Synthetic Seed Production as a Tool for the Conservation and Domestication of Celastrus paniculatus: A Rare Medicinal Plant

Abstract

The black-oil tree (Celastrus paniculatus Willd) is a highly valued medicinal plant species belong to the Celastraceae family, known as Jyothishmathi in Ayurveda and Duhundu in Sri Lanka and grows as a perennial vine. It is an endangered medicinal plant species recorded in the red list of endangered fauna and flora of Sri Lanka in 1999. The seed oil of Celastrus paniculatus contains sesquiterpene alkaloids namely; celapagine, celapanigine, celapanine and celastrol, used in traditional system of medicine for various disorders and because of its high pharmaceutical value, plants are over exploited in natural habitats. Owing to poor seed germination and lack of successful vegetative propagation methods, domestication and commercial planting of this important medicinal plant species to meet the demand seems impossible. Therefore, it is of high importance to develop a reliable and efficient in vitro propagation to produce black oil plants for commercial use. In this study, it was attempted to produce synthetic seeds of Celestrus paniculatus via in vitro multiple shoot proliferation. Nodal segment explants were collected from freshly emerged age of sprouts, surface sterilized and cultured in Murashige and Skoog medium supplemented with different 6-benzylaminopurine (BAP) and Thidiazuron (TDZ) concentrations for shoot induction. The highest soot proliferation rate; 25 shoot tips/explant were observed with 0.1 mg/L TDZ. Induced shoot tips were used for synthetic seed production after encapsulating with BAP and a-naphthalene acetic (NAA) enriched sodium alginate. Shoot tip encapsulated beads produced with 4% sodium alginate were firm, clear, round and uniform in size and easy to handle. The influence of growth regulators (BAP and NAA) and storage period on the germination of encapsulated shoot tips was studied to evaluate the success of encapsulated shoot tips as a propagule. The beads germinated with 2 mg/L BAP and 0.2 mg/L NAA provided 80% in vitro germination percentage. Shoot tips of synthetic seeds remained green and healthy after storage at 5°C for a period of 8 weeks. Current findings suggest that encapsulated micro shoots (synthetic seeds) could be produced successfully, as the first step in domestication and conservation of Celastrus paniculatus. Further studies required on rooting of micro shoots, acclimatization and transferring of plantlets produced from synthetic seeds to in vivo conditions for domestication and conservation purposes.

Micropropagation, encapsulation, physiological, and genetic homogeneity assessment in Casuarina equisetifolia

“…Similarly, the optimized nutrient composition medium BA (5.0 μM) + NAA (0.5 μM) was found more appropriate for the conversion of encapsulated beads into the young shoot in C. equisetifolia in in vitro culture. Our results were according to the findings in Swertia chirayita (Kumar and Chandra, 2014 ), Urginea altissima (Baskaran et al, 2018 ), and Celastrus paniculatus (Fonseka et al, 2019 ). Unlike our study, CaCl 2 · 2H 2 O (75 mM) + Na 2 -alginate (3%) was used for obtaining ideal synthetic seeds in Rauvolfia serpentina (Gantait et al, 2022 ), and CaCl 2 · 2H 2 O (80 mM) + Na 2 -alginate (3%) in Solanum trilobatum (Shilpha et al, 2021 ).…”

Abscisic acid in preservation of Taraxacum pieninicum in the form of synthetic seeds in slow growth conditions

“…The simplest method to slow down the growth of the plant material is to lower the culture temperature (Divakaran et al 2006). Storage of synseeds at a reduced temperature was used to protect endangered species such as Celastrus paniculatus (Fonseka et al 2019), Ceropegia barnesii (Ananthan et al 2018), Cymbidium aloifolium (Pradhan et al 2016), Eclipta alba (Salma et al 2019), Mondia whitei (Baskaran et al 2015), Spilanthes acmella (Sharma et al 2009) and Withania coagulans (Rathore and Kheni 2017).…”

Conservation, Regeneration and Genetic Stability of Regenerants from Alginate-Encapsulated Shoot Explants of Gardenia jasminoides Ellis

“…In addition, high concentrations of sodium alginate (4 or 5%) or calcium chloride (200 mM), within an ion exchange with a duration of 30 min, resulted in the formation of hard-texture beads and delayed their germination [23]. On the other hand, lower concentrations of sodium alginate (1 or 2%) or calcium chloride (25 or 50 mM) produced weak structures with no define shape which disintegrated while being handled [45,60]. In general, it is concluded that 2-3% sodium alginate gel exposed for 30 min to 100 mM calcium chloride is an optimal combination for acceptable bead production and subsequent satisfactory germination response [29,30,61].…”

“…In the present study, the combination of 2.5% sodium alginate with 100 mM of calcium chloride for a 30 min complexation time resulted in the formation of high quality beads, easy to handle (hardness 0.27 ± 0.02 N), followed by an unimpeded germination response. The use for complexation 100 mM calcium chloride for 30 min has been reported for many woody plant species such as Photinia fraseri and Syringa vulgaris [47], Simmondsia chinensis [51], Rauvolfia tetraphylla [23], Acacia hybrids [31], Nerium oleander [47,50], Terminalia arjuna [62], grapevine rootstock '5BB' [19], Celastrus paniculatus [60], Viburnum dentatum [29], and several others.…”

“…This gradual decline may have derived from the obstructed respiration of encapsulated explants, probably due to the protective coating of the alginate matrix or from partial desiccation of explants during cold storage, causing a loss of moisture [19,43,50,[66][67][68][69]. Regeneration decline has also been observed after a short-term cold storage of artificial seeds in numerous woody plant species, among them in Rauvolfia tetraphylla [70], Decalepis hamiltonii [71], Cassia angustifolia [27], Nerium oleander [47,50], Citrus sinensis [52], grapevine rootstock 'Kober 5BB' [19], Rosa damascena trigintipetala [54], Celastrus paniculatus [60] and Viburnum dentatum [29].…”