Optimization of in vitro micropropagation of ethnomedicinally important underexplored plant Maytenus emarginata

Abstract

In vitro callus induction and shoot emergence protocols for Maytenus emarginata (Willd) Ding Hou. have been established using young leaves and stem explants of in vivo growing, one and half year-old plants. Plants were growing in the month of August 2016 at department of Botany, Ch. Charan Singh University, Meerut. However, explants were collected in the month of August, 2019. MS (Murashige and Skoog) medium and WPM (Woody Plant Medium), supplemented with different concentrations and combinations of plant growth regulators (PGRs) such as 0.5-2.0 mg/l Naphthalene acetic acid (NAA), 0.5-1.0 mg/l Benzyl Amino Purine (BAP), 2, 4-D (1.0-2.0 mg/l) and 1.0-1.5 mg/l Gibberellic acid (GA3) and temperature regimes were used for callus induction and shoot emergence. The presence of GA3 was found necessary for callus induction and shoot emergence from both explants (leaf and stem). The best response of callus formation from leaf explants was obtained at 24°C on WPM supplemented with 0.5 mg/l NAA+1.0mg/l BAP+1.5mg/l GA3 and MS medium supplemented with 2.0 mg/l NAA+ 0.5 mg/l BAP+ 1.0mg/l GA3. Stem explants exhibited best degree of callus induction only on MS medium supplemented with 0.5mg/l NAA+ 1.0 mg/l BAP+1.5 mg/l GA3. Light and temperature play very crucial role in shoot emergence because exposure of callus or nodal section of stem, to 12 hours dark period followed by 12 hours PAR (photosynthetically active radiation) at 27±2 °C induced shoot emergence on MS medium supplemented with 0.5mg/l NAA+1.0mg/l BAP+1.5 mg/l GA3 after 42 days. This is the first optimization report on tissue culture and medicinal use of callus of Maytenus emarginata.

Keywords

• BAP
• Callus
• GA3
• Maytenus emarginata
• NAA
• Shoot emergence