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 62 毫秒
1.
Grateloupia turuturu Yamada is the currently accepted name for the invasive red alga that is present on coasts of the North Atlantic. Previously considered as G. doryphora (Montagne) M.A. Howe, populations of this invasive species were examined and their taxonomic position revised using molecular and morphological techniques. It was also thought that similar invasive populations in the Mediterranean should be identified as G. turuturu. This investigation used rbcL based molecular analyses to clarify the taxonomic position of Grateloupia “doryphora’ from the Straits of Messina. Our results indicate that this population is neither G. doryphora nor G. turuturu. It was placed separately in all analyses and grouped consistently with other Grateloupia species from the Pacific. On the basis of molecular data from this and previous investigations, it is evident that the status of the foliose Atlantic and Mediterranean entities is still unclear and a re-evaluation of the old names connected to them should be undertaken.  相似文献   

2.
Grateloupia doryphora (Montagne) M.Howe is an invasive foliose alga that was reported for the first time in Rhode Island, USA in 1997. The population has since increased in size and expanded in range. In this study, the genetic variation and potential sources of the Rhode Island G. doryphora population were examined using three types of molecular markers: randomly amplified polymorphic DNA (RAPD), nuclear internal transcribed spacer (ITS) sequences, and mitochondrial cox2–cox3 intergenic spacer (COX) sequences. No variation was detected in ITS or COX sequences among Rhode Island G. doryphora individuals. RAPDs, however, did reveal genetic variation, although banding patterns were similar, with RAPD genetic distances between individuals ranging from 0.00 to 0.17. The low level of genetic diversity observed within the Rhode Island population may be due to a small founder population or a founder population derived from a genetically uniform source. To identify possible sources of the Rhode Island invasion, individuals from nine geographically diverse populations of foliose Grateloupia were compared. Phylogenetic trees inferred from RAPD distances and ITS and COX sequences had similar topologies; thus there was phylogenetic congruence among these independent loci. The Rhode Island G. doryphora specimens were genetically similar to specimens from G. doryphora populations located in Portsmouth, England; Tholen Island, The Netherlands; and Brittany and Hérault, France. Interestingly, the G. doryphora population in each of these locations is itself due to an introduction event within the past 40 years.  相似文献   

3.
The floridoside content of the marine red alga Grateloupiadoryphora was measured using a new, alternative High PerformanceLiquid Chromatography method suitable for the analysis of a large number ofsamples. This assay was to study the quantitative changes in floridosideconcentration in G. doryphora cultivated in differentsalinities for 10 days. Marked changes in floridoside concentration occurredrapidly observed in reponse to osmotic stress, providing evidence of itsosmoregulatory function. Interestingly, after a rapid decrease at low salinityand a strong increase at high salinity, the floridoside content then slowlyreturned to its initial level over the last 3 days of culture. This observationconfirms the high physiological capacity of G. doryphoratowithstand environmental variations and probably contributes to its actualproliferation along French coasts.  相似文献   

4.
Isethionic acid (2‐hydroxyethane sulfonic acid) and N‐methyl‐L‐methionine sulfoxide (4‐methane sulfinyl‐2‐methylamino butyric acid) were isolated from the red alga Grateloupia doryphora (Cryptonemiales) collected from Brittany (France); they were identified as major organic solutes together with floridoside (α‐D‐galacto‐pyranosyl‐(1–2)‐glycerol). The presence of isethionic acid has recently been reported in certain red algae, however, the occurrence of N‐methyl‐L‐methionine sulfoxide is still very rare. This report deals with the first isolation of isethionic acid and N‐methyl‐L‐methionine sulfoxide from G. doryphora and their subsequent NMR characterization.  相似文献   

5.
Floc'h  Jean-Yves  Pajot  Régis  Mouret  Véronique 《Hydrobiologia》1996,326(1):217-222
Since its first introduction into the Atlantic for farming purposes in 1983, the brown alga Undaria pinnatifida has been found at several sites along the European coasts. The present study deals with an ecological experiment that was performed at the island of Ushant (Brittany, France) in order to check the ability of Undaria to recruit to a rocky substratum in situ. On the one hand, the authors were unsuccessful in getting Undaria to colonize a previously denuded area of shore, which was subsequently colonized by other native species, a result that may speak for a competition between Undaria and the local kelps. On the other hand, evidence is presented that Undaria pinnatifida has become a member of the Atlantic flora for good. The sporophytes can be found growing from low water mark of neap tide (+1.5 m) down to at least –15 m below lower water mark of spring tide. Its propagation is thought to occur in at least two ways: either step by step from cultivation sites along the coasts, or from the hulls of ships sailing from harbour to harbour. The preference of Undaria for settlement is on artificial structures.  相似文献   

6.
Molecular markers belonging to the three different genomes, mitochondrial (cox2‐cox3 spacer), plastid (rbcL), and nuclear (internal transcribed spacer [ITS] 2 region), were used to compare samples of the two morphologically related species Gracilaria gracilis (Stackh.) Steentoft, L. M. Irvine et Farnham and G. dura (C. Agardh) J. Agardh collected along Atlantic coasts. In northern Europe, the distinction between these two species is ambiguous, and they are currently recognized under the single name of G. gracilis. The low but congruent patterns of genetic divergence observed for markers of the three genomic compartments highly suggest that these two taxa correspond effectively to two different genetic entities as previously described 200 years ago, based on morphological traits. However, thanks to the combination of different DNA markers, occurrence of “incongruent” cytotypes (i.e., mitotypes of G. dura associated with chlorotypes of G. gracilis) in individuals collected from Brittany, suggests interspecific hybridization between the two sibling species studied.  相似文献   

7.
Stempellinella coronata sp. n. is described and illustrated based on male imagines. The new species can be separated from other Stempellinella species by its small size, low antennal ratio, high front leg ratio, minute frontal tubercles, a comparatively long median volsella, lacking median tergal setae, and lacking well-developed anal crests on the tergite IX. The generic diagnosis of Stempellinella is emended mainly to accommodate S. coronata. The species has so far been collected only from autumn to winter at pools in the unpolluted upper to mid reaches and was recorded first from the Ohta River system, Hiroshima, Japan.  相似文献   

8.
We investigated patterns of genetic structure in two sister kelp species to explore how distribution width along the shore, zonation, latitudinal distribution and historical factors contribute to contrasting patterns of genetic diversity. We implemented a hierarchical sampling scheme to compare patterns of genetic diversity and structure in these two kelp species co‐distributed along the coasts of Brittany (France) using a total of 12 microsatellites, nine for Laminaria hyperborea and 11 for Laminaria digitata, of which eight amplified in both species. The genetic diversity and connectivity of L. hyperborea populations were greater than those of L. digitata populations in accordance with the larger cross‐shore distribution width along the coast and the greater depth occupied by L. hyperborea populations in contrast to L. digitata populations. In addition, marginal populations showed reduced genetic diversity and connectivity, which erased isolation‐by‐distance patterns in both species. As L. digitata encounters its southern range limit in southern Brittany (SBr) while L. hyperborea extends down to mid‐Portugal, it was possible to distinguish the effect of habitat continuity from range edge effects. We found that L. digitata did not harbour high regional diversity at its southern edge, as expected in a typical rear edge, suggesting that refuges from the last glacial maximum for L. digitata were probably not located in SBr, but most likely further north. For both species, the highest levels of genetic diversity were found in the Iroise Sea and Morlaix Bay, the two regions in which they are being currently harvested. Preserving genetic diversity of these two foundation species in these areas should, thus, be a priority for the management of this resource in Brittany.  相似文献   

9.
Grateloupia doryphora (Montagne) Howe, originally described from Peru, has repeatedly been reported as an invasive species in Atlantic and Mediterranean waters. Various attempts to explain this species' route of introduction have been unsatisfactory. New evidence from comparative rbcL sequence analysis and morphology suggests that this adventive species in the NE and NW Atlantic corresponds with G. turuturu Yamada, originally described from Japan. This provenance follows a well-recognized trend of invasive marine organisms that have colonized the Atlantic Ocean and Mediterranean Sea from Pacific NE Asia.  相似文献   

10.
The recent (2008–2016) occurrence of a boreal intertidal amphipod Gammarus oceanicus along the Spitsbergen coast is compared with corresponding data from 1980 to 1994. We aimed to compare the pace of environmental changes in the area (ice retreat, temperature increase) with distribution change of G. oceanicus. Material for the study was collected from intertidal, at low water level from over 100 locations on Spitsbergen, the main island of Svalbard archipelago (expanding from 76 to 80°N). The west coast of the island has been exposed to a steady increase in sea surface and air temperature (2°C in 20 years), as well as a significant decrease in fast ice duration (from over 5 months to less than 1 per year). A total length of more than 3,600 km of the island's coastline has been recently impacted by warming. Of the two sibling Gammarus species that dwell in the Spitsbergen littoral, G. setosus, the local cold water species remains generally where it was observed about 20–30 years ago. By contrast, boreal G. oceanicus has expanded its distribution range by over 1,300 km along the west and north coasts of Spitsbergen and gained dominating position on the number of sites, where it was previously just an occasional species.  相似文献   

11.
Robaina  R. R.  Garcia-Reina  G.  Luque  A. 《Hydrobiologia》1990,204(1):137-142
Explants of Gelidium versicolor, Grateloupia doryphora and Laurencia sp. were cultivated in Provasoli enriched seawater culture medium (PES) adjusted to several osmolalities (0.5, 0.7, 1.0 and 1.5 Os kg–1) and solidities (agar concentration = 3, 8 and 15 g L–1). Osmolality was adjusted by dilution of seawater with distilled water (50, 70 and 100% seawater) and by NaCl addition. Explants of Laurencia sp. and Grateloupia doryphora showed bud regeneration and callus formation. Explants of Gelidium versicolor only showed bud regeneration. Osmolalities of 0.5 and 1.05 Os kg–1. inhibited or drastically reduced bud regeneration and callus formation. The highest callus formation and bud regeneration were observed at 0.7 to 1.0 Os kg–1. An increase in the agar concentration of the culture medium was positively correlated with callus formation and negatively correlated with bud regeneration. An increase in the percentage of seawater increased the solidity of the culture medium and was positively correlated with callus formation. Glycerol was an effective carbon source for the vegetative propagation of axenic explants of Grateloupia doryphora, promoting growth and bud regeneration. An increase in glycerol concentration in the culture medium increased its osmolality, inhibiting the growth of the explants and their morphogenetic development.  相似文献   

12.
白毛算盘子(叶下珠科)在中国无分布   总被引:1,自引:0,他引:1  
张文华  郭永杰  李玉玲  姚纲 《广西植物》2022,42(10):1645-1651
长期以来,白毛算盘子(Glochidion arborescens Blume)被认为广布于中国云南西部至南部地区。该研究基于多年野外考察及标本查阅工作发现,由于白毛算盘子在中国的分布实为标本错误鉴定所致,相关错误鉴定的标本绝大部分属于绒毛算盘子[G.heyneanum(Wight&Arn.) Wight],少部分属于里白算盘子(G.acuminatum var.acuminatum Müll. Arg.)、毛果算盘子(G.eriocarpum Champ. ex Benth.)、艾胶算盘子[G.lancolarium(Roxb.) Voigt]或厚叶算盘子[G.zeylanicum var.tomentosum(Dalzell) Trimen]等物种,故在此将白毛算盘子在中国的分布予以排除。另外,对白毛算盘子进行了后选模式指定,并提供了白毛算盘子与相关混淆种的物种检索表。  相似文献   

13.
The status of the four currently recognised species in the Littorina saxatilis species-complex, i.e. Littorina nigrolineata Gray, L. arcana Hannaford Ellis, L. saxatilis (Olivi) and L. neglecta Bean is reviewed briefly, with notes on their characteristic features and location on the shore. Since the taxonomy of these rough periwinkles has only become stable relatively recently much of the previously published information on distribution is of little or no use. In this paper their distribution around the coastline of England and Wales (with some notes on Scotland) is described and discussed. L. saxatilis is found in a wide range of habitats from exposed peninsulas to estuaries on all shores where there is a suitable rocky or stony substrate; also in salt marsh pools. L. arcana has a more restricted distribution and is notably absent along much of the south English coast, central Cardigan Bay and possibly northern Scotland; it is not found in estuaries. L. nigrolineata has an even more restricted distribution, although it occurs both on exposed coasts and in estuaries; it has only been found by us in one locality on the east coast. L. neglecta is probably fairly widely distributed but we have few details so far. The implications of the different patterns of distribution are discussed.  相似文献   

14.
Sexual reproduction of Bonnemaisonia hamifera Hariot is the rule on the western coast of Brittany. Each spring the alga is luxuriant in the Molène Islands, indicating that optimum conditions for growth occur there. These conditions, which include a sandy substrate and frequently renewed clear water, seem to be essential for the maturation of the male and female organs of Bonnemaisonia hamifera on the coasts of Brittany.  相似文献   

15.
Pancratium maritimum L. is an Amaryllidaceous species whose presence is severely endangered in its original range, the sandy coasts of the Mediterranean sea. A molecular analysis has been performed to evaluate the genetic distance among populations coming from different locations, in order to define the best repopulating strategy. The plant genome, analysed by AFLP markers, was found to be extremely homogeneous and conserved, evoking vegetative or autogamous reproductive habits. Seeds from two different locations showed a good germination capability in greenhouse tests, indicating the potential presence of an efficient sexual reproduction. The combination of molecular data and germination tests would support the hypothesis of an autogamous reproduction for this species.  相似文献   

16.
Mollion  J.  Andriantsiferana  M.  Sekkal  M. 《Hydrobiologia》1990,204(1):655-659
Several species of red algae known to contain agar or carrageenan are abundant on the southeast and southwest coasts of Madagascar. The agarophyte Gelidium madagascariense, collected in the Fort Dauphin area, has been exported on a small scale to Japan for several years. FT-IR and GLC analysis show that it contains an agar polymer, of which the methylated fraction contains predominantly 6-O-methyl galactose and traces of 4-O-methyl galactose. Eucheuma denticulatum grows profusely on the coral reefs in the Tulear area. FT-IR and GLC analysis show that it contains iota-carrageenan, with no methyl-derivative contaminants. The 3,6-anhydro-galactose content was found to be rather low, suggesting a possible contamination with deviant iota. The economic potential of other sources of phycocolloids, as well as the possibility of farming different species of Eucheuma in the Tulear area, is discussed.  相似文献   

17.
This study analyzed the genetic diversity and patterns of genetic structure in Colombian populations of Avicennia germinans L. using microsatellite loci. A lower genetic diversity was found on both the Caribbean (Ho = 0.439) and the Pacific coasts (Ho = 0.277) than reported for the same species in other locations of Central American Pacific, suggesting the deterioration of genetic diversity. All the populations showed high inbreeding coefficients (0.131–0.462) indicating heterozygotes deficience. The genetic structure between the Colombian coasts separated by Central American Isthmus was high (FRT = 0.39) and the analyses of the genetic patterns of A. germinans revealed a clear differentiation of populations and no-recent gene flow evidence between coasts. Genetic structure was found within each coast (FST = 0.10 for the Caribbean coast and FST = 0.22 for the Pacific coast). The genetic patterns along the two coasts appear to reflect a forcing by local geomorphology and marine currents. Both coasts constitute a different Evolutionary Significant Unit, so we suggest for future transplantations plans that propagules or saplings of the populations of the Caribbean coast should not be mixed with those of the Pacific Colombian coast. Besides, we suggest that reforestation efforts should carefully distinguish propagules sources within each coast.  相似文献   

18.
Lathrolestes nigricollis(Thomson) and Grypocentrus albipes Ruthe,Palearctic specialist parasitoids of thebirch-leafmining sawfly Fenusa pusilla(Lepeletier), were imported from central Europe andreleased at three locations in Edmonton, Alberta,Canada during 1994–1996. Parasitoids becameestablished at two locations, L. nigricollis atboth and G. albipes at one, and were recoveredfor 3–5 years after release. Lathrolestesnigricollis has dispersed throughout most ofEdmonton, and at least 13 km from release sites, butG. albipes has been recovered only 400–500 mfrom one release site. Five years after introductionat one site, percent parasitism by L.nigricollis was 78% and 84% for the first andsecond generations, respectively, and about 48% ofparasitoid eggs were encapsulated.  相似文献   

19.
Prostrate ecotypes ofUlex gallii, an atlantic species with autumnal flowering, grow on capes in Brittany (France).U. europaeus, a widespread species, has winter and spring flowering, but some plants can precociously flower in autumn, so that hybridization can be possible between these two species in areas where their ranges overlap. By using different isoenzyme systems and crossed immunoelectrophoresis obtained with seed proteins, it is possible to consider plants with intermediate morphological characters betweenU. gallii andU. europaeus as natural hybrids.  相似文献   

20.
Two marine sibling species of the Gyratrix hermaphroditus complex were found to occur sympatrically at Roscoff (Brittany, France). Both share the same chromosome number 2n = 6, but differ for the values of centromeric indices, length ratio of chromosomes and absolute length of the haploid genome. Differences were also found in body size and male cuticular apparatus morphology. They are furthermore distinct for the above characters from the other two marine species of the complex already known (from the Mediterranean and the North Sea). Chromosomal evolution and phylogenetical relationships within the marine species of the G. hermaphroditus complex are discussed in detail.  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