Plantlet Regeneration from Callus Cultures of Kappaphycus alvarezii for Cultivation in Coastal Waters at Myeik Archipelago, Myanmar.

<b>Background and Objective:</b> The cultivation of <i>Kappaphycus alvarezii</i>, the most economically valuable rhodophyte seaweed species, began in Myanmar in 2004, primarily on islands in the Myeik Archipelago. Since <i>K. alvarezii</i> is not native to Myanmar, it was initially imported from the Philippines and Indonesia. This study aimed to develop a tissue culture procedure for the generation of <i>K. alvarezii</i> plantlets to ensure a continuous supply of seaweed for commercial farming in the coastal waters of Myanmar. <b>Materials and Methods:</b> Specimens of <i>K. alvarezii</i>, two-month-old, were procured in the Myeik Archipelago, Myanmar. After being cleared epiphytes and clinging materials, the specimens were placed in glass aquarium tanks with circulating seawater. Axenic explant culture was established using 1% povidone-iodine for 1 min and a 1% antibiotic mixture for 24 hrs. Plant growth regulators, 6-benzyl aminopurine (BAP) and indole 3 acetic acid (IAA) were supplemented in solid Provasoli's enriched seawater (PES) media to induce callus formation and somatic embryogenesis. <b>Results:</b> The optimal culture conditions were incubation at 22-25°C under cool-white fluorescent-light (15-20 μmol photons/m²/sec) with a 12:12 hrs light and dark cycle. Water quality during the culturing process was maintained at a pH of 8 and salinity of 30 PSU. The tissue-cultured <i>K. alvarezii</i> plantlets exhibited an average daily growth rate of 9.70±0.25% over the growth period. <b>Conclusion:</b> Therefore, plantlet regeneration from <i>K. alvarezii</i> callus cultures can be utilized as seedlings for revenue-generating cultivation along the Myanmar coastline.