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1.
The Teloschistaceae is a widespread family with considerable morphological and ecological heterogeneity across genera and species groups. In order to provide a comprehensive molecular phylogeny for this family, phylogenetic analyses were carried out on sequences from the nuclear ribosomal ITS region obtained from 114 individuals that represent virtually all main lineages of Teloschistaceae. Our study confirmed the polyphyly of Caloplaca, Fulgensia and Xanthoria, and revealed that Teloschistes is probably non-monophyletic. We also confirm here that species traditionally included in Caloplaca subgenus Gasparrinia do not form a monophyletic entity. Caloplaca aurantia, C. carphinea and C. saxicola s. str. groups were recovered as monophyletic. The subgenera Caloplaca and Pyrenodesmia were also polyphyletic. In the subgenus Caloplaca, the traditionally recognized C. cerina group was recovered as monophyletic. Because this study is based solely on ITS, to maximize taxon sampling, the inclusion of phylogenetic signal from ambiguously aligned regions in MP (recoded INAASE and arc characters) resulted in the most highly supported phylogenetic reconstruction, compared with Bayesian inference restricted to alignable sites.  相似文献   

2.
Nine sterols and triterpenes isolated from Codonopsis pilosula and Adenophora stricta were used as reference compounds fir thin layer chromatographic identification of hydrophobic constituents in the roots of 28 species belonging to four genera of the family Campanulaceae: Codonopsis, Adenophora, Campanumoea and Platycodon. Two of the subgenera of Codonopsis (subgen. Codonopsis and subgen. Obconicicapsula) and two sections of Subgenus Codonopsis (sect. Codonopsis and sect. Erectae) were included in the study. The results indicated that the four genera could be distinguished from one another. β-Sitosterol and taraxerol were present in all the four genera studied. -Spinasterol was the characteristic compound in Codonopsis while β-sitosteryl palmitate was diagnostic to Adenophora.  相似文献   

3.
Fourteen herbarium specimens of Polytrichadelphus aristatus (Polytrichaceae, Musci) from the northern Andes were found to be colonized by ascomycetes. Thirty fungal specimens are indicated representing nine species and six genera. They belong to the first records of bryophilous fungi of northern South America. Five taxa are proposed as new: the genus Aphanotria, and the species A. paradoxa, Bryochiton macrosporus, Bryorella imitans, and Massarina polytrichadelphi. Most frequently found were Rogellia triseptata with six and Bryochiton macrosporus with five records. Four species develop their ascomata between the photosynthetic leaf lamellae, three are immersed within the abaxial side of the leaf nerve and two grow below the adaxial cuticle. The hypocrealean A. paradoxa, which has huge but almost invisible ascomata, merits special attention. Apart from a pronounced rostrum, these are completely immersed within the leaf nerve but longitudinally orientated occupying a type of microniche hitherto unknown. Hyphae of several species attack the thick-walled stereids of the leaf nerve and strongly contribute to leaf decomposition. Polytrichadelphus aristatus has an assemblage of parasitic ascomycetes quite different from that of P. magellanicus from southern South America.  相似文献   

4.
Using the drop-diffusate technique, a number of isoflavonoid phytoalexins have been obtained from the excised, fungus-inoculated leaflets of 41 species belonging to the legume genus Trigonella. Leaf diffusates variously contained pterocarpan (medicarpin and maackiain) and isoflavan (vestitol and sativan) derivatives previously associated with genera closely allied to Trigonella. In diffusates from T. calliceras, medicarpin was accompanied by a phytoalexin (designated TC-1) provisionally identified as a new hydroxylated pterocarpan. Most of the Trigonella species were also examined for their ability to release coumarin upon tissue maceration. The combined phytoalexin/coumarin data suggest that three major intrageneric chemical divisions occur in Trigonella; two of these apparently link the genus to Medicado/Factorovskya and Melilotus respectively, whilst the third provides some evidence for a connection with Trifolium. The taxonomic aspects of these findings are discussed in the light of earlier morphological studies which provided evidence for a distinct floral dichotomy amongst Trigonella species.  相似文献   

5.
The presence of alkaloids in six species of Brongniartia and three species of Harpalyce is reported. This survey revealed remarkable qualitative differences in the alkaloid profiles of these two genera. B. discolor, B. lupinoides, B. sousae and B. intermedia showed a typical -pyridone pattern, with cytisine, anagyrine and baptifoline as major alkaloids. In leaves of the first three species ormosanine-type alkaloids occurred additionally. B. flava and B. vazquezii are devoid of -pyridones, but accumulate lupanine, hydroxylated lupanines and ester alkaloids. All three species of Harpalyce were similar in accumulating -pyridones, but H. formosa differed from H. brasiliana and H. pringlei in the presence of epilupinine. In general the alkaloid profiles of Brongniartia and Harpalyce show similarities to those of the Australian genera Hovea, Lamprolobium, Plagiocarpus and Templetonia and support therefore the actual concept of the enlarged tribe Brongniartieae.  相似文献   

6.
Leaf resins in the leguminous genera Hymenaea and Copaifera may play a role in restricting infection by the associated leaf fungus, Pestalotia. We tested this hypothesis by assessing growth of the geographically widespread Pestalotia subcuticularis presented with different compositions of resins. Leaf resins of Hymenaea and Copaifera are composed of the same suite of sesquiterpene hydrocarbons, but these vary quantitatively to form discrete compositional patterns among individuals and populations. Leaf resins may also contain sesquiterpene oxides; caryophyllene oxide, which may have been formed from the caryophyllene precursor common in these resins, inhibited fungal growth in vitro.  相似文献   

7.
The family Prosthogonimidae (Trematoda) in Australia. International Journal for Parasitology 3: 853–862. The family Prosthogonimidae has previously been known in Australia by three species of Prosthogonimus Lühe, 1899 (from birds) and by Coelomotrema Angel, 1970 (from marsupials). Two new genera are now proposed: Cylindrotrema cygni from Cygnus atratus (Latham) (caecum), and Mawsonotrema eudyptulae from Eudyptula minor (Forster) (liver). Prosthogonimus vitellatus Nicoll, 1914 is recorded from three new hosts, Gymnorhina tibicen leuconota (Latham), Phalacrocorax melanoleucos (Vieillot) and Chlidonias hybrida (Pallas), and the species is redescribed from 11 specimens from the first of these. The life history, not known for any Australian species, is discussed.

The only plump-bodied genera in the family are Coelomotrema, Cylindrotrema and Mawsonotrema, all of which are confined to Australia.

Mawsonotrema differs from all other members of the family in the position of the genital pore, which is away from the anterior end of the body, lying against the anterior border of the acetabulum.  相似文献   


8.
Species concepts are a notoriously difficult taxonomic problem in plant–parasitic fungal-like organisms such as downy mildews (Peronosporomycetes, Peronosporales). This is particularly evident in the largest downy mildew genus, Peronospora, which contains a number of economically important pathogens. Here, we investigate relationships of Peronospora species infecting Fabaceae (angiosperms, Rosidae) originating from various collections from different species of host plants and from different European locations by molecular phylogenetic analysis of ITS sequences. Molecular trees were inferred with ML, MP and Bayesian methods and rooted with Pseudoperonospora. As in other downy mildew groups, molecular data mainly support the use of narrow species delimitations and host range as a taxonomic marker. Fabaceae parasites appear to be subdivided into a number of lineages displaying a considerable degree of host specialization with respect to host genera, as well as host subgenera or species. The number of repeats of a repetitive part of the ITS1 is, within limits, characteristic of subgroups within the cluster of Trifolium parasites. We reveal new hosts for Peronospora found on the Iberian Peninsula.  相似文献   

9.
Four flavonols based on either quercetin or kaempferol are found in Margaranthus. The compounds are uniform throughout the populations examined and no evidence is present for the recognition of more than one species. The flavonols are similar to those found in related in genera, and do not provide a basis for the exclusion of Margaranthus from the subtribe Solaninae.  相似文献   

10.
詹玲  于晶  郭水良 《植物学报》2017,52(2):241-253
木灵藓科(Orthotrichaceae)是藓类植物中的第3大科。该科不仅种类多, 生态类型特殊, 而且是世界公认的多样化程度高、分类难度大、系统关系复杂的类群。当代木灵藓科植物分类系统学研究主要集中在该科的地区志编写和专属分类修订。目前, 除了热带美洲、热带非洲的变齿藓属(Zygodon)和火藓属(Schlotheimia)部分类群外, 木灵藓科主要类群的分类修订工作已基本完成, 但是有关亚科和属的划分和地位以及各属之间的关系等方面仍存在众多争议。木灵藓科分支系统学研究也不够系统全面, 有的仅应用了单个基因片段, 或者只涉及少数类群。因此, 需要基于更多的分子和形态学性状, 进一步开展世界木灵藓科植物的系统发育研究, 建立一个更趋自然的木灵藓科分类系统。  相似文献   

11.
In the genus Gentiana s.l. (Gentianaceae), the status of the section Crossopetalum Froel, is still very much debated. On Morphological grounds. Ma regarded this section as an independent genus which he called Gentianopsis. In this paper we discuss this proposal, taking into account chemotaxonomic data (xanthones, carbohydrates and C-glycosylflavones) arising from an examination of leaves and flowers of 13 species including the type-species Gentianopsis barbata. Isoscoparin, primeverose. 1,3,7- and 1,3,7,8-O-substituted xanthones were present in all species, while 1,3,5,8-O-substituted xanthones were absent. These criteria clearly differentiate the group from Gentianella (occurrence of 1,3,5,8-O-substituted xanthones, absence of 1,3,7-O-substituted xanthones, presence of swertisin, absence of primeverosel in which they were previously included. Furthermore, a comparison of Crossopetalum with two species belonging to Gentiana s.s. (the type G. lutea L. and G. orbicularis Schur.) discloses some analogy with respect to xanthone composition (only 1,3,7- or 1,3,7,8-substitution, respectively). However, the presence of gentianoise in Gentiana s.s., in contrast to its absence in Gentianopsis, indicates that the latter should be excluded from Gentiana. The assessment on morphological grounds of the validity of the genus Gentianopsis Ma is thus reinforced. The evolutionary signification of the chemical characters and the phyletic relationships of Gentianopsis with the other genera of the Gentianinae are discussed.  相似文献   

12.
We demonstrate the existence of polymorphic DNA minisatellites in Drosophila mauritiana, a close relative of D. melanogaster. One of these sequences (minisatellite mD4.2) consists of 13 tandemly repeated monomers, 10 of which are 33 base pairs long. Each of the repeat monomers contains sequences identical or very similar to the Chi sequence (GCTGGTGG), a signal for recBCD-dependent recombination in Escherichia coli. Sequences hybridizing to the mD4.2 minisatellite are present in at least 20–25 genomic locations and exhibit substantial variability among different populations of three Drosophila species and two populations of the house fly, Musca domestica. Interpopulational variation is a result of length differences rather than restriction site polymorphisms and genetic crosses establish that the hybridizing restriction fragment patterns have an underlying genetic basis. The presence of these sequences in the genetically well known Drosophila species allows critical examination of processes that produce and maintain the remarkable variability associated with these genomic regions.  相似文献   

13.
Reports of quinolizidine alkaloids in Styphnolobium Schott and Cladrastis Raf. (Leguminosae) conflict with their position in recent molecular phylogenies because they are not members of a major clade of quinolizidine alkaloid-accumulating taxa. The alkaloid status of these two genera was therefore re-investigated using gas chromatography–mass spectrometry. Quinolizidine alkaloids could not be detected in extracts of leaves, flowers or seeds of S. japonicum (L.) Schott, nor in leaves of S. affine (Torrey & A. Gray) Walp., C. delavayi (Franch.) Prain, C. kentukea (Dum.-Cours.) Rudd or C. platycarpa Mak. In contrast, Calia secundiflora (Ortega) Yakovlev, also currently placed outside the major clade of quinolizidine alkaloid-producing genera in molecular phylogenies, was confirmed to accumulate a range of quinolizidine alkaloids.  相似文献   

14.
The isoenzymes from seven populations of Solea senegalensis or aegyptiaca were compared et 24–30 loci, six of which display significant differences in their allelic frequencies. In addition, these populations were compared to six other Soleidae species, namely Solea vulgaris, S. impar, S. lascaris, S. lutea, Michrochirus azevia, and M. variegatus. It was shown that S. senegalensis and S. aegyptiaca can be separated into two distinct genetic groups. Their high genetic similarity in comparison with the other species of Soleidae studied suggests that they have a common origin. The systematic status (species or semispecies) of these taxa could not, however, be elucidated. The high degree of genetic polymorphism observed in the regions where the two taxe are found together suggests that there still is some gene flow between them. However, this could be due to selection.  相似文献   

15.
Ray flower and leaf flavonoids were investigated for the three species of Helianthus series Microcephali. Ray flowers of all species contain coreopsin, sulphurein, and quercetin 7-O-glucoside; those of H. microcephalus also contain quercetin 3-O-glucoside. A mixture of flavonoid aglycones, mostly methoxylated flavones, occurs in leaves of H. microcephalus, but not in H. glaucophyllus or H. laevigatus which also lack the glandular trichomes that in Helianthus are typically associated with flavonoid aglycones. The presence of compounds with the 6,8,4′ pattern of methoxylation in H. microcephalus suggests that the series is more similar in flavonoids to series Angustifolii than to series Corona-solis.  相似文献   

16.
Four species of spirotrichonymphids representing three genera Spirotrichonympha, Spironympha and Microjoenia symbiotic in the termite Hodotermopsis sjoestedti, have been studied by light and immunofluorescence microscopy and transmission electron microscopy. The genus Spirotrichonympha represented by Spirotrichonympha cincta n. sp. is characterized by a compound axostyle composed of several fibers or subaxostyles, and this species has peculiar undescribed structures associated with the flagellar lines. The genus Spironympha is characterized by flagellar lines restricted to the anterior area and a simple tubular axostyle limited by 1–3 layers of microtubules. The two new Spironympha species Spironympha obtusa and Spironympha oblonga are distinguished by peculiarities in the flagellar lines and the axostyle, as revealed by immunofluorescence and electron microscopy. The genus Microjoenia represented by Microjoenia minuta n. sp. has radiating flagellar lines and an axostyle with two microtubular rows originating from the pelta-axostyle rows covering the anterior cap. Four new species were named and one was assigned to the SSU rRNA sequences provided by the molecular phylogenetic studies by Ohkuma et al. [2000. Phylogenetic identification of hypermastigotes, Pseudotrichonympha, Spirotrichonympha, Holomastigotes, and parabasalian symbionts in the hindgut of termites. J. Eukaryot. Microbiol. 47, 249–259; 2005. Molecular phylogeny of parabasalids inferred from small subunit rRNA sequences, with emphasis on the Hypermastigea. Mol. Phylogenet. Evol. 35, 646–655].  相似文献   

17.
Species of the freshwater gastrotrich taxon Dasydytidae show a set of conspicuous structural and behavioural adaptations to a semi-planktonic life. Conspicuously, most dasydytids have several groups of strong, moveable spines that can actively be abducted to perform saltatory movements, change the overall direction of locomotion, or enable the animals to rest in a defensive position. So far, there are only vague ideas of how these spine movements are achieved in dasydytid species. In order to gain insight into the possible morpho-functional coupling of body musculature and motile spines, we have carried out a study targeting the muscular system in two species of Dasydytidae by means of phalloidin staining and confocal laser scanning microscopy.

For spine movements in both species studied, Stylochaeta scirtetica and Dasydytes (Setodytes) tongiorgii, we have identified an antagonistic system of segmented longitudinal and oblique somatic muscle pairs. In both species, contraction of the musculi obliqua abduct the paired groups of ventro-lateral spines; contraction of the segments of musculi laterales causes their adduction.

A comparison of the muscular system of the studied species to that of other gastrotrichs reveals several homologous muscle pairs, visceral as well as somatic, that might be features of the stem species of a clade comprising all Paucitubulatina exclusive of Xenotrichulidae. The pairs of oblique somatic muscles are most probably an autapomorphy of Dasydytidae.  相似文献   


18.
中国松科花粉形态研究   总被引:8,自引:0,他引:8  
张金谈 《植物研究》1989,9(3):87-98
本文研究了我国松科(Pinaceae)9属61种的花粉形态, 其中有6种进行扫描电子显微镜观察和照相, 4种进行透射电子显微镜观察和照相, 每属都有代表种的绘图, 对该科花粉形态类型、科下的分类及演化问题进行讨论, 为本科的亚科、属、种的划分提供孢粉学方面的参考依据。  相似文献   

19.
While polyploidy (whole-genome multiplication) is generally considered rare in extant gymnosperms (with the exception of Ephedra, Ephedraceae), the occurrence of sporadic polyploid individuals belonging to various genera in the conifer family Cupressaceae has been reported in the literature. In addition, recent studies have revealed that polyploidy is not uncommon in the genus Juniperus (Cupressaceae), with tetraploid and hexaploid individuals reported in individuals collected from wild populations. Given these findings, we undertook a comprehensive screening of ploidy levels in 32 species belonging to the four genera that are phylogenetically closest to Juniperus (i.e.,Callitropsis, Hesperocyparis, Xanthocyparis, and Cupressus), referred to as the CaHXCu complex. In addition, we also determined the ploidy level of two accessions in the poorly studied tetraploid, Fitzroya cupressoides. Using flow cytometry together with published chromosome counts to assign ploidy levels, we show that all species of the CaHXCu complex are diploid except Xanthocyparis vietnamensis, which is tetraploid, with a genome size of 44.60 pg/2 C. This study opens up new opportunities for studying the impact and consequences of polyploidy on the evolution and adaptation of species in Cupressaceae.  相似文献   

20.
This study examined predation by the blue crab, Callinectes sapidus Rathbun, within intertidal Spartina alterniflora (Loisel) marshes of Dauphin Island, Alabama. Species and size preferences displayed by the predator when foraging within the marsh were investigated using nektonic, epifaunal, and infaunal prey populations including Fundulus similis Baird and Girard, Littorina irrorata Say, and Geukensia demissa Dillwyn.

Short-term field experiments involving the use of predator inclusion cages, in which the relative abundances of all prey species and the density of macrophyte vegetation were manipulated, indicated that mean mortality differed significantly among species. Blue crabs exhibited a distinct species preference for Littorina, and to a lesser extent, for Fundulus. However, the predator rarely choses infaunal individuals. Within predator inclusion cages, size selection by the crabs among three size classes of each prey was evident for Littorina and Fundulus but not for Geukensia. Blue crabs tended to select intermediate-sized snails and large fish while not exhibiting a size preference for infaunal bivalves.

In the marsh, mean percentage of the Littorina population within the 14–18 mm size class exhibited an increased mortality as compared to two other size classes, which was negatively correlated with increasing tidal height. Such a relationship may have been due to a decreasing gradient of crab predation associated with increasing tidal height. Geukensia size class distributions showed little evidence of differences along the tidal height gradient. No data are available for Fundulus, a mobile species which would not experience such differential predation along a marsh gradient.

In comparing crab predation patterns among prey species, it is apparent that Callinectes utilizes prey species differentially. Such differential utilization may be based on optimization of energy yield and minimization of energy expenditure. Thus, the preference of blue crabs for nektonic and epifaunal prey is hypothesized to be the result of a smaller energy expediture as a result of the crab's visual evaluation of these prey. Infaunal prey species (e.g., Geukensia) require a greater energy investment because of the necessity of excavating the prey item. Such prey also allow little selection by size because of being cryptic.  相似文献   


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