Universal Journal of Plant Science 10(1): 26-37, 2023 http://www.hrpub.org DOI: 10.13189/ujps.2023.100102 Germination and Early Growth of Acacia nubica Benth. In vitro Kauther Sir El-Khatim Ali 1 , H. M. Daffalla 2,* , Magdoleen G. Osman 2 , A. M. A. Musa 1 1 Department of Biotechnology, College of Applied and Industrial Sciences, University of Bahri, Khartoum North, 12217, Khartoum, Sudan 2 Department of Pant Cell and Tissue Culture, Commission for Biotechnology and Genetic Engineering, National Center for Research, Khartoum, 11111, Khartoum, Sudan Received October 16, 2022; Revised March 6, 2023; Accepted March 21, 2023 Cite This Paper in the Following Citation Styles (a): [1] Kauther Sir El-Khatim Ali, H. M. Daffalla, Magdoleen G. Osman, A. M. A. Musa , "Germination and Early Growth of Acacia nubica Benth. In vitro," Universal Journal of Plant Science, Vol. 10, No. 1, pp. 26 - 37, 2023. DOI: 10.13189/ujps.2023.100102. (b): Kauther Sir El-Khatim Ali, H. M. Daffalla, Magdoleen G. Osman, A. M. A. Musa (2023). Germination and Early Growth of Acacia nubica Benth. In vitro. Universal Journal of Plant Science, 10(1), 26 - 37. DOI: 10.13189/ujps.2023.100102. Copyright©2023 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Acacia nubica is a well-adapted shrub to harsh conditions that provides valued socioeconomic and environmental advantages. In vitro culture of A. nubica is critical not only for investigating factors affecting cultivation conditions but also for producing juvenile tissue as a potential explants for various in vitro techniques. This research was aimed to study A. nubica seed germination and seedling growth in vitro in response to varied levels of sodium hypochlorite, sucrose, and Murashige and Skoog (MS) medium. The synchrony, percentage, and rate of germination of A. nubica seed were investigated. The shoot, root, and number of nodes were measured to gauge seedling development. Sodium hypochlorite at 10% resulted in the highest percentage of germination, whereas 5% resulted in a faster and more uniform emergence. Sucrose has various effects on seed emergence and germination depending on the concentrations; 30 g/L elicited the highest germination, while 10 g/L improved seed emergence rate with higher uniformity. Although ¼-MS medium produced the highest seed germination, 0-MS strength recorded faster and more synchronized germination. The development of A. nubica seedlings was influenced by sucrose concentrations and MS medium strengths. Sucrose at 20 g/L produced the maximum shoot length and vigor index, 30 g/L produced the maximum number of nodes, and 50 g/L produced the maximum root length and root/shoot ratio. Full MS medium supplemented with 30 g/L was shown to be the most effective in improving all assessed growth parameters. This is the first successful report on the seed germination and seedling growth of A. nubica in vitro. Keywords Acacia nubica, Dormancy, Germination, In Vitro, Seedling, Synchronization 1. Introduction Acacia nubica Benth. (Acacia oerfota (Forssk.) Schweinf.) [family Leguminosae], known in Sudan as Laout or El Ifein, is a green-grey or whitish-green multi-stemmed shrub 1-5 m high with basal branching merged into an irregular or obconical crown [1,2]. It is distributed through the arid and semi-arid zones or short grass savanna woodlands of Africa to Arabia, Persia and India in Asia [3]. In Sudan, known as Laout or El Ifein, A. nubica usually occupied dry-hard, bared and exhausted clay fields and rocky-dry slopes under 100‒200 mm rainfall of Central and Northern parts [1,2]. It is capable to germinate at temperatures ranging from 20 to 40 °C [4]. Due to its ability to withstand extremely harsh conditions, A. nubica is an indispensable component of agro-pastoral systems in dry areas and with exceedingly fundamental environmental roles. Rural people within the arid area where A. nubica occurs rely on the plant to