Cryopreservation of Dendrobium cruentum Rchb. f. Seeds by D Cryo-plate and V Cryo-plate Techniques

Abstract

Dendrobium cruentum Rchb. f. is a native Thai orchid species that has faced extinction because of its attractive characteristics. Consequently, conservation of this species is urgently needed. In this study, cryopreservation technique was applied to D. cruentum Rchb. f. seeds for long-term conservation. A successful protocol for D. cruentum Rchb. f. seed cryopreservation was developed by using D cryo-plate and V cryo-plate techniques. Seed viability was tested by TCC solution and 93.8 % of dyed seeds were shown. For cryo-plate technique, seeds were encapsulated over the cryo-plate by using 2 % (w/v) sodium alginate and polymerized with 100 mM CaCl2. Encapsulated seeds were desiccated by using a laminar airflow and PVS2 solution treatment with the same exposure time (0, 30, 60, 90, and 120 min). After cryopreservation, encapsulated seeds were cultured on modified VW agar medium. From the results, the maximum germination and regrowth percentage were observed; D cryo-plate technique with 60 min of dehydration time gave the highest germination (68.9 %) and regrowth (57.8 %). Thus, the excess of dehydration may cause the reduction of germination and plant regeneration. In conclusion, D cryo-plate technique proved to be appropriate for D. cruentum Rchb. f. seed cryopreservation.

Effect of Cryopreservation Method Supported With Biochemical Analyses in the Axillary Bud of Jewel Orchid, Ludisia Discolor

“…Within Cymbidium species, varied responses were documented when vitri cation technique was employed on different explants such as PLBs of C. nlaysonianum and Cymbidium Twilight Moon 'Day Light' endured well in 60 min and 80 min of PVS2 respectively, on ice, whereas optimum durations were documented for seeds to be 30 min for C. nlaysonianum and 60 min for C. goeringii and C. macrorhizon (Hirano et al 2011;Teixeira da Silva 2013;Rittirat et al 2019). By contrast, increased temperature is suitable for cryopreserved orchids to be su ciently dehydrated in Dendrobium cruentum, D. signatum and Paphiopedilum niveum (Chaireok et al 2016;Jitsopakul et al 2019;Prasongsom et al 2020;Soonthornkalump et al 2020).…”

Effect of Cryopreservation Method Supported with Biochemical Analyses in the Axillary Bud of Jewel Orchid, Ludisia discolor

“…In contrast, optimum durations were documented for seeds to be 30 min for C. finlaysonianum and 60 min for C. goeringii and C. macrorhizon [ 42 , 46 , 57 ]. By contrast, increased temperature is suitable for cryopreserved orchids to be sufficiently dehydrated in Dendrobium cruentum , D. signatum , and Paphiopedilum niveum [ 58 , 59 , 60 , 61 ].…”