アマノリの日周変化に関する生理的研究-I

Abstract

Diurnal variation of cell size, photosynthesis, respiration and content of photosynthetic pigmenes in the thallus of porphyra sp. Were investigated in an artificial medium under 12-hour light (50, 000lx) and 12-hour dark cycles. Of these above mentioned four subjects under study, the first three showed similarly each of the diurnal rhythm characteristics. Cell size and photosynthesis exhibited their maxima toward the middle of the light period and minima in the middle of the dark period. Respiration gradually increased during the light period and tapered with the start of dark. The cell size of the younger thallus was generally smaller than that of older ones. Cell division in the former occurred over the whole thallus, while it was rather limited in the marginal parts in the latter. Content of photosynthetic poigments per dry weight or per area of the thallus was almost unchanged during the experimental period, except for some significant random changes in the content of phycoerythrin and phycocyanin.