Purple Leaves Like Sexual Reproduction Organization Formed During Photosynthesis Characteristic Research

Porphyra is eurythermic and distribute widely in the world. In China P. katadai var. hemiphylla distributed mainly along western areas of Yellow sea from Qingdao, Shandong Province to Dalian, Liaoning Province, and P. yezoensis distributed mainly along sea areas from Shandong Province to Jiangsu Province, while P. haitanensis distributed mainly along sea areas from Zhejiang Province to Guangdong Province. There should be some differences among their adaptation to primary environmental factors including light and temperature due to their different distribution and thallus color. Changes of pigment systems during the formation of sexual reproductive tissues of Porphyra blades might have effects on photosynthetic performances, which have rarely been reported. Sexually different parts of P. katadai var. hemiphylla could be distinguished with eyes, for their colors differ even on the immature blades, which made it easy to analysis the development of Porphyra blades and also suggested their different photosynthetic characteristics. In this study, chlorophyll fluorescence parameters (effective quantum yield, Yield; optimal quantum yield, Fv/Fm) and oxygen evolution were followed during the formation of reproductive tissues when vegetative tissues of P. katadai var. hemiphylla were cultured indoor, and photosynthetic characteristics were compared among sexually different vegetative and reproductive tissues of three Porphyra species mentioned above, with various distribution from the North to the South. Pigments were also measured including chlorophyll a (Chl a), UV-absorbing compounds (UVACs), carotenoids, phycocyanin (PC) and phycoerythrin (PE).In indoor culture female vegetative tissues (FV) and male vegetative tissues (MV) of P. katadai var. hemiphylla were cultured (5-20℃,10and80μmol m-2s-1) for20days, and photosynthetic performances of female vegetative tissues in mixed culture with male vegetative tissues (FV-M) were also followed. The formation of reproductive tissues was closely correlated with the decreasing of photosynthetic activities. At the same temperature the tissues cultured under80μmol m-2s-1showed a greater extent of maturation than those under10μmol m-2s-1did, whereas their decreasing degree of photosynthesis was also larger. Under the same light intensity the extent of maturation ascended with our increasing temperature. At the same time photosynthetic activity of MV culture was the highest at10℃and the lowest at20℃, but the decreasing degree of photosynthesis of FV culture was smaller at higher temperature. Under the same culture condition the differentiation of FV-M culture was relatively faster than that of FV culture, and their photosynthetic activity, especially the yield, was also lower.Comparative studies among different tissues showed that in three Porphyra species female reproductive tissues (FR) had the highest PE/PC ratio, while male reproductive tissues (MR) showed the lowest contents of pigments, though their ratios of U VAC/Chl a and Carotenoids/Chl a could keep the same levels as other tissues. Vegetative tissues had more pigments and higher Yield and Fv/Fm than their respective reproductive ones did, and such differences were more significant between male tissues. Contents of PC, PE and carotenoids were significantly higher in FV than those in MV of P. katadai var. hemiphylla, but were not different between FV and MV of P. haitanensis. Light-saturated photosynthetic rate (Pmax) and light saturation point (Ik) from (O2-based photosynthesis-irradiance (P-I) curves reached higher values at10℃in tissues of P. katadai var. hemiphylla, and at20℃in tissues of P. yezoensis, and at15-20℃in tissues of P. haitanensis. This might be due to acclimation of our experimental materials, for both samples of P. yezoensis and P. haitanensis were collected from Nantong sea area.