Abstract
Stabilization of seedling production is an urgent issue in the land-based cultivation of Ulva prolifera. In this study, we established a new seedling production method, in which branching formation from ground fragments is stimulated by addition of the Solution Extracted from Homogenized Thalli (SHET) of U. prolifera. The cells in the fragments cultured with SHET differentiated into six types of cells: swelled cells, branch cells, rhizoid cells, matured cells, empty cells, or dead cells. As the amount of the added SHET increased, the proportion of the fragments with branch cells increased. The branch cells grew normally, forming leaves after 7 days of culture period. Within the tested settings, the rate of branch formation increased accordingly to the extension of storage period and increase in culture temperature. We recommend storage period of 6 weeks and incubation temperature of 25℃ for seedling production, as the increase of maturing cells at 30℃ makes seedling production unstable, especially after extended storage period.
