Pyrenoids found in green algae Order Ulvales have taxonomical significance.Their morphology,microstructure,and the location and number in the cells have been widely used as identification criteria. As these traits can...Pyrenoids found in green algae Order Ulvales have taxonomical significance.Their morphology,microstructure,and the location and number in the cells have been widely used as identification criteria. As these traits can be affected by environmental conditions,it is necessary to look for other different characteristics.Here pyrenoids in several algae species collected along the Qingdao coast were studied for such purpose. The morphology and distribution of pyrenoids in the cells,as well as their change in different parts of the frond and at different times were studied with light microscope.The results are as follows.Pyrenoids appeared to be spherical or oval in observed Ulvales'algae cells.They were embedded in chloroplasts with the number of 1-3 per cell on average.The number of pyrenoids for Ulva pertusa could change drastically with continuing culture and could reach up to 10-20 per cell in late-growth stages.Generally, the pyrenoids in the marginal part were more observable than those in the central part for Ulva pertusa. In addition, the basal part of frond had more distinct pyrenoids with an average diameter of 2.42 μm for Enteromorpha linza. For some species the pyrenoids were difficult to be observed while dark treatment made them more distinguishable.The apoptosis rate of pyrenoids in different species varied under continuing dark treatment, which could be used to identify different species. Pyrenoids disappeared faster in E. linza than those in E.intestinalis.展开更多
Elevated CO2 concentration had insignificant effect on shape and size of Chlorella pyrenoidosa, but increased the amount of Chloroplast. Pyrenoids were found in low-CO2-grown cells, but not in high-CO2-grown cells. Th...Elevated CO2 concentration had insignificant effect on shape and size of Chlorella pyrenoidosa, but increased the amount of Chloroplast. Pyrenoids were found in low-CO2-grown cells, but not in high-CO2-grown cells. The chloroplast lamella of low-CO2-grown cells had higher electrical density than that of high-CO2-grown cells.展开更多
Comparative ultrastructural investigations on twenty-three isolates of Tetraselmis from the South China Sea, East China Sea and Huanghai Sea, have revealed that these isolates belong to:(1)Tetraselmis chui Butcher; (2...Comparative ultrastructural investigations on twenty-three isolates of Tetraselmis from the South China Sea, East China Sea and Huanghai Sea, have revealed that these isolates belong to:(1)Tetraselmis chui Butcher; (2)T. cordiformis (H. J. Carter) Stein; (3)T. helgolandica Kylin; (4)T. suecica (Kylin) Butcher; (5)T. guangdongensis sp. nov. Except T. helgolandica, the others are new records in China. T. guangdongensis sp. nov. is a new species. Its external and anatomical features closely resemble those of T. impellucida McLachlan et Parke. As in that species the pyrenoid is penetrated from many directions by cytoplasmic channels delimited by a double membrane. The protoplast withdraws from the apical portion of the theca, that portion which overlaid the trough inverts and pops out in the form of a teat. But unlike that species a starch sheath is present; pyrenoid matrix is surrounded by thylakoids which intervenes between the matrix and the starch sheath surrounding pyrenoid; the theca is stratified.展开更多
The genus Neglectella Vodenicarov&Benderliev has a morphology similar to the well-known genus Oocystis,except for the numerous chloroplasts stacked in the surface layer of the cell.Neglectella subsequently experie...The genus Neglectella Vodenicarov&Benderliev has a morphology similar to the well-known genus Oocystis,except for the numerous chloroplasts stacked in the surface layer of the cell.Neglectella subsequently experienced complex taxonomy changes with members being transferred in and out,and five species are now accepted.In this study,a new alga with morphology corresponding to this genus was collected in China and successfully cultured in laboratory.Morphological observations in light microscopy and transmission electronic microscopy(TEM)and phylogenetic analyses revealed that it is a new species,described here as Neglectella glomerata sp.nov.It differed from other Neglectella species due to a morphological difference in its unique mucilaginous colony with a large number of cells,multiple pyrenoids in each chloroplast,smaller cell size,and more elongated cell shape.Phylogenetic analyses placed this alga in the subfamily Eremosphaeroideae of the family Oocystaceae and showed its close relationship with Neglectella peisonis.Further morphological comparisons combined with phylogenetic results revealed three different morphological types in Neglectella.The new type represented by our new species may represent a transitional morphology in intermediate taxonomic position between the other two types.The diversity of morphological types in Neglectella suggests that further unknown species of this genus are likely to be discovered in the future.More collections and DNA sequence data will be needed in the future for this genus.展开更多
基金supported by the National Natural Science Foundation of China(Nos.40876081 and 30570125)
文摘Pyrenoids found in green algae Order Ulvales have taxonomical significance.Their morphology,microstructure,and the location and number in the cells have been widely used as identification criteria. As these traits can be affected by environmental conditions,it is necessary to look for other different characteristics.Here pyrenoids in several algae species collected along the Qingdao coast were studied for such purpose. The morphology and distribution of pyrenoids in the cells,as well as their change in different parts of the frond and at different times were studied with light microscope.The results are as follows.Pyrenoids appeared to be spherical or oval in observed Ulvales'algae cells.They were embedded in chloroplasts with the number of 1-3 per cell on average.The number of pyrenoids for Ulva pertusa could change drastically with continuing culture and could reach up to 10-20 per cell in late-growth stages.Generally, the pyrenoids in the marginal part were more observable than those in the central part for Ulva pertusa. In addition, the basal part of frond had more distinct pyrenoids with an average diameter of 2.42 μm for Enteromorpha linza. For some species the pyrenoids were difficult to be observed while dark treatment made them more distinguishable.The apoptosis rate of pyrenoids in different species varied under continuing dark treatment, which could be used to identify different species. Pyrenoids disappeared faster in E. linza than those in E.intestinalis.
文摘Elevated CO2 concentration had insignificant effect on shape and size of Chlorella pyrenoidosa, but increased the amount of Chloroplast. Pyrenoids were found in low-CO2-grown cells, but not in high-CO2-grown cells. The chloroplast lamella of low-CO2-grown cells had higher electrical density than that of high-CO2-grown cells.
文摘Comparative ultrastructural investigations on twenty-three isolates of Tetraselmis from the South China Sea, East China Sea and Huanghai Sea, have revealed that these isolates belong to:(1)Tetraselmis chui Butcher; (2)T. cordiformis (H. J. Carter) Stein; (3)T. helgolandica Kylin; (4)T. suecica (Kylin) Butcher; (5)T. guangdongensis sp. nov. Except T. helgolandica, the others are new records in China. T. guangdongensis sp. nov. is a new species. Its external and anatomical features closely resemble those of T. impellucida McLachlan et Parke. As in that species the pyrenoid is penetrated from many directions by cytoplasmic channels delimited by a double membrane. The protoplast withdraws from the apical portion of the theca, that portion which overlaid the trough inverts and pops out in the form of a teat. But unlike that species a starch sheath is present; pyrenoid matrix is surrounded by thylakoids which intervenes between the matrix and the starch sheath surrounding pyrenoid; the theca is stratified.
基金Supported by the National Natural Science Foundation of China(Nos.31900187,32000167)the Shanxi Province Science Foundation for Youths(Nos.201901D211132,201901D211421)+2 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(Nos.2019L0073,2020L0524)the Key Laboratory of Algal Biology,Institute of Hydrobiology,Chinese Academy of Sciences(No.2018-002)the Shanxi“1331 Project”。
文摘The genus Neglectella Vodenicarov&Benderliev has a morphology similar to the well-known genus Oocystis,except for the numerous chloroplasts stacked in the surface layer of the cell.Neglectella subsequently experienced complex taxonomy changes with members being transferred in and out,and five species are now accepted.In this study,a new alga with morphology corresponding to this genus was collected in China and successfully cultured in laboratory.Morphological observations in light microscopy and transmission electronic microscopy(TEM)and phylogenetic analyses revealed that it is a new species,described here as Neglectella glomerata sp.nov.It differed from other Neglectella species due to a morphological difference in its unique mucilaginous colony with a large number of cells,multiple pyrenoids in each chloroplast,smaller cell size,and more elongated cell shape.Phylogenetic analyses placed this alga in the subfamily Eremosphaeroideae of the family Oocystaceae and showed its close relationship with Neglectella peisonis.Further morphological comparisons combined with phylogenetic results revealed three different morphological types in Neglectella.The new type represented by our new species may represent a transitional morphology in intermediate taxonomic position between the other two types.The diversity of morphological types in Neglectella suggests that further unknown species of this genus are likely to be discovered in the future.More collections and DNA sequence data will be needed in the future for this genus.
