首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Vegetative and reproductive development of Neosiphonia flavimarina gen. et sp. nov. (Rhodomelaceae, Ceramiales) from Bangpo on the western coast of Korea was investigated. This species is superficially similar to Polysiphonia, but differs distinctly from the latter in vegetative and reproductive structures. The plants attach by a solid disk composed of a dense cluster of rhizoids cut off from the pericentral cell wall, and bear erect indeterminate branches producing the lateral-branch initials from successive segments in a spiral arrangement. The procarps have a three-celled carpo-gonial branch. Spermatangial branches are formed on a primary branch of the trichoblasts, terminating in a single or occasionally two large, sterile cells. Tetra-sporangia are produced from the second pericentral cell adjacent to the trichoblast basal cell on indeterminate branches, and arranged spirally. Comparing several taxonomic characters among related genera, Neosiphonia occupies an independent phylogenetic position from Polysiphonia and leads to the conclusion that the genus may have a strong link with Fernandosiphonia which has a unilateral branching system. Relevant nomenclatural changes for several Polysiphonia species are also proposed.  相似文献   

2.
ABSTRACT

A new species of the genus Polysiphonia from the Mediterranean Sea is described. It is an ecorticate species, with 4 pericentral cells, showing prostrate axes from which erect axes arise. Rhizoids are formed by pericentral cells in a median position remaining in open connection with them. Erect axes are straight, simple throughout or pseudodichotomous at the base then simple or with one (rarely two-three) orders of branching; trichoblasts and scar cells not observed. Only tetrasporangial plants were found. They show ellipsoid tetrasporangia borne in short straight series, often interrupted by sterile segments. The new species is also characterized by a peculiar habit consisting of prostrate axes, adhering to lower faces of Peyssonnelia spp. by means of rhizoids growing upward, from which erect upright axes perforating thalli of the supporting species arise. A comparison with the related species of Polysiphonia was also carried out.  相似文献   

3.
Two species of Phycodrys, Phycodrys quercifolia (Bory) Skottsberg and Phycodrys profunda E.Y.Dawson were previously recorded from New Zealand. However, an examination of Phycodrys collections from the New Zealand region showed that all were morphologically different from P. quercifolia (Type locality: the Falkland Islands) and P. profunda (Type locality: CA, USA). RbcL sequence analyses established that the New Zealand Phycodrys species formed a natural assemblage within the genus, consisting of three new species: P. novae-zelandiae sp. nov., P. franiae sp. nov. and P. adamsiae sp. nov. Phycodrys novae-zelandiae is the largest of the three, up to 20 cm in height, with a distinct midrib and multicellular, opposite to subopposite lateral macroscopic veins. It has entirely monostromatic blades except near the midrib and veins, and its procarp contains a three-celled sterile group one (st1) and a one-celled sterile group two (st2). Phycodrys franiae was previously treated as a cryptic species among herbarium collections of P. ‘quercifolia’. It is smaller (4–11 cm high) with weakly developed midribs and veins, the blade is tristromatic throughout, except at the growing margins, and the procarp consists of a four-celled st1 and a two–three-celled st2. Phycodrys adamsiae, previously reported as P. profunda, is a small decumbent or prostrate plant, 1–8 cm long, with a midrib and inconspicuous lateral veins. The blades are tristromatic with serrated margins, two–four-celled surface spines and multicellular marginal holdfasts that differ from those of Californian specimens. The tetrasporangia are borne on marginal bladelets. Phylogenetic analyses place the New Zealand species in a separate group that is distantly removed from most other Phycodrys species.  相似文献   

4.
5.
The taxonomic positions of soil isolates known as Streptomyces groups A, B and C were clarified. Comparative 16S rDNA sequence studies indicated that representatives of all three taxa formed distinct phyletic lines within the Streptomyces tree though the group A strains were shown to be related to Streptomyces griseus and associated validly described species. The taxonomic integrity of all three groups was highlighted by DNA:DNA relatedness and ribotype data though the group A strains encompassed a higher degree of genetic variation than the group B and C strains. In light of these and earlier phenotypic data it is proposed that Streptomyces groups A, B and C be given species status as Streptomyces sanglieri sp. nov., Streptomyces aureus sp. nov. and Streptomyces laceyi sp. nov., respectively. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

6.
Two new marine diatom species from Argentinean coastal waters, Pleurosigma hinzianum Sterrenburg, Sunesen & Sar, sp. nov. and P. frenguellianum Sunesen, Sterrenburg & Sar, sp. nov., are described. The characters permitting their identification are specified, based on comparison with type material of the morphologically similar species P. amara Stidolph and P. elongatum W. Smith in the light (LM) and scanning electron microscope (SEM). New information on the type material of P. elongatum is presented and its taxonomic concept is emended. The main criteria for separation of the species discussed here are: valve outline, path of the raphe-sternum, raphe angle and angle of intersection of the oblique striae in LM; and external central and terminal raphe fissures, internal details of the central area, external and internal apical structure, and morphology of the hymen-occluded internal pores in SEM. The occurrence of these (and probably other) species in the genus Pleurosigma in net samples is adventitious and not indicative of a true planktonic mode of life.  相似文献   

7.
Two new species of heliobacteria isolated from cyanobacterial mats of two alkaline sulfidic hot springs are formally described. Strains BR4 and BG29 are assigned to anoxygenic phototrophic bacteria of the familyHeliobacteriaceae, since they possess the unique properties of this taxon: strict anaerobiosis, formation of bacteriochlorophyllg, the lack of extensive intracytoplasmic membranes and chlorosomes, an unusual cell wall structure, and phylogenetic relatedness to the low G+C gram-positive eubacteria. Based on the 16S rDNA sequence similarity, strains BR4 and BG29 are assigned to the genusHeliobacterium and described as two new species of this genus:Heliobacterium sulfidophilum sp. nov. andHeliobacterium undosum sp. nov. The G+C content of the DNA is 51.3 mol % inHbt. sulfidophilum and 57.2-57.7 mol % inHbt. undosum. The cells ofHbt. sulfidophilum are rods, and the cells ofHbt. undosum are slightly twisted spirilla or short rods. Both new bacteria are motile by peritrichous flagella.Hbt. sulfidophilum produces endospores. The new bacteria are strict anaerobes growing photoheterotrophically on a limited range of organic compounds. In the dark, they can switch from photosynthesis to the slow fermentation of pyruvate. Biotin is required as a growth factor. Both species are highly tolerant to sulfide (up to 2 mM at pH 7.5) and oxidize it photoheterotrophically to elemental sulfur; photoautotrophic growth was not observed. The temperature optimal for growth ofHbt. sulfidophilum andHbt undosum is 30–35‡C, and the optimal pH is 7–8.  相似文献   

8.
Two new taxa of Liagoraceae (Nemaliales) are described from Western Australia. Gloiotrichus fractalis gen. et sp. nov. has been collected from 3–20 m depths at the Houtman Abrolhos, Western Australia. Plants are calcified, extremely lubricous, and grow to 17 cm in length. Carpogonial branches are straight, 6 or 7 cells in length, arise from the basal or lower cells of cortical fascicles, and are occasionally compound. Branched sterile filaments of narrow elongate cells arise on the lower cells of the carpogonial branch prior to gonimoblast initiation, at first on the basal cells, then on progressively more distal cells. Following presumed fertilisation the carpogonium divides transversely, with both cells giving rise to gonimoblast filaments. The distal cells of the carpogonial branch then begin to fuse, with fusion progressing proximally until most of the cells of the carpogonial branch are included. As fusion extends, the filaments on the carpogonial branch are reduced to the basal 2 or 3 cells. The gonimoblast is compact and bears terminal carposporangia. Spermatangial clusters arise on subterminal cells of the cortex, eventually displacing the terminal cells. The sequence of pre- and post-fertilisation events occurring in the new genus separates it from all others included in the Liagoraceae, although it appears to have close affinities with the uncalcified genus Nemalion. Ganonema helminthaxis sp. nov. was collected from 12 m depths at Rottnest Island, Western Australia. Plants are uncalcified and mucilaginous, the axes consisting of a few (< 10) primary medullary filaments, each cell of which gives rise to a cortical fascicle at alternate forks of the pseudodichotomies borne on successive medullary cells. Subsidiary (adventitious) filaments and rhizoids comprise the bulk of the thallus. Carpogonial branches are straight, (3-)4(-6) cells in length, arise on the basal 1–4 cells of the cortical fascicles, and are frequently compound. Carposporophytes develop from the upper of two daughter cells formed by a transverse division of the fertilised carpogonium. Ascending and descending sterile filaments girdle the carpogonial branch cells and arise mostly on the supporting cell prior to fertilisation. Ganonema helminthaxis is the first completely non-calcified member of the genus, and its reproductive and vegetative morphology supports the recognition of Ganonema as a genus independent from Liagora. Liagora codii Womersley is a southern Australian species displaying features of Ganonema, to which it is transferred.  相似文献   

9.
Three isolates belonging to the ascomycetous genus Zygotorulaspora were obtained from the fruits of Cornus officinalis and Smilax china, and flowers of Dendranthema zawadskii var. latilobum in Gongju-si, Korea. Phylogenetic Analyses of the LSU D1/D2 domain and ITS region sequences supported the recognition of two new species: Zygotorulaspora cornina sp. nov. (type strain NIBRFGC000500475 = KACC93346PPP) and Zygotorulaspora smilacis sp. nov. (type strain NIBRFGC000500476 = KACC93347PPP). The two novel species revealed no growth on D-Galactose, unlike the other six species in the genus Zygotorulaspora. They are distinguished from each other by their phylogenetic differences and phenotypic characteristics such as assimilation of xylitol, 5-keto-D-gluconate, and ethanol. All species in the genus Zygotorulaspora including the two novel species have phenotypic traits of genus Zygotorulaspora: asci are persistent, sucrose and raffinose are assimilated, and m-inositol is not required for growth, and they are mainly associated with plants.  相似文献   

10.
An anaerobic phthalate isomer-degrading strain (JTT) that we previously isolated was characterized. In addition, a strictly anaerobic, mesophilic, syntrophic phthalate isomer-degrading bacterium, designated strain JIT, was isolated and characterized in this study. Both were non-motile rods that formed spores. In both strains, the optimal growth was observed at temperatures around 37°C and neutral pH. In syntrophic co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei, both strains could utilize two or three phthalate isomers for growth, and produce acetate and methane as end products. Strain JTT was able to grow on isophthalate, terephthalate, and a number of low-molecular weight aromatic compounds, such as benzoate, hydroquinone, 2-hydroxybenzoate, 3-hydroxybenzoate, 2,5-dihydroxybenzoate, 3-phenylpropionate in co-culture with M. hungatei. It could also grow on crotonate, hydroquinone and 2,5-dihydroxybenzoate in pure culture. Strain JIT utilized all of the three phthalate isomers as well as benzoate and 3-hydroxybenzoate for growth in co-culture with M. hungatei. No substrates were, however, found to support the axenic growth of strain JIT. Neither strain JTT nor strain JIT could utilize sulfate, sulfite, thiosulfate, nitrate, fumarate, Fe (III) or 4-hydroxybenzoate as electron acceptor. Phylogenetically, strains JTT and JIT were relatively close to the members of the genera Pelotomaculum and Cryptanaerobacter in ‘Desulfotomaculum lineage I’. Physiological and chemotaxonomic characteristics indicated that the two isolates should be classified into the genus Pelotomaculum, creating two novel species for them. Here, we propose Pelotomaculum terephthalicum sp. nov. and Pelotomaculum isophthalicum sp. nov. for strain JTT and strain JIT, respectively. The type strains are strains JTT (= DSM 16121T = JCM 11824T = NBRC 100523T) and JIT (= JCM 12282T = BAA-1053T) for P. terephthalicum and P. isophthalicum, respectively.Nucleotide sequence accession number: The GenBank/EMBL/DDBJ accession numbers of the 16S rRNA gene sequences of strains JTT and JIT are AB091323 and AB232785, respectively  相似文献   

11.
An elachistacean epiphyte, Neoleptonema yongpilii E.-Y. Lee & I.K. Lee, gen. et sp. nov., is reported from Korean coasts. The plants are distinguished by having unbranched assimilatory filaments with intercalary plurilocular sporangia as well as lateral plurilocular sporangia from the cortex. The new genus differs from the genera Leptonematella P. Silva and Halothrix Reinke by having pod-shaped plurilocular sporangia on the medulla, and from Elachista Duby and Proselachista Y.P. Lee & Garbary by having intercalary plurilocular sporangia and a poorly developed medulla. The phylogenetic relationships of Neoleptonema yongpilii were inferred from the spacer sequences between the genes coding for the large and small subunits of the RuBisCO gene. The new genus is a member of a poorly resolved clade consisting of several genera within the Elachistaceae, within which it is more closely related to Halothrix and Elachista nipponica than to Leptonematella.  相似文献   

12.
The present paper documents the morphology and systematic positions of three new oligotrich ciliates, P arallelostrombidium obesum sp. nov. , P arallelostrombidium ellipticum sp. nov. , and S trombidium tropicum sp. nov. , which were sampled from habitats with different salinities in southern China. P arallelostrombidium obesum sp. nov. is characterized by a fat body and the posterior portions of the girdle and ventral kineties extending transversely on the dorsal side. P arallelostrombidium ellipticum sp. nov. is recognizable by the anterior ends of the girdle and ventral kineties being close to each other and the posterior ends of the girdle and ventral kineties intersecting on the dorsal side. S trombidium tropicum sp. nov. is distinguished by a ventrally opened girdle kinety that is slightly spiralled with the right end shifted posteriad. Small subunit rRNA gene trees show that P . obesum sp. nov. and P . ellipticum sp. nov. fall into a mixed group composed of Parallelostrombidium and some Novistrombidium species, and that S . tropicum sp. nov. branches at the base of the clade containing non‐Strombidium species. The relationships of Parallelostrombidium species and that of Strombidium species are both not resolved considering their low support values in our phylogenetic analysis. © 2015 The Linnean Society of London  相似文献   

13.
Thecadinium inclinatum Balech and four new marine sand‐dwelling species of the dinoflagellate genus Thecadinium are described from the sandy beaches along the coast of Shikoku, Japan. Thecadinium inclinatum is thecate, bilaterally flattened, elliptical in shape, non‐photosynthetic, and measures 55–75 μ in length and 43–59 μ in depth. The epi‐ and hypotheca theca are semielliptical and the thecal surface is smooth with small pores. The plate formula is Po (pore plate), 3′, 7″,?c,?s, 5″′1″′.Thecadinium ovatum sp. nov. is thecate, non‐photosynthetic, bilaterally flattened and almost oval in lateral view. The cell measures 40–50 μm in length and 33–40 μm in depth. The hypotheca has two or three strong antapical spines. The plate formula is 3′, 6″,6c, 5s?, 5″′, 1″′. Thecadinium striatum sp. nov. is thecate, non‐photosynthetic, bilaterally flattened and somewhat elliptical in lateral view. The cell is 33–41 μm long and 23–30 μm deep. Several striae are present on the hypotheca. The plate formula is 3′, 6″, 6c, 5s?, 5″′, 1″″. Thecadinium yashimaense sp. nov. is bilaterally flattened, photosynthetic and elliptical in ventral view. The cell is 44–65 μm long and 23–36 μm wide. The thecal surface is smooth with small pores. he cingulum forms a steep left–handed spiral. The plate formula is Po, 3′, la, 6″, 5c, 4s, 5″′, 1″′. Thecadinium arenarium sp. nov. is somewhat wedge‐shaped in ventral view, photosynthetic with brownish chloroplasts and almost rounded in cross section. The cingulum forms a steep left‐handed spiral. The cell measures 35–41 μm in length and 25–30 μm in width. The thecal surface is weakly reticulated with small pores. The hypotheca is conical. The plate formula is Po, 3′, la, 6″, 5c, 4s, 5″′, 1″″.  相似文献   

14.
Viet Nam has a coastline of 3200 km with thousands of islands providing diverse habitats for benthic harmful algal species including species of Gambierdiscus. Some of these species produce ciguatera toxins, which may accumulate in large carnivore fish potentially posing major threats to public health. This study reports five species of Gambierdiscus from Vietnamese waters, notably G. australes, G. caribaeus, G. carpenteri, G. pacificus, and G. vietnamensis sp. nov. All species are identified morphologically by LM and SEM, and identifications are supported by molecular analyses of nuclear rDNA (D1–D3 and D8–D10 domains of LSU, SSU, and ITS1-5.8S-ITS2 region) based on cultured material collected during 2010–2021. Statistical analyses of morphometric measurements may be used to differentiate some species if a sufficiently large number of cells are examined. Gambierdiscus vietnamensis sp. nov. is morphologically similar to other strongly reticulated species, such as G. belizeanus and possibly G. pacificus; the latter species is morphologically indistinguishable from G. vietnamensis sp. nov., but they are genetically distinct, and molecular analysis is deemed necessary for proper identification of the new species. This study also revealed that strains denoted G. pacificus from Hainan Island (China) should be included in G. vietnamensis sp. nov.  相似文献   

15.
Based upon COI‐5P, LSU rDNA, and rbcL sequence data and morphological characteristics, six new members of the noncalcified crustose genus of red algae Ethelia are described in a new family, Etheliaceae (Gigartinales), sister to the recently described Ptilocladiopsidaceae. The novel species are described from subtropical to tropical Atlantic and Indo‐Pacific Ocean basins; E. mucronata sp. nov. and E. denizotii sp. nov. from southern and northern Western Australia respectively, E. wilcei sp. nov. from the Cocos (Keeling) Islands of Australia, E. suluensis sp. nov. from the Philippines, E. umbricola sp. nov. from Bermuda and E. kraftii sp. nov. from Lord Howe Island, Australia. The generitype, Ethelia biradiata, originally reported from the Seychelles, Indian Ocean, is added to the Western Australian flora.  相似文献   

16.
Two strains of xylose-containing and Q-10-having ballistoconidiogenous yeasts isolated from plant leaves collected in Taiwan were found to represent two new species of the genus Bullera. In the phylogenetic trees based on the sequence analysis of 18S rDNA and D1/D2 domain of 26S rDNA, these species are located in the Bullera variabilis (Bulleribasidum) cluster in Hymenomycetes. They are described as Bullera begoniae sp. nov. and Bullera setariae sp. nov., respectively.  相似文献   

17.
A new bitterling, Rhodeus pseudosericeus sp. nov., is described on the basis of 31 specimens from five localities included in the Namhan River system, South Korea. The new species is distinguished from other Rhodeus species by the following combination of characters: branched dorsal fin rays 9–10 (mode 9); branched anal fin rays 9–11 (mode 10); longest simple ray of dorsal fin strong and stiff, distally segmented; pelvic fin rays i, 6–7; iris of males blackish; dorsal and anal fins of males grayish in breeding season; karyotype with 2n = 48 (8m + 20sm + 20st). Rhodeus pseudosericeus sp. nov. is similar to Rhodeus sericeus sericeus in the number of pelvic fin and branched dorsal fin rays and the melanophores present on the dorsal fin membrane, but differs from the latter in having a greater body depth, more branched anal fin rays, fewer vertebrae, a lower number of scales in the lateral series, and differing male nuptial coloration. Received: June 30, 2000 / Revised: February 21, 2001 / Accepted: March 6, 2001  相似文献   

18.
Yasumatsusa Togashi, 1970 and Aproceros Malaise, 1931 are recorded for the first time from South Korea. A new species, Yasumatsua koreana Lee & Lee sp. nov., and newly recorded species, Aproceros pallidicornis (Mocsáry, 1909), are described. Photographs of the new species and a key to genera of Korean Sterictiphorinae are provided.  相似文献   

19.
20.
A novel actinobacterium, designated strain MSW-19T, was isolated from a seawater sample in Republic of Korea. Cells were aerobic, Gram-positive, non-endospore-forming, and non-motile cocci. Colonies were circular, convex, opaque, and vivid yellow in colour. A phylogenetic tree based on 16S rRNA gene sequences exhibited that the organism formed a distinct clade within the radius encompassing representatives of the family Propionibacteriaceae. The phylogenetic neighbors were the type strains of the genera Friedmanniella, Microlunatus, Micropruina, Propionicicella, and Propionicimonas. Levels of 16S rRNA gene sequence similarity between the isolate and members of the family were less than 95.3%. The cell wall peptidoglycan of the organism contained LL-diaminopimelic acid as the diagnostic diamino acid. The isolate contained MK-9(H4) as the predominant menaquinone, ai-C15:0 as the major fatty acid and polar lipids including phosphatidylglycerol, phosphatidylethanolamine, and an unknown phospholipid. The G+C content of the DNA was 69.6 mol%. On the basis of the phenotypic and phylogenetic data presented here, the isolate is considered to represent a novel genus and species in the family Propionibacteriaceae, for which the name Ponticoccus gilvus gen. nov., sp. nov. is proposed. The type strain is strain MSW-19T (= KCTC 19476T= DSM 21351T).  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号