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1.
TheAntennaria neodioica polyploid agamic complex is a polymorphic species occurring across North America mainly north of the terminal margin of the Wisconsin glacier. This taxonomically difficult group has recently been treated as consisting of the four subspeciesA. neodioica subsp.canadensis, subsp.howellii, subsp.neodioica, and subsp.petaloidea. TheA. neodioica agamic complex has been considered of hybrid origin with several sexual diploid species constituting its parentage. Crosses were made among five sexual diploid species ofAntennaria, morphologically similar toA. neodioica s.l., in an attempt to discover its origins. Representative specimens of the five diploid species,A. neodioica s. l., and the synthetic interspecific F1 hybrids were subjected to various analyses including PCA, cluster (UPGMA), and discriminant analyses. Results suggest that theA. neodioica complex is of multiple hybrid origin involving the four diploid speciesA. neglecta, A. plantaginifolia, A. racemosa, andA. virginica. BecauseA. neodioica is the result of diverse origin it is more desirable to consider the agamic complex as a separate, distinct species from its sexual diploid relatives. Several morphological characters in the diploid species were determined to be polygenically inherited.Investigations into the Evolutionary History of the Polyploid Complexes inAntennaria (Asteraceae: Inuleae). I.  相似文献   

2.
TheAntennaria rosea species complex is circumscribed to contain four subspecific taxa. A complete synonymy and key to the subspecies ofA. rosea is presented. The following new combinations are proposed:Antennaria rosea subsp.arida (E. Nels.) R. Bayer,A. rosea subsp. confinis (Greene) R. Bayer, andA. rosea subsp. pulvinata (Greene) R. Bayer. The affinities ofA. rosea to other species ofAntennaria are discussed and a key to separateA. rosea from related polyploid complexes is provided.  相似文献   

3.
The Antennaria parlinii and A. neodioica agamic complexes are widely distributed across North America. Morphological data have suggested that these dioecious, perennial, entire-leaved herbs are of multiple hybrid origin from among five sexual diploid species. Antennaria neglecta, A. plantaginifolia, A. racemosa, and A. virginica are hypothesized to be the diploid progenitors of the A. neodioica complex, whereas A. parlinii sensu lato is thought to include the genomes of A. plantaginifolia, A. racemosa, and A. solitaria. An electrophoretic study was initiated to assess the degree of divergence among the five diploid species and to test the hypotheses of the hybrid (allopolyploid) origins of A. parlinii and A. neodioica. Twenty genetic loci were surveyed in 76 populations of the diploid and polyploid taxa. The diploid species are well defined morphologically, although the genetic basis of differences distinguishing them have not been determined. The species exhibit little divergence at genes specifying soluble enzymes, however each species has unique alleles in highest frequency at one or two genes. Allozymes indicate that gene diversity in the obligately outcrossing diploids occurs primarily within rather than among populations. The shale barren endemic, A. virginica, is as genetically diverse as the more edaphically diverse and widespread species. Tetraploid cytotypes of diploid (2n = 28) A. virginica possess the same allozymes as the diploids and these cytotypes appear to be of autopolyploid (non-hybrid) origin. Enzyme electrophoresis is concordant with morphological data in suggesting that A. neodioica contains the genomes of A. neglecta, A. virginica, A. plantaginifolia, A. racemosa and perhaps A. solitaria whereas the latter three species are the progenitors of A. parlinii.  相似文献   

4.
5.
Somatic chromosome numbers have been determined for the followingCerastium taxa:C. eriophorum (2n = 36),C. alpinum (2n = 72),C. transsylvanicum (2n = 108),C. arcticum (2n = 108),C. latifolium (2n = 36),C. carinthiacum (2n = 36),C. banaticum (2n = 36),C. arvense subsp.glandulosum (2n = 36),C. arvense subsp.arvense (2n = 72) andC. fontanum (2n = 144). Karyotypes of three diploid species (C. eriophorum, C. banaticum andC. latifolium), belonging to three different taxonomic groups, were analysed and found to be similar. The relative nuclear DNA contents of all taxa were determined by flow cytometry and, for five species, also by Feulgen cytophotometry. The values obtained by the two methods are similar. A comparison of nuclear DNA contents among diploids shows that values differ significantly between different taxonomic groups, and are correlated with average chromosome size. Within closely related polyploid groups nuclear DNA amounts increase from 2x- to 4x- and 6x taxa as 1 : 1.4 : 2.4 in theC. alpinum complex, whereas DNA amounts are doubled comparing 2x- and 4x-subspecies in theC. arvense complex.  相似文献   

6.
TheAntennaria rosea polyploid agamic complex is one of the most morphologically diverse and widespread complexes of N. AmericanAntennaria. The group is taxonomically confusing because of numerous agamospermous microspecies, having been recognized as distinct species. Morphometric analyses have demonstrated that the primary source of morphological variability in the complex derives from six sexually reproducing progenitors,A. aromatica, A. corymbosa, A. media, A. microphylla, A. racemona, andA. umbrinella. Additionally, two other sexually reproducing species,A. marginata andA. rosulata, may have contributed to the genetic complexity of theA. rosea complex. Cluster analysis indicates that four discrete morphological groups exist within theA. rosea complex. Each group could be the result of predominance of genes from different groups of sexual progenitors. AsA. rosea is of multiple hybrid origin, from among several sexual progenitors, it is advisable to recognizeA. rosea as a distinct species from its sexual progenitors.Investigations into the evolutionary history of the polyploid complexes inAntennaria (Asteraceae: Inuleae). 3. TheA. rosea complex.  相似文献   

7.
TheAntennaria media polyploid species complex has been evaluated, at least in part, on numerous occasions without consensus on either the taxa that should be included within the complex or the rank at which these taxa should be recognized. The primary purpose of this quantitative, multivariate, phenetic study is to propose a taxonomy for the polyploid species complex that not only is independent of a knowledge of either chromosome number or reproductive biology but that concurrently minimally reflects morphological variation associated with each. The use of canonical discriminant analysis facilitates this purpose. In an attempt to maintain consistency with other recent revisions of polyploid complexes within the genus, the rank of subspecies (A. media subsp.media, A. media subsp.ciliata, A. media subsp.compacta, A. media subsp.fusca, andA. media subsp.pulchella) is selected as the infraspecific rank that satisfies the purpose of the phenetic study and is supported by the analyses. These subspecies differ to varying degrees with respect to reproductive characters (corolla length, pappus length), vegetative-reproductive characters (involucre length, peduncle length, cauline leaf length, cauline leaf width), and vegetative characters (basal leaf length and basal leaf width).Antennaria media subsp.pulchella is a sexually reproducing, diploid subspecies, whereas the remaining four subspecies are essentially agamospermous polyploids.  相似文献   

8.
The orophilous plant, Ranunculus parnassiifolius L., is a polyploid complex that is widespread throughout the southern European mountains, where at least five taxa have traditionally been recognized. The aim of this study was to test whether R. parnassiifolius subsp. cabrerensis should be treated as an independent species of the R. parnassiifolius polyploid complex and constitutes, therefore, an evolutionary line in itself. To disentangle its evolutionary history and taxonomy, we used genome size estimation based on flow cytometric measurements (FCM), multivariate morphometric analyses, polymerase chain reaction-restriction fragment length polymorphisms (PCR–RFLPs) and subsequent sequencing of cpDNA regions (trnS, trnR-atpA, atpH-atpI). This study provides molecular and morphological evidence for the recognition of R. cabrerensis at the species level, rather than as an intraspecific taxon of R. parnassiifolius. Furthermore, it is concluded that those plants previously known as R. parnassiifolius subsp. muniellensis should be systematized at the subspecies level as R. cabrerensis subsp. muniellensis. This contribution highlights the benefit of combining diverse approaches to obtain knowledge about relict populations and for the implementation of suitable conservation measures.  相似文献   

9.
Valeriana officinalis L. is an extremely polymorphic polyploid complex. On the basis of morphological, cytological, and phytochemical investigations of Bulgarian populations ofV. officinalis the two subspeciesV. officinalis subsp.officinalis (2n = 14, 28) andV. officinalis subsp.collina (2n = 14, 28) were each subdivided into diploid and tetraploid cytotypes.  相似文献   

10.
通过标本检查,发现越南产毛茛科沙巴银莲花(Anemone chapaensis Gagnep.)与主要分布于我国的拟卵叶银莲花(A.howellii J.F.JeffreyW.W.Smith)属于同一种植物,故将前者处理为后者的异名。  相似文献   

11.
Meiosis in seven interspecificCucumis hybrids has been analysed i.a. inC. metuliferus ×C. zeyheri, where the parents belong to different sections. In the triploid hybrids a remarkably high number of trivalents has been found. Additional data from literature on geographical distribution, cucurbitacins, flavonoid patterns, isozymes, C-banding, genome size, DNA amount and chloroplast DNA are used to discuss species relationships and evolution. The African cross-compatible group is divided into theMyriocarpus subgroup with the diploid speciesC. africanus, C. myriocarpus subsp.leptodermis and subsp.myriocarpus, and theAnguria subgroup withC. anguria, C. dipsaceus, C. ficifolius, C. prophetarum, C. zeyheri and all polyploids (exceptC. heptadactylus). It is argued that the Asian subg.Melo with x = 7 is derived from the African subg.Cucumis with x = 12; the latter contains all the polyploid species and has the most common basic chromosome number of theCucurbitaceae. This phylogenetic advance is interpreted with concepts of the quantum model of evolution.  相似文献   

12.
A new subspecies,A. grandiflora subsp.gomarica (Caryophyllaceae), is described from the mountains of northern Morocco. The new taxon is tetraploid and has been confused in the past either with the Balearic endemicA. grandiflora subsp.glabrescens or with the widespreadA. grandiflora subsp.grandiflora, which is also present in the African continent. Detailed morphological analysis showed that plants from the Rif mountains are closely related toA. grandiflora subsp.glabrescens, but differ from it in having a longer calyx, smaller seed size, and a glandular indument on pedicels, leaves and calyx.Arenaria grandiflora subsp.gomarica can be distinguished from all infraspecific taxa of theA. grandiflora complex by the combined presence of a heterotrichous (simple and pluricellular eglandular hairs, glandular hairs) indument on the inflorescences and glandular hairs on the calyx.  相似文献   

13.
Macromorphological variation within theOrnithogalum umbellatum L. (Hyacinthaceae) complex in France was studied. The resulting data were treated by numerical taxonomy methods. Three morphs can be identified: one corresponding to diploid plants, another made up of triploids and a third which encompasses plants having ploidy level above 3x (4x, 5x, and 6x). A systematic interpretation of the complex is proposed wherein only one species,O. umbellatum, is retained. This species corresponds to a polyploid complex undergoing evolution.  相似文献   

14.
The karyotypes of four taxa in theIxeris dentata complex collected from Mt. Ishizuchi were investigated.I. dentata subsp.dentata var.dentata f.dentata had 2n=21 in all the examined individuals and its karyotypes were classified into four different types. Var.dentata f.amplifolia showed 2n=21 in all individuals and had three different karyotypes.I. dentata subsp.dentata var.albiflora showed 2n=21 and two different karyotypes.I. dentata subsp.alpicola showed three different karyotypes with 2n=21 and four different ones with 2n=28. Judging from the results of the karyotype analyses, the morphological variation of chromosomes in theI. dentata complex is assumed to be in the process of increasing asymmetry in the shape of chromosomes. Following Levitzky's principle, it can be said that the a-, b-, and c-chromosomes exist in different advanced stages in the process of chromosome variation. The c-group chromosomes are at the most advanced stage in morphological variation, the b-group in the second and the a-group in the least advanced stage. The above-mentioned structural diversity of chromosomes may be related to apomictic reproduction of theI. dentata complex.  相似文献   

15.
Indigofera howellii Craib & W.W. Smith from NW Yunnan and NE Myanmar is described and illustrated. Cultivated specimens of I. howellii from several gardens are discussed.  相似文献   

16.
Nations, James D. Tropical Rainforest: Endangered Environment . New York: Franklin Watts, 1988. 143 pp. $12.90 hardcover. Reviewed by Jorge Zamacona Evenes.

Sharp, D.W.A., ed. The Penguin Dictionary of Chemistry , 2d ed. New York: Penguin, 1990. 434 pp. $9.95 paperback. Reviewed by Wayne Hanley.

Hale, W.G., and J.P. Margham. The HarperCollins Dictionary of Biology. New York: Harper Collins, 1991. 569 pp. $12.95 paperback; $25.00 hardcover. Reviewed by Wayne Hanley.

Sparks, John, and Tony Soper. Penguins. New York: Fact On File, 1987. 246 pp. $1995 hardcover. Reviewed by Wayne Hanley.

Mountfort, Guy. Rare Birds of the World . A Collins/ICBP Handbook. New York: Penguin (The Stephen Greene Press), 1988. 256 pp. $2995 hardcover. Reviewed by John W. McLure.

Woodcock, Martin. Collins Handguide to the Birds of the Indian Subcontinent . New York: Penguin (The Stephen Greene Press), 1989. 176 pp. $11.95 paperback. Reviewed by James Scheib.

Harris, Michael. The Collins Field Guide to the Birds of Galapagos . New York: Penguin (The Stephen Greene Press), 1989. 160 pp. $1995 hardcover. Reviewed by Jim Fuller.

Brudenell-Bruce, P. G. C. The Collins Guide to the Birds of New Providence and the Babama Islands. New York: Penguin (The Stephen Greene Press), 1989. 142 pp. $14.95 paperback. Reviewed by Carol A. Thompson.  相似文献   

17.
Jacobaea vulgaris subsp. vulgaris (syn. Senecio jacobaea subsp. jacobaea) constitutes an intricate polyploid complex distributed in Europe. Four cytotypes have been reported in this species, three with euploid (diploid, tetraploid and octoploid; 2n=20, 40 and 80) and one with aneuploid (2n=32) chromosome numbers. Here we report that the diploid chromosome number (2n=20) reported from Bulgaria is due to misidentification with Jacobaea aquatica. On the other hand, we have discovered a new, hexaploid (2n=6x=60) cytotype within J. vulgaris subsp. vulgaris using flow cytometry. The new cytotype occurs within four sympatric populations of otherwise tetraploid and octoploid plants in Pannonia (one locality in the eastern Czech Republic and two localities in southwestern Slovakia) and in Podillya (one locality in western Ukraine). The frequency of hexaploid individuals within 76 studied populations is very low (only 10 of 693 analysed plants), and hexaploids probably represent hybrids between tetraploid and octoploid plants. Three mixed populations with hexaploid plants were subjected to detailed morphological and pollen fertility analyses. Multivariate morphometric analysis reveals partial separation of tetraploid and octoploid plants, whereas hexaploid individuals are similar in morphology to octoploids. In comparison with tetraploids, octoploids and hexaploids exhibit slightly longer ray florets, involucral bracts and tubular florets and more hairy outer achenes. Hexaploid plants display larger pollen grains and lower pollen fertility compared to tetraploids and octoploids.  相似文献   

18.
Analyses of mitotic chromosome numbers and nuclear DNA content were performed for 39 populations of 17 perennial Cerastium taxa from south‐eastern Europe. The DNA content ranged from 2C = 2.43 to 8.78 pg, revealing four ploidy levels corresponding to 4x (2n = 36), 8x, 12x and 16x. High‐polyploid cytotypes with a greater range of ploidy (up to 2n = 144) occur mostly in the central mountainous parts of the Balkan Peninsula. The chromosome number was determined for the first time for C. dinaricum (2n = 36 + 1B), C. decalvans subsp. orbelicum (2n = 36), C. decalvans subsp. glutinosum (2n = 36), C. neoscardicum (2n = 144), C. malyi subsp. serpentini (2n = 144) and C. moesiacum s.s. (2n = 144). New chromosome counts were recorded for C. arvense subsp. strictum (2n = 108), C. banaticum subsp. kosaninii (2n = 36) and C. grandiflorum (2n = 36). For the first time, flow cytometry was used to estimate C values for six species (15 taxonomic entities). The intraspecific variation quotient of C values is high, ranging from 1.003 in C. malyi to 1.306 in C. decalvans subsp. decalvans. The variation in chromosome size among both tetra‐ and octoploid members of Cerastium is much more prominent than in most other angiosperm polyploid series. Significant genome downsizing after polyploidization was observed in some investigated taxa. Differences in ploidy levels and monoploid genome size values confirm the taxonomic status of C. decalvans subsp. glutinosum and C. decalvans subsp. leontopodium. The results obtained indicate a possible close relationship between C. banaticum and C. grandiflorum, but not C. arvense. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 182 , 205–224.  相似文献   

19.
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.
  相似文献   

20.
Expressions of theSalvia dorrii (Kellogg) Abrams complex, a member of subg.Audibertia Benth., are distributed over much of the western United States. The complex consists of two species,S. dorrii andS. pachyphylla Epling ex Munz.Salvia dorrii is divided into subsp.dorrii and subsp.mearnsii (Britton) McClintock, the latter endemic to central Arizona. Subspeciesdorrii is composed of four varieties: var.carnosa (Douglas ex Greene) Cronq., a large-leaved erect shrub of Washington and Idaho southward through Oregon into extreme north-central California: var.dorrii, a small-leaved erect shrub of southern Oregon and Idaho southward through the Great Basin of Nevada and western Utah to southeastern California and northern Arizona: var.pilosa (A. Gray) Strachan & Reveal, a small-leaved erect shrub differing from var.dorrii by pilose bracts and calyx, in southern California and western Arizona with disjunct populations in the Lahontan Basin of northwestern Nevada and northestern California; and var.clokeyi Strachan, var. nov., a low mat-forming subshrub of the high mountains of Clark Co., Nevada.Salvia pachyphylla ranges from southern California southward to the high mountains of Baja California Norte, Mexico, and eastward across extreme southern Nevada to (as a disjunct) northeastern Arizona. Each entity is described in detail, mapped and illustrated.  相似文献   

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