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1.
Polygonum sect.Tovara comprises three morphologically very similar species;P. virginianum,P. filiforme, andP. neofiliforme. Sequences of internal transcribed spacers (ITSs) of nuclear ribosomal DNA of these were determined to examine phylogenetic relationships and the levels of differentiation among them. The size of ITS 1 was 241 bp inP. filiforme andP. neofiliforme, and 242 bp inP. virginianum. The size of ITS 2 was 243 bp, and that of the 5.8S rRNA coding region was 163 bp. The ITS sequences clearly separate North AmericanP. virginianum from the eastern Asian species. Nucleotide divergence between them ranges from 3.3% to 3.8% for ITS 1 and from 9.3% to 10.7% for ITS 2. The molecular data also revealed that two eastern Asian species are closely related but should be treated as distinct species.  相似文献   

2.
Coreopsis nuecensoides andC. nuecensis are narrowly distributed endemics of southeastern Texas. While they overlap in range, they differ in chromosome number, and F1 hybrids exhibit strong sterility barriers. Previous morphological, cytogenetic, and allozyme studies suggested thatC. nuecensoides andC. nuecensis are very closely related members of a progenitor-derivative species pair. The two species differ substantially in terms of their leaf flavonoid chemistry, but the flavonoid data do not address the exact nature of the relationship between them. We have further examined the relationship between the species by analyzing genetic diversity within both species using chloroplast DNA (cpDNA) restriction site data. Sixteen restriction site changes were used to define thirteen distinct cpDNA haplotypes. The pattern of relationships among haplotypes provides some support for the presumed ancestor-descendent relationship, but other interpretations are possible. Only one cpDNA haplotype was shared by the two species; of the remaining twelve, seven were unique to one species and five to the other. This result is consistent with results of flavonoid studies, in which each species exhibited flavonoid compounds not seen in the other, but differs from the allozyme results, in which the vast majority of alleles were shared by both species and only the presumed progenitor exhibited unique alleles. Taken together, the data support a very close relationship between the species, but are equivocal with regard to a progenitor-derivative relationship.  相似文献   

3.
Phylogenetic relationships among those yeast species that form saturn-shaped ascospores and which are assigned to the generaWilliopsis andPichia were estimated from their extent of nucleotide sequence divergence in three regions of ribosomal RNA. ThePichia species (P. dispora, P. saitoi, P. zaruensis andP. sp. nov.) are a closely clustered group only distantly related toWilliopsis, and it is proposed that they be reassigned toSaturnospora gen. nov. The extent of divergence amongWilliopsis species (W. californica, W. mucosa, W. pratensis, W. saturnus andW. sp. nov.) is greater than that previously observed within other ascomycetous yeast genera.  相似文献   

4.
In a flavonoid survey of direct and hydrolysed leaf extracts of sixteenAttalea, sevenScheelea and fourOrbignya species free tricin, tricin 7-glycosides, tricin 5-glucoside and flavone C-glycosides were the most frequent constituents; present in 100, 89, 70, and 81% of species, respectively. Luteolin, quercetin and isorhamnetin were each found in only 15% of the sample. The present results confirm the findings of a previous survey thatAttalea, Scheelea andOrbignya are chemically heterogeneous with as much variation between species as between genera. Furthermore, threeAttalea species,A. allenii, A. guaranitica andA. victoriana showed some infraspecific variation. On the other hand all three accessions ofA. ferruginea and six ofA. geraensis examined gave identical flavonoid profiles. The results support the view thatA. geraensis andA. guaranitica are closely related but do not support the suggested close relationship based on morphology betweenA. oleifera, A. burretiana andA. piassabossu.  相似文献   

5.
The subfamilyPhytelephantoideae comprises three genera (Ammandra, Aphandra, andPhytelephas) and seven species of dioecious palms. The floral scents ofAmmandra dasyneura, A. decasperma, Aphandra natalia, Phytelephas aequatorialis, P. macrocarpa, andP. seemannii were analyzed by gas chromatography-mass spectrometry. We studied the pollination biology ofA. natalia, P. aequatorialis, andP. macrocarpa, and tested how the synthetically produced main constituents of the floral scents ofAphandra andPhytelephas attracted insects in two natural populations ofPhytelephas. The genera are distinct in terms of floral scents.Ammandra has sesquiterpenes,Aphandra (+)-2-methoxy-3-sec-butylpyrazine, andPhytelephas p-methyl anisol. These constituents dominated the scents quantitatively and qualitatively. The similarity between scents of male and female inflorescences was 76.5% inAmmandra, 84.2% inAphandra, and >99% inPhytelephas. Different species ofAleocharinae (Staphylinidae) pollinateAphandra natalia andPhytelephas species and reproduce in their male inflorescences.Derelomini (Curculinoidae) andMystrops (Nitidulidae) only visit and pollinatePhytelephas in which male inflorescences they reproduce. A species ofBaridinae (Curculionidae) only visits and pollinatesAphandra natalia, and reproduces in its female inflorescence. The apparent reliance on one or a few floral scent constituents as attractants and few and specific pollinators may indicate co-evolution. Sympatric species ofPhytelephantoideae have different scents. We suggest that species with similar scents have allopatric distributions due to the absence of a pollinator isolation mechanism.  相似文献   

6.
Thirteen flavonoid compounds were isolated and identified from five Korean species in theA. jaluense complex; they were glycosylated derivatives of the flavonols kaempferol, quercetin, and isorhamnetin, and of the flavone apigenin. The flavonoid data revealed the presence of two entities in the complex in Korea; one includesA. jaluense s. str. and the other includes the remaining four species which have identical flavonoid profiles. Based on these results, in conjunction with evidence from the morphology, it is suggested that the taxa should be recognized as two sub-species ofA. jaluense s. l. The flavonoid data also provide strong evidence for the occurrence of hybridization betweenA. jaluense s. str. andA. japonicum subsp.napiforme at Mt. Chiri in southern Korea.  相似文献   

7.
Pelargonium incarnatum is a tetraploid species (2n = 40) andP. patulum is diploid (2n = 22). A natural hybrid, collected at the same locality as the parent species, has 2n = 42 chromosomes. The meiosis of the hybrid is practically normal and its pollen fertility corresponds to that ofP. incarnatum. The flavonoid patterns of the parent species and the hybrid are very similar. The origin and phylogenetic implications of this intersectional hybrid are discussed.  相似文献   

8.
A new taxonomic treatment is proposed for thePottia starckeana species complex. The peristome development is not considered to be a useful feature to separate the taxa. On the basis of spore morphology only two species are accepted:P. starckeana, with spores wavy in outline, andP. davalliana, with variously-shaped and developed processes on the spores.Pottia starckeana var.brachyoda is reduced to synonymy withP. starckeana; P. conica andP. commutata are treated as synonyms ofP. davalliana. The speciesP. mutica, P. affinis, P. salina, P. microphylla, P. texana, andP. arizonica (included var.mucronulata) are considered taxa of doubtful affinity, as they have spore features intermediate between the two spore types established for the group. The identity ofP. appertii andP. recurvifolia has not been elucidated because the type material has been destroyed.  相似文献   

9.
Cytotaxonomical investigations on 11 species from the Western Himalayas show that 8 are diploid and the remaining tetraploid. The numbers for three species are new.P. prescottianum (2x) andP. thomsoni (4x), andP. stimulans (2x) andP. acanthophyllum (4x) are closely related but distinct species pairs.  相似文献   

10.
For the first time, three cases of capture and forced interaction were observed between bonobos (Pan paniscus)and two other species of primates (Colobus angolensisand Cercopithecus ascanius)in the Lilungu (Ikela) region, Republic of Zaire. The bonobos interacted with the captured primates as if they were dealing with individuals of their own species. They sought cooperation in their interactions with the captured young primates without scccess. There is no evidence that they ate the captives.  相似文献   

11.
Paracaryum intermedium andP. boissieri differ only in their inflexed or flattened fruit wings, and often occur in mixed populations on Mt. Katherina, Sinai. This and cultivation experiments suggest that they may represent forms of a single species only. The fruit characters mentioned therefore are hardly useful for a generic separation ofParacaryum andMattiastrum.  相似文献   

12.
Electrophoretic data show thatPolytrichastrum pallidisetum, P. ohioense, andP. sexangulare are allopolyploids. They display fixed, heterozygous banding patterns at five to six of the 11 enzyme loci that we screened. In total, we sampled 304 populations representing three genera (Polytrichastrum, Polytrichum, andPogonatum) and 18 species in our examination of the allopolyploids and their putative haploid progenitors. There were no extant species that fit perfectly as a progenitor of any allopolyploid. BothP. pallidisetum andP. ohioense appear to have originated as intergeneric hybrids between one progenitor with aPolytrichastrum-type genome and another with aPolytrichum-type genome. The extant haploid species with the most similar genomes to the putative progenitors ofP. pallidisetum werePolytrichastrum appalachianum andPolytrichum commune, whereas forPolytrichastrum ohioense the species werePolytrichastrum formosum (orP. longisetum) andPolytrichum commune. Polytrichastrum sexangulare was genetically more similar to species ofPogonatum, as was one taxon that appears to be one of its progenitors,P. sexangulare var.vulcanicum ( =Polytrichum/Pogonatum sphaerothecium). The other progenitor also must have possessed alleles that are common in species ofPogonatum. The Polytrichaceae are a relatively ancient group of mosses, and the hybridizations that gave rise to these allopolyploids may have occurred long ago. It is likely that the genomes of the original progenitors have changed over time or that those progenitors are now extinct.  相似文献   

13.
Pelargonium otaviense Knuth andP. spinosum Willd. are excluded from sect.Glaucophyllum, whileP. grandiflorum (Andr.)Willd.,P. patulum Jacq. andP. tabulare (Burm. f.)L'Hérit. of sect.Eumorpha are included. Sect.Glaucophyllum is characterized by green to glaucous vegetative organs and zygomorphic white to pink corolla with five narrow petals. All the species have an identical pollen and chromosome morphology, the same basic chromosome number (x = 11) and similar flavonoid patterns. A close relationship between sect.Glaucophyllum and sect.Pelargonium is indicated by the occurrence of natural hybrids and concordant characters. Isorhamnetin and luteolin have been detected in the genus for the first time.  相似文献   

14.
James C. Zech 《Brittonia》1999,51(4):415-421
Flavonoid chemistry of the genusMulinum and selected Mulineae taxa was studied. Both flavones and flavonols were identified as C- and O-glycosides. AllMulinum species contain 6,8-di-C-glycosyl chrysoeriol (flavone) and, with the exception of one, quercetin (flavonol). The presence of both flavones and flavonols in this genus weakens previous generalizations that the mulineae contain only flavonols and are primitive compared to other Apiaceae tribes. Based on the selected taxa studied,Azorella appears to differ from bothMulinum andGymnophyton in producing more kinds of flavonols, andGymnophyton appears similar toMulinum in the production of both chrysoeriol and quercetin as well as relatively few compounds. The flavonoid profile ofAsteriscium glaucum is reported as well. In general, a more homogeneous flavonoid compound composition for the Apiaceae is suggested.  相似文献   

15.
Phylogenetic analyses of the genusActaea were performed using morphological, ecological and biogeographical characters. Using solely morphological characters, the relationships of the three identified species-groups remain uncertain. Close biogeographical examination and comparison of the areas with ecological peculiarities as well as climate data gave important insight into the phylogeny ofActaea and the whole tribe. Consequently, the obtained biogeographical data were used for phylogenetic reconstructions. Both, from the point of view of morphological and biogeographical data,A. pachypoda andA. asiatica are the most ancestral species. They grow on the east sides of the continents, mainly in broad-leaved forests. In West Eurasia the apomorphicA. spicata andA. acuminata occur under similar climatic and ecological conditions, but these species are adapted to another climate rhythm. The most advanced species (A. erythrocarpa, A. rubra) are to be found in the boreal forests where they are widely distributed. This biogeographical approach revealed that the evolution of the species led to a gradual widening and shifting of their ecological constitutions.  相似文献   

16.
The genusPlectranthus (Lamiaceae) shows remarkable radiation on the sandstones of southern Natal and northern Transkei in South Africa, where six endemic species occur. Two of these endemic species,P. hilliardiae andP. oribiensis, are included in this study, as well asP. reflexus, for which only limited data are available. The other species that were studied areP. ambiguus, P. ciliatus, P. ecklonii, P. madagascariensis andP. zuluensis. Four of these taxa,P. ambiguus, P. hilliardiae, P. reflexus andP. saccatus var.longitubus, have uniquely long corolla-tubes (20–30mm) and this is related to pollination by nemestrinid flies of the genusStenobasipteron that have proboscides of similar length. Other nemestrinid species of the genusProsoeca have shorter proboscides and pollinate two species ofPlectranthus with shorter corolla-tube lengths (6–15mm). Acrocerid flies, tabanid flies and anthophorid bees are also important visitors to these species. This study on the pollination of seven species of varying corolla-tube lengths shows a correlation between floral tube length and proboscis length of insect visitors, many of which are recorded for the first time as pollinators ofPlectranthus.  相似文献   

17.
The floral and pollination biology of three closely related species,Tricyrtis flava, T. nana andT. ohsumiensis, were comparatively investigated. The primary pollinator wasBombus diversus in all the three species observed, andAmegilla sp. also acted forT. ohsumiensis. The flowers ofT. flava andT. ohsumiensis bloom for two days and are protandrous. Thus autogramy seems to be prevented in these species when the larger bees forage on them, though geitonogamy may also occur. On the other hand,T. nana appears to be a primarily self-pollinating species. The flowers of this species open only during one day and are homogamy. The stigmata seem to receive much pollen of their own flower by the visit of bumblebees. Moreover, many flowers ofT. nana fruited without any visit of pollinators.T. nana has many features characterizing the autogamous derivatives.  相似文献   

18.
New combinations for three species ofPolypleurum have been proposed. The Apinagia type of embryo sac is recorded for the first time in a species ofPolypleurum, P. filifolium. The Dicraea type of embryo sac found inP. dichotomum andP. munnarensis has been reinterpreted and renamed as the Polypleurum type. The embryo sac types met with in the family are discussed. The nucellar plasmodium organizes before the embryo sac attains maturity in all the three investigated species.  相似文献   

19.
An investigation of randomly amplified polymorphic DNA (RAPD) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) marker distribution was made for two well-characterised hybrids and their parents,Leucaena leucocephala andL. esculenta andParkinsonia aculeata andCercidium praecox. Three chloroplast DNA (cpDNA) markers identified the maternal parent of eachL. leucocephala ×L. esculenta hybrid. Fifteen species-diagnostic RAPD markers (invariant in one taxon and absent from the other) were always present in theLeucaena hybrid and assumed to be of nuclear origin, whilst three RAPD markers showed expression patterns identical to the cpDNA markers and were assumed to be of organellar origin. No RAPD or PCR-RFLP taxon-diagnostic markers were discovered for eitherP. aculeata orC. praecox. However, 21 RAPD markers were species-specific (polymorphic within one taxon but absent from the other) and Southern analysis indicated that none of the markers were of organellar origin. Only 67% additivity of markers specific toP. aculeata andC. praecox was demonstrated in the hybrids between these two species, whilst inLeucaena 97% additivity was demonstrated. Differences between the two hybridising situations were related to the behaviour of the molecular markers and the biology of the species.  相似文献   

20.
Synopsis The densities, habitat use, and feeding behaviors of 13 fish species belonging to the benthic invertebrate-feeding guild were studied by snorkeling at three localities in the Little River of eastern Tennessee, U.S.A. Resource partitioning occurred by habitat, feeding behavior and time of activity. Differences were also found at the generic level.Cottus was a nocturnal feeder, whereasPercina andEtheostoma were, for the most part, diurnally active.Percina moved about rapidly and spent most of its time above the bottom. In contrast,Etheostoma varied considerably in the amount of time spent under cover, spent little time above the bottom, and exhibited low levels of swimming activity. Nearly all species sought cover at night, suggesting they may be particularly sensitive to predation at night. Species with small adult sizes (Etheostoma, Cottus andP. evides) were concentrated in shallow water habitats, whereas species with large adult sizes (Percina) were more abundant in deep water habitats. The habitat use data are consistent with the hypothesis that size-selective predation by centrarchid bass may cause smaller fish to avoid deep water areas. Large species should have a lower risk of predation due to their size and behavior.  相似文献   

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