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1.
Pilea carautae M. D. M. Vianna & R. J. V. Alves (Urticaceae) is described and illustrated. This new species is endemic to the Cabo Frio region in Rio de Janeiro State, Southeastern Brazil. P. carautae is considered threatened by IUCN standards due to its extremely restricted geographic area of occurrence.  相似文献   

2.
Loss of function of duplicated genes plays an important role in the evolution of postzygotic reproductive isolation. The widespread occurrence of gene duplication followed by rapid loss of function of some of the duplicate gene copies suggests the independent evolution of loss-of-function alleles of duplicate genes in divergent lineages of speciation. Here, we found a novel loss-of-function allele of S27 in the Asian annual wild species Oryza nivara, designated S27-niv s , that leads to F1 pollen sterility in a cross between O. sativa and O. nivara. Genetic linkage analysis and complementation analysis demonstrated that S27-niv s lies at the same locus as the previously identified S27 locus and S27-niv s is a loss-of-function allele of S27. S27-niv s is composed of two tandem mitochondrial ribosomal protein L27 genes (mtRPL27a and mtRPL27b), both of which are inactive. The coding and promoter regions of S27-niv s showed a number of nucleotide differences from the functional S27-T65 + allele. The structure of S27-niv s is different from that of a previously identified null S27 allele, S27-glum s , in the South American wild rice species O. glumaepatula, in which mtRPL27a and mtRPL27b are absent. These results show that the mechanisms for loss-of-function of S27-niv s and S27-glum s are different. Our results provide experimental evidence that different types of loss-of-function alleles are distributed in geographically and phylogenetically isolated species and represent a potential mechanism for postzygotic isolation in divergent species.  相似文献   

3.
4.
The Scorpaena cardinalis complex, including S. cardinalis, S. jacksoniensis and S. orgila, is defined. The genus Ruboralga (type species: S. jacksoniensis) is regarded as a junior synonym of Scorpaena. Scorpaena jacksoniensis Steindachner 1866, previously treated as a junior synonym of Scorpaena cardinalis Solander and Richardson 1842, is regarded here as a valid species. Scorpaena cookii Günther 1874, previously treated as a valid species, is regarded here as a junior synonym of S. cardinalis. Thus, recent recognition of the two Australasian scorpionfishes, i.e., S. cardinalis and S. cookii, are re-identified in this study as S. jacksoniensis and S. cardinalis, respectively. Scorpaena plebeia Solander 1842 is regarded as a junior synonym of S. cardinalis. Scorpaena jacksoniensis is distributed along the east coast of Australia from southern Queensland to eastern Victoria, whereas S. cardinalis occurs around northern New Zealand, the Kermadec Islands and offshore islands of the Tasman Sea. A neotype is designated for S. cardinalis. Morphological changes with growth in the two species are described in detail.  相似文献   

5.
Two new species of Sloanea are described and illustrated: S. fasciculata D. Samp. & V. C. Souza and S. hatschbachii D. Samp. & V. C. Souza. Both species are endemic to the Atlantic Forest states of Espírito Santo and Paraná in Brazil. S. fasciculata is similar to S. hirsuta (Schott) Planch. ex Benth., but has a fasciculate inflorescence and deeply-divided stigma. S. hatschbachii is similar to S. lasiocoma K. Schum. with regard to the morphology of the leaves, flowers and inflorescence, which is a frondose-bracteate raceme, but can be differentiated by the size of the style, the extension of the connective, and the length of the sepals.  相似文献   

6.
Material of the genus Salda F. from Russia and adjacent territories, deposited in the Zoological Institute of the Russian Academy of Sciences (St. Petersburg), is revised. Data on the distribution of eight species (S. henschii Reut., S. kiritshenkoi Cobben, S. littoralis L., S. micans Jak., S. morio Zett., S. muelleri Gmel., S. sahlbergi Reut., S. splendens Jak.) with dotted maps and a key to the species are given.  相似文献   

7.
Sinningia lutea (Gesneriaceae) is described and illustrated as a new species from the Pampa Biome, in Southern Brazil. In the literature, this species has hitherto been confused with S. allagophylla from which it can be easily separated using a set of floral and vegetative features (especially corolla color and size and leaf shape). An artificial key to separate S. lutea from S. allagophylla and S. curtiflora (another sympatric species, with some morphological similarities) is presented. Some ecological remarks on the differential distribution of S. lutea and S. allagophylla are also made.  相似文献   

8.
The morphometric analyses and genetic variability assessed by RAPD markers have been used to analyse relations among six Serapias taxa from Croatia (S. istriaca, S. pulae originally described as hybrid, S. ionica, S. vomeracea, S. lingua and S. cordigera). S. istriaca distributed in southern Istria and the island of Lošinj and S. pulae stenoendemic taxon distributed only in southern Istria S. ionica is endemic to the Ionian and Dalmatian islands, while the remaining taxa are more widely distributed. The obtained results shows that the endemic S. istriaca is a well characterised taxon, that S. pulae is a hybrid between S. istriaca and S. lingua and that the hybrid is morphologically and genetically more similar to S. lingua than the second parental species S. istriaca. The division into the subsections Steno-, Medio- and Platypetalae is founded based on the floral morphology while the division into the sections Serapias and Bilamellaria is not evident in the quantitative morphological and genetic analyses. Furthermore, considerable genetic resemblance between S. vomeracea and S. ionica was established.  相似文献   

9.
10.
Spongipellis litschaueri, described in 1931 from Austria, is often synonymised with S. delectans in current literature. Morphological and molecular approaches were applied to revise the taxonomic position of this species. The basidiospore dimensions and DNA sequences confirmed differences between S. delectans and S. litschaueri, thus the latter should be kept as a distinct species. However, the relationship between S. litschaueri and its North American kin S. unicolor is complex. Although most of the examined specimens of S. unicolor differ significantly from S. litschaueri in morphological and molecular characters, one American isolate showed markedly high DNA sequence similarity to the European species. Moreover, specimens of S. unicolor from the more or less western USA have larger basidiospores than the others and the respective values are similar to S. litschaueri. Thereby, S. unicolor may split in two taxa where one is closely related to S. litschaueri. Additionally, DNA sequences of a large subunit of the nuclear ribosomal RNA gene were analysed to elucidate the position of Spongipellis within the Polyporales. The results revealed unexpected polyphyly when the generic type S. spumeus fell into a separate lineage from S. delectans, S. litschaueri, S. pachyodon, and S. unicolor. In addition, Tyromyces fissilis occasionally kept in Spongipellis is not related to any species of the genus nor to Tyromyces chioneus, the generic type of Tyromyces. An identification key of European Spongipellis species is provided.  相似文献   

11.
To evaluate the effects of changes in water level and temperatures on performance of four Sphagnum mosses, S. magellanicum, S. rubellum, S. imbricatum and S. fuscum were grown at two water levels, −5 cm and −15 cm, and at two temperatures, 15°C and 20°C. These species differ in their position along the microtopographical gradient and in their geographical distribution. Height increment, subcapitulum bulk density, biomass production, capitulum water content and cumulative evaporation were measured. Height increment and biomass production of S. magellanicum was lower at low water table than at high water table, whereas height increment and biomass production of S. rubellum, S. imbricatum and S. fuscum were unaffected. Height increment of S. magellanicum, S. rubellum and S. imbricatum was higher at high temperature than at low temperature. Biomass production of only S. magellanicum and S. rubellum was higher at high temperature than at low temperature, corresponding with their more southern distribution. Cumulative evaporation of S. magellanicum and S. rubellum was lower at low water table and could be explained by hampered water transport towards the capitula. We conclude that changes in water table and temperature may alter the Sphagnum composition on raised bogs, which may result in changes to important ecosystem processes. Therefore, it is important that species composition and changes therein are taken into account when evaluating global change effects on raised bog ecosystems.  相似文献   

12.
Three new species of the genus Stelis from Mexico are described and illustrated; they were recently collected in the Tacana volcano region of Chiapas, and are named as S. annedamoniae, S. hagsateri, and S. soconuscana. For each species information is provided about habitat, phenology, and conservation status, and the relationships with similar taxa are discussed. Stelis andamoniae is similar to S. hagsateri and both are sympatric at the Tacana volcano; they are members of the Stelis argentata complex. The first has red-wine flowers, and glabrous sepals, while S. hagsateri has greenish-yellow flowers and glandular-papillose sepals. Stelis soconuscana is similar to S. bidentata, from which it is different by its broader leaves, raceme as long as the leaf, smaller flowers, and its distribution.  相似文献   

13.
Karyotype study was performed in 13 populations of 11 Silene species (sect. Auriculatae L., Caryophyllaceae) growing in Iran. All the species studied showed 2n = 2x = 24 chromosome number supporting the earlier report on S. meyeri, while the chromosome number of S. palinotricha, S. sojakii, S. gertraudiae, S. elymaitica, S. pseudonurensis, S. dschuparensis, S. eriocalycina, S. araratica, S. prilipkoana and S. commelinifolia are new to science. The chromosomes were mainly metacentric or sub-metacentric and their size varied from 1.10 μm in S. pseudonurensis to 7.11 μm in S. dschuparensis. The species studied differed significantly in the total size of the chromosomes, the size of the short arms and the long arms, indicating the role of quantitative genomic changes in the Silene species diversification. They also differ in their karyotype formulae indicating the occurrence of structural changes in their chromosomes. The Silene species were placed in 1A, 2A, 1B and 2B classes of Stebbins karyotype symmetry showing symmetrical karyotypes. Clustering of the species based on karyotype features grouped the species of S. palinotricha, S. prilipkoana, S. commelinifolia, S. eriocalycina, S. meyeri, S. araratica and S. Sojakii together while the species of S. gertraudiae and S. elymaitica showed more similarity and were placed close to each other.  相似文献   

14.
Dave Goulson 《Plant Ecology》2009,205(2):201-211
The relative importance of floral versus ecological isolation in preventing introgression remains unclear. This study examines whether ecological isolation can explain the continuing integrity of Silene dioica and S. latifolia where floral isolation is weak and hybrids are fully viable. Eighteen small replicate founder populations of 6 individuals (3 males and 3 females) of either S. latifolia, S. dioica or hybrids were created in woodland and in open sites in southern UK. Survival, reproduction and introgression of these populations were examined over 9 years. S. latifolia and hybrid plants suffered higher mortality than S. dioica in woodland. In open sites, there was extensive introgression, with few or no pure S. latifolia or S. dioica surviving by the end of the experiment. The experiment suggests that the integrity of S. dioica is maintained by its ability to survive in shaded habitats where S. latifolia and hybrids cannot persist. However, how S. latifolia survives as a distinct species in the study area remains a puzzle. Immigration from regions where S. latifolia occurs in isolation (i.e. large-scale ecological isolation) may balance introgression in the study area.  相似文献   

15.
We used morphological and molecular characteristics to perform a taxonomic reappraisal ofSuaeda australis (Brown) Moquin-Tandon from Korea. Populations of this species are dispersed at the bottoms of sand zones, and usually exhibit a depressed habit. Except for their total heights and leaf lengths, the morphology of these plants does not differ from that ofS. maritima. Molecular traits were examined based on ITS and psbB-psbH spacer region sequences. The former region included ITS-1, 5.8S, and ITS-2, which were 629 nucleotide bases long. Pair-wise distances (p-distance) among KoreanSuaeda species ranged from 1.12 to 17.84. The psbB-psbH spacer region sequences were 618 nucleotide bases long, and were conserved in the alignment of KoreanSuaeda species. In our ML and MrBayesian analysis of ITS sequences aligned with other sequences from GenBank, the plants of KoreanSuaeda made three clades: 1)S. japonica;S. australis, andS. maritima;2)S. malacosperma; and 3) S.glauca. However, the psbB-psbH region sequences could not be resolved amongS. japonica, S. maritima, andS. australis from Korea. Molecular and vegetative characteristics indicated that the plants now classified asS. australis from Korea should instead be named as S.maritima (L.) Dumont.  相似文献   

16.
Strangles is an acute and contagious disease characterized by inflammation of the upper respiratory tract of horses. The etiological agent of strangles is the bacteria S. equi subsp. equi, which belongs to the Lancefield group C. Opportunistic agents from the same group are frequently isolated from horses with strangles and may induce mistaken diagnoses. Among the subspecies of S. equi, the phenotypic features are almost undistinguishable; however, the pathogenic potential is widely differentiated. The aim of this study was to characterize S. equi isolates obtained from clinical samples of strangles by phenotypic tests and to analyze the partial sequences obtained from fragments of the hsp60 gene. In this work, 26 strains of Streptococcus spp. isolated from horse clinical samples were analyzed. By phenotypical assays, 18 were characterized as S. equi subsp. equi, five as S. equi subsp. zooepidemicus, two as S. dysgalactiae subsp. equisimilis, and one as Streptococcus sp. However 21 isolates were identified as S. equi subsp. equi and five as S. equi subsp. zooepidemicus by DNA sequencing. The sequencing of the partial hsp60 gene was demonstrated to be an alternative method to analyze and differentiate strains of Streptococcus spp. In addition, this method can be useful as a discriminatory tool for characterization of atypical isolates.  相似文献   

17.
The phylogenetic relationships of the following 14 Septoria species pathogenic to Asteraceae were inferred from sequence analyses of the 5.8 S gene of nuclear rDNA and flanking internal transcribed spacers: Septoria atropurpurea, S. astericola, S. calendulae, S. erigerontis, S. gerberae, S. helianthi, S. helianthicola, S. lactucae, S. leucanthemi, S. obesa, S. schnabliana, S. senecionis, S. socia, and S. taraxaci. Fifteen additional Septoria species originating from other host families, eight of which have a known Mycosphaerella teleomorph, were included in the alignment. Also included were selected strains of Cercospora, Pseudocercospora (including Paracercospora), Ramularia, and several other anamorph genera linked to Mycosphaerella available from previous studies. The analyses indicate that the Septoria species from Asteraceae are all closely related, and share an evolutionary history within the Mycosphaerellaceae, grouping amongst miscellaneous Mycosphaerella species, Cercospora and Pseudocercospora spp. Septoria socia is relatively distant from the other Septoria on Asteraceae, and the data suggest that it is more closely related to the maple pathogen S. aceris (tel. M. latebrosa) and poplar pathogen S. populicola (tel. M. populicola). Differences in the ITS sequences indicate that S. socia and S. leucanthemi, which have very similar phenotypes and have been considered to be conspecific in the past, are specifically distinct.  相似文献   

18.
19.
To study the evolution of the polymeric β-fructosidase (invertase) genes (SUC) of yeasts Saccharomyces, new SUC gene of S. cariocanus was cloned and sequenced and the nucleotide and amino acid sequences were compared for all known β-fructosidases of Saccharomyces species. The proteins showed 90–97% homology. The most divergent was S. bayanus β-fructosidase. The results testified again to high conservation of yeast β-fructosidases. Transitions C-T prevail in the total spectrum of nucleotide substitutions observed in the coding regions of the SUC genes; most of these transitions are in the third codon position and cause no changes in the amino acid sequences of the encoded proteins. The six Saccharomyces species each carry one (probably, non-telomeric) β-fructosidase gene. SUC is on chromosome IX in S. cerevisiae, S. bayanus, S. kudriavzevii, S. mikatae, and S. paradoxus and in a translocation region on chromosome XV in S. cariocanus.__________Translated from Molekulyarnaya Biologiya, Vol. 39, No. 3, 2005, pp. 413–419.Original Russian Text Copyright © 2005 by Korshunova, Naumova, Naumov.  相似文献   

20.
Sarcocornia decussata, S. freitagii and S. tegetaria from South Africa are described as new taxa. Sarcocornia decussata and S. freitagii are narrow endemics of the West Coast of South Africa where they are found in inland saline habitats (quartz patches, salt pans and saline alluvia) while S. tegetaria is an endemic of southern African coasts (spanning Namibia, South Africa and Mozambique) where it is confined to low-lying intertidal habitats of estuaries.  相似文献   

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