growth & development; D012639:Seeds / Q000254:growth & development
chemical_list: D003470:Culture Media