共查询到20条相似文献,搜索用时 78 毫秒
1.
Nucleotide sequences of the small-subunit (SSU) ribosomal DNA were determined for Pelvetia babingtonii, P. canaliculate, Pelvetiopsis limitata, and Ascophyllum nodosum in the family Fucaceae. A total of 1755 positions were aligned for the whole sequence. The positional differences in the
primary structure among the taxa ranged from 16 to 30 nucleotide changes in pairwise comparisons. There was a minimum divergence
between Ps. limitata and P. babingtonii while a maximum between Ps. limitata and P. canaliculata. The SSU rDNA trees showed that the genus Pelvetia was not monophyletic and the genus Pelvetiopsis was not closely related to Pelvetia. Our results suggest that the taxonomic revision of the genus Pelvetia as well as the family Fucaceae is needed based on detailed morphological observations. 相似文献
2.
The dental and cranial morphologies of all species of Saguinus, S. oedipus, S. geoffroyi, S. leucopus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S.
bicolor, and S. midas are examined. The following hypotheses are developed by cladistic methodology, using only synapomorphic characters to assess
the interspecific relationships of Saguinus. Saguinus are divided into two main groups; one consists of S. oedipus, S. geoffroyi, and S. leucopus, and the other includes S. inustus, S. nigricollis, S. fuscicollis, S. labiatus, S. mystax, S. imperator, S. bicolor, and S. midas. In the former group, S. oedipus is more closely related to S. geoffroyi than either is to S. leucopus. In the latter group, S. labiatus, S. mystax, and S. imperator are classified into one group, and S. bicolor and S. midas form one monophyletic group. 相似文献
3.
The taxonomic positions of Retzia, Desfontainia, and Nicodemia have been much discussed, and all three genera have been included in Loganiaceae ( Gentianales). We have made a cladistic analysis of rbcL gene sequences to determine the relationships of these taxa to Gentianales. Four new rbcL sequences are presented; i.e., of Retzia, Desfontainia, Diervilla ( Caprifoliaceae), and Euthystachys ( Stilbaceae). Our results show that Retzia, Desfontainia, and Nicodemia are not closely related to Loganiaceae or the Gentianales. Retzia is most closely related to Euthystachys and is better included in Stilbaceae. The positions of Desfontainia and Nicodemia are not settled, but Desfontainia shows affinity for the Dipsacales s.l. and Nicodemia for the Lamiales s.l. 相似文献
4.
The systematics of Scleromitrula and Verpatinia of the family Sclerotiniaceae is reevaluated on the basis of morphological, cultural and molecular criteria. Scleromitrula shiraiana, Verpatinia species and Ciborinia candolleana share gross morphological, microanatomical and cultural features which clearly distinguish them from the closely related Ciborinia and Rutstroemia species. Phylogenetic analyses of sequences from the internal transcribed spacer region (ITS1, ITS2, and the 5.8S gene) of
nuclear ribosomal DNA demonstrate that the stipitate-capitate specimens of Scleromitrula and Verpatinia species plus the stipitate-cupulate Ciborinia candolleana constitute a monophyletic clade separate from a clade including the type species of Ciborinia. Scleromitrula is emended to include S. shiraiana, the new species S. rubicola, C. candolleana, and specimens formerly assigned to Verpatinia. A key to the accepted species of Scleromitrula is provided. 相似文献
5.
Interrelationships of the ribbed araphid diatoms have been reinvestigated using a cladistic analysis of a revised morphological dataset. The presence of silicified transapical ribs has previously been used to distinguish between different groups and its ability to serve as a distinguishing feature is reevaluated. The importance of valve symmetry, not fully appreciated in a previous paper, is examined. The evolution of heteropolarity, and its importance in taxonomy appear more complex than is implied by a simple dichotomy dividing groups of species into heteropolar and isopolar forms, involving an inferred evolutionary transformation from one condition to the other. This analysis proposes a close relationship between Diatoma, Fragilariforma, Asterionella, Distrionella, Meridion, Tabellaria, and Tetracyclus. It also confirms the sub-division of Diatoma into two closely related taxa. The genus Meridion, however, should not include both heteropolar and isopolar species in a single genus. Although the species are closely related, the isopolar species are more closely related to Tabellaria and Tetracyclus than they are to the heteropolar species of Meridion. 相似文献
6.
Ten enzyme systems coding for 13 putative loci were studied in 12 European species of Sphagnum sect. Acutifolia (peat mosses). On average seven plants from each of 73 collections made throughout N Europe were analysed. Despite complex morphological variation, all species expressed unique allele combinations. Principal components and cluster analyses based on allele frequencies showed that sect. Acutifolia can be divided into two major groups; one comprising Sphagnum fimbriatum, S. girgensohnii and S. molle; the second comprising S. capillifolium, S. angermanicum, S. fuscum, S. quinquefarium, S. rubellum, S. subfulvum, S. subnitens and S. warnstorfii. These groups are linked by S. russowii, which is shown to be an allopolyploid, with fixed heterozygosity at 6 to 8 of the loci. The presumed progenitors of S. russowii are S. girgensohnii and S. rubellum. Allelic data also indicate that S. teres from sect. Squarrosa is related to S. girgensohnii and S. fimbriatum. The bisexual species tend to be less variable than the unisexual species. 相似文献
8.
Sequences of the internal transcribed spacer region (ITS-1, 5.8S, and ITS-2) of nuclear ribosomal DNA were obtained from 16 species representing all six genera of Fucaceae ( Ascophyllum, Fucus, Hesperophycus, Pelvetia, Pelvetiopsis, and Xiphophora ) plus one outgroup ( Hormosira ). Parsimony analysis indicated that the family Fucaceae is monophyletic and that the northern hemisphere taxa are highly divergent from the only southern hemisphere genus, Xiphophora. The genus Pelvetia is not monophyletic because the European P. canaliculata is more closely related to Fucus, Hesperophycus, and Pelvetiopsis than to other Pelvetia species. We establish Silvetia, gen. nov. and transfer the 3 Pacific species of Pelvetia to the new genus. Fucus is monophyletic and not ancestral in the Fucaceae. The ITS sequences identified two strongly supported lineages within Fucus, one with F. serratus sister to the clade containing F. gardneri, F. distichus, and F. evanescens and a second including F. vesiculosus, F. spiralis, F. ceranoides, and F. virsoides. The ITS was not useful for resolving relationships within each of these clusters and between populations of F. vesiculosus. Within-individual variation in ITS sequences is high in Fucus, a derived genus, compared to Ascophyllum, a more ancestral genus. Mapping of the two characters that form the basis of Powell's model for speciation in the Fucaceae showed that 1) number of eggs per oogonium has not followed a gradual reduction and that 2) monoecy/dioecy has changed several times during evolution of this family. 相似文献
9.
Resistance in accession PI 134417 of Lycopersicon hirsutum f. glabratum to Manduca sexta L. results from the presence of the methyl ketones 2-tridecanone and 2-undecanone in the type VI trichome glands on foliage
of these plants. Short (24 h) and long term (neonate to adult) laboratory experiments using M. sexta-resistant and susceptible foliage and methyl ketone treated filter paper disks were conducted to evaluate the direct (plant-mediated),
and indirect (prey-mediated) effects of this resistance on two predators of Helicoverpa zea eggs, Coleomegilla maculata (DeGeer) and Geocoris punctipes (Say). Direct effects of resistance were manifest as reduced egg consumption and increased mortality for both predators.
Indirect effects were manifest as reduced egg consumption by G. punctipes, but were not observed for C. maculata. Results of experiments using methyl ketone-treated filter paper disks instead of foliage were similar. 相似文献
10.
A cladistic study of Dipsacaceae ( Asteridae, Dipsacales) was undertaken, based mainly on morphological and palynological characters, obtained by investigations of herbarium material and from the literature. Outgroups included Morinaceae, Triplostegiaceae, and a subset of Valerianaceae. The consensus tree resulting from three equally parsimonious cladograms shows that Dipsacaceae are divided into two major clades, one with Dipsacus and Cephalaria, the other including the remaining genera. Within the latter clade, Knautia is the sister group of the rest of the taxa. This study is a reappraisal of Dipsacaceae phylogeny, and the results broadly match previous evidence. 相似文献
11.
Parasitism of Lygus lineolaris (Palisot de Beauvois) eggs by three species of Mymaridae, Anaphes iole Girault, Erythmelus miridiphagus Dozier and Polynema pratensiphagum Walley and one species of Scelionidae, Telenomus sp., was investigated at Ste-Anne-de-Bellevue, Québec. The maximum level of field parasitism of L. lineolaris eggs by individual species was 15.4, 53.8, 70.0 and 16,7%, respectively.
Parasitoids were retrieved from eggs of L. lineolaris inserted in stems and branches of Amaranthus retroflexus L., Chenopodium album L., Coronilla varia L., Rumex obtusifolius L. and Solanum tuberosum L.
Amaranthus retroflexus and S. tuberosum sustained a large population of L. lineolaris and egg parasitism was high enough to consider it as a potential control factor.
相似文献
12.
The genusSabazia is expanded to include the genusTricarpha, Calea palmeri, and several newly described taxa,S. tridacoides var.tridacoides and var.latifolia, S. palmeri var.lancifolia, andS. longiradiata. Comparative studies of several morphological features suggest thatSabazia is most clearly related toSelloa andGalinsoga. Karyological data reinforce this observation: inSelloa andGalinsoga x = 8 whereas inSabazia x = 4 andn = 4, 8, 16, or 24. Several species ofCalea are very similar toSabazia in floral features and may be of close phyletic affinity, but most species ofCalea differ conspicuously, suggesting more remote relationships. Other taxa in the Galinsoginae apparently fairly closely allied toSabazia includeOteiza andTridax. 相似文献
13.
Recent systematic studies of Bartsia and Odontites showed the necessity to exclude the closely related perennial species Bartsia aspera (Portugal and northern Morocco) and Bartsia spicata (Central Pyrenees) from the genus Bartsia as a segregate genus named Nothobartsia. Morphologically this new genus combines characteristic features of Bartsia and of Odontites. Its autonomous systematic position is supported by the cladistic analysis, showing that Nothobartsia represents a relatively primitive genus standing close to the common ancestral root of Bartsia, Euphrasia, and Odontites. 相似文献
14.
Polymorphism in enzymatically amplified ribosomal DNA (rDNA) were examined in 18 strains of Saccharomyces. Restriction patterns generated from the region spanning the internal transcribed spacers (ITS) and the 5.8S rDNA produced two clusters corresponding to S. bayanus and S. cerevisiae. The type culture of S. carlsbergensis (ATCC 76529), which could not be separated from the S. cerevisiae group by small subunit (SSU) rDNA patterns, showed a ScrfI profile that was distinct from all the other strains. The type culture of s. intermedius var. turicensis (ATCC 76519) is assigned to S. bayanus on the basis of the combined results of SSU and ITS restriction analyses. S. kluyveri occurred at a separate branch of the distance tree and is unrelated to any of the strains. Results were in general agreement with reported DNA homologies and are discussed in relation to other molecular and genetic data. 相似文献
15.
Phylogenetic relationships among the nine species of Crossostylis (Rhizophoraceae) were elucidated using cladistic analysis of restriction site variations of chloroplast DNA. As a result,
this genus was found to comprise two pronounced monophyletic groups as follows: C. biflora, C. grandiflora, C. multiflora and C. sebertii; and C. cominsii, C. pachyantha, C. parksii, C. richii and C. seemannii. Moreover, the monophyly of C. biflora, C. grandiflora and C. sebertii in the former group and the monophyly of C. pachyantha, C. parksii, C. richii and C. seemannii in the latter group were also suggested. The molecular tree corresponded well with that inferred from morphological data
and no discrepancy was recognized. Many of the floral morphological characters reflected lineage, but all seed coat characters
were homoplasious. Evolutionary trends in some morphological characters were optimized on the cpDNA tree obtained. Species
from New Caledonia and Polynesia were monophyletic, as were those from the Solomon Islands, Vanuatu and the Fiji Islands.
All species endemic to the Fiji Islands made a cluster, and this suggests that speciation occurred from a single ancestral
species on the Islands. 相似文献
16.
The spawing behavior of Hexagrammos otakii. H. octogrammus and H. agrammus was observed in two different regions of northern Japan using underwater video cameras placed near nests guarded by males.
The spawning behavior of the three species consisted of similar patterns, although body size and nuptial coloration and nest
location of territorial male H. otakii differed from those of the other two Hexagrammos species. The courtship display of territorial males in each species involved rushing, butting and undulation of the trunk.
When a female entered the nest, the male leaned his head on the future spawning bed in the nest and spasmodically undulated
his trunk. The female that responded to the courtship laid her eggs within the seaweed bed. The territorial male then passed
over the eggs, touching his genital pore to the egg mass, and released sperm. Sneaking by other males was frequently observed
following the sperm emission. In both regions, females of H. octogrammus and H. agrammus commonly responded to courtship of male H. otakii and mated with them, but not vice versa. Possble reasons for the natural occurrence of such unidirectional hybridization
are discussed. 相似文献
17.
The phylogenetic relationships of the angiosperm genera Byblis and Roridula have been the subject of ongoing taxonomic controversy. Twenty-eight taxa of varying degrees of alleged relationship, including 3 members of the Winteraceae (as an outgroup), were investigated using partial sequences of 18S rRNA (small subunit) and also compared against the morphological data set from Hufford's (1992) cladistic treatment of 80 members of the Rosidae-Asteridae. The morphological analysis placed the two genera in a clade with the Sarraceniaceae in the Corniflorae-Asterid group as a sister taxon to an Ericales-Hydrangeales clade. The 18S rRNA analysis supports the recently published rbcL DNA analysis of Albert & al. (1992), with Roridula joined to taxa in the lower Rosidae, but Byblis joining instead to members of the Asteridae near the Solanaceae. Comparisons for congruence between the three analyses place Byblis in the higher Asterid group near the Solanaceae, and Roridula possibly nearer the Sarraceniaceae and Ericales. These results imply that the traditional morphological characters used to relate the two genera are possibly the result of convergence towards similar ecological and life-history strategies rather than synapomorphies. 相似文献
18.
The taxonomy of Cuscuta nevadensis and C. veatchii is investigated. Cuscuta nevadensis is more closely related to C. veatchii and C. denticulata than to C. salina, and the former two taxa are accepted as species. A summary of relevant taxonomic and biological information is provided,
including synonymy, distribution and ecology, keys, and a comparison of the morphology of flowers and seeds are examined.
The morphological basis of vivipary in C. nevadensis is discussed. The status of Cuscuta vivipara, an invalid name in recent use, is clarified. 相似文献
19.
Although several investigations have been made from different viewpoints, the classification or interspecific relationships
of Saguinus still remain uncertain.
In the present study, we applied multivariate analysis methods to dental measurements of part of Saguinus populations of sufficient sample size and obtained the following conclusions. Saguinus can be classified into two main groups: one consists of S. oedipus and S. leucopus, and the other of S. fuscicollis, S. nigricollis, S. labiatus, and S. mystax. Concerning the former group, the two subspecies of S. oedipus, S. o. oedipus, and S. o. geoffroyi, show a close affinity with each other and also a close relationship to S. leucopus, while the latter group consists of two subgroups of species, one including S. fuscicollis and S. nigricollis, and the other including S. labiatus and S. mystax. The biological distance between S. oedipus oedipus and S. o. geoffroyi is slightly larger than that between the pairs of S. fuscicollis and S. nigricollis and of S. labiatus and S. mystax. Factor analysis revealed significant factors which could explain the differences among the seven male Saguinus populations.
Taking all the results into account, it seems necessary to reconsider the phylogenetic relationships within the genus Saguinus. 相似文献
20.
Ten rust species are reported with new information on range of distribution and host relations. Among these, Puccinia fagopyricola and Uromyces junci were new to Japan, and Aecidium araliae was newly found in northern Honshu. Additional collections were made of Blastospora smilacis, Puccinia malvacearum and P. orbicula in northern Honshu. New hosts were added to Coleosporium solidaginis, C. tussilaginis, Phragmidium miyakeanum and Puccinia caricis, and a new Japanese host to Puccinia malvacearum.V: Trans. Mycol. Soc. Japan 29: 471–478, 1988. 相似文献
|