Growth Responses of Early Sporophytes of Alaria esculenta and Laminaria hyperborea to Light Qualities

Algae > Volume 9(1); 1994 > Article

Algae 1994;9(1): 67-76.

Tae jun Han

Port Erin Marine Laboratory, University of Liverpool, United Kingdom

ABSTRACT

Growth response of laminarian early sporophytes to spectral light fields was examined in laboratory culture. The growth of Alaria esculenta seemed to depend on light quantity than on light quality, showing that there was little difference in the growth rates between different light qualities, but incrase in irradiance from 5to 13 μmol m super(-2) s super(-2) resulted in more than 45% higher growth in all the spectral light fields. On the other hand, Laminaria hyperborea exhibited significantly lower growth rate in red than in blue or green light at 5 μmol m super(-2) s super(-1). In red light, even an increase in irradiance did not cause an increase of the growth rate as much as in the other spectral light fields, suggesting the inefficiency of the red waveband for the growth of L. hyperborea at a very early stage, such as sporophytes younger than 10 days. However, at 36 μmol m super(-2) s super(-1) no difference in the growth rates between different light qualities was found in L. hyperborea. The change in the arrangement of phaeoplasts of L. hyperborea was observed in blue and green light, but there appeared little relationship between growth and phaeoplast arrangement.

Key words: Alaria esculenta, Laminaria hyperborea, light quality, phaeoplast