High frequency somatic embryogenesis and synthetic seed production of the endangered species Swertia chirayita

Abstract

An efficient protocol for plant regeneration through somatic embryogenesis was established from in vivo leaf explants of Swertia chirayita, a critically endangered medicinal herb. The highest frequency (76%) of embryogenic callus was induced on Murashige & Skoog (MS) medium supplemented with 0.5 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L kinetin (Kn) from in vivo leaf explants. Globular somatic embryos were induced and further matured from such embryogenic calli by subsequent culture on the same medium. The highest number of somatic embryos (48.83 ± 4.6) was recovered from embryogenic calli derived from leaf explants after 6 weeks of culture. Synthetic seeds were produced by encapsulating of torpedo stage embryos in sodium alginate (4% W/V) gel, dropped into 100 mM calcium chloride (CaCl2 · 2H2O) solution. The synthetic seeds were germinated on MS medium. The highest frequency of synthetic seed germination (84%) was observed on MS medium supplemented with 1.0 mg/L BA and 0.5 mg/L NAA. Regenerants were successfully acclimatized under ex vitro condition. This is the first report on synthetic seed production of S. chirayita. Application of these protocols would be helpful in reducing stress in natural habitat, and in long-term storage of elite genotypes through synthetic seed production.

A Review of Swertia chirayita (Gentianaceae) as a Traditional Medicinal Plant

“…It is believed that the development of efficient micropropagation protocols, can guarantee an adequate supply of S. chirayita plants (devoid of environmental-imposed constraints) with subsequent reduction in uncontrolled harvesting pressure on wild populations. Several studies reported on micropropagation, somatic embryogenesis and acclimatization procedures with the capacity to produce many uniform S. chirayita clones throughout the year (Kumar and Chandra, 2013 , 2014 ; Kumar et al, 2014 ). As shown in Table 5 , micropropagation protocols have successfully been established for S. chirayita using different explants.…”

“…Due to its excessive over-exploitation from the natural habitat, narrow geographic occurrence (Bhat et al, 2013 ) and unresolved inherent problems of seed viability and seed germination (Badola and Pal, 2002 ; Joshi and Dhawan, 2005 ), alternative approaches for propagation and conservation are urgently required to avoid the possible extinction of this important species. Consequently, S. chirayita has been receiving increasing attention from a wide range of researchers as evident from the number of publications appearing in the literature (Chen et al, 2011 ; Nagalekshmi et al, 2011 ; Ghosh et al, 2012 ; Kumar and Chandra, 2013 , 2014 , 2015 ; Fan et al, 2014 ; Kumar et al, 2014 ; Sharma et al, 2014 , 2015 ; Padhan et al, 2015 ; Zhou et al, 2015 ). However, a comprehensive review detailing the documented ethnomedicinal uses, pharmacological properties and safety evaluation carried out on S. chirayita and identifying the existing knowledge gap is lacking.…”

In vitro organogenesis secondary metabolite production and heavy metal analysis in Swertia chirayita

“…Direct organogenesis in S. chirayita was investigated by different explants such as nodal explants [1], shoot tip [7], leaf explants [8] and immature seed cultures [9]. Efficient regeneration protocols from shoot tip of field grown plants and high frequency somatic embryogenesis and regeneration from synthetic seed has previously published [10,11]. Callus induction from different explants of Swertia angustifolia and indirect regeneration from calli in Swertia mussotti was reported respectively [12,13].…”

Utilization of Swertia chirayita Plant Extracts for Management of Diabetes and Associated Disorders: Present Status, Future Prospects and Limitations

“…Among them, Swertia chirayita, popularly known as "chirayata or chirayita", is considered to have diverse therapeutic properties, including anti-diabetic, anti-inflammatory, hypoglycemic, hepatoprotective, antibacterial, wound healing, antipyretic, antihelmintic, antioxidant and antitussive [12,13]. Large number of publications [14][15][16][17][18][19][20] in the research field clearly suggests the increasing importance and application of such important medicinal plant in various therapeutic fields. Brahmachari et al [21] clearly indicated Swertia genus as a rich sources of xanthones, flavonoids, irridoid, terpenoids and alkaloids.…”