不同品系条斑紫菜光合效率比较研究

用叶绿素荧光仪测试了7个品系紫菜叶状体在不同光照和温度条件下的光合效率,分析了受强光抑制后光合效率恢复的情况,并测试了这些品系的光合色素含量。结果显示,随着光照强度从20μmol.m-2.s-1提高到1 200μmol.m-2.s-1,总的趋势是光合效率逐渐降低,但下降幅度在不同品系间又有差异:相比20μmol.m-2.s-1光照下条件下光合效率,Yjs在1 200μmol.m-2.s-1时的光合效率下降了27%,Yw下降了33%,Gm下降了53%,Yqd下降了50%。在120μmol.m-2.s-1光照条件,5~20℃实验范围内,15~20℃条件下光合效率最高,除Yh2和Wjs,其它品系叶状体均在15℃达到顶峰,Yh2和Wjs则在20℃达到顶峰。在受到高光抑制(200μmol.m-2.s-1)后,处于光照60μmol.m-2.s-1,温度12℃条件下紫菜光合效率可在30~60 min内恢复。未发现光合色素含量与光合效率的相关性。文章还对紫菜光合效率与生态条件的关系进行了分析和讨论。

Research on Photosynthetic Efficiency of Seven Strains of Porphyra yezoensis

Photosynthetic efficiency of seven strains of Porphyra yezoensis was tested under different light intensities, different temperatures by mini-PAM, the content of the photosynthetic pigments and the recover time after photoinhibiting were also measured in the experiment. Results showed that from 20 μmol·m(-1)·s~(-1) to 1 200 μmol·m(-2)·s(-1), the efficiency decreased gradually with increasing light intensity, however, the degree of decrease varied among strains of Porphyra yezoensis: the photosynthetic efficiency of Yjs when it suffered from the highest light intensity decreased by 27% compared with the photosynthetic efficiency at the lowest light intensity, while Yw by 33%, Gm by 53%, and Yqd by 50%. Within the temperature range from 5 ℃ to 20 ℃, all the samples obtained the highest efficiency under the condition of 15～20 ℃ and 120 μmol·m(-2)·s(-1), and most of them reached the peak at the 15 ℃, except Yh2 and Wjs, which reached the peak at 20 ℃. After the photoinhibiting (200 μmol·m(-2)·s(-1)), the strains could recover in 30～60 min, under the condition of 60 μmol·m(-2)·s(-1) and 12 ℃. No direct relationship was found between the photosynthetic efficiency and the content of photosynthetic pigments. The relationship between the photosynthetic efficiency and ecological conditions was discussed in this paper as well.