Comparative studies on pigments and photosynthetic characteristics of sexually different vegetative and reproductive tissues of Porphyra katadai var. hemiphylla (Bangiales, Rhodophyta)

Abstract

Porphyra katadai Miura var. hemiphylla Tseng & T.J. Chang, a native species of China, is monoecious with female and male parts in distinct halves separated by a longitudinal line in the blades, and photosynthetic characteristics and pigment contents were compared among different tissues. Female parts contained significantly more phycobiliprotein and carotenoids than male parts did, accompanied by higher photochemical efficiency of photosystem II than the latter. Vegetative tissues had more pigments and higher ΔF/F _m′ and F _v/F _m than their respective reproductive tissues, and male reproductive tissues even exhibited lower P _max based on oxygen evolution than their vegetative tissues at 5–10 °C. Female vegetative tissues showed the highest ΔF/F _m′ among all tissues, while male reproductive tissues had the lowest P _max at low temperatures and the lowest pigment contents. Photosynthesis rates reached the highest values at 10 °C and the lowest values at 20 °C in most tissues, but male reproductive tissues exhibited the best performances at 20 °C, which rarely happened in its natural habitats and growth season. Thus growth capacity and response to seasonal temperature change varied not only between vegetative and reproductive tissues but also between female and male tissues in P. katadai var. hemiphylla, accompanied by their different color and size on wild plants.