Algae 2022, 37(2): 105-121 https://doi.org/10.4490/algae.2022.37.5.11 Open Access Review Copyright © 2022 The Korean Society of Phycology 105 http://e-algae.org pISSN: 1226-2617 eISSN: 2093-0860 Recent advances in seaweed seedling production: a review of eucheumatoids and other valuable seaweeds Calvin Jiksing 1 , McMarshall M. Ongkudon 2 , Vun Yee Tien 3 , Kenneth Francis Rodrigues 1 and Wilson Tau Lym Yong 1,4, * 1 Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia 2 Seadling Sdn. Bhd., Lot 32A-36, KKIP Industrial Zone 4, Phase 2, 88450 Kota Kinabalu, Sabah, Malaysia 3 Innovation Center, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria, 43900 Sepang, Selangor Darul Ehsan, Malaysia 4 Seaweed Research Unit, Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia Modern seaweed farming relies heavily on seedlings from natural beds or vegetative cuttings from previous harvests. However, this farming method has some disadvantages, such as physiological variation in the seed stock and decreased genetic variability, which reduces the growth rate, carrageenan yield, and gel strength of the seaweeds. A new method of seedling production that is sustainable, scalable, and produces a large number of high-quality plantlets is needed to support the seaweed farming industry. Recent use of tissue culture and micropropagation techniques in eucheumatoid seaweed production has yielded promising results in increasing seed supply and growing uniform seedlings in large numbers in a shorter time. Several seaweed species have been successfully cultured and regenerated into new plant- lets in laboratories using direct regeneration, callus culture, and protoplast culture. Te use of biostimulants and plant growth regulators in culture media increases the seedling quality even further. Seedlings produced by micropropagation grew faster and had better biochemical properties than conventionally cultivated seedlings. Before being transferred to a land-based grow-out system or ocean nets for farming, tissue-cultured seedlings were recommended to undergo an acclimatization process to increase their survival rate. Regular monitoring is needed to prevent disease and pest in- festations and grazing by herbivorous fsh and turtles during the farming process. Te current review discusses recent techniques for producing eucheumatoid and other valuable seaweed farming materials, emphasizing the efciency of micropropagation and the transition from laboratory culture to cultivation in land-based or open-sea grow-out systems to elucidate optimal conditions for sustainable seaweed production. Keywords: acclimatization; biostimulants; grow-out; micropropagation; plant growth regulators; seaweed seedlings Abbreviations: 2,4-D, 2,4-dichlorophenoxyacetic acid; AMPEP, Ascophyllum marine plant extract powder; BAP, 6-ben- zylaminopurine; IAA, indole-3-acetic acid; NAA, 1-naphthaleneacetic acid; PAA, phenylacetic acid; PES, Provassoli’s En- riched Seawater; PGRs, plant growth regulators Received August 11, 2021, Accepted May 11, 2022 *Corresponding Author E-mail: wilsonyg@ums.edu.my, wilsonyong80@yahoo.com Tel: +60-88-320027, +60-88-320000 (ext. 5593), Fax: +60-88-320993 Tis is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.