共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Hedrén 《Plant Systematics and Evolution》2001,229(1-2):23-44
Material of Dactylorhiza were sampled from 49 localities in Turkey and investigated for allozyme variation at ten loci (nine enzyme systems). Among
diploids, the Anatolian D. osmanica and D. umbrosa were allozymically variable, but not distinct from each other or from D. incarnata. Dactylorhiza saccifera contained the same alleles as the European D. fuchsii. Dactylorhiza iberica and D. euxina were distinct from each other and the other diploids. On basis of allozyme patterns three distinct allotetraploid genotypes
were distinguished, and each of them could be treated as a separate species. Dactylorhiza nieschalkiorum is similar to European allotetraploids, and may have arisen from hybridization between D. incarnata s.l. and D. saccifera. Dactylorhiza urvilleana may have arisen from parents related to present-day D. saccifera and D. euxina, but it also contains additional alleles that have not been found in any of the diploids investigated. A third allotetraploid
known from four populations in the Ardahan and Kars provinces of north-eastern Turkey combines the allozyme patterns found
in material of D. incarnata s.l. from the same area with those from D. euxina. It is here described for the first time as D. armeniaca.
Received November 14, 2000 Accepted June 20, 2001 相似文献
2.
Karol Marhold Hiroshi Kudoh Jae-Hong Pak Kuniaki Watanabe Stanislav ?paniel Judita Lihová 《Annals of botany》2010,105(2):249-264
Background and Aims
Intraspecific ploidy-level variation is an important aspect of a species'' genetic make-up, which may lend insight into its evolutionary history and future potential. The present study explores this phenomenon in a group of eastern Asian Cardamine species.Methods
Plant material was sampled from 59 localities in Japan and Korea, which were used in karyological (chromosome counting) and flow cytometric analyses. The absolute nuclear DNA content (in pg) was measured using propidium iodide and the relative nuclear DNA content (in arbitrary units) was measured using 4,6-diamidino-2-phenylindole fluorochrome.Key Results
Substantial cytotype diversity was found, with strikingly different distribution patterns between the species. Two cytotypes were found in C. torrentis sensu lato (4x and 8x, in C. valida and C. torrentis sensu stricto, respectively), which displays a north–south geographical pattern in Japan. Hypotheses regarding their origin and colonization history in the Japanese archipelago are discussed. In Korean C. amaraeiformis, only tetraploids were found, and these populations may in fact belong to C. valida. C. yezoensis was found to harbour as many as six cytotypes in Japan, ranging from hexa- to dodecaploids. Ploidy levels do not show any obvious geographical pattern; populations with mixed ploidy levels, containing two to four cytotypes, are frequently observed throughout the range. C. schinziana, an endemic of Hokkaido, has hexa- and octoploid populations. Previous chromosome records are also revised, showing that they are largely based on misidentified material or misinterpreted names.Conclusions
Sampling of multiple populations and utilization of the efficient flow cytometric approach allowed the detection of large-scale variation in ploidy levels and genome size variation attributable to aneuploidy. These data will be essential in further phylogenetic and evolutionary studies. 相似文献3.
BACKGROUND AND AIMS: Hybridization is an important evolutionary phenomenon, and therefore a detailed understanding of the dynamics of interspecific gene flow and resulting morphological and genetic patterns is of widespread interest. Here hybridization between the polyploids Cardamine pratensis and C. raphanifolia at four localities is explored. Using different types of data, the aim is to provide simultaneous and direct comparisons between genotype and phenotype variation patterns in the studied hybrid populations. METHODS: Evidence of hybridization has been gathered from morphology, molecular markers (amplified fragment length polymorphism and chloroplast DNA sequences), pollen viability, karyology and nuclear DNA content. KEY RESULTS: All data support extensive gene flow occurring in the hybrid populations. A wide range of morphological and genetic variation is observed, which includes both parental and intermediate types. Unbalanced pollen fertility and several ploidy levels are recorded. CONCLUSIONS: Incongruence reported between genotype and phenotype suggests that parental phenotypes are affected by introgression, and intermediate hybrid phenotypes can be genetically closer to one of the parents. Thus, it is evident that morphology, when used alone, can be misleading for interpreting hybridization, and critical evaluation of other data is needed. 相似文献
4.
A. R. Hagen T. Sæther L. Borgen R. Elven O. E. Stabbetorp C. Brochmann 《Plant Systematics and Evolution》2002,230(3-4):203-219
The high polyploids Cerastium alpinum (8x) and C. nigrescens (12x) were investigated in a mixed population in central Norway to evaluate whether hybridisation has resulted in continuous variation
in morphology and genetic markers, a hypothesis previously proposed to account for the extensive taxonomic confusion in this
species group. Isozyme, fertility, and morphological (37 characters) variation were examined among 347, 265, and 237 plants,
respectively. A PCO analysis based on 23 quantitative morphological characters identified two main groups, corresponding to
C. alpinum and C. nigrescens. The groups were also clearly separated in isozyme markers, several qualitative morphological characters, and chromosome numbers.
Only 20 plants (8.4%) were more or less intermediate in the PCO analysis. These plants had a parental or hybrid isozyme multilocus
phenotype and typically few well-developed anthers, low pollen stainability, and no seed set. Several plants within the C. nigrescens group also had reduced pollen stainability. These results indicate that later-generation hybrids and/or backcrosses towards
C. nigrescens are formed. Thus, interspecific, interploidal gene flow probably occurs, but at rates that are insufficient to break down species integrity.
Received July 5, 2000 Accepted August 2, 2001 相似文献
5.
A. Franzke K. Mummenhoff 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1999,98(5):831-834
The very recent allopolyploid speciation of Cardamine insueta and Cardamine schulzii is well documented. We used this system for a further understanding of the evolution of the internal transcribed spacers
(ITS) of nuclear ribosomal DNA in recently formed hybrids. The ITS sequencing of the two parent species and the alloploid
offspring suggests a synopsis of the types of ITS evolution, reported so far in the literature. We detected homogenization
to one parental ITS type with a very strong bias to the maternal sequence. Nevertheless, maintainance of both parental ITS
sequences in the alloploids was also recorded. Our data suggest: (1) rapid genomic change in newly formed alloploids, and
(2) a multiple origin of C. insueta and C. schulzii.
Received: 24 August 1998 / Accepted: 8 September 1998 相似文献
6.
7.
M. H. Urbani C. L. Quarin F. Espinoza M. I. O. Penteado I. F. Rodrigues 《Plant Systematics and Evolution》2002,236(1-2):99-105
Paspalum simplex is a grass distributed throughout the phytogeographic Chaco region in South America from which sexual diploid and apomictic
tetraploid races have been reported. We analysed native populations to determine their homogeneity of ploidy level, and the
relationship between geographic distribution, ploidy levels, and reproductive systems. The ploidy level was established for
379 plants from 32 wild populations. Tetraploidy and apomixis constitute the most common combination for this species all
over the Chaco region. Apomictic hexaploid plants were found associated with 4x populations. Diploids were confined to a small
sector of the region. One sexual triploid plant arose from seed harvested in a pure 2x population, and one apomictic 3x plant
was found in a mixed 2x-4x population. The results suggest that P. simplex is a core agamic complex characteristic of the Chaco region from which other apomictic polyploid species of the subgenus
Anachyris could have evolved.
Received July 24, 2002; accepted September 12, 2002 Published online: December 11, 2002 相似文献
8.
MARIÁN PERNÝ REAS TRIBSCH TOD F. STUESSY fls KAROL MARHOLD fls 《Botanical journal of the Linnean Society. Linnean Society of London》2005,148(1):101-116
Endemic Cardamine silana from Calabria (southern Italy) previously reported to be related to C. raphanifolia was found to be hexaploid. Morphological characters and AFLP data were analysed to evaluate the degree of differentiation of C. silana from closely related taxa and to find parental taxa of this polyploid. Cardamine apennina from the C. pratensis group was examined as one putative parent, as indicated in previous studies of nuclear ITS sequences, along with other related taxa based on both cpDNA and ITS sequences. Both multivariate morphometric analyses of quantitative characters and evaluation of qualitative morphological characters showed: (1) closest position of C. silana to two diploids: C. acris from the Balkan Peninsula and C. apennina from Central Italy; (2) good extent of morphological separation of C. silana from related taxa; and (3) within C. acris subspecies, C. acris ssp. vardousiae from Central Greece as closest to C. silana . Neighbour-joining tree and PCoA ordinations of AFLP data, as well as patterns of AFLP bands sharing, corroborated results of multivariate morphometrics. This evidence supports an allopolyploid origin of C. silana , with C. apennina and C. acris as parental taxa. Its origin may be dated to Pleistocene glacial events, because of the presumably wider geographical distributions of its parental taxa during more humid periods at that time. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 101–116. 相似文献
9.
The hybrid Potamogeton×fluitans Roth is thought to have resulted from hybridization between P. lucens L. and P. natans L. This hybrid has only been recorded at a few locations in the British Isles. At most of these sites the number of individuals
found have been quite low. The one exception to this being a population in the Moors River, Dorset and South Hampshire, England,
where a substantially larger population exists. Using seven different enzyme systems, this study provided support for the
putative parental origin of this hybrid. In addition, the population in the Moors River was shown to contain numerous multi-locus
phenotypes suggesting that these individuals may be partially fertile and may backcross to one of its parental species, or
alternatively undergo selfing or crossing to produce an F2 generation.
Received December 1, 2000 Accepted June 20, 2001 相似文献
10.
Italian representatives of the Cardamine pratensis group were investigated using morphometric, karyological, and molecular (AFLP-fingerprinting) analyses. Focus was on resolving the taxonomic and evolutionary position of C. granulosa from Piemonte (NW Italy) and of populations from central Italy, previously included in C. granulosa or C. pratensis s. str. Results show that C. granulosa is a morphologically and genetically well defined diploid species, but is extremely rare and restricted to a small area in Piemonte. Central Italian populations differ from both C. granulosa and C. pratensis s. str., and, although the morphological differentiation is not strongly pronounced, they show marked molecular divergence, suggesting recognition as a new species, Cardamine
apennina. Because of their restricted distribution and diploid chromosomal level, C. apennina and C. granulosa may represent basal and quite isolated lineages, whereas reticulation on diploid and polyploid level has affected remaining lineages of the C. pratensis group. Both Italian endemics are endangered due to rarity and habitat loss. A key for identification of the Italian taxa of the C. pratensis group is also provided. 相似文献
11.
Eleusine (Poaceae) includes six diploid and three polyploid species and has three basic chromosome numbers, x=8, 9 and 10. The species
are annual as well as perennial and all are wild except E. coracana, which is cultivated for grain and fodder in Africa and the Indian subcontinent. Eleusine coracana and E. africana have the same genome and chromosome number (2n=36). Eleusine indica and E. floccifolia are identified as two genome donors to these polyploid species. Eleusine kigeziensis is the third polyploid species of the genus with 2n=38. Its genome may have come from E. jaegeri and from one of the species with x=9, most probably from E. indica. Eleusine indica, E. tristachya, E. floccifolia and E. intermedia with x=9 and two polyploid species, E. coracana and E. africana, are closely related and there is free genetic flow between them. Eleusine multiflora with x=8 is significantly different in morphology and at genomic level from other species. Eleusine jaegeri with x=10 is morphologically similar to E. indica, however, more information is needed to ascertain its position in the genus. Eleusine coracana, which is commonly called finger millet, is a potential and nutritious crop for the increasing population of the world, particularly
in arid and semi-arid regions. It can also serve as a gene pool for various important characters and disease resistant genes.
Received February 11, 2002; accepted May 27, 2002 Published online: October 14, 2002
Addresses of the authors: Madho Singh Bisht and Yasuhiko Mukai (e-mail: ymukai@cc.osaka-kyoiku.ac.jp), Laboratory of Plant
Molecular Genetics, Division of Natural Science, Osaka Kyoiku University, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582, Japan. 相似文献
12.
Morphological and electrophoretic data were studied to examine species delimitation, patterns of morphological and genetic
variation in three Korean Hepatica including two endemics, H.␣maxima and H. insularis. Based on a phenogram using 15 morphological characters, taxa were distinct; it was consistent with the phenogram based on
genetic distance. In the enzyme electrophoresis study, the genetic identities suggested that three taxa were genetically divergent
enough to be recognized as different species, falling within the range expected␣for congeners. The genetic identity between
H.␣asiatica and H. insularis was higher than the values between these two taxa and H.␣maxima, a restricted endemic of Ulleung Island. The least genetic variation was found in H. maxima and the greatest in widespread H. asiatica. These data are consistent with theoretical expectations that small populations are more likely to be genetically depauperate.
Received November 13, 2001; accepted May 10, 2002 Published online: December 11, 2002 相似文献
13.
K. Tremetsberger C. König R. Samuel W. Pinsker T. F. Stuessy 《Plant Systematics and Evolution》2002,233(3-4):163-181
Genetic variation in 42 populations throughout the range of Biscutella laevigata L. (Brassicaceae), a morphologically variable central European species, has been investigated by enzyme electrophoresis with
three loci (Amy1, Amy2, and Gpi2). Genetic identities and the Fitch-Margoliash tree suggest differentiation into four regional groups: 1) a northwestern
diploid group (northern France and northern Germany), 2) a northeastern diploid group (southern Germany, Upper Austria, northern
Lower Austria, Poland, and Romania), 3) a central diploid group in southern Lower Austria corresponding to subspecies austriaca, and 4) a southern tetraploid group in Alpine areas of France, Germany, Switzerland, Austria, Italy, and Slovenia corresponding
to subspecies laevigata. Geographically isolated diploid relic populations that are genetically depauperate are found in the NW and NE diploid groups.
On the other hand, the diploid relic subspecies austriaca from the NE Prealps and Alps is highly variable. Subspecies laevigata appears to be a genetical autotetraploid with multiple origins involving several diploid progenitors (the NW diploids, subspecies
austriaca and B. prealpina).
Received April 6, 2001; accepted March 6, 2002 Published online: October 14, 2002
Addresses of the authors: Karin Tremetsberger (e-mail: k.tremetsberger@gmx.net), Christiane K?nig, Rosabelle Samuel, Tod
F. Stuessy, Department of Higher Plant Systematics and Evolution, Institute of Botany, University of Vienna, Rennweg 14, A-1030
Vienna, Austria. Wilhelm Pinsker, Institute of Medical Biology, University of Vienna, Waehringerstra?e 10, A-1090 Vienna,
Austria. 相似文献
14.
The taxonomy of the Paeonia obovata polyploid complex in E-Asia has been controversial with treatments ranging from one species and two varieties to five species
and numerous infraspecific taxa. Extensive observations in the field, analysis of morphological characters based on 32 populations
sampled, and the examination of a large amount of herbarium specimens show that all the characters used by previous authors
for distinguishing the species are variable between or even within populations: Leaf position, petal colour, stamen number
(from 21 to 110 in the red-flowered and from 58 to 239 in the white-flowered form), filament and anther colour, style length
as well as follicle number and position. Therefore, all these characters are of no value for species delimitation. However,
an extensive chromosome survey and the analysis of morphological characters show that the ploidy level is basically correlated
with the geographical distribution and with the indumentum on the lower leaf surface. Thus, the recognition of one species
with two subspecies is proposed: Paeonia obovata subsp. obovata, mostly diploid, widely distributed in the north, east and south of the distribution range and glabrous to sparsely pubescent
or hirsute on the lower leaf surface, and subsp. willmottiae, tetraploid, limited to the west and with leaves densely hirsute or pubescent below.
Received October 30, 1998 Accepted June 21, 2000 相似文献
15.
E. Hörandl 《Plant Systematics and Evolution》2002,233(1-2):65-78
In the partly apomictic Ranunculus cassubicus group, a subgroup of the R. auricomus complex, two species were studied by morphometric analyses: R. cassubicifolius W. Koch (with three diploid and two autotetraploid sexual populations), and R. carpaticola Soó (with three diploid sexual populations and a hexaploid apomictic one). Multidimensional scaling analyses (MDS) of individuals,
boxplots and cluster analyses of populations revealed a differentiation of R. cassubicifolius and R. carpaticola, whereby in MDS the hexaploid apomictic individuals are partly intermediate between R. cassubicifolius and R. carpaticola. The cytodemes of R. cassubicifolius showed no morphological and only a weak genetic differentiation. A comparison of morphology, isozymes, reproductive system
and ploidy levels showed only partly congruence of data sets in respect of grouping populations, thus illustrating the problem
to find criteria for a taxonomic concept. A treatment of the apomictic population as a separate group is indicated by all
data sets, afterwards R. cassubicifolius and diploid R. carpaticola represent two other well-defined groups. Canonical variate analysis including all characters confirmed the three suggested
groups as significantly different and showed that a total of 89.3% of individuals are correctly classified; number of teeth
of stem leaf segments and number of petals are the most discriminating characters. Herbarium studies confirm the morphological
differentiation yielded from population samples. The three population groups are even better separated in a canonical variate
analysis of isozyme data (presence/absence of 25 alleles) of the same material, here 92.6% of individuals are correctly classified.
Morphology and isozyme data suggest that the hexaploid apomict originated from hybrids of R. cassubicifolius and diploid R. carpaticola and must be excluded from the sexual taxa; the final classification and naming of the apomicts must be left for further studies
on a larger material. The sexual taxa should be classified as separate species. Herbarium studies indicate that R. carpaticola s.str. is widespread over the Carpathians and might include other populations hitherto ascribed to other microspecies as
well.
Received November 20, 2001; accepted May 10, 2002 Published online: September 13, 2002 相似文献
16.
We investigated patterns of isozyme variation and the hierarchic structure of genetic diversity in 25 Scandinavian populations
of the lilioid herb, Anthericum liliago. Isozyme data suggest that tetraploid A. liliago has an allopolyploid origin and that A. ramosum may be one of its diploid progenitors. Two populations contained known or suspected hybrids between A. liliago and A. ramosum. Isozymes show that one population from S Sweden contains both triploid (hybrid) and tetraploid individuals whereas a putatively
hybrid Danish population represents diploid A. liliago. There is an overall northward and eastward decline in allelic richness in the tetraploid populations, with the highest numbers
of alleles in Denmark and SW Sweden. This pattern is consistent with a progressive loss of allelic variation during the species'
postglacial colonization of Scandinavia. The between-population component of genetic diversity is 4% (compared with 12% in
diploid A. ramosum), the between-region diversity component is 7% and 89% of the total diversity is stored within populations.
Received March 13, 2002; accepted September 24, 2002 Published online: December 11, 2002 相似文献
17.
Andrew Tedder Matthias Helling John R. Pannell Rie Shimizu-Inatsugi Tetsuhiro Kawagoe Julia van Campen Jun Sese Kentaro K. Shimizu 《Annals of botany》2015,115(5):763-776
Background and Aims The coexistence of hermaphrodites and female-sterile individuals, or androdioecy, has been documented in only a handful of plants and animals. This study reports its existence in the plant species Cardamine amara (Brassicaceae), in which female-sterile individuals have shorter pistils than seed-producing hermaphrodites.Methods Morphological analysis, in situ manual pollination, microsatellite genotyping and differential gene expression analysis using Arabidopsis microarrays were used to delimit variation between female-sterile individuals and hermaphrodites.Key Results Female sterility in C. amara appears to be caused by disrupted ovule development. It was associated with a 2.4- to 2.9-fold increase in clonal propagation. This made the pollen number of female-sterile genets more than double that of hermaphrodite genets, which fulfils a condition of co-existence predicted by simple androdioecy theories. When female-sterile individuals were observed in wild androdioecious populations, their ramet frequencies ranged from 5 to 54 %; however, their genet frequencies ranged from 11 to 29 %, which is consistent with the theoretically predicted upper limit of 50 %.Conclusions The results suggest that a combination of sexual reproduction and increased asexual proliferation by female-sterile individuals probably explains the invasion and maintenance of female sterility in otherwise hermaphroditic populations. To our knowledge, this is the first report of the coexistence of female sterility and hermaphrodites in the Brassicaceae. 相似文献
18.
Fifty natural Datura populations, belonging to eleven species (D. ceratocaula, D. discolor, D. inoxia, D. kymatocarpa, D. lanosa, D. metel, D. pruinosa, D. quercifolia, D. reburra, D. stramonium, D. wrightii) from Mexico and adjacent USA, were investigated using starch gel electrophoresis. A total of 64 alleles were scored at 17
loci (DIA1, DIA2, GOT1, GOT2, G6PDH, IDH, MDH1, MDH2, MDH3, ME, PGD1, PGD2, PGM1, PGM2, PHI, SAD, SOD). The heterozygosity
among the species ranged from 0.166 (D. ceratocaula) to 0.276 (D. wrightii). Most genetic diversity was found within populations (average Hs=0.242), while values between populations are relatively low (average Dst=0.066, Gst=0.171). The analysis of the genetic distance
suggested new taxonomic relationships among the species. Rather than supporting the conventional infrageneric classification
with three sections, the results revealed that the herbaceous members of the genus Datura form four groups. One group included four of the eight species of the section Dutra and was more similar to the section Ceratocaulis than it was to the other group that contained the remaining taxa of Dutra.
Received February 13, 2001 Accepted December 25, 2001 相似文献
19.
Isozyme markers and morphological characters were studied in four populations of Sphagnum capillifolium and S. quinquefarium. Recombinant plants were found in three populations, where the two species occur sympatrically. All recombinants possessed
different haplotypes and combinations of morphological characters, which show that they are results of independent hybridization
events. Strongly male-biased sex ratios were found for Sphagnum capillifolium in all populations where it grew sympatrically with S. quinquefarium. Most of the recombinants were also male fertile. These observations suggest that S. quinquefarium is the female parent in the primary crosses and in subsequent backcrosses.
Received September 3, 2001; accepted March 16, 2002 Published online: November 7, 2002
Addresses of the authors: Nils Cronberg (e-mail: Nils.Cronberg@sysbot.lu.se), Department of Systematic Botany, Lund University,
S?lvegatan 37, SE-223 62 Lund, Sweden. Rayna Natcheva (e-mail: renimoss@iph.bio.bas.bg), Institute of Botany, Bulgarian Academy
of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria. 相似文献
20.
M. Koch 《Plant Systematics and Evolution》2002,232(1-2):35-49
Significant geographic partitioning of genetic variation within Cochlearia bavarica was found within populations from Allg?u and SE Bavaria (Germany) exhibiting significant genetic differentiation. It has
been demonstrated that allohexaploid C. bavarica evolved via hybridization between diploid C. pyrenaica and tetraploid C. officinalis. Presently, only C. pyrenaica is distributed throughout inland Central Europe. It has been concluded that C. bavarica is of inter- or postglacial origin, and its speciation was not influenced by human activities. Isozyme analysis revealed
that there is a correlation between interpopulational genetic distances and geographic distances among C. bavarica populations from both regions, and which is not the case for C. pyrenaica in Germany and Austria. Only high alpine C. excelsa is significantly differentiated among the diploid taxa analysed here. Geographically structured distribution of alleles and
their frequencies in C. bavarica populations could not be explained with the distribution of these alleles in C.
pyrenaica. The presented findings favour disruption of a former wider distribution area rather than migration of C.
bavarica or a polytopic origin of this species.
Received April 17, 2001 Accepted February 1, 2002 相似文献