BIOSCIENCES BIOTECHNOLOGY RESEARCH ASIA, September 2021. Vol. 18(3), p. 533-542 Published by Oriental Scientific Publishing Company © 2021 This is an Open Access article licensed under a Creative Commons license: Attribution 4.0 International (CC-BY). *Corresponding author E-mail: dr.nsabbas@bcas.du.ac.in An Alternate Cost-effective Medium for In Vitro Regeneration of Therapeutically Important Ocimum citriodorum Vis. Anamika Tripathi 1 , N.S. Abbas 2 *, Amrita Nigam 1 , Sujata Bhardwaj 2 , Babeeta C Kaula 3 and Alka B Vadakan 4 1 School of Sciences, Indira Gandhi National Open University, Maidan Garhi, New Delhi, India. 2 Department of Botany, Bhaskaracharya College of Applied Sciences, University of Delhi, New Delhi-110 075, India. 3 Department of Botany, Zakir Husain Delhi College, University of Delhi, J.L.N. Marg, New Delhi-110002, India. 4 Department of Botany, Maitreyi College, University of Delhi, Bapudham complex, Chanakyapuri, New Delhi- 110021, India. http://dx.doi.org/10.13005/bbra/2938 (Received: 03 September 2021; accepted: 14 October 2021) A novel cost-effective in vitro regeneration protocol has been evolved for the therapeutically important Ocimum citriodorum Vis. In the present study, table sugar (3%) and isabgol (Psyllium husk) (3.5%) were used as an alternate source of carbon and gelling agent respectively in Murashige and Skoog’s (MS) medium. The explant used in the current study was nodal segment. A significant observation revealed that all the cultures resulted in shoot induction and maximum number of shoots/ culture (6.04) and their average length (2.15 cm) was obtained on modified MS-medium supplemented with table sugar, isabgol and BAP. However, best root induction (95.83%) was obtained on ½ MS-medium augmented with table sugar (3%) , isabgol (3.5%) and NAA. An increase in average number of roots per shoot (6.91%) as well as average root length (2.73 cm) was also observed in the same modified medium. The in vitro regenerated plantlets were successfully transferred to the field and no notable variation was observed in their morphology. The overall cost of culture medium for in vitro propagation of O. citriodorum Vis. was reduced significantly by 92.69% when agar and sucrose were replaced by isabgol and table sugar, respectively. Keywords: Cost-effective medium; Isabgol; Ocimum plants; Regeneration; Table sugar. Ocimum citriodorum Vis. (Lemon basil) is an important medicinal plant, abundant in volatile aromatic essential oils and is known to possess culinary properties 1,2 . It is an interspecific hybrid obtained between Ocimum basilicum and O. americanum. This herb is mainly cultivated in some parts of Asia and Africa not only for its essence but also as an important source of antioxidants. It is one of the most economically important spice used for flavor in many cuisines 3 . Due to its medicinal value, it has been used as anti-inflammatory agent 4 and to treat people suffering from premature ejaculation, delayed menstruation cycle and stomach spasms 5 . The oil of Ocimum is valued for its therapeutic properties and possess antimicrobial, nematocidal, fungistatic and insecticidal activities 6, 7 . The essential oils of Ocimum species have been reported to elicit a greater escape response against