World Journal of Advanced Research and Reviews, 2020, 06(02), 103–109 World Journal of Advanced Research and Reviews e-ISSN: 2581-9615, Cross Ref DOI: 10.30574/wjarr Journal homepage: https://www.wjarr.com  Corresponding author: Mouaad Amine Mazri Copyright © 2020 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0. (R ESEARCH A RTICLE ) Effects of culture medium strength and antioxidants on adventitious bud multiplication, hyperhydricity and tissue browning of date palm cv. Aziza Bouzid Saida Elmaataoui 1 , Mouaad Amine Mazri 1, * , Reda Meziani 2 and Fatima Bouchiha 1 1 Institut National de la Recherche Agronomique, CRRA-Marrakech, UR Agro-Biotechnologie, Laboratoire de Biotechnologie Végétale, BP 533, Marrakech, Morocco 2 Institut National de la Recherche Agronomique, CRRA-Errachidia, UR Systèmes Oasiens, Laboratoire National de Culture des Tissus du Palmier Dattier, Avenue Moulay Ali Cherif, BP 2, Errachidia, Morocco. Publication history: Received on 01 May 2020; revised on 11 May 2020; accepted on 13 May 2020 Article DOI: https://doi.org/10.30574/wjarr.2020.6.2.0137 Abstract The effects of medium strength as well as different antioxidant types and concentrations on adventitious shoot bud multiplication, hyperhydricity and tissue browning of date palm cv. Aziza Bouzid were evaluated. Organogenic cultures of date palm cv. Aziza Bouzid were cultured on semi-solid Murashige and Skoog medium at half-strength (MS/2) or one- third-strength (MS/3), supplemented with 0.5 mg/L 2-naphthoxyacetic acid (NOA), 0.5 mg/L kinetin, and different concentrations of activated charcoal and polyvinylpyrrolidone (PVP). The findings of the present study showed that the use MS/3 media resulted in lower hyperhydricity rates than MS/2 media. Besides, activated charcoal significantly reduced tissue browning. The lowest rates of hyperhydricity (35%) and tissue browning (20%) were observed in MS/3 medium supplemented with 1.5 g/L activated charcoal. Interestingly, this culture medium showed also the highest number of adventitious shoot buds per explant (35.20), with a significant difference with all the other media (25.55- 30.15 adventitious shoot buds per explant). Increasing the concentration of activated charcoal to 2 g/L did not decreased the browning rate. The use of PVP alone showed tissue browning rates varying from 30 to 55% while combining PVP and activated charcoal showed browning percentages ranging from 20 to 30%. Shoot elongation and rooting were successfully achieved and plantlet were acclimatized and showed normal growth and development under the greenhouse conditions. Keywords: Date palm; Hyperhydricity; In vitro; Organogenesis; Regeneration; Tissue browning. 1. Introduction Date palm is a multipurpose plant species widely cultivated in the Middle East and North Africa (MENA) region. It belongs to the family Arecaceae (Palmae). Date palm is an economically important species mainly cultivated for its delicious and nutritious fruits. However, it is also used to create favorable microclimate for agriculture and as shelter in the extreme conditions of desert. Besides, date palm plants are used to make paper and fibers and to manufacture handicraft products, thus contributing to the income of the inhabitants of the arid and semi-arid regions [1]. In Morocco, date palm is threatened by bayoud, a very dangerous wilt disease caused by the fungus Fusarium oxysporum f. sp. albedinis and that killed millions of date palm plants [2]. To date, the only way to fight bayoud and to preserve the best date palm genotypes is through rapid and large-scale propagation [3]. Date palm propagation can be achieved either conventionally by seeds or offshoots, or through in vitro culture techniques [4]. Propagation through seedlings cannot be used for the large-scale production of true-to-type plantlets, while propagation through offshoots is hampered by the limited number of offshoots produced by a date palm plant,