抄録
In order to increase the algal fresh weight of a red alga, Gracilariopsis
chorda (Holmes) Ohmi, with indoor culture, four kinds of the algal
fragments (5A: 5 mm long apical, 5I: 5 mm long intercalary, 3I: 3 mm long
intercalary, 2I: 2 mm long intercalary fragments) were evaluated to
determine a suitable starting material for unialgal culture. During the
unialgal culture, new multiple branches grew from a regeneration surface of
intercalary fragments. Although the algal fresh weight after eight weeks of
cultivation were significantly larger in 5A and 5I than in 3I and 2I, the
rate of increase (i.e., the ratio of the fresh weight to initial fresh
weight after eight weeks of cultivation) were in the order of 5I
(53.0-fold), 3I (80.4-fold), 5A (93.7-fold), and 2I (114-fold). The relative
growth rate (RGR) of 5A was higher than that of 2I before three
weeks of cultivation, but after four weeks of cultivation RGR of 2I was
higher than that of 5A. From these results, among the algal fragments
tested, 2I seems to be the best initial fragment for G. chorda
unialgal culture. On 20 l scale culture, the average fresh weight of 2I was
7.28 g/tank after eighth week culture.
