INCORPORATION OF C-14 RADIOACTIVITY INTO LIPID CLASSES AT DIFFERENT MATURITY OF LAMINARIA-JAPONICA ARESCH CULTURED UNDER NATURAL AND PARTIALLY CONTROLLED CONDITIONS

A study to assess which environmental or developmental factors predomi nate in the biosynthesis of lipids of Laminaria japonica Aresch. blade s was undertaken by mean s of C-14-labelling technique. In experiment 1, kelp blades at different growth stages were collected in different cultural seasons. In experiment 2, kelp blades of different sizes and maturity cultured simultaneously for two months in the same sea area w ere collected at the same time. The following results were obtained. I n experiment 1, the C-14-incorporation into whole lipids was lowest in juvenile blades collected at the end of autumn and highest in blades of middle size collected in winter. However, the highest counts were i ncorporated in PC among complex lipid classes from all size classes of blades in both experiments 1 and 2. In experiment 2, C-14-incorporati on patterns of individual lipid classes were characteristically differ ent depending on the sizes of blades even under the same cultural cond ition. Thus, the biosynthesis of lipids in this kelp seems to be affec ted essentially by developmental factors.