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The karyotypes ofElymus dentatus from Kashmir andE. glaucescens from Tierra del Fuego, both carrying genomesS andH, were investigated by C- and N-banding. Both taxa had 2n = 4x = 28. The karyotype ofE. dentatus was symmetrical with large chromosomes. It had 18 metacentric, four submetacentric and six satellited chromosomes. The karyotype ofE. glaucescens resembled that ofE. dentatus, but a satellited chromosome pair was replaced by a morphologically similar, non-satellited pair. The C-banding patterns of both species had from one to five conspicuous and a few inconspicuous bands per chromosome. N-banding differentiated the chromosomes of the constituent genomes by producing bands in theH genome only. TheS genomes of both species were similar with five metacentric and two satellited chromosomes having most conspicuous C-bands at telomeric and distal positions. They resembled theS genome of the genusPseudoroegneria. TheH genomes had four similar metacentric and two submetacentric chromosomes. The seventhH genome chromosome ofE. dentatus was satellited, that ofE. glaucescens nonsatellited, but otherwise morphologically similar. The C-bands were distributed at no preferential positions. TheH genome ofE. dentatus resembles theH genomes of some diploidHordeum taxa.  相似文献   

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25 populations from Turkey and one of Syria belonging to theSabulina section of the genusMinuartia have been karyologically examined. New chromosome numbers have been recorded forM. mesogitana andM. hybrida subsp.turcica, and a new variety was found in theM. hybrida complex. The origin of the taxa with n = 23 and n = 35 is discussed.
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The morphology, anatomy, and chemistry of five taxa belonging to theLecanactis grumulosa group from several localities of the Mediterranean area have been analysed in detail. One new saxicolous species,L. subgrumulosa, is described from Spain and Morocco. The new combinationL. farinosa is made.L. nothiza, L. monstrosa, L. ramosus, andOpegrapha alboatra are proposed as synonyms ofL. grumulosa. L. werneri andL. farinosa are cited for the first time in Europe and northern Africa, respectively. Anthraquinones are reported as new forLecanactis.  相似文献   

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Among the morphological variation in wild annual populations of sect.Beta only tepal characters show a geographic pattern, and hence can be used to distinguish different taxa. Two morphological types correspond with taxa already described:B. macrocarpa (incl.B. bourgaei) has a Macaronesian and W. to E. Mediterranean andB. adanensis an E. Mediterranean distribution area. A third type in the Aegean region is not well known yet and possibly has to be included inB. macrocarpa. Both diploid and tetraploid (x = 9) cytotypes are found withinB. macrocarpa, the latter exclusively on the Canary Islands.  相似文献   

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TEM observations were carried out on 40 taxa of the familyVerbenaceae and 35 taxa of the familyOleaceae, in order to ascertain distribution, ultrastructure and morphology of the intranuclear proteinic inclusions in the mesophyll parenchymatic cells. The investigated genera amount to some 25% and 60% respectively of the genera of the two families. Inside theVerbenaceae, lamellar inclusions (L-type) occur in 6 out of 23 investigated genera: they are mostly present inside the tribesCitharexyleae andVerbeneae (both belonging toVerbenoideae), while they are absent in other subfamilies. All of the investigatedOleaceae genera show intranuclear crystalline inclusions (C 1-type) of three different shapes. Among theAsteridae this is a character peculiar toOleaceae. They appear to be a well defined natural group, including the controversial genusNyctanthes.  相似文献   

8.
The taxonomic positions ofRetzia, Desfontainia, andNicodemia have been much discussed, and all three genera have been included inLoganiaceae (Gentianales). We have made a cladistic analysis ofrbcL gene sequences to determine the relationships of these taxa toGentianales. Four newrbcL sequences are presented; i.e., ofRetzia, Desfontainia, Diervilla (Caprifoliaceae), andEuthystachys (Stilbaceae). Our results show thatRetzia, Desfontainia, andNicodemia are not closely related toLoganiaceae or theGentianales. Retzia is most closely related toEuthystachys and is better included inStilbaceae. The positions ofDesfontainia andNicodemia are not settled, butDesfontainia shows affinity for theDipsacales s.l. andNicodemia for theLamiales s.l.  相似文献   

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Nucleotide sequences from the internal transcribed spacer (ITS) regions of the 18S–26S nuclear ribosomal DNA have been studied from ten species ofQuercus (representing four subgenera),Castanea sativa andFagus sylvatica, as a preliminary molecular contribution to the still poorly understood systematics and evolution ofFagaceae. The resulting matrix has been used to calculate pair-wise sequence divergence indices and to construct a maximum parsimony tree forQuercus coding indels as a fifth state. Divergence is greater forQuercus vs.Fagus than forQuercus vs.Castanea. The tree for theQuercus taxa studied reveals two clearly divergent clades. In clade I the evergreen W MediterraneanQ. suber appears in a basal position as sister to more distal deciduous taxa, i.e. the E MediterraneanQ. macrolepis and the E AsiaticQ. acutissima (all formerly united as different sections under the apparently polyphyletic subg.Cerris), andQ. rubra (a representative of the N American subg.Erythrobalanus), forming a pair withQ. acutissima. In clade II the evergreen southeastern N AmericanQ. virginiana is basal and sister to the remaining three branches, i.e. a pair of evergreen Mediterranean taxa withQ. ilex andQ. coccifera (subg.Sclerophyllodrys), the deciduous but otherwise plesiomorphic SE European/SW AsiaticQ. cerris (type species of subg.Cerris), and the related but more apomorphic European pairQ. petraea andQ. robur (subg.Quercus). These results partly conflict with current taxonomic classification but are supported by some anatomical and morphological characters. They document polyphyletic lines from evergreen to deciduous taxa and suggest Tertiary transcontinental connections within the genus.  相似文献   

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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   

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A cytological analysis of 37 experimental interspecific hybrids withinEpilobium sect.Epilobium, involving 23 taxa, has indicated that the CC chromosome arrangement differs from BB by a single reciprocal translocation and was probably, like AA and DD, derived from it. Preliminary results suggest that the CC arrangement may characterize the AsianE. cephalostigma andE. platystigmatosum, which do not closely resemble the species in which it had earlier been detected. The BB arrangement is shown to occur in all North American species of theE. palustre group, includingE. oregonense. Direct evidence on chromosome arrangement is now available for some 85 of the approximately 185 species of the section, and may be inferred for at least 25 more.  相似文献   

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Erythrina lectins possess similar structural and carbohydrate binding properties. Recently, tri- and tetra-antennary complex type carbohydrates with non-reducing terminal galactose residues have been shown to be precipitated as tri- and tetravalent ligands, respectively, with certainErythrina lectins [Bhattacharyya L, Haraldsson M, Brewer CF (1988) Biochemistry 271034-41]. The present work describes a comparative study of the binding and precipitating activities of fourErythrina lectins,viz. E. corallodendron, E. cristagalli, E. flabelliformis, andE. indica, with multi-antennary complex type carbohydrates and synthetic cluster glycosides. The results show that though their binding affinities are very similar, theErythrina lectins show large differences in their precipitating activities with the carbohydrates. The results also indicate significant dependence of the precipitating activities of the lectins on the core structure of the carbohydrates. These findings provide a new dimension to the structure-activity relationship of the lectins and their interactions with asparagine-linked carbohydrates.Abbreviations EAL, ECorL, ECL, EFL, and EIL represent the lectins from the seeds ofErythrina arborescens, - E. corallodendron, E. cristagalli, E. flabelliformis, andE. indica respectively - AFOS thetri-antennary complex type oligosaccharide from asialofetuin - AFGP the tri-antennary glycopeptide from asialofetuin - MeGal methyl -d-galactopyranoside Unless stated otherwise all sugars are in thed-configuration.  相似文献   

16.
The sieve-element plastids of 126 species of theArales were investigated by transmission electron microscopy. With the exception ofPistia (with S-type plastids) all contained the monocotyledon specific subtype-P2 plastids characterized by cuneate protein crystals. While the species studied from bothAcoraceae andLemnaceae have form-P2c plastids (i.e., with cuneate crystals only), those of theAraceae belong to either form P2c (14 species), P2cs (the great majority) or P2cfs (Monstera deliciosa, only, with form-P2cs plastids in the otherMonstera species studied). The form-P2cs plastids of theAraceae are grouped into different categories according to the quantity and quality of their protein and starch contents. The subfamilyLasioideae is redefined to comprise all aroid P2c-taxa and those P2cs-genera that contain only one or very few starch grains. Only little starch is also recorded in the sieve-element plastids ofGymnostachys (Gymnostachydoideae), with the other plastid data denying a close relationship toAcorus. While equal amounts of starch and protein are generally present in sieve-element plastids of the subfamiliesPothoideae, Monsteroideae, Colocasioideae, Philodendroideae, andAroideae, maximum starch content and only very few protein crystals are found in form-P2cs plastids ofCalla (Calloideae),Ariopsis (Aroideae), andRemusatia (Colocasioideae?). In the latter, both morphology and size of sieve-element plastids are close to those ofPistia.—In theAraceae the diameters of the sieve-element plastids exhibit a great size range, but are consistent within a species and within a defined part of the plant body. Comparative data are mainly available for stem and petiole sieve-element plastids.—The accumulated data are used to suggest an affiliation of the species to subfamilies and to discuss the phylogeny of theArales. Forms and sizes of their plastids support a separation of bothAcoraceae andLemnaceae from theAraceae. The presence of S-type plastids inPistia does not favour direct and close relationships to the form-P2c genusLemna.—The prevailing form-P2cs plastids might support proposals that place theArales (together with also form-P2cs plastid containingDioscoreales) in the neighbourhood of basal dicotyledons. BesidesAsarum andSaruma (Aristolochiaceae), with monocotyledonous form-P2c plastids,Pistia (with dicotyledonous S-type plastids) gives another example for a link between the two angiosperm classes.  相似文献   

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Multivariate analysis of vegetative and reproductive characters was used to examine morphological relatedness amongAntennaria alborosea A. E. Porsild,A. corymbosa E. Nels.,A. marginata Greene,A. microphylla Rydb.,A. parvifolia Nutt.,A. rosea Greene, andA. umbrinella Rydb. Both pistillate and staminate plants were examined. Some of the characters examined were variable in one species, but stable in another (i.e., presence or absence of papillae on the achenes). Our analyses indicate that the seven species are morphologically distinct. It is hypothesized that theA. rosea agamic complex arose through hybridization amongA. corymbosa, A. microphylla, A. umbrinella, and possiblyA. dioica (L.)Gaertn. However, hybridization between the three former species and others, as well as their subsequent morphological responses to different environmental conditions causes confusion in recognizing the taxa.Antennaria angustifolia Rydb.,A. arida E. Nels.,A. confinis Greene,A. scariosa E. Nels.,A. foliacea humilis Rydb.,A. concinna E. Nels., andA. viscidula E. Nels. are considered to represent F 1 hybrids.  相似文献   

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The fertility relationships ofOrnithogalum umbellatum, O. angustifolium and 9 related taxa were studied.O. umbellatum andO. angustifolium, which are not interfertile, are both recognized as a comparium. Pollination of five species belonging to theO. umbellatum/angustifolium polyploid complex, i.e.O. umbellatum, O. angustifolium, O. baeticum, O. monticolum andO. algeriense, resulted in a moderate seed set. However, the seeds obtained after these interspecific crosses did not germinate. Six related species, i.e.O. exscapum, O. nivale, O. comosum, O. collinum, O. gussonei andO. woronowii showed a very low seed set after being crossed. One exception occurs:O. nivale ×O. exscapum. The seed set was also low after the complex species had been crossed with some related species, but there was one exception: both reciprocal crosses betweenO. monticolum andO. woronowii yielded some viable seeds. No other interspecific crosses gave rise to viable seeds. Bulbil-producing species have a lower seed set after self-pollination than species which do not produce bulbils.Biosystematic Studies on theOrnithogalum umbellatum/angustifolium Complex IV.—Previous contributions: (I–III):Raamsdonk (1982, 1985a, 1985b).  相似文献   

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