The population of many splendid orchids is reducing from their natural habitats at an alarming ra... more The population of many splendid orchids is reducing from their natural habitats at an alarming rate and their conservation is becoming a matter of global concern. Asymbiotic seed germination has been applied for ex situ conservation of rare, endangered and threatened orchid taxa and could provide rapid means their multiplication. In the present study reported here, seeds of an epiphytic and rare orchid, Cymbidium eburneum were germinated asymbiotically in different basal media viz., Murashige and Skoog (MS), Knudson C, Mitra et al. (Mitra), Gamborg et al. (B 5) and Nitsch. The highest germination rate was observed in Mitra medium, whereas the development of the protocorms was found to be best in MS medium. Effects of growth regulators viz., indole-3 acetic acid (IAA), a-naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), thidiazuron (TDZ), 6-benzyl aminopurine (BAP) and kinetin (Kn) both singly and in combination incorporated in the MS medium were studied on growth and development of seedlings. It was observed that MS medium nourished with 15 lM each of BAP and NAA in combination was found to enhance shoot number and length, and root number and length in the seedlings. The rooted seedlings were successfully acclimatized.
Cryopreservation of the threatened orchid Cymbidium eburneum L. was successfully achieved using e... more Cryopreservation of the threatened orchid Cymbidium eburneum L. was successfully achieved using encapsulation-vitrification and vitrification. Comparing the two methods tested, it was observed that regeneration of protocorms cryopreserved using encapsulation-vitrification was higher than with vitrification. To achieve optimal regrowth after cryopreservation, protocorms were precultured for 24 h with 0.2 M sucrose for vitrification and with 0.7 M sucrose for encapsulation-vitrification, reaching 60 percent and 70 percent regeneration, respectively. With both techniques employed, a 20 min exposure duration to Plant Vitrification Solution 2 (PVS2) led to optimal regeneration after cryopreservation. A maximum of 66 percent regeneration was achieved after cryopreservation using encapsulation-vitrification, whereas it was only 50 percent after cryopreservation using vitrification. The same regeneration pattern was observed with protocorms cryopreserved using both techniques employed. This...
In Vitro Cellular & Developmental Biology - Plant, 2013
A successful cryopreservation protocol for the longterm conservation of protocorms of two threate... more A successful cryopreservation protocol for the longterm conservation of protocorms of two threatened and vulnerable orchids, Cymbidium eburneum Lindl. and Cymbidium hookerianum Rchb. f., was developed using encapsulationdehydration. Protocorms were osmoprotected in liquid Murashige and Skoog medium (MS) containing 0.7 M sucrose for 20 h at 25±2°C on a rotary shaker, and incorporated into an encapsulation matrix [consisting of 3% (w/v) sodium alginate and 100 mM CaCl 2 ]. The encapsulated protocorms, which were desiccated in a laminar airflow cabinet for 6 h, were able to withstand cryostorage in liquid nitrogen. Maximum regeneration into complete plantlets (72% for C. eburneum and 70% for C. hookerianum) of the cryostored, encapsulated protocorms was obtained using MS medium containing 3% sucrose and 0.8% agar. Using this protocol of cryopreservation, long-term preservation for ex situ conservation of these two threatened orchids can be accomplished.
The population of many splendid orchids is reducing from their natural habitats at an alarming ra... more The population of many splendid orchids is reducing from their natural habitats at an alarming rate and their conservation is becoming a matter of global concern. Asymbiotic seed germination has been applied for ex situ conservation of rare, endangered and threatened orchid taxa and could provide rapid means their multiplication. In the present study reported here, seeds of an epiphytic and rare orchid, Cymbidium eburneum were germinated asymbiotically in different basal media viz., Murashige and Skoog (MS), Knudson C, Mitra et al. (Mitra), Gamborg et al. (B 5) and Nitsch. The highest germination rate was observed in Mitra medium, whereas the development of the protocorms was found to be best in MS medium. Effects of growth regulators viz., indole-3 acetic acid (IAA), a-naphthalene acetic acid (NAA), 2,4-dichlorophenoxyacetic acid (2,4-D), thidiazuron (TDZ), 6-benzyl aminopurine (BAP) and kinetin (Kn) both singly and in combination incorporated in the MS medium were studied on growth and development of seedlings. It was observed that MS medium nourished with 15 lM each of BAP and NAA in combination was found to enhance shoot number and length, and root number and length in the seedlings. The rooted seedlings were successfully acclimatized.
Cryopreservation of the threatened orchid Cymbidium eburneum L. was successfully achieved using e... more Cryopreservation of the threatened orchid Cymbidium eburneum L. was successfully achieved using encapsulation-vitrification and vitrification. Comparing the two methods tested, it was observed that regeneration of protocorms cryopreserved using encapsulation-vitrification was higher than with vitrification. To achieve optimal regrowth after cryopreservation, protocorms were precultured for 24 h with 0.2 M sucrose for vitrification and with 0.7 M sucrose for encapsulation-vitrification, reaching 60 percent and 70 percent regeneration, respectively. With both techniques employed, a 20 min exposure duration to Plant Vitrification Solution 2 (PVS2) led to optimal regeneration after cryopreservation. A maximum of 66 percent regeneration was achieved after cryopreservation using encapsulation-vitrification, whereas it was only 50 percent after cryopreservation using vitrification. The same regeneration pattern was observed with protocorms cryopreserved using both techniques employed. This...
In Vitro Cellular & Developmental Biology - Plant, 2013
A successful cryopreservation protocol for the longterm conservation of protocorms of two threate... more A successful cryopreservation protocol for the longterm conservation of protocorms of two threatened and vulnerable orchids, Cymbidium eburneum Lindl. and Cymbidium hookerianum Rchb. f., was developed using encapsulationdehydration. Protocorms were osmoprotected in liquid Murashige and Skoog medium (MS) containing 0.7 M sucrose for 20 h at 25±2°C on a rotary shaker, and incorporated into an encapsulation matrix [consisting of 3% (w/v) sodium alginate and 100 mM CaCl 2 ]. The encapsulated protocorms, which were desiccated in a laminar airflow cabinet for 6 h, were able to withstand cryostorage in liquid nitrogen. Maximum regeneration into complete plantlets (72% for C. eburneum and 70% for C. hookerianum) of the cryostored, encapsulated protocorms was obtained using MS medium containing 3% sucrose and 0.8% agar. Using this protocol of cryopreservation, long-term preservation for ex situ conservation of these two threatened orchids can be accomplished.
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