Planned seedling production in the distribution area of <i>Saccharina japonica</i> : Sorus formation through the induction of sporophyte maturation and the culture of the seedlings produced

Inconsistency in maturation of saccharinan kelp due to changes the marine environment is a problem terms securing seedlings for aquaculture. In Hokkaido, main producing area Saccharina japonica, it has become challenge stably secure parental algae species When was induced by short-day conditions naturally collected S. japonica sporophytes as well from them and cultivated, sorus formation began approximately 3 weeks spread 0.4%–16.8% on upper side 23.2%–41.1% underside after about 5 weeks, with highest rates, 23.2%–59.5%, observed around base part underside. Sorus middle parts top-intact thalli marginal top-cut thalli. The released zoospore germlings grew steadily aquaculture seedlings, blade width wet weight August subjected mariculture November were significantly larger five half months compared those cultivated using conventional method (i.e. just prior mariculture). Seedling production through induction would be feasible option seedling facilities helpful without effect natural environment.