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本文纪录了淡水红藻串珠藻属Batrachospermum的二个新种。它们采自中国的亚热地区,按其形态特征,它们属于旋转组Section Contorta。采自湖北省的弯形中珠藻B.curvatum与扭曲串珠藻B.tortuosum Kumano相似,但按其轮节、顶毛和受精丝等的形态与后者相区别。采自江西省的弯转串珠藻B.torsivum与赫罗西串珠藻B.hirosei Ratnasabapathy et Kumano相似,但轮节、中轴细胞、节丝和节间丝、果胞枝和受精丝等的大小和形态与后者相区别。 相似文献
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钙质红藻是指可以发生生物钙化作用在其细胞壁上沉淀碳酸钙的红藻。钙质红藻可以保存为化石,是红藻古生物研究中的重要类群,具有重要的生态意义,但以往的研究对钙质红藻类群的系统分类及地史分布缺乏清晰认识。本文详细综述了钙质红藻化石的系统分类,归属于红藻门(Rhodophyta)红藻纲(Rhodophyceae)的4个目7个科,分别为珊瑚藻亚纲(Corallinophycidae)珊瑚藻目(Corallinales)的珊瑚藻科(Corallinaceae)、石叶藻科(Lithophyllaceae)、宽珊藻科(Mastophoraceae)和管孔藻科(Solenoporaceae),混石藻目(Hapalidiales)的混石藻科(Hapalidiaceae),孢石藻目(Sporolithales)的孢石藻科(Sporolithaceae)以及真红藻亚纲(Florideophycidae)耳壳藻目(Peyssonneliales)的耳壳藻科(Peyssonneliaceae)。最早的钙质红藻为管孔藻科,出现于中奥陶世,于中新世灭绝。珊瑚藻科最早出现于晚志留世并于白垩纪辐射演化至今,其他科均于白垩纪... 相似文献
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研究采用4种DNA序列, 分析了各片段序列特征以及在串珠藻科植物中种属水平的鉴定能力, 包括线粒体COI-5P、cox2-3 spacer序列, 以及叶绿体rbcL、UPA序列。结果表明, COI-5P、cox2-3 spacer、UPA以及rbcL序列的PCR扩增成功率分别为96%、100%、96%和98%。其中, COI-5P、cox2-3 spacer和UPA的片段大小符合标准DNA条形码的判定标准, 即片段大小在300—800 bp, 能够通过单对引物双向测序获得。系统发育分析的结果显示, 这4种DNA片段在串珠藻属植物的鉴定中能够鉴定大部分的种类, 但COI-5P、cox2-3 spacer以及rbcL序列均不能将两种中国特有种洪洞串珠藻B. hongdongense和长柄串珠藻B. longipedicellatum与弧形串珠藻B. arcuatum分开。在种水平的鉴定中, UPA基因的种间差异最大, 显示了较好的分离效果, 在串珠藻科植物的鉴定中可以作为一个标准的DNA条形码。 相似文献
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从生物分类学的研究历史来探讨化石在分类学中地位的变化,以及这种变化和思想观念更新的关系。用脊椎动物高级类群关系的变化作例子,说明化石类群在动物系统发育研究中的作用。 相似文献
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几种海洋红藻中的R—藻红蛋白对胰鸟素抗体的免疫反… 总被引:1,自引:0,他引:1
本文利用点免疫结合测定法研究了条斑紫菜,红毛菜,多管藻,海萝和江蓠中两种不同分子量的R-和r-藻红蛋白(PE)对胰岛素抗体的免疫反应性。这5种红藻中的R-藻红蛋白都可用蔗糖密度线性梯度超速离心法,得到分子量不同的两种R-PE。它们与胰岛素抗体都发生免疫结合反应,但用反射扫描色谱测定,在抗原量相同的比较实验中,反映它们免疫结合反应的棕色斑点的扫描峰面积有所不同。即它们与胰岛素抗体的结合率不同,其中海 相似文献
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通过形态学观察和rbcL序列分析报道产自海南省文昌的红藻门海膜科蜈蚣藻属一新种: 博鳌蜈蚣藻(Grateloupia boaoensis Wang et Luan sp. Nov.)。博鳌蜈蚣藻的藻体紫红色, 表面光滑, 软骨质, 高15-40 cm; 主枝侧枝均扁形, 叶片状; 分枝顶端呈剑形, 厚度为400-800 m, 由4-9层皮层细胞和髓部组成, 髓丝纵走, 错综交织; 助细胞生殖枝丛为典型的Grateloupia型; 囊果在主枝与分枝上均有分布并分布密集。在用rbcL序列构建的系统树中, 四个博鳌蜈蚣藻样品聚在一起并与莺歌海蜈蚣藻(G. yinggehaiensis)聚成一个小分支。通过形态观察和rbcL序列分析, 认为博鳌蜈蚣藻和莺歌海蜈蚣藻的亲缘关系最近。 相似文献
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通过形态学观察和rbcL序列分析报道产自海南省文昌的红藻门海膜科蜈蚣藻属一新种:博鳌蜈蚣藻(Grateloupia boaoensis Wang et Luan sp.Nov.)。博鳌蜈蚣藻的藻体紫红色,表面光滑,软骨质,高15—40 cm;主枝侧枝均扁形,叶片状;分枝顶端呈剑形,厚度为400—800μm,由4—9层皮层细胞和髓部组成,髓丝纵走,错综交织;助细胞生殖枝丛为典型的Grateloupia型;囊果在主枝与分枝上均有分布并分布密集。在用rbcL序列构建的系统树中,四个博鳌蜈蚣藻样品聚在一起并与莺歌海蜈蚣藻(G.yinggehaiensis)聚成一个小分支。通过形态观察和rbcL序列分析,认为博鳌蜈蚣藻和莺歌海蜈蚣藻的亲缘关系最近。 相似文献
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The Corallinales includes ca. 40 genera of calcified red seaweeds. Species are of two distinct morphotypes; those that possess genicula (uncalcified nodes) and those that lack genicula. Most nongeniculate species take the form of crusts. The presence (or absence) of genicula, secondary pit connections, and tetrasporangial conceptacle features have traditionally been used as key characters for delimiting coralline subfamilies. In this study, nuclear encoded 18S and 26S rRNA gene sequences were determined and used to reexamine relationships among coralline taxa. Separate and combined phylogenetic analyses of these data yielded similar trees in which four major lineages are resolved. Heydrichia and Sporolithon (Sporolithaceae) are positioned at the base of the tree and appear to be distantly related to other species examined. Within the Corallinaceae, the nongeniculate Melobesioideae is resolved as a monophyletic group. All members of this subfamily produce mutiporate tetraspoangial conceptacles. The Corallinoideae, which are characterized by unizonate genicula, are resolved as sister to a clade containing species placed in the Lithophylloideae, Mastophoroideae and Metagoniolithoideae. The molecular data indicate that geniculate and nongeniculate species characterized by the presence of secondary pit connections are closely related. For example, both data sets robustly support a sister taxon relationship between Amphiroa and Titanoderma. Our results indicate that: 1) all taxa in which secondary pit connections are present should be referred to the Lithophylloideae and, 2) genicula are nonhomologous structures that are independently derived in Amphiroa, Lithothrix, Metagoniolithon and the last common ancestor of the Corallinoideae. 相似文献
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Conflicting classifications for the Corallinales were tested by analyzing partial sequences for the nuclear small-subunit ribosomal RNA (SSU) gene of 35 species of coralline algae. Parsimony and likelihood analyses of these data yielded congruent hypotheses that are inconsistent with classifications for the group that include as many as eight subfamilies. Four major clades are resolved within the order, including the early-diverging Sporolithaceae as well as the Melobesioideae and Corallinoideae. The fourth clade, which is supported robustly, includes both nongeniculate and geniculate species classified in the subfamilies Mastophoroideae, Metagoniolithoideae, Lithophylloideae, and Amphiroideae. Molecular and morphological data support the proposal that the latter two subfamilies are sister taxa. Although relationships among some genera are not resolved clearly, the order of branching of taxa among and within the four principal lineages is concordant with paleontological evidence for the group. Relationships inferred among genera within each of the clades is discussed. Seven morphological characters delimiting higher taxonomic groups within the order were combined with the sequence data, analyzed, and optimized onto the resulting tree(s). Except for the presence or absence of genicula, all other characters were found to be phylogenetically informative. Genicula are nonhomologous structures that evolved independently in the Amphiroideae, Corallinoideae, and Metagoniolithoideae. The phenetic practice of separating coralline algae into two categories solely on the basis of the presence or absence of genicula does not accurately reflect the evolutionary history of the group. 相似文献
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Ahnfeltia plicata (Hudson) Fries, the type species of Ahnfeltia Fries, is reported to be a widespread alga which is an important source of agar. However, after characterizing type material and representative populations of A. plicata, we found that several taxa usually considered to be synonyms of A. plicata instead represent separate species with differing geographic distributions. Ahnfeltia plicata sensu stricto is characterized by the development of external carposporophytes on female sori that are present only on mature axes. Pseudocarposporophytes bearing monosporangia and cortical monosporangial sori occur on both young and old axes. Characteristic vegetative features include long medullary cells and cortical growth rings. Ahnfeltia plicata s.s. is circumpolar in both hemispheres and is harvested for agar in the White Sea. Ahnfeltia setacea (Kútzing) Schmitz from the Falkland Islands, Gymnogongrus comosus Kützing from Chile and Gymnogongrus filiformis Kützing from southern Argentina appear to be synonymous with A. plicata. Ahnfeltia fastigiata (Postels et Ruprecht) Makienko, from the North Pacific, differs from A. plicata principally in the development of female sori and carposporophytes only near apices; medullary cells are shorter and cortical growth rings, cortical monosporangia and pseudocarposporophytes are not formed. It is dioecious and its life history involves the development from carpospores of a crustose Porphyrodiscus tetrasporophyte. We suggest that A. plicata var. tobuchiensis Kanno et Matsubara, the principal form of Ahnfeltia utilized for agar production in the North Pacific, represents an unattached ecad of A. fastigiata. Ahnfeltia elongata Montagne, known only from Chile and with carposporophytes restricted to main axes, is more closely related to A. plicata than to A. fastigiata. Thalli are large and regularly dichotomous, with long medullary cells, and do not form pseudocarposporophytes or monosporangia. 相似文献
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Eucheuma acanthocladum (Harvey) J. Agardh, E. gelidium (J Agardh) J. Agardh, E. echinocarpum Areschoug and E. schrammii(P. et H. Crouan) J. Agardh from the tropical and warm temperate waters of the western Atlantic Ocean and Caribbean Sea are transferred to a new genus, Meristiella. Meristiella exhibits the following Unique combination of characters among genera in the Solieriaceae: (1) rotated periaxial cells, (2) a loosely filamentous medulla. (3) an auxiliary cell complex, (4) Single and twin connecting filaments and (5) spinose cystocarps composed of a central, small-celled placentum, based on its reproductive features, Meristiella. is assigned to the tribe Agardhielleae. Culture experiments and herbarium studies provide evidence that E, gelidium and E. acantghocladum are conspecific. Lectotypes are designated for the included species. 相似文献
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Taxonomic studies of an extensive collection of flattened members of the Solieriaceae considered by many authors to be species of Agardhiella, Eucheuma, Meristotheca, and Meristiella lead us to conclude that they represent only two genera in Brazil: Agardhiella, including A. ramosissima (Harvey) Kylin and A. floridana (Kylin) Gabrielson ex Guimarães et Oliveira, and Meristiella, with only one species, M. gelidium (J. Agardh) Cheney et Gabrielson. Accordingly, we propose that 1) Meristotheca gigartinoides Joly et Ugadim be synonymized with Agardhiella floridana, and 2) Meristiella echinocarpa (Areschoug) Cheney et Gabrielson and M. schrammii (P. et H. Crouan) Cheney et Gabrielson be synonymized with Meristiella gelidium. 相似文献
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The subfamily Mastophoroideae (Corallinaceae, Rhodophyta) is characterized by species possessing nongeniculate, uniporate tetrasporangial conceptacles without apical plugs, the presence of cell fusions, and the absence of secondary pit connections. However, molecular phylogenetic studies not including the type genus Mastophora indicated that the Mastophoroideae was polyphyletic. Our molecular phylogenetic analysis of the subfamily including the type genus using DNA sequences of SSU rDNA and plastid‐encoded gene of PSII reaction center protein D1 (psbA) revealed that Mastophora formed a robust clade only with Metamastophora. The other mastophoroid genera were divided into six lineages within the family Corallinaceae. Five supported lineages—(i) Pneophyllum; (ii) Hydrolithon gardineri (Foslie) Verheij et Prud’homme, Hydrolithon onkodes (Heydr.) Penrose et Woelk., and Hydrolithon pachydermum (Foslie) J. C. Bailey, J. E. Gabel et Freshwater; (iii) Hydrolithon reinboldii (Weber Bosse et Foslie) Foslie; (iv) Spongites; and (v) Neogoniolithon—were clearly distinguished by the combination of characters including the presence or absence of palisade cells and trichocytes in large, tightly packed horizontal fields and features of tetrasporangial and spermatangial conceptacles. Therefore, we amend the Mastophoroideae to be limited to Mastophora and Metamastophora with a thin thallus with basal filaments comprised of palisade cells, tetrasporangial conceptacles formed by filaments peripheral to fertile areas, and spermatangia derived only from the floor of male conceptacles. This emendation supports Setchell’s (1943) original definition of the Mastophoroideae as having thin thalli. We also propose the establishment of three new subfamilies, Hydrolithoideae subfam. nov. including Hydrolithon, Porolithoideae subfam. nov. including the resurrected genus Porolithon, and Neogoniolithoideae subfam. nov. including Neogoniolithon. Taxonomic revisions of Pneophyllum and Spongites were not made because we did not examine their type species. 相似文献
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The genus Lenormandia is composed of nine species from Australia and New Zealand. Some of the these are well known, but others are rare, obscure and ill-defined. We have examined material of all described species and found that they fall into two discrete groups that differ in apex morphology and position of reproductive structures. Plants of the first group, containing the type species L. spectabilis , have a cleft apex and reproductive structures produced directly on the blade surface, whereas those of the second group have a strongly inrolled apex and produce reproductive structures dorsally on small branchlets which arise either from the margins or the midrib. The groups were also found to form discrete clades on analysis of 18S rRNA sequences. All the members of the first group are endemic to Australia, whereas the second group, designated by the new genus name Adamsiella , contains two previously described New Zealand species and a single Australian representative. In addition, two new species are described in this group from New Zealand. Members of the closely related genus Lenormandiopsis were also examined and the type species, L. latifolia , was found to conform in apex morphology and position of reproductive structures to the genus Lenormandia. Accordingly Lenormandiopsis has been subsumed within Lenormandia. The remaining three members of the former genus Lenormandiopsis , however, were found to differ from both the type species and the genus Lenormandia and consequently have been transferred to the separate genus Geraldia , along with a new species from Geraldton, Western Australia which is designated as the type. 相似文献
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Dorit Van-Moppes Ze'ev Barak David M. Chipman Natan Gollop Shoshana Arad 《Journal of phycology》1989,25(1):108-112
The unicellular red alga Porphyridium sp. is, like many bacteria, fungi and higher plants, sensitive to the sulfonylurea herbicide sulfometuron methyl (SMM). However, the minimal inhibitory concentration for SMM in Porphyridium (55 μM) is higher than in green plants. We isolated a spontaneous SMM-resistant mutant SMR1 of Porphyridium sp. by use of a double-layered agar technique. The mutation frequency and the similarity of the mutant's morphology and growth patterns to the parent strain strongly suggest that SMR1 is a single gene mutation. The activity of the enzyme acetohydroxy acid synthase (AHAS) in crude extracts of the mutant SMR1 is at least two orders of magnitude less sensitive to SMM than that of the parent strain, which indicates that AHAS is the target of SMM (as has been shown in a variety of organisms). We propose that such a mutation, the first isolated in a unicellular rhodophyte, would be a useful marker for genetic studies of Porphyridium. It may also be useful for maintaining unialgal cultures in large scale open ponds. 相似文献
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Joan G. Stewart 《Journal of phycology》1989,25(3):436-446
The dominance of Corallina thalli in an intertidal algal assemblage was examined by a series of algal removal experiments to test the hypothesis that other tam are competitively excluded from rock substrate. An alternate explanation, that environmental factors seasonally filter out taxa leaving Corallina as the only alga adapted for year to year survival, was considered. Development of vegetation on patches of naturally exposed bare rock was monitored and compared with manipulated surfaces. Thalli of several species were selectively removed from exposed surfaces and intact turf;. changes in tam occupying primary substrate were recorded over more than three years. No significant differences in mean percent cover for Corallina, Lithothrix, bare rock, or algal crusts were found among treatments. Except for initial growth of colonizing species, abundances of other species dad not increase in the absence of Corallina. Large amounts of rock remained bare or intermittently covered by transient populations of short-lived algae. Data from single quad-rats, where individual clumps of Lithothrix were followed from month to month, indicated that the continued presence of this co-occurring and often abundant species depended on turnover of short-lived thalli rather than persistence of the same clumps. No interactions were found among the several categories of species that appeared after rock substrate was cleared. Most species were the same ones that grew, epiphytically in intact turf at the same time. In control quadrats Corallina maintained 59-95% cover while slowly increasing on surfaces earlier exposed. I predict that Corallina species will regain their dominance in the absence of competitors for primary substrate if the slowly spreading basal crusts remain undisturbed. Morphological and life history characteristics are identified that adapt Corallina to its dominant role in this habitat. 相似文献