Photosynthetic characteristics of female vegetative tissues of Porphyra katadai var. hemiphylla (Bangiales, Rhodophyta) in culture

摘要

In this study, chlorophyll fluorescence parameters (a dagger F/F (m)', F (v)/F (m)) and oxygen evolution of female vegetative tissues of Porphyra katadai var. hemiphylla in unisexual culture (FV) and in mixed culture with male vegetative tissues (FV-M) were followed at 5-20 A degrees C, 10 and 80 mu mol photons m(-2) s(-1). The formation of reproductive tissues was closely correlated with decreasing photosynthetic activities. At the same temperature the tissues cultured under 80 mu mol photons m(-2) s(-1) showed a greater extent of maturation than those under 10 mu mol photons m(-2) s(-1), and their decrease in photosynthesis was also larger. Under the same light intensity the extent of maturation increased with increasing temperature, and both cultures showed higher values of a dagger F/F (m)' and F (v)/F (m) at 10 and 15 A degrees C, while their oxygen evolution became negative at 15-20 A degrees C during the later period. Under the same culture condition the maturation of FV-M culture was relatively faster than that of FV culture, while their photosynthetic activity, especially a dagger F/F (m)', was lower.