PLANT GROWTH REGULATORS, LICORICE EXTRACT, AND SALTS USED IN MEDIA FOR MICROPROPAGATION OF GARDENIA JASMINOIDES

Abstract

The study for improving the multiplication and rooting systems of Gardenia jasminoides cv. veitchii ensued in 2020–2021 at the Department of Horticulture, College of Agriculture, University of Kerbala, Kerbala, Iraq. The first experiment comprised multiplication, using Benzyl adenine (BA) at the concentrations of 0, 2, 4, and 6 mg L-1 and licorice extract at the concentrations of 0, 1, 2, and 3 g L-1. The second experiment involved the rooting system, including cultivation of gardenia, shoots on MS media with different formulations, i.e., MS media with half strength of basal salts, and a) IBA (0, 0.5, 1, 1.5 mg L-1), b) licorice extract concentrations ( 0, 1, 2, 3 g L-1), MS medium with the full strength of basal salts, c) IBA (0, 0.5, 1, 1.5 mg L-1), and d) licorice extract (0.1, 2, 3 g L-1). The results showed the superiority of benzyl adenine (4 mg L-1) in achieving the highest number of shoots per plant, and the concentration of 2 mg L-1 showed superior in giving the maximum shoot length and the number of leaves per plant. The licorice extract (2 g L-1) achieved the highest number of shoots per plant, while the concentration of 3 gm L-1 proved superior in reaching the maximum shoot length and number of leaves per plant. The Indole 3-butyric acid- IBA (1 mg L-1) revealed the highest rooting percentage, root length, and root dry weight, with IBA (2 mg L-1) being the highest root number. Also, licorice extract (3 g L-1) supplemented to the media with half strength of basal salts displayed superior rooting percentage, root length, and root dry weight.