In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the sur- face and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxy- graph technolog...In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the sur- face and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxy- graph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and bottom thalli, respectively. The results showed that the maximal PSII quantum yield of the floating thalli was significantly lower than the normal level although their photosynthetic activities were relatively high; the photosynthetic potential of the thalli form the mud surface was extremely low. Thus, it is indicated that the floating thalli are seriously stressed by their environment and the thalli from the mud surface are already dead or are dying. On the other hand, the results of the laboratory cultivation showed that the sedimentary thalli cannot regain normal photosynthetic activity even under normal illumination condi- tions. Thus, the thalli from the mud surface cannot become reproductive source of the alga even if they can reach sea surface again. Therefore, a preliminary conclusion can be reached that, up to mid-July 2008, the environmental conditions of the Qingdao sea area are not suitable for the growth of the alga E. prolifera and for this reason the biomass of E. prolifera, in the area, could be declining.展开更多
A Gymnodinium-like species was studied with light microscopy(LM) and scanning electron microscopy(SEM).Also,the internal transcribed spacers(containing 5.8S rDNA) and large ribosomal subunit DNA(D1-D2) sequences were ...A Gymnodinium-like species was studied with light microscopy(LM) and scanning electron microscopy(SEM).Also,the internal transcribed spacers(containing 5.8S rDNA) and large ribosomal subunit DNA(D1-D2) sequences were obtained by PCR amplification,and then sequenced to explore the rela-tionships within our isolate,Gymnodinium and other Gymnodinium-like species,including Karenia,Gyrodinium,Karlodinium and Symbiodinium.The LM observation showed that the species was characterized by moving in a levorotatory direction,visible hypocone,epicone and transverse groove,all of which are typical for Gymnodinium.In addition,two flagella could be found under SEM.The phylogenetic analysis revealed that the isolate grouped with Symbiodium,rather than other relevant dinoflagellates.All results showed our isolate belongs to Symbiodium.The strain was isolated from a red tide展开更多
基金Supported by National Natural Science Foundation of China (Grant No. 30830015)Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (Grant No. 2006BAD09A04)National High Technology Research and Development Program of China (Grant Nos. 2006AA10A402, 2007AA09Z406, 2006AA05Z112, 2006AA10A413)
文摘In this work, the photosynthetic performances of Enteromorpha prolifera thalli collected from the sur- face and bottom of the sea of Qingdao sea area were studied with chlorophyll fluorescence and oxy- graph technology. The samples with the highest photosynthetic activity among their kinds, the floating thalli from the sea surface of the south of the Qingdao Olympic Sailing Center and the sedimentary thalli from the mud surface of the bottom Tuandao bay, were chosen as representatives of surface thalli and bottom thalli, respectively. The results showed that the maximal PSII quantum yield of the floating thalli was significantly lower than the normal level although their photosynthetic activities were relatively high; the photosynthetic potential of the thalli form the mud surface was extremely low. Thus, it is indicated that the floating thalli are seriously stressed by their environment and the thalli from the mud surface are already dead or are dying. On the other hand, the results of the laboratory cultivation showed that the sedimentary thalli cannot regain normal photosynthetic activity even under normal illumination condi- tions. Thus, the thalli from the mud surface cannot become reproductive source of the alga even if they can reach sea surface again. Therefore, a preliminary conclusion can be reached that, up to mid-July 2008, the environmental conditions of the Qingdao sea area are not suitable for the growth of the alga E. prolifera and for this reason the biomass of E. prolifera, in the area, could be declining.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40476059, u0633006)Qingdao Scientific Foundation (BC3052407)Harbin Institute of Technology (Weihai)(HIT(WH)07)
文摘A Gymnodinium-like species was studied with light microscopy(LM) and scanning electron microscopy(SEM).Also,the internal transcribed spacers(containing 5.8S rDNA) and large ribosomal subunit DNA(D1-D2) sequences were obtained by PCR amplification,and then sequenced to explore the rela-tionships within our isolate,Gymnodinium and other Gymnodinium-like species,including Karenia,Gyrodinium,Karlodinium and Symbiodinium.The LM observation showed that the species was characterized by moving in a levorotatory direction,visible hypocone,epicone and transverse groove,all of which are typical for Gymnodinium.In addition,two flagella could be found under SEM.The phylogenetic analysis revealed that the isolate grouped with Symbiodium,rather than other relevant dinoflagellates.All results showed our isolate belongs to Symbiodium.The strain was isolated from a red tide
