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1.
Porphyra and Bangia (Bangiaceae, Rhodophyta) in warm temperate waters of eastern Australia: Morphological and molecular analyses 总被引：2，自引：0，他引：2
Morphological observations confirm the presence of only three species of the Bangiaceae (Rhodophyta) in warm temperate waters of eastern Australia: Bangia atropurpurea, Porphyra columbina and Porphyra denti-culata. Analyses of DNA sequence data from the inter-generic spacer region between the large- and small-sub-unit ribulose-l,5-bisphosphate carboxylase/oxygenase gene (rbcL and rbcS, respectively) and portions of the flanking regions, confirm these taxonomic conclusions for the two Porphyra species: there is clear sequence divergence between the two species, and strong genetic similarity between P. columbina isolates over a wide geographical region. Sequence analyses also reveal a strong similarity between Bangia isolates over a wide geographical range, but the taxonomy of B. atropurpurea may need to be re-examined in light of sequence differences between these and northern hemisphere isolates of B. atropurpurea. Molecular analyses support the view that Bangia and Porphyra species are sufficiently closely related to be placed in a single genus. 相似文献
2.
Sverine Cohen Sylvain Faugeron Enrique A. Martínez Juan A. Correa Frdrique Viard Christophe Destombe Myriam Valero 《Journal of phycology》2004,40(4):742-747
Molecular markers belonging to three different genomes, mitochondrial (cox2‐3 spacer), plastid (RUBISCO spacer), and nuclear (internal transcribed spacer 1), were used to compare Gracilaria chilensis samples collected along the Chilean coast with samples ascribed to G. chilensis from the West Pacific Ocean (New Zealand and Australia). Our data are in agreement with previous studies suggesting two sibling species currently going under the name G. chilensis that co‐occur in New Zealand. One of these, a New Zealand sample previously examined by Bird and others in 1990, is conspecific with G. chilensis from Chile. Finally, our results demonstrate clearly that most of the sequences in GenBank reported as G. chilensis are based on misidentified material. 相似文献
3.
There is currently conflict in the literature on the taxonomic status of the reportedly cosmopolitan species Neosiphonia harveyi, a common red alga along the coast of Atlantic Canada and New England, USA. Neosiphonia harveyi sensu lato was assessed using three molecular markers: COI‐5P, ITS and rbcL. All three markers clearly delimited three genetic species groups within N. harveyi sensu lato in this region, which we identified as N. harveyi, N. japonica and Polysiphonia akkeshiensis (here resurrected from synonymy with N. japonica). Although Neosiphonia harveyi is considered by some authors to be introduced to the Atlantic from the western Pacific, it was only confirmed from the North Atlantic suggesting it is native to this area. In contrast, Neosiphonia japonica was collected from only two sites in Rhode Island, USA, as well as from its reported native range in Asia (South Korea), which when combined with data in GenBank indicates that this species was introduced to the Northwest Atlantic. The GenBank data further indicate that N. japonica was also introduced to North Carolina, Spain, Australia and New Zealand. Despite the fact that all three markers clearly delimited N. harveyi and N. japonica as distinct genetic species groups, the ITS sequences for some N. harveyi individuals displayed mixed patterns and additivity indicating introgression of nuclear DNA from N. japonica into N. harveyi in the Northwest Atlantic. Introgression of DNA from an introduced species to a native species (i.e. ‘genetic pollution’) is one of the possible consequences of species introductions, and we believe this is the first documented evidence for this phenomenon in red algae. 相似文献
4.
Diatom assemblages were monitored at weekly intervals over a 5 week period on Verde limestone, Supai sandstone, and Andesitic basalt substrata in a mountain stream in northern Arizona, U.S.A. Density, Shannon-Weiner diversity, evenness, and community similarity (SIMI) were used to compare colonization patterns and community structure between individual substratum types. Average standing crop values were nearly two-fold higher on sandstone than on either basalt or limestone substrata after the first week of the study. It is proposed that differences in micro-surface features between substrata and possibly the rate of substratum solubilization may cause these differences in density early in the colonization period. Following the initial week, standing crop and community structure were significantly similar on all substrata for the remainder of the study period. Maximum densities were attained by the third week and remained relatively constant on all substrata for the remainder of the study. SEM micrographs demonstrated that surfaces of submerged substrata in streams are modified after the first week by the accumulation of organic aggregates. The establishment of an “organic matrix” early in the colonization process may provide relatively similar attachment surfaces for microbial invasion. This appears to reduce the initial microtopographic differences displayed by substrata and allows for a more uniform colonization pattern. 相似文献
5.
Christopher D. Neefus Arthur C. Mathieson Troy L. Bray Charles Yarish 《Journal of phycology》2008,44(6):1399-1414
6.
Porphyra tenera Kjellman, widely cultivated in nori farms before the development of artificial seeding, is currently listed as an endangered species in Japan. To confirm whether a wild‐collected gametophytic blade was P. tenera or the closely related species P. yezoensis Ueda, morphological observations and molecular analyses were made on the pure line HGT‐1 isolated from a wild blade. This pure line was identified as P. tenera based on detailed morphological features. Sequences of the nuclear internal transcribed spacer region 1 and the plastid RUBISCO spacer revealed that P. tenera HGT‐1 was clearly different from P. yezoensis f. narawaensis Miura, the main species cultivated in Japan. PCR‐RFLP analysis of the internal transcribed spacer region was found to be a convenient method for rapid discrimination between P. tenera and cultivated P. yezoensis. The restriction patterns generated by the endonucleases Dra I and Hae III were useful for differentiating between both gametophytic and conchocelis stages of P. tenera HGT‐1 and P. yezoensis f. narawaensis strains. Thus, PCR‐RFLP analysis will serve as a valuable tool for rapid species identification of cultivated Porphyra strains, culture collections of Porphyra strains for breeding material and conservation of biodiversity, and, as codominant cleaved amplified polymorphic sequence markers for interspecific hybridization products between P. tenera and P. yezoensis f. narawaensis. Under the same culture conditions, rate of blade length increase and the blade length‐to‐width ratio were lower in P. tenera HGT‐1 than in P. yezoensis f. narawaensis HG‐4. The HGT‐1 became mature more rapidly than HG‐4 and had thinner blades. 相似文献
7.
Phylogenetic relationships of the Ceramium sinicola complex (C. interruptum and C. sinicola) including C. codicola were studied using nucleotide sequences of rbcL and small subunit rDNA, and the RUBISCO spacer was used for sequence comparison of each species. A reassessment of the taxonomic rank and the evolutionary trend within the complex was inferred from a comparative morphological study and molecular data sets based on 11 samples from eight populations from the Pacific coast of the United States and Mexico. Intraspecific relationships were poorly resolved, but the resurrection of C. interruptum as a distinct species was strongly supported by both morphological and molecular data. Ceramium interruptum is distinguished by the combination of the following features: thalli uncorticated at the first internode above the dichotomy, presence of four corticating filaments, 7–11 segments between branching points, rhizoids digitate, and epiphytic on a variety of hosts. Our molecular analyses show that C. sinicola is the sister group to C. codicola, and C. interruptum is basal to them. These phylogenetic relationships allowed for an assessment of the trend in the evolution of cortication pattern and attachment mode to the host. 相似文献
8.
A new species of Porphyra is described from the south western Cape, South Africa. The gametophyte of Porphyra aeodis sp. nov. grows epiphytically on Aeodes orbitosa (Suhr) Schmitz, and has a seasonal life history that matches that of its host. Although P. aeodis has been confused with P. capensis Kützing in the past, P. aeodis is more similar to the sympatric but epilithic P. saldanhae Stegenga, Bolton et Anderson. There is considerable morphological overlap between P. aeodis and P. saldanhae, although they may be distinguished using a combination of morphological and ecological characters. The taxonomic separation of P. aeodis and P. saldanhae was confirmed using isozyme electrophoresis. 相似文献
9.
Chi Chiu Cheang Ka Hou Chu Daisuke Fujita Goro Yoshida Masanori Hiraoka Alan Critchley Han Gil Choi Delin Duan Yukihiko Serisawa Put O. Ang Jr. 《Journal of phycology》2010,46(6):1063-1074
Sargassum muticum (Yendo) Fensholt is one of the most well‐known invasive species in the world. There have, however, been few genetic investigations on both its introduced and native populations. There are also some questions about the taxonomic status of this species. This study is the first to assess the genetic diversity of S. muticum on a global scale, by utilizing one marker each from the extranuclear genomes, namely, plastidial RUBISCO and mitochondrial TrnW_I spacers, as well as the nuclear internal transcribed spacer 2 (ITS2). Based on the markers investigated, both the invasive as well as the native populations of this species appeared very homogenous, when compared with other invasive and brown macroalgae. No variation in ITS2 and RUBISCO spacer was revealed in S. muticum populations, including those from its native ranges in Asia and the introduced ranges in Europe and North America. Two TrnW_I spacer haplotypes with a fixed two‐nucleotide difference were found between the populations of eastern Japan and the other 15 populations examined. This study confirms that there is no cryptic diversity in the introduced range of this species. All the materials collected globally are indeed S. muticum. Results depicting the distribution range of the two TrnW_I spacer haplotypes also support the earlier suggestion that the source of the introduced S. muticum populations is most likely western and central Japan (Seto Inland Sea), where the germlings of S. muticum were likely to have been transported with the Pacific oysters previously introduced for farming in Canada, UK, and France in earlier years. 相似文献
10.
Kyosuke Niwa Satoko Iida Aki Kato Hiroshi Kawai Norio Kikuchi Atsushi Kobiyama Yusho Aruga 《Journal of phycology》2009,45(2):493-502
We investigated the genetic variations of the samples that were tentatively identified as two cultivated Porphyra species (Porphyra yezoensis Ueda and Porphyra tenera Kjellm.) from various natural populations in Japan using molecular analyses of plastid and nuclear DNA. From PCR‐RFLP analyses using nuclear internal transcribed spacer (ITS) rDNA and plastid RUBISCO spacer regions and phylogenetic analyses using plastid rbcL and nuclear ITS‐1 rDNA sequences, our samples from natural populations of P. yezoensis and P. tenera showed remarkably higher genetic variations than found in strains that are currently used for cultivation. In addition, it is inferred that our samples contain four wild Porphyra species, and that three of the four species, containing Porphyra kinositae, are closely related to cultivated Porphyra species. Furthermore, our PCR‐RFLP and molecular phylogenetic analyses using both the nuclear and plastid DNA demonstrated the occurrence of plastid introgression from P. yezoensis to P. tenera and suggested the possibility of plastid introgression from cultivated P. yezoensis to wild P. yezoensis. These results imply the importance of collecting and establishing more strains of cultivated Porphyra species and related wild species from natural populations as genetic resources for further improvement of cultivated Porphyra strains. 相似文献
11.
Red algae of the Bostrychia radicans/B. moritziana complex are common in warm temperate areas of North America. Phylogenetic analysis of both plastid and mitochondrial DNA sequence data revealed seven distinct evolutionary lineages among worldwide samples. Although only two haplotypes (plastid and mitochondrial) were found in Pacific Mexico, four plastid and 11 mitochondrial haplotypes were found in a similar latitudinal spread along the Atlantic coast of the United States. On the U.S. Atlantic coast only one plastid haplotype was found in northern samples (Connecticut to North Carolina), whereas further south several plastid haplotypes were found. Phylogenetic analyses suggested that this single plastid haplotype found among northern samples could be the result of a northward range expansion possibly since the last glacial maximum. Crossing data of samples within the same evolutionary lineage showed that samples with the same plastid haplotypes were generally sexually compatible; samples with different plastid haplotypes were reproductively isolated. Samples from Pacific Mexico were partially reproductively compatible with some samples from the Atlantic USA (plastid haplotype C) and were more closely related to these samples than these U.S. samples were to other U.S. Atlantic samples. Compatible solute types mirrored the plastid haplotype, with plastid haplotype B having only sorbitol, whereas all other haplotypes also contained dulcitol. Samples from Atlantic USA, with different plastid haplotypes (e.g. B vs. C), but within the same evolutionary lineage, were reproductively isolated from each other. Data indicate that reproductive isolation occurs between and within supported evolutionary lineages and that the number of cryptic species is high. 相似文献
12.
The phenology and seasonal growth of Porphyra linearis Grev. were investigated in two morphologically dissimilar populations from the west coast of Ireland. Thallus size and reproductive status of individuals were monitored monthly between June 1997 and June 1998. Both populations exhibited a similar phenology: gametophyte stages appeared on the shore in October, with spermatangial and zygotosporangial sori appearing the following February; the gametophyte stage began to degenerate in April and had disappeared completely by June. However, significant differences in growth and reproduction in the field and in cultures of plants from the two populations were observed. Thallus length and width of individuals from one population were significantly longer throughout the sample period, and reproduction and sporulation occurred 1 month earlier. Also, in situ relative growth rates (RGRs) of plants differed significantly and were correlated with different climatic factors (sunshine, day length, irradiance, rainfall, seawater temperature, and intertidal temperatures), suggesting that plants were affected by two different microhabitats. At one site, blades were more exposed to wave action, sunshine, and extreme minimum temperatures, while at the other site, blades were more protected in winter, spring, and early summer. In culture, RGRs of blades from the second site were higher than RGRs of blades from the first site under short days, corroborating the field results and suggesting a degree of phenotypic differentiation between the two populations. However, there were no sequence divergences of the RUBISCO spacer between strains of the two P. linearis populations. 相似文献
13.
A preliminary investigation of the order Bangiales (Bangiophycidae, Rhodophyta) based on sequences of nuclear small-subunit ribosomal RNA genes 总被引：3，自引：0，他引：3
Mariana C. Oliveira Joelius Kurniawan Carolyn J. Bird Ellen L. Rice Colleen A. Murphy Rama K. Singh Robin R. Gutell Mark A. Ragan 《Phycological Research》1995,43(2):71-79
We investigated phylogenetic relationships among red algae of the order Bangiales by analysis of sequences of the nuclear gene encoding cytosolic small-subunit ribosomal RNA in Bangia atropurpurea (Roth) C. Ag. and eight samples representing seven species of Porphyra. The ssu-rDNA range from 1818 to 1845 nucleotides in length, with guanosine plus cytosine ratios between 47.0% and 48.6%. A group IC1 intron occurs in the B atropurpurea ssu-rDNAs at the same position as in P. spiralis var. amplifolia Oliveira Filho et Coll and several other eukaryote ssu-rDNAs. The nine sequences form a stable monophyletic group upon phylogenetic analysis. The ssu-rDNA from B. atropurpurea nests stably within the Porphyra group and is closely related to P. amplissima (Kjellm.) Setchell et Hus in Hus, making the genus Porphyra paraphyletic. No correlation is seen between phylogenetic position and number of cell layers in the Porphyra thallus. We discuss possible taxonomic and evolutionary implications of these observations. 相似文献
14.
Zuccarello and West (2003) reported on the phylogenetic diversity of algae identified as Bostrychia radicans (Montagne) Montagne and B. moritziana (Sonder ex Kützing) J. Agardh from around the world. They showed that the species complex consisted of seven distinct lineages, of which two lineages were common on the East Coast of the USA and eastern Gulf of Mexico. The distribution of haplotypes within these lineages on the East Coast of the USA showed a general north–south distribution. One haplotype of lineage 5 (B) was mostly collected in northern areas, while the other common haplotype (C) was more southerly in distribution. Samples in lineage 6 (haplotype D) were not found north of Sapelo Island, Georgia. Increased sampling from the eastern USA over 5 years later has revealed an altered pattern. Haplotype D is distributed in North Carolina and is common in some populations. Haplotype C is rare or absent in many sampled populations. Haplotype B is only observed in the northern sampled sites on both sides of the Florida peninsula. This disjunct distribution agrees with geological scenarios for a strait between the western Gulf of Mexico and southern Georgia in the Miocene/Pliocene, which closed in the late Pliocene. This paper highlights the importance of increased sampling to determine phylogeographic patterns and hypotheses of dispersal scenarios in algae. 相似文献
15.
The Japanese red alga Grateloupia lanceolata (Okamura) Kawaguchi was discovered in southern California at Santa Catalina Island in spring 2003 and April 2008 and in central California at the mouth of the Elkhorn Slough in Moss Landing in May, June and July of 2008. The morphology of thalli from both localities agrees with published figures. Sequences from the rbc L gene and the nuclear marker, internal transcribed spacer-1 from Californian G. lanceolata were identical to those from two specimens of G. lanceolata introduced to the Thau Lagoon, Mediterranean France and a specimen from Japan. It is likely that the import of oysters for mariculture played a role in its introduction into California. 相似文献
16.
Pilar García-Jiménez Paul John L. Geraldino Sung Ming Boo Rafael R. Robaina 《Phycological Research》2008,56(3):166-171
Specimens of Grateloupia from Gran Canaria in the Canary Islands were used to molecularly ascertain which of the species has been used in physiological and bio-technological experiments. The rbc L sequence analysis revealed that four out of five analyzed specimens (i.e. those commonly collected for physiological research) formed a monophyletic clade with G. imbricata from Korea, Japan, and China, and were quite different from any other species of the genus. Another sample, which was associated with cage nets used for fish aquaculture, was grouped with G. lanceolata from Japan, though it appears too early as yet to identify it as such. This is, thus, proof of a new introduction of a marine macroalga, since G. imbricata is an Asian species, native to Japan and Korea, in the Canary Islands. The role of international shipping in the introduction of the species is discussed. 相似文献
17.
Two species of Dasya in the Dasyaceae (Ceramiales, Rhodophyta) are reported from Bonin Islands, southern Japan. Dasya murrayana Abbott et Millar, new to Japan, is characterized by the following set of features: the tufted habit (up to 30 erect axes developing from a basal disc), small‐sized (6–10 mm high and 350–500 μm in diameter in the middle region), thinly but completely corticated axes, rigid and incurved pseudolaterals forming corymbose heads at the apices of axes and branches, the absence of adventitious monosiphonous filaments, a large number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral and slender spermatangial branches (35–45 μm in diameter). Dasya boninensis Masuda, Kurihara et Kogame, sp. nov. is characterized by short but thick (10–30 mm high and 600–1000 μm in diameter at the middle portion), heavily corticated axes, indistinct pericentral cells except for the upper portion in transverse sections, soft, straight pseudolaterals and adventitious monosiphonous filaments densely covering the axis and branches, a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral, thick spermatangial branches (65–90 μm in diameter), and short‐necked cystocarps. A dichotomous key to the taxa found in Japanese waters is given. 相似文献
18.
Agnes Mols-Mortensen Christopher D. Neefus Ruth Nielsen Karl Gunnarsson Svanhildur Egilsdóttir Poul MØller Pedersen 《欧洲藻类学杂志》2013,48(2):146-159
Foliose species of the Bangiales (Porphyra sensu lato) have a long history of study in the N Atlantic, but there are still regions, especially in the northern parts of the N Atlantic that need more attention. A molecular study using rbcL and cox1 sequences was undertaken to assess the diversity of foliose Bangiales species in Iceland and the Faroe Islands. Herbarium collections from the intertidal and subtidal of Iceland (summer and winter) and the Faroe Islands (all seasons) revealed a total of 13 species (11 common to both areas), which were referred to four of the genera recognized in a recent two-gene global phylogeny. Boreophyllum birdiae, Porphyra dioica, P. linearis, P. purpurea, P. umbilicalis, Pyropia ‘leucosticta’ A, Pyropia njordii Mols-Mortensen, J. Brodie & Neefus, sp. nov., Wildemania amplissima and W. miniata were common to both areas, while Pyropia thulaea and Wildemania abyssicola (Kjellman) A. Mols-Mortensen & J. Brodie, comb. nov. (=Porphyra abyssicola Kjellman) were reported from Iceland but not from the Faroe Islands; Porphyra sp. FO and Pyropia elongata were reported from the Faroe Islands but not from Iceland. Boreophyllum birdiae is reported for the first time for Iceland and Porphyra sp. FO is reported for the first time for the Faroe Islands. Pyropia njordii is described from the Faroe Islands and is also recorded for Iceland, Greenland, New England, USA and Nova Scotia, Canada. A total of 25 foliose Bangiales species are now reported from the N Atlantic and these results demonstrate the importance of investigating as many areas as possible to reach a more complete understanding of species diversity and distribution. 相似文献
19.
Porphyra lilliputiana sp. nov. (Bangiales, Rhodophyta): A diminutive New Zealand endemic with novel reproductive biology 总被引：1，自引：0，他引：1
A new species of Porphyra, Porphyra lilliputiana, is described for the New Zealand region. This species is very small ([5] 10–20 [35] mm) and is found growing epiphytically, epilithically and epizoically on upper inter-tidal shores of moderate exposure. Field-collected material of P. lilliputiana possessed archeosporangia, endosporangia, spermatangia and zygotosporangia. In culture, archeospores vi/ere released and germinated to form thalli. Endosporangia either developed directly into thalli or released endospores which individually formed thalli. Zygotospores developed into the concho-celis phase, which formed conchosporangia. Released conchospores formed thalli. This species is distinguished by its small size, arrangement of reproductive cells, occurrence of endosporangia, dentate margin and habitat. 相似文献
20.
Our previous study revealed that apomixis, recycling of tetrasporophytes, can be generated through outcrossing between genetically divergent entities of Caloglossa monosticha M. Kamiya, though such apomicts have never been found in nature. In the case of C. leprieurii (Mont.) G. Martens, the most widespread species in this genus, many apomictic strains have been isolated worldwide, but it is unknown whether these apomicts evolved through an outcrossing process similar to that in C. monosticha. In this study, heterogeneity of the apomicts and their sexual relatives as well as their evolutionary relationships was examined using the nuclear‐encoded actin gene and plastid‐encoded RUBISCO spacer region. Thirteen out of 18 apomictic strains were heterogeneous and contained divergent actin alleles, whereas only two out of 23 sexual strains were heterogeneous. The five homogeneous apomicts were genetically identical, or quite similar, to the sexual strains isolated from adjacent sites. Furthermore, three of the five homogeneous apomicts frequently produced tetraspores that grew into gametophytes, while all the heterogeneous apomicts never generated gametophytes. Apomictic strains from Florida were allotriploid, and each of the three actin sequences was closely related to those of sexual strains from Florida, Peru, and Mexico/Guatemala. In crossing tests, obligate apomixis was generated through the outcrossing between the male from Madagascar and the female from the northwestern Atlantic. These results suggest that outcrossing between genetically divergent sexual entities is one factor that induces apomixis in C. leprieurii. 相似文献