硅藻和淡水绿藻的77K低温荧光特性的研究

Studies in Characteriztion of Fluorescence Emission Spectra of Diatom and Flesh Chlorophyta at 77 K

实验测定了9种单细胞藻包括：5种淡水绿藻雪衣藻Chlamydomonas nivalis UTEX2765、椭圆小球藻Chlorella ellipswal CH、绿球藻Chloroccum tatrense UTEX2227、斜生栅藻Scenedesmus obliqnus、雨生红球藻Haematococcus sp．CSIRO：CS-321和四种硅藻三角褐指藻Phaeodactylum tricornutum、牟氏角毛藻Cheatoceros mulleri CH、中肋骨条藻Skeletonema costatum、尖刺拟菱形藻Pseudcrnitzsehia pungens Grunow的77K荧光光谱，并与大型海洋绿藻、其它杂色藻以及高等植物菠菜进行了比较。结果表明，9种单细胞藻都缺少作为高等植物PSI主要表征的730nm长波荧光峰。9种单细胞藻的荧光主峰的位于684nm，而淡水绿藻在714nm还有一个明显的发射峰。这个结果与海洋管藻目绿藻和某些大型海洋绿藻的荧光特性一致。四种硅藻也有一个明显的荧光发射主峰位于684～686nm，类囊体膜的荧光光谱中在700nm附近有个不明显的肩峰。以上结果表明，淡水绿藻和硅藻PSI缺少730nm长波荧光峰可能具有其普遍性，预示这些藻类在PSI结构以及能量传递等方面与高等植物具有很大的差异。

Fluorescence emission spectra of nine species of unicellular algae, including five species of flesh green algae Chlamydomonas nivalis UTEX 2765, Chlorella ellipswal CH, Chloroccum tatrense UTEX 2227, Scenedesmus obliqnus, Haematococcus sp. CSIRO： CS-321; four species of diatom Phaeodactylum tricornutum, Cheatoceros mulleri CH, Skeletonema costatum, Pseudo-nitzschia pungens Grunow were determined and compared to marine green algae, other Chromaphytae algae and the higher plant Spinacia oleracealarge at 77 K. The results showed that nine species of unicellular algae were significantly different from higher plant, they had no fluorescence emission at 730 nm which is taken as the characteristic of PSI . The wavelength of major fluorescence emission nine species of unicellular algae were at 684 nm. And the flesh unicellular green algae had a fluorescence emission at 714 nm. The major fluorescence emission wavelength of the four species of diatom were at 684--686 nm, and had a not so significant shoulderperk near 700 nm from thylakoid membrane. All those results showed that it may be common of lacking the long-wavelength fluorescence emission of green algae and diatom at 730 nm in PSI. The characterizations of fluorescence emission spectra at 77 K may foresee the differences of PSI structure and energy transfer between algae and higher plant.