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1.
Phylogenetic relationships within Malvaceae s.l., a clade that includes the traditional families Bombacaceae, Malvaceae s.str., Sterculiaceae, and Tiliaceae, have become greatly clarified thanks to recent molecular systematic research. In this paper, we use DNA sequences of four plastid regions (atpB, matK, ndhF, and rbcL) to study relationships within Malvadendrina, one of the two major clades of Malvaceae s.l. The four data sets were generally in agreement, but five terminal taxa manifested highly unexpected affinities in the rbcL partition, and the non-coding sequences of the trnK intron were found to provide limited phylogenetic information for resolving relationships at the base of Malvadendrina. The remaining data strongly support the existence of six major clades within Malvadendrina: Brownlowioideae, Dombeyoideae, Helicteroideae, Malvatheca (comprising Bombacoideae and Malvoideae), Sterculioideae, and Tilioideae. These data also resolve the placement of two problematic taxa: Nesogordonia (in Dombeyoideae) and Mortoniodendron (in Tilioideae). The relationships among the six clades are not definitively resolved, but the best-supported topology has Dombeyoideae as sister to the remainder of Malvadendrina (posterior probability PP=80%) and Sterculioideae as sister to Malvatheca (PP=86%). This early branching position of Dombeyoideae is supported by similarities in floral characters between members of that clade and outgroup taxa in Byttnerioideae. Similarly, the sister-group relationship of Sterculioideae and Malvatheca receives support from androecial characteristics, like subsessile or sessile anthers and an absence of staminodes, shared by these two clades.  相似文献   

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Cladistic methodology is used to test the hypothesis that three major monophyletic groups exist among living mammals–the oviparous monotremes (Prototheria), and the viviparous marsupials (Metatheria) and placentals (Eutheria). Evaluation is made of the polarity (i.e. the direction of change in a primitive-to-derived sequence) of numerous characters which distinguish some or all of these groups, and of the usefulness of these characters in phylogenetic inference. An attempt is made to establish the state of these characters in the common Late Jurassic-Early Cretaceous therian ancestor of marsupials and placentals.
It is concluded that the most basic division of the Mammalia is the dichotomy into the subclasses Prototheria (including Monotremata, Multituberculata, Triconodonta, Docodonta) and Theria (including Metatheria, Eutheria, Pantotheria and Symmetrodonta). Two major groups exist among living viviparous mammals, the Metatheria and Eutheria; in a cladistic framework these are sister-groups. It is demonstrated that there is no special (sister-group) relationship between monotremes and marsupials, and there is no justification for placing them in a group Marsupionta.  相似文献   

4.
A cladistic analysis of Asarum was conducted to examine relationships among species within the genus and to test the monophyly of several groups of taxa that have often been treated as segregate genera. Thirty-two species were drawn from throughout the range of the genus, representing a broad sample of sections and all segregate genera. The data matrix included 37 characters derived from various aspects of vegetative and floral morphology. A strict consensus of all most parsimonious trees suggests that Asarum s.l. is monophyletic and consists of two main clades: an Asarum clade, which is characterized by connate styles and inferior ovaries, and an Asiasarum-Hexastylis-Heterotropa clade, which is characterized by ridges on the inner perianth surface, dorsal stigmas, and bifid style extensions. The latter is a large and morphologically diverse clade that includes the North American segregate Hexastylis and two Asiatic segregates. Examination of pollination mechanisms in the context of this phylogeny supports the conclusion that herkogamy, and thus obligate insect pollination, is derived from a plesiomorphic condition of autonomous self-pollination. Associated with herkogamy are characters such as glandular trichomes and other ornamentation of the surface of the calyx that probably represent increased specialization to attract insect pollinators. This study also indicates that chromosomal evolution has occurred via aneuploid decrease from an ancestral chromosome number of 2n = 26 to 2n = 24 in Heterotropa. The recognition of two subgenera, subgenus Asarum and subgenus Heterotropa, corresponding to the two clades in the cladistic analysis, is recommended.  相似文献   

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This study examined in detail the rbcL sequence and morphological support for subfamilial relationships and monophyly of Lecythidaceae. Initially we needed to establish relationships of Lecythidaceae among other dicot families. To complete this we examined 47 rbcL sequences of 25 families along with molecular observations from several large analyses of rbcL data. All analyses strongly support the monophyly of the asterid III grouping. This analysis revealed Lecythidaceae to be paraphyletic and indicated potential outgroup relationships with Sapotaceae. Once relationships had been evaluated using molecular data we then concentrated on analyzing separate and combined morphological and molecular databases. The topology of the morphological data set was similar to the rbcL sequence and combined data sets except for the positioning of Napoleonaeoideae, Grias, Gustavia, and Oubanguia. According to the combined results, Planchonioideae, Lecythidoideae. and Foetidioideae are monophyletic, whereas the subfamily Napoleonaeoideae are paraphyletic. Nested within Napolconaeoideae, we found Asteronthos forms a strongly supported clade with Oubanguia (Scytopetalaceae). Foetidia, the only genus of Foetidioideae, is sister to Planchonioideae, and this clade is sister to Lecythidoideae. The [(Planchonioideae, Foetidioideae) Lecythidoideae are sister to Asteranthos/Oubanguia. Napoleonaeoideae are sister to the rest of Lecythidaceae.  相似文献   

7.
This study was based on the analysis of staminal tube and epicalyx morphology of species ofPavonia (Malvaceae) from northeastern and southeastern Brazil. The importance of characters in the infrageneric taxonomy is discussed. In general, the variability in staminal tube and epicalyx characters are useful mainly in separating closely related species and a few sections; these characters, however, cannot be used to separate subgenera.  相似文献   

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《Mycoscience》2014,55(5):417-422
A new Perenniporia species, P. cinereofusca, is described based on morphological and molecular characters. It is characterized by an annual growth habit, resupinate basidiocarps with gray to pale brown pore surface, tissues becoming black in 5% potassium hydroxide (KOH), a dimitic hyphal system with weakly dextrinoid skeletal hyphae and hyaline to pale yellowish, distinctly thick-walled and indextrinoid basidiospores (6.5–7.7 × 5.3–6.3 μm), and presence of dendrohyphidia and large rhomboid crystals. Both morphological and molecular evidence confirmed the placement of the new species in Perenniporia sensu stricto and showed its relationships with similar species in the genus.  相似文献   

9.
BAUM, B. R. & SAVILE, D. B. O., 1985. Rusts (Uredinales) of Triticeae: evolution and extent of coevolution, a cladistic analysis. Established evolutionary trends in Uredinales as a whole are reviewed, and primitive and advanced characters are presented. The rusts of all Poaceae arc presented in a table that strongly indicates Bambusoideae to be the oldest and Pooideae the youngest subfamily. The rusts of Triticeae and their ecogeography are outlined; the rusts of Cyperaceae, selected as an out-group, are beiefly summarized; and the available characters and character states for rusts of Triticeae are given. Host alternation complicates the analysis. The aerial host (never a grass) is ecologically associated with the unrelated telial (grass) host. There are no appropriate methods to permit analysis of the combined components: aecial host evolution, telial host evolution, rust evolution, and their coevolution. Also, several aecial hosts are unknown. Consequently it was necessary to omit aecial hosts from the analysis. Cladistic analysis of the rusts of Triticeae was performed using five methods and consisted of cycles of tree analysis and modification of character state trees. A cladogram put together from a Dollo and a Wagner cladogram was used as a basis for the classification of rusts given. Subsequently a cladistic analysis of genera of Triticeae, using presence/absence of rusts as characters (Brooks' approach) was performed. The Triticeae cladogram of Baum (1983) was also analysed. Distances between the cladogram generated by various methods and that of Baum were computed for each possible pair, using the method of Robinson & Foulds, and then the resulting distance matrix was reduced in dimensionality by principal components and non-metric multidimensional scaling. The results are discussed in light of the limitation of the analyses and the data. It is concluded that coevolution is limited and that frequent jumps to ecologically associated hosts explain the parallelism in evolution of rusts on Triticeae.  相似文献   

10.
Current sea anemone systematics is based on relatively few morphological characters, and potentially could benefit from the use of molecular characters. In this paper, the phylogenetic relationships of 12 species from 6 genera in the family Actiniidae have been investigated using electrophoretically separated isozymes. A numerical cladistic analysis has produced an estimated phylogeny. The implications of this phylogeny for the taxonomic use of certain morphological characters are discussed.  相似文献   

11.
A cladistic study of Anllastrum, Angophora and Eucalyptus (Myrtaceae). Transformed cladistic; character compatibility; branch and bound, and Farris-Wagner methods gave similar solutions in a cladistic study of Arillastrum, Angophora and Eucalyptus. These analyses, based on morphological characters, indicate that Eucalyptus is a monophyletic group and that its sister taxon is Angophora.
Within Eucalyptus , subgenera Blakella and Corymbia are sister taxa to all other groups; subgenera Monocalyptus, Idiogenes and Gaubaea form a monophyletic group with subgenus Monocalyptus sister to subgenera Idiogenes and Gaubaea ; subgenera Symphyomyrtus and Telocalyptus together also form a monophyletic group and, with Eucalyptus similis (subgenus Eudesmia group 4), are sister to the Monocalyptus group. Eucalyptus subgenus Telocalyptus (4 species), Eucalyptus subgenus Idiogenes (1 species) and Eucalyptus subgenus Gaubaea (2 species) should not be recognized as subgenera and some individual species need further examination. Eucalyptus subgenus Eudesmia is a paraphyletic group.
Some characters are identified as parallelisms, e.g. axillary inflorescences, sepaline operculum, bristle glands, and clustered anthers. A more congruent interpretation of the single operculum of Eucalyptus subgenus Monocalyptus as at least partly petaline rather than solely sepaline in origin is suggested.
The area relationships for the taxa are concordant with those derived from geological and climatological information. New Caledonia is sister area to Australia, and within Australia southwestern Australia is sister area to south-eastern and north-eastern Australia.  相似文献   

12.
Phylogenetic relationships of 24 taxa of Platycephalid fish were examined for up to 40 loci using starch and polyacrylarnide gel electrophoresis. Over 400 different enzyme mobilities were scored. The extent of homoplasy was estimated to be between 5 and 12%. Polymorphism at the 1% level was observed at 26 of the 40 loci. The importance of shared polymorphic alleles in cladistic analysis was endorsed by the different results obtained from multistate and binary coding of alleles. Many loci were shown to contain phylogenetically informative ancestral alleles which appear irregularly in extant species. The polymorphism parsimony method provided the most informative results. Genetic similarities between endemic Australian species from each family stem provide the basis for a major revision of subfamilies and genera within the family.  相似文献   

13.
A cladistic analysis of 45 genera ofCardueae for 75 characters is presented, taking into account characters of bracts, corolla, stamens, styles and cypselas. Forty-six binary characters completeBremer's (1994) work. Some of the characters considered byBremer are criticised. The traditionalCarlininae is a paraphyletic group, the ten genera studied sharing no common derived character. A new classification of theCardueae is proposed and the distribution of the tribe is presented. Several new combinations are proposed. The nomenclature ofCentaurea is discussed and the status of the genusSerratula is analysed.  相似文献   

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The first cladistic analysis of the relationship of Malagasy vangas (Vangidae) based on morphological characters is presented here. The comparative morphological analysis provides new arguments for the exclusion of several taxa traditionally or recently assigned to Vangidae such as Tylas 'Vanga' ( Tylas eduardi ), Crossley's Babbler ( Mystacornis crossleyi ) and newtonias ( Newtonia spp.), but also for the exclusion of the Red-tailed 'Vanga' ( Calicalicus madagascariensis ) from the Vangidae. It leads also to the hypothesis that vangas sensu stricto , the Australasian woodswallows (Artamidae) and the Australo-Papuan butcherbirds (Cracticidae) form a monophyletic group, with the New Guinean peltops ( Peltops spp.) as its probable sister taxon. Such a relationship implies that the last common ancestor of vangas reached Madagascar from the east by means of a dispersal event across the Indian Ocean. This hypothesis is partly in accordance with that of William Pycraft (1907) published a century ago, but in conflict with contemporary hypotheses based on DNA sequence analysis which favour helmet-shrikes, bush shrikes and relatives as the closest relatives of vangas and therefore an African origin of this group.  相似文献   

17.
The family of polygyrid land snails in North America is significant for its sympatric shell convergences, diversity of mating systems and complex zoogeography; its monophyly and its relation to other families has long been questionable. Cladistic analysis has been performed on one representative each of 17 subfamilies, including all three polygyrid subfamilies and one or more subfamilies each from all ten of the families that have been proposed as the polygyrid sister groups. Eighteen anatomical synapomorphies are used, of which eight are newly discovered, four are differently assessed from previous studies, and six are traditional. The resulting strict consensus tree of alternative maximum-parsimony cladograms is: (Acavidae (Ammonitellidae Corillidae ((Discidae Oreohelicidae) (Helminthoglyptidae Bradybaenidae Polygyridae (Thysanophoridae (Camaenidae Sagdidae)))))).
According to this working hypothesis, the Polygyridae are monophyletic, and their sister group remains unresolved, although the Acavidae, Ammonitellidae, Corillidae, Discidae and Oreohelicidae can be ruled out. Of the five classifications of stylommatophoran families that have been proposed in the past 12 years, the consensus tree is closest to that of Nordsieck. For future morphological work, three regions are recommended as potentially rich in unused phylogenetic information: the fertilization pouch-seminal receptacle complex, the ureter at the pneumostome and the ventral-chain ganglia. Simultaneous dissection, wkh side-by-side comparisons, is recommended over other methods for detecting homologies in land snails. Molecular characters should be exploited, because of the scarcity and the frequent homoplasy of morphological characters.  相似文献   

18.
In order to establish the general environmental conditions under which the plants of the El Cien Formation grew during the Miocene, wood anatomical features from several extant ecological categories (southern California flora) and communities (Brazil, Mexico and Suriname) as well as those of the El Cien paleocommunity were analysed using different statistical approaches. We find a significant correlation between 42 characters of 199 species and 11 climate variables which suggests a close association of wood characters with temperature, whereas characters such as diameter, frequency, and grouping of vessels are more closely related to evaporation. The expression of various wood characters depends on more than one climate variable. There are no doubts regarding the tropical affiliation of the El Cien fossil flora but water availability and seasonality of the system are less clear. Principal component and cluster analyses of two different datasets (423 species, 9 characters and 223 species, 32 characters) suggest that the physiognomy of the fossil assemblage of El Cien was highly efficient in water transport, but also highly vulnerable to embolisms. Characters such as vessel diameter, frequency and grouping suggest proximity to a tropical rain forest, whereas the proportion of ring semi ring porous woods brings the El Cien paleoflora closer to forests with slightly xeromorphic physiognomy, probably a tropical deciduous or semi-deciduous forest. This condition is paralleled with the taxonomic composition of the El Cien fossil plants since their Nearest Living Relatives (NLR) can be referred to both humid or more (seasonally) dry environments. Derived regression analysis models suggest that the paleoflora prospered under conditions with an evaporation regime similar to that of the tropical rain forest.  相似文献   

19.
Based on the sequence analysis of 5.8S subunit and internal transcribed spacers (ITS ) of ribosomal RNA gene (rDNA), the molecular phylogenetic tree of representative species of Pipizini and three groups of Syrphidae with different feeding habits (seven species belong to six genera) was constructed. Meanwhile, the phylogenetic tree of tribes (including Pipizini and other 17 tribes of Syrphidae) was constructed using morphological characteristics of adults and larvae and the number of chromosomes. Both the results show that the relationship between Pipizini and predatory groups is closer than that between Pipizini and saprophagous groups. So it is suggested that Pipizini be transferred from Milesiinae to Syrphinae.  相似文献   

20.
Emine Alçitepe 《Biologia》2008,63(3):338-342
The morphological, anatomical and palynological features of Asyneuma michauxioides (Boiss.) Damboldt (Campanulaceae) were investigated. This species is an East Mediterranean Floristic Element and an endemic in Turkey. In anatomical studies, cross-sections of the root and stem were examined and demonstrated by photographs. It has conspicuous endodermis in which the Casparian bands are indistinct in the stem. According to the result of this study, it was found that pollen grain of this taxon was 3-porate sometimes 4-porate and oblate-spheroidal. Its structure was tectate and sculpture was small granules and pits with densely spaced spinules. The seeds of the taxon were eliptic to ovate in shape, laterally compressed, brown to light brown in colour, glabrous and shiny.  相似文献   

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