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1.
Based on a critical review of the literature, and on abundant material recently collected along the coast of Brazil, a synthesis of the occurrence and distribution of the Brazilian species of seagrasses is presented. Two species of Hydrocharitaceae, namely Halophila baillonii Aschers. and H. decipiens Ostenf., and three species of Potomogetonaceae, Halodule emarginata den Hartog, H. wrightii Aschers. and Ruppia maritima L. s.s., were found. Ruppia maritima was found all along the Brazilian coast, from about 3 to 32°S latitude, in brackish water ponds and lakes, with salinities varying from 0.3 to 28?.. The other species are restricted to normal seawater (±35?.), although Halodule wrightii was also found in hypersaline waters (45?.). This last species is the most common seagrass in Brazil. The species of Halophila are restricted to warmer waters and were not found further south than Rio de Janeiro State, being especially common on the NE coast at depths down to 62 m. During the course of these studies, Halophila baillonii was found for the second time in Brazil since its original collection in 1888. A critical comparison of a large number of plants leads us to the conclusion that Halodule brasiliensis Lipkin cannot be distinguished from H. wrightii, and H. lilianae den Hartog cannot be distinguished from H. emarginata. Reproductive structures of H. emarginata are described for the first time.  相似文献   

2.
Halophila baillonii Ascherson was found in Belize, Central America in 2003 and 2005. The observation extends the known range of this seagrass species to the western Caribbean. H. baillonii was previously recorded only in the eastern Caribbean and at one Pacific site in Panama. Both fruits and flowers of H. baillonii were observed at two locations in Belize in 2005. H. baillonii in Belize is an important food for manatee, forms a productive seagrass-based ecosystem, and is adversely affected by shoreline development and watershed run-off.  相似文献   

3.
Megagametogenesis, the development of a megaspore into an embryo sac, has been identified in the seagrass Halophila johnsonii, a threatened species with no known sexual reproduction or seeds. Megagametogenesis in H. johnsonii was compared with megagametophyte development in Halophila decipiens, a related species known to readily produce viable seeds. In both species, ovules were structurally similar, megaspore mother cells were seen in premeiotic ovules, and linear tetrads and megagametophytes with two to eight nuclei were present in postmeiotic ovules. However, H. decipiens postmeiotic ovules had a chalazal pouch that was absent in the postmeiotic ovules of H. johnsonii. Late-stage H. decipiens ovules also contained embryos, indicating that they had been fertilized, whereas all late-stage H. johnsonii ovules were degrading and showed no signs of fertilization. These observations suggest that meiosis does occur in H. johnsonii megasporocytes, leading to the formation of viable megagametophytes and egg cells that could be fertilized if pollination occurred. Thus, the lack of seed set is due to a lack of pollination rather than any loss of capacity to produce seeds in this species.  相似文献   

4.
Although many macroalgae that occur throughout Western Antarctic Peninsular waters are known to produce defensive secondary metabolites that deter grazing, the rhodophyte, Palmaria decipiens is palatable to several sympatric meso- and macro-grazers. It has been hypothesized that high levels of mesoherbivory by amphipods may account for the conspicuous lack of filamentous epiphytes emerging from the thalli of marcophytes in this region. Nonetheless, Elachista antarctica is a filamentous phaeophyte found growing within, and emerging from the thallus of the rhodophyte P. decipiens. It is surprising that E. antarctica occurs exclusively in association with a palatable species of macroalgae considering the standing biomass of other chemically defended unpalatable species is very high. We tested the hypothesis that E. antarctica grows on P. decipiens due to the host's overwhelming palatability compared to that of the epiphyte. That is, the hypothesis that mesograzers prefer the host over the epiphyte, grazing around emerging filaments. Choice and no choice feeding assays with live tissues of E. antarctica and P. decipiens were conducted in three different trials with four sympatric amphipod species (Prostebbingia gracilis, Gondogeneia antarctica, Oradarea bidentata, and Paraphimedia integricauda) commonly found in association with P. decipiens. G. antarctica consumed both species but ate P. decipiens at a faster rate than the epiphyte in two of three trials. P. gracilis, O. bidentata, and P. integricauda fed on the epiphyte, E. antarctica at faster rates than upon P. decipiens. Aggressive grazing of the epiphyte by this suite of amphipods indicates that differences in palatability and differences in grazing pressure on host and epiphyte do not explain the exclusive epiphytism of E. antarctica on P. decipiens.  相似文献   

5.
John C. Semple 《Brittonia》1990,42(3):221-228
Nomenclatural problems involving closely related North American goldenasters are resolved. No original type material (a collection by John Bradbury) is known forAmellus villosus Pursh, which is the basionym for the taxon referred to asChrysopsis villosa and more recently asHeterotheca villosa. The species is the first-described taxon inHeterotheca sect.Phyllotheca. A collection by Bradbury (LIV) was found to belong inH. camporum and does not match Pursh's protologue. A neotype (PH) was selected from collections by Thomas Nuttall. A problem in the typification of the second oldest taxon in sect.Phyllotheca was encountered. The specimen filed at K as the type ofDiplopappus hispidus Hook. was not the specimen cited in the protologue. A lectotype has been designated from collections by Richardson at BM. Other taxa placed in synonymy are also typified.  相似文献   

6.
The somatic chromosome numbers of the eleven Australian seagrass species belonging to five genera in the Family Cymodoceaceae were determined. The chromosome numbers in Amphibolis and Thalassodendron are reported for the first time. Cymodocea and Halodule species have the following chromosome numbers: Cymodocea angustata Ostenf., 2n = 14, 28; C. rotundata Ehrenb. & Hempr. ex Asch., 2n = 14; C. serrulata (R. Br.) Asch. & Magnus, 2n = 14, 28; Halodule pinifolia (Miki) den Hartog, 2n = 32; H. uninervis (Forsk.) Asch., 2n = 32; H. tridentata (Steinh.) Endl. ex Unger, 2n = 14. Halodule has the highest chromosome numbers among the seagrasses and they are the largest in sizes with a distinct bimodal type in the family. Syringodium isoetifolium (Asch.) Dandy has 2n = 20. Both endemic Amphibolis antarctica (Labill.) Sonder ex Asch. and A. griffithii (J. Black) den Hartog have 2n = ca. 36 and have the smallest chromosomes in the family appearing as small dots. Thalassodendron pachyrhizum den Hartog has 2n = 28. Chromosome numbers appear to be identical or closely related among different species in the same genus but they vary in the five genera in the Cymodoceaceae suggesting that these five genera may have evolved independently in the past.  相似文献   

7.
8.
In this paper we have attempted to clarify the taxonomy and nomenclature of thirteen taxa of the genus Cortinarius subgenus Telamonia (sections Hydrocybe, Fraternii) well represented in the southwestern Mediterranean area of Europe (C. atrocoeruleus, C. bombycinus, C casimiri, C. contrarius, C. decipiens, C. fraternus, C. gallurae, C. hoffmannii, C. petroselineus, C. sertipes, C. subturibulosus, C. urdaibaiensis and C. vernus). To this end we have performed a combined study of morphological and molecular data (rDNA ITS sequences). The morphological analysis was carried out on 114 collections and the molecular analysis involved 31 of the 114 collections, including 11 type collections (types for C. casimiri and C. fraternus were not available). In addition, a study of spores under field emission scanning electron microscopy (FESEM) was conducted. The results of the combined analysis allowed us to asign the studied material to five species (C. casimiri s.l., C. decipiens s.l., C. gallurae, C. subturibulosus s.l. and C. vernus s.l.). Thus, all collections from more continental areas, which were originally identified as six different taxa (C. atrocoeruleus, C. contrarius, C. decipiens, C. fraternus, C. sertipes, C. flexipes fo. sertipes) corresponded to C. decipiens sensu lato, a widely distributed, genetically and morphologically variable species. Cortinarius casimiri is also found in such habitats, but it is confirmed as distinct taxon. Collections from Mediterranean sclerophyllous communities correspond to C. gallurae, C. vernus sensu lato and C. subturibulosus sensu lato. Due to close phylogenetic relationships we propose the new combinations C. casimiri var. hoffmannii (=C. decipiens var. hoffmannii non C. hoffmannii) and C. subturibulosus var. bombycinus (=C. bombycinus), and the new variety C. vernus var. nevadavernus (=C. vernus H. Lindstr. & Melot sensu auct.).  相似文献   

9.
Tapeworms of the genus Spirometra are pseudophyllidean cestodes endemic in Korea. At present, it is unclear which Spirometra species are responsible for causing human infections, and little information is available on the epidemiological profiles of Spirometra species infecting humans in Korea. Between 1979 and 2009, a total of 50 spargana from human patients and 2 adult specimens obtained from experimentally infected carnivorous animals were analyzed according to genetic and taxonomic criteria and classified as Spirometra erinaceieuropaei or Spirometra decipiens depending on the morphology. Morphologically, S. erinaceieuropaei and S. decipiens are different in that the spirally coiled uterus in S. erinaceieuropaei has 5-7 complete coils, while in S. decipiens it has only 4.5 coils. In addition, there is a 9.3% (146/1,566) sequence different between S. erinaceieuropaei and S. decipiens in the cox1 gene. Partial cox1 sequences (390 bp) from 35 Korean isolates showed 99.4% (388/390) similarity with the reference sequence of S. erinaceieuropaei from Korea (G1724; GenBank KJ599680) and an additional 15 Korean isolates revealed 99.2% (387/390) similarity with the reference sequences of S. decipiens from Korea (G1657; GenBank KJ599679). Based on morphologic and molecular databases, the estimated population ratio of S. erinaceieuropaei to S. decipiens was 35: 15. Our results indicate that both S. erinaceieuropaei and S. decipiens found in Korea infect humans, with S. erinaceieuropaei being 2 times more prevalent than S. decipiens. This study is the first to report human sparganosis caused by S. decipiens in humans in Korea.  相似文献   

10.
Most macroalgal species along the Western Antarctic Peninsula (WAP) are defended against predation, many using chemical defenses. These subtidal communities are also mostly devoid of free living filamentous algae. However, one endo/epiphyte, Elachista antarctica, is found growing exclusively out of the palatable rhodophyte Palmaria decipiens. To understand this unusual and exclusive epiphytization, we tested whether macroalgal secondary metabolites such as those responsible for deterring sympatric grazers, affect the behaviors of the epiphyte's spores. Settlement, germination, and swimming behaviors of the epiphyte's motile spores were quantified in the presence of fractionated lipophilic and hydrophilic extracts of host P. decipiens and other rhodophytes from the shallow subtidal. Host P. decipiens was the only alga tested that did not inhibit spore settlement or germination. We also examined whether extracts from these chemically rich algae affect spore swimming behaviors and found spores to be chemotactically attracted to seawater soluble extract fractions of host P. decipiens. These results indicate that chemosensory behaviors of the epiphyte's spores to metabolites associated with these chemically defended macrophytes can explain this exclusive epiphyte–host interaction.  相似文献   

11.
The new combination Stigmaphyllon bonariense, based on Banisteria bonariensis Hook. & Arn., is proposed to replace the more recent name Stigmaphyllon littorale Adr. Juss. for a species from southern South America. Because the publication dates of Hooker's Botanical Miscellany, the journal in which the basionym was published, are in part incorrectly given in the widely used reference Taxonomic Literature, the correct dates for all parts are listed and are based on a previously published review by H. S. Marshall.  相似文献   

12.
Phylogenetic analysis of new ribosomal DNA (rDNA) data for Heterodera mediterranea, H. hordecalis, H. carotae, and H. fici from Italy and H. ciceri from Syria, along with published data for other species, showed high bootstrap support for the following relationships: (((((H. carotae H. cruciferae) H. goettingiana) (((H. trifolii H. ciceri) H. mediterranea) ((H. avenae H. latipons) H. fici))) (Cactodera betulae H. hordecalis)) (Globodera rostochiensis G. pallida)). The rDNA sequence data were for the two internal transcribed spacers (ITS1 and ITS2) plus the 5.8S gene between them. These inferred relationships support the classic ''''Goettingiana Group'''' of H. carotae, H. cruciferae, and H. goettingiana. A clade comprised of Cactodera betulae and H. hordecalis is only distantly related to the other species in the analysis.  相似文献   

13.
报道了中国腐生兰科植物二新记录种,即二色肉果兰(Cyrtosia integra (Rolfe ex Downie) Garay)和反瓣山珊瑚(Galeola cathcartii Hook. f.),并提供简要描述和图片。  相似文献   

14.
Morphological variation in Turonian and Coniacian Micraster (Irregular Echinoids) from Picardy is analysed in samples from 4 beds stratigraphically superimposed in the chalk cliff and numbered C2, C3, C4 and C5. The statistical study is made of 23 characters (12 quantitative and 11 qualitative).In first part, uni- and multivariate analysises, complementedby observations of populations, have enabled us to recognize M. leskei (Des Moulins) in the two lower beds and M. decipiens (Bayle) in the upper ones.The growth of M. leskei is analysed in the second part. The biometrical study (bi- and multivariate analysises) of growth processes of the C2-bed urchins (which are small) and of the C3- bed urchins (which are sometimes much bigger) shows the homology of their ontogeny and confirms the name «large M. leskei given by R.B. Stokes for the C3 urchins. The genetic or ecological origin of that variation is discussed.In the third part, the analysis (multivariate) has enabled to understand the considerable variability of M. decipiens. This species contains several morphological types: trapezoidal or heart-shaped urchins, and conical- shaped urchins. The study shows that «gibbous forms are simple variants and that the two first forms may be considered as morphs of the same species. It is possible that these forms are separate species.  相似文献   

15.
Large quantities of plants are traded annually in South Africa's traditional medicine or ‘muthi’ markets. A resource in high demand in the Faraday (Johannesburg) and Warwick (Durban) markets is uMavumbuka, a root holoparasite usually identified as either Hydnora africana Thunb. or Sarcophyte sanguinea Sparrm. subsp. sanguinea. However, rhizomes regularly observed in Faraday between 1994 and 2008 did not resemble either species, thereby suggesting that a third, and undocumented, species was being harvested. This was confirmed when the rhizomes were identified as H. abyssinica A.Br. by an American parasitic plant expert. An ethno-ecological study was initiated to verify its occurrence in selected muthi markets. The study further aimed to investigate the distribution of H. abyssinica through trader interviews, host species localities and some previously misidentified herbarium specimens. The study revealed that H. abyssinica was the only uMavumbuka species present in Faraday and Warwick in 2009. Furthermore, the rhizomes were being harvested in KwaZulu-Natal—an area not previously known to be part of its distribution range. Re-evaluated herbarium vouchers and recent photographs taken in the Kruger National Park have confirmed that H. abyssinica occurs in KwaZulu-Natal, Limpopo, Mpumalanga, Gauteng and Swaziland and hence eastern southern Africa. Fragments of Acacia xanthophloea Benth. roots were identified on 93% of the samples that had host roots attached, and we suspect that H. abyssinica follows the distribution of A. xanthophloea in suitable habitats north from KwaZulu-Natal and adjoining the South African border with Swaziland and Mozambique. Acacia karroo Hayne and A. grandicornuta Gerstner have also been positively identified as host species in South Africa from herbarium records. Plant harvesters in the markets cited the common names of several other species that uMavumbuka “grows under” that may be identified as hosts to H. abyssinica in the future. The collection of specimens in areas identified by the harvesters and in areas of suitable habitat is important to verify the occurrence, distribution and habitat of H. abyssinica in eastern southern Africa.  相似文献   

16.
17.
The distribution and ecology of seagrasses along parts of the Egyptian Red Sea coasts have been investigated. Five of the 10 species ever reported from the Red Sea have been found in this area, i.e. Halodule uninervis (Forssk.) Aschers., Thalassodendron ciliatum (Forssk.) den Hartog, Halophila stipulacea (Forssk.) Aschers., Halophila ovalis (R. Br.) Hook. f. and Halophila ovata Gaud. H. ovata is recorded here for the first time for the west coast of the Red Sea. The finding of Halophila decipiens Ostenfeld represents a new record to the Red Sea; this species has been found at a depth of 30 m, near Ras Ghârib in the Gulf of Suez.  相似文献   

18.
The homogeneity of a large sample of Gassendiceras alpinum is tested statistically. The quantitative analysis did not reject the null hypothesis and the homogeneity of the sample is accepted. As a result, the different taxa used in the literature (G. alpinum, “Barrancyloceras barremense”, Leroyiceras mascarellii and Spinocrioceras sauvanae) all fall into the variability of a single species, although some doubt subsist for L. dolloi. Taxonomically, by the priority principle the only name that should be used is G. alpinum. The results and other examples about the intraspecific variability confirm the importance of the Westermann's laws in ammonites, but they show that there are other important sources of covariation. In Gassendiceras the variability is tripolar (both the classic robust-slender poles of the Westermann's laws plus a third morphological pole with thick section and not so robust ornamentation), which implies that the intraspecific variability is not always uniform or consistent from one group to another, or in any case do not necessarily respond to the same factors in equivalent proportions. Heterochronies, erasing of the ornamentation and uncoiling of the heteromorph ammonites are also considered as factors of the intraspecific variability.  相似文献   

19.
Hermeuptychia intricata Grishin, sp. n. is described from the Brazos Bend State Park in Texas, United States, where it flies synchronously with Hermeuptychia sosybius (Fabricius, 1793). The two species differ strongly in both male and female genitalia and exhibit 3.5% difference in the COI barcode sequence of mitochondrial DNA. Setting such significant genitalic and genotypic differences aside, we were not able to find reliable wing pattern characters to tell a difference between the two species. This superficial similarity may explain why H. intricata, only distantly related to H. sosybius, has remained unnoticed until now, despite being widely distributed in the coastal plains from South Carolina to Texas, USA (and possibly to Costa Rica). Obscuring the presence of a cryptic species even further, wing patterns are variable in both butterflies and ventral eyespots vary from large to almost absent. To avoid confusion with the new species, neotype for Papilio sosybius Fabricius, 1793, a common butterfly that occurs across northeast US, is designated from Savannah, Georgia, USA. It secures the universally accepted traditional usage of this name. Furthermore, we find that DNA barcodes of Hermeuptychia specimens from the US, even those from extreme south Texas, are at least 4% different from those of H. hermes (Fabricius, 1775)—type locality Brazil: Rio de Janeiro—and suggest that the name H. hermes should not be used for USA populations, but rather reserved for the South American species. This conclusion is further supported by comparison of male genitalia. However, facies, genitalia and 2.1% different DNA barcodes set Hermeuptychia populations in the lower Rio Grande Valley of Texas apart from H. sosybius. These southern populations, also found in northeastern Mexico, are described here as Hermeuptychia hermybius Grishin, sp. n. (type locality Texas: Cameron County). While being phylogenetically closer to H. sosybius than to any other Hermeuptychia species, H. hermybius can usually be recognized by wing patterns, such as the size of eyespots and the shape of brown lines on hindwing. “Intricate Satyr” and “South Texas Satyr” are proposed as the English names for H. intricata and H. hermybius, respectively.  相似文献   

20.
The origin of Hordelymus genome has been debated for years, and no consensus conclusion was reached. In this study, we sequenced and analyzed the RPB2 (RNA polymerase subunit II) gene from Hordelymus europaeus (L.) Harz, and its potential diploid ancestor species those were suggested in previous studies. The focus of this study was to examine the phylogenetic relationship of Hordelymus genomes with its potential donor Hordeum, Psathyrostachys, and Taeniatherum species. Two distinguishable copies of sequences were obtained from H. europaeus. The obvious difference between the two copies of sequences is a 24 bp indel (insertion/deletion). Phylogenetic analysis showed a strong affinity between Hordeum genome and Hordelymus with 85% bootstrap support. These results suggested that one genome in tetraploid H. europaeus closely related to the genome in Hordeum species. Another genome in H. europaeus is sister to the genomes in Triticeae species examined here, which corresponds well with the recently published EF-G data. No obvious relationship was found between Hordelymus and either Ta genome donor, Taeniatherum caput-medusae or Ns genome donor, Psathyrostachys juncea. Our data does not support the presence of Ta and Ns genome in H. europaeus, and further confirms that H. europaeus is allopolyploid.  相似文献   

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