Effect of shading colours on growth and pigment content of Gracilaria fisheri (Xia Abbott) Abbott, Zhang Xia (Gracilariales, Rhodophyta)

摘要

Sporeling and tissue propagation of agarophytic seaweed, Gracilaria fisheri, aimed to investigate the optimal shading colour for the preservation. This study was conducted under different shading colours indoor and outdoor experiments. The indoor experiment: tissues and sporelings of the seaweed were cultured in plastic chambers under fluorescent lights and were wrapped with white, green, blue and red colour PVC sheets of light intensity of 20 +/- 1 molm(-2)s(-1). The outdoor tissues were cultured in the plastic tanks under different shadings of Saran sheets: white, green, blue and black covering the hoop-houses with light intensity of 110 +/- 10 molm(-2)s(-1). The results showed that different shading colours strongly influenced growth of G.fisheri sporelings and tissues but little effect on pigmentation. After 40days, the highest growth rates of G.fisheri tissues and sporelings were found under red light with 1.44 and 1.89 day(-1) respectively. There was no significant difference (P>0.05) on pigment content of tissues indoor, whereas it was found that chlorophyll concentration of the sporelings under green light with 416.8gg(-1) fresh weight was significantly higher (P<0.05) than those in other treatments. After 8-week culture, outdoor tissues showed the highest growth rate with 1.71 day(-1) in the green hoop-house. The study has found that G.fisheri cultivation was less influenced by epiphytes in the back hoop-house with 15. This study showed the feasibility of successful cultivation of G.fisheri sporelings and tissues.