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1.
New C-banding pattern for chromosome identification in cucumber (Cucumis sativus L.) 总被引：2，自引：0，他引：2
A chromosome study of cucumber, C. sativus L., was performed using orcein and C-banding techniques. The diploid and tetraploid plants investigated here showed the somatic chromosome numbers 2n=14 and 28, respectively. The haploid chromosome complement was composed of five metacentric and two submetacentric chromosomes. All C. sativus chromosomes had clearly visible C-bands, and each chromosome could be identified unequivocally after C-banding staining, with 13 C-bands appearing in the haploid complement. The haploid complement had a 44.9% ratio of total C-band length to total chromosome length. Chromosomes 1, 2, 4, 5 and 7 had stable C-bands. Three large, dark C-bands appeared at the proximal regions of chromosomes 1 and 2. Chromosome I had quite a large C-band and with a 68.4% ratio of C-band length to short arm length. Chromosome 2 also had quite a large C-band in the pericentromeric region with a 57.6% ratio of C-band length to the full length of this chromosome and possessed an elongated primary constriction in early metaphase. In prometaphase, chromosome 2 showed that the long arm was completely separated from the short arm. The number of secondary constrictions could not be clearly observed because these chromosomes are small and they could not be counted in every metaphase cell. However, six chromosomes seemed to have secondary constrictions in the diploid plants. Two silver-stained bands were observed at primary constrictions of two of the large chromosomes. 相似文献
2.
Giemsa N-banding pattern in cabbage and Chinese kale 总被引：1，自引：0，他引：1
Summary In cabbage (Brassica oleracea var. capitata) and Chinese kale (B. oleracea alboglabra) four types of N-bands can be distinguished: pericentromeric, telomeric (terminal), intercalary and satellite bands. Typical NOR bands were not observed. The pericentromeric bands appear at the pericentric regions, possibly even at the centromeres of all chromosomes. Telomeric bands are observed on the short arms of chromosomes 1,5 and 6 in cabbage and chromosomes 1 and 5 in Chinese kale. Intercalary bands stained weakly in the long arms of chromosome 3 in cabbage and chromosome 2 in Chinese kale. Satellite bands cover the entire satellites in both Brassica species. The N-banding pattern is very similar in appearance to the C-banding pattern in both species and much more convenient to apply. 相似文献
3.
Summary Tetraploid Bromus ciliatus L. is a North American bromegrass that has been placed in the Pnigma section of Bromus. The objective of this study was to characterize the genome of tetraploid B. ciliatus by cytogenetic methods and compare it to the genomes of other species included in the section Pnigma. All the plants of the accession (USDA PI 232214) selected for chromosome counting were tetraploids (2n = 28). The mean 2C nuclear DNA content for tetraploid B. ciliatus was 19.13± 0.07 pg as determined by flow cytometry which is significantly greater than the tetraploid DNA content of B. inermis Leyss. (11.74± 0.16 pg). C-banding procedures were used to identify individual mitotic chromosomes and to develop a karyotype
for B. ciliatus. The genome of the tetraploid B. ciliatus consisted of 16 median chromosomes, eight submedian chromosomes, and four chromosomes with satellites which included one
pair with a large satellite and one pair with a small satellite. The general pattern of the distribution of constitutive heterochromatin
in B. ciliatus was quite different than the other bromegrasses that have been analyzed to date. Except for two pairs of chromosomes, all
chromosomes in tetraploid B. ciliatus had telomeric bands on one or both arms. Some of the chromosomes with telomeric bands had centromeric bands that were located
at one or both sides of the centromere and intercalary bands which were generally absent in the other bromegrass species.
It was possible to identify all chromosomes of tetraploid B. ciliatus and to match the pairs of homologous chromosomes by using chromosome lengths, arm length ratios and C-banding patterns. The
results of this study indicate that tetraploid B. ciliatus has different genomes than the European species evaluated to date in the section Pnigma. 相似文献
4.
Detection of H. villosa chromosomes in telosomic addition and translocation lines of common wheat was undertaken using genomic in situ hybridization (GISH), C-banding techniques and polyacrylamide gels electrophoresis. The result of GISH on mitotic metaphase
cells of the addition line `95039' indicated that the added telochromosomes originated from H. villosa, and it was probably 6VS or 7Vs of H. villosa according to the C-banding pattern. Furthermore, the analysis of gliadin profiles demonstrated that the telochromosome was
6VS. A pair of 1RS/1BL translocation chromosome was also found in `95039'. In addition, mitotic GISH analysis showed that
the 6VS/6AL translocation chromosome remained unchanged after being transferred into new wheat background.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Summary The meiotic pairing behaviour at metaphase I of a Triticum aestivum×Triticum monococcum hybrid has been studied by means of the C-banding technique to ascertain the homology between the chromosomes in the A genome of the two species. The technique allowed the A and B genome chromosomes and the 2D, 3D and 5D chromosomes to be identified. Differences in the level of chromosome pairing in the A genome were noted. The T. monococcum 4A chromosome did not pair with any of the T. aestivum chromosomes in any of the metaphase I cells analysed. Two reciprocal translocations between the 2B and 2D chromosomes on one side and the 2A and 3D on the other side have been identified. The usefulness of the C-banding technique in the study of chromosome homology among species related to wheat is discussed. 相似文献
6.
Summary The sequential combination of C-banding and in situ hybridization techniques applied in this or in a reverse order, are used to recognize targeted chromosomal regions in cereals. Both methods are described whereby standard chromosome squash preparations are followed by: i) C-banding technique using Leishman stain and a slightly modified in situ hybridization technique using biotin-labeled DNA probes, or ii) fluorescence in situ hybridization technique and C-banding. Both approaches have been successfully used onto mitotic chromosomes of rye and wheat resulting suitable for both their identification and detection of targeted sites. 相似文献
7.
J. Sybenga 《Euphytica》1996,89(1):143-151
Summary Cytological tester sets include series of aneuploids (nullisomics, monosomics, trisomics of different types, tetrasomies), series of rearranged chromosomes (translocations, inversions, duplications, deficiencies) and series of chromosomes recognizable by specific microscopically visible markers (C- or other banding, molecular markers). In rye, only a few (mainly tertiary and telocentric) monosomics and no viable nullisomics have been found. Several sets of primary trisomics and some telocentric sets, usually not fully complete, have been developed, but few are still available for gene localization. A few tertiary trisomics have been derived from translocation heterozygotes. Extensively used are different sets of additions of rye chromosomes to wheat. A relatively widely distributed set of marked chromosomes is the Wageningen translocation tester set, complemented with translocations from different other institutions. A disadvantage of rye translocations is insufficient heterozygote semisterility. Series of otherwise rearranged chromosomes have not been reported. Sets of lines with chromosomes conspicuously differing from the standard C-banding pattern have been obtained. Molecular markers are available for most rye chromosome, but lack of heterozygosity, necessary for classification after in situ hybridization is a restriction for use as cytological testers. In the cases of most translocations, C-banding and in situ molecular markers, each separate plant in a segregating population must be screened cytologically, whereas with aneuploid markers or with translocations having sufficient heterozygote semisterility, analyzing segregations is sufficient. 相似文献
8.
Summary A Giemsa-C-banded karyotype of a partial amphiploid, Triticum turgidum L. var. durum cv. Nodak × Agropyron intermedium (Host) P.B., called MT-2, was analyzed. MT-2 is a winterhardy grasslike octoploid germplasm which survived 5 winters in Montana, and its seed weight is 3 times that of A. intermedium seed. The MT-2 C-banding karyotype shows 6 chromosome pairs each of the A and B wheat genomes with 3A and 4B missing. Chromosomes 1B and 2B are involved in a reciprocal homozygous translocation (T1BS·2BS, T1BL·2BL) which was also confirmed by a nucleolus-associated quadrivalent in an MT-2 × durum wheat backcross. In addition to the wheat chromosomes, MT-2 consistently shows 16 A. intermedium chromosome pairs which are designated from A to P. These chromosomes show C-banding patterns similar to those reported earlier in the literature. A large amount of C-banding polymorphism and structural rearrangements in A. intermedium itself presently make a definite chromosome assignment to the homeologous groups of the Triticeae difficult. The data presented are crucial for further directed manipulation of this germplasm aimed at producing valuable chromosome additions and substitutions in wheat.contribution No. J-2767 from Montana Agric. Exp. Stn. 相似文献
9.
Numerous cytogenetic studies have been performed on alfalfa (Medicago sativa L. 2n= 4x= 32), but only a few have examined the somatic chromosomes. Because the major factor limiting the study of somatic chromosomes of M. sativa is their rather uniform morphology, characterization was attempted using the C-banding technique instead of the traditional Feulgen method. Chromosome morphology and position of the heterochromatic bands resulted in satisfactory characterization of the chromosomes and provided further evidence of the autotetraploid origin of the species. It was possible to identify the homologous chromosomes and arrange them into eight groups of four. The ideogram of the basic genome of eight chromosomes was constructed. The impact of these results on cytogenetic studies and breeding research in alfalfa is discussed. 相似文献
10.
S. E. Zorinyants A. V. Nosov E. D. Badaeva I. N. Smolenskaya N. S. Badaev 《Plant Breeding》1995,114(3):219-225
In vitro culturing of plant cells can cause changes in karyotype. Chromosome variations following long-term propagation in suspension culture of Triticum timopheevii (Zhuk.) Zhuk. were studied by routine staining and C-banding. The culture was highly heterogeneous with respect to the number and structure of chromosomes. The modal class cells had a lower chromosome number than T. timopheevii (2n= 28). This data was confirmed by cytophotometric analysis of nuclear-DNA content. Frequencies of chromosome loss varied for different homoeologous groups. At genome chromosomes tended to be preferentially eliminated in cells of different ploidy levels. Deletions, insertions, translocations, telocentric chromosomes, isochromosomes and dicentrics and their derivatives were observed in cultured cells. Chromosomes of various homoeologous groups differed in the frequencies and spectra of re—arrangements, but most aberrations occurred in the G-genome chromosomes. In vitro chromosome modifications did not correspond to in vivo variation. Presumably, this difference was caused by differences in the mechanisms of adaptation to the environment at the levels of the cell and the whole organism. G-genome chromosomes were more frequently involved in this process, both in vivo and in vitro. 相似文献
11.
Three tetraploid (2n= 4x= 28) wheat Triticum turgidum L. landrace morphotypes (= genotypes) from Ethiopia were found to carry a variant karyotype directly discernible under the microscope. This was possible because the rearrangement involved one of the satellited chromosomes. Giemsa C-banding revealed that the rearrangement resulted from a 5BS.6BS(5BL.6BL) centric reciprocal translation. The banding pattern on 5BL was polymorphic, suggesting that this translocation might have occurred more than once. There was little C-band polymorphism for the remaining chromosomes, except for 2A. As pure lines, all three morphotypes showed normal chromosome pairing at metaphase I (MI) in pollen mother cells (PMCs). indicating that they are genomically stable. Meiotic analyses of F1 hybrids and F2 segregates derived from crosses with tester varieties clearly indicated that one of them (B-l–9) carried another translocation. However, we were not successful in delecting the chromosomes involved, presumably the interchanged segments did nol include C-banding regions. By using T5BS.6BS, direct evidence for segregation distortion against translocation homozygotes in intervarietal hybrids was obtained. The distorted segregation was attributed lo zygotic selection. No aneuploid plants were obtained from the F2 segregates. However, translocation heterozygotes resulting in unstable meiosis were abundant in the F2 generation. The implications of the results in using the indigenous landraces in hybridization breeding are discussed. 相似文献
12.
Summary The meiotic behaviour of a hybrid between Triticum aestivum and the amphiploid Hordeum chilense x T. turgidum conv. durum, was studied using a C-banding staining method. This hybrid has the genome formula of AA BB D Hch with 2n=6x=42 chromosomes. The durum wheat chromosomes (genomes A and B) were easily recognized, whereas the D and Hch chromosomes were recognized as a whole. Meiotic pairing was homologous, as expected (14 bivalents from A and B genomes +14 univalents from D and Hch genomes). However, some pollen mother cells at metaphase-I presented pseudobivalents that could have been caused by either homoeologous or autosyndetic pairing amongst D and Hch chromosomes. 相似文献
13.
Zu-Jun Yang Guang-Rong Li Ju-Qing Jia Xue Zeng Meng-Ping Lei Zi-Xian Zeng Tao Zhang Zheng-Long Ren 《Euphytica》2009,167(2):197-202
Two amphiploids, AF-1(Triticum aestivum L. cv. Anyuepaideng–Secale africanum Stapf.) and BF-1 (T. turgidum ssp. carthlicum–S. africanum), were evaluated by chromosomal banding and in situ hybridization. The individual S. africanum chromosomes were identified in the BF-1 background by sequential C-banding and genomic in situ hybridization (GISH), and
were distinguishable from those of S. cereale, because they exhibited less terminal heterochromatin. Fluorescence in situ hybridization (FISH) using the tandem repeat
pSc250 as a probe indicated that only 6Ra of S. africanum contained a significant hybrid signal, whereas S. cereale displayed strong hybridization at the telomeres or subtelomeres in all seven pairs of chromosomes. Extensive wheat–S. africanum non-Robertsonian translocations were observed in both AF-1 and BF-1 plants, suggesting a frequent occurrence of chromosomal
recombination between wheat and S. africanum. Moreover, introgression lines selected from the progeny of wheat/AF-1 crosses were resistant when field tested with widely
virulent strains of Puccinia striiformis f. sp. tritici. Three highly resistant lines were selected. GISH and C-banding revealed that resistant line L9-15 carried a pair of 1BL.1RS
translocated chromosomes. This new type of S. africanum derived wheat–Secale translocation line with resistance to Yr9-virulent strains will broaden the genetic diversity of 1BL.1RS for wheat breeding. 相似文献
14.
J. Sybenga 《Euphytica》1995,83(1):53-61
Summary Cytological tester sets include series of aneuploids (nullisomics, monosomics, trisomics of different types, tetrasomics), series of rearranged chromosomes (translocations, inversions, duplications, deficiencies) and series of chromosomes recognizable by specific microscopically visible markers (C-or other banding, molecular markers). In rye, only a few (mainly tertiary and telocentric) monosomics and no viable nullisomics have been found. Several sets of primary trisomics and some telocentric sets, usually not fully complete, have been developed, but few are still available for gene localization. A few tertiary trisomics have been derived from translocation heterozygotes. Extensively used are different sets of additions of rye chromosomes to wheat. A relatively widely distributed set of marked chromosomes is the Wageningen translocation tester set, complemented with translocations from different other institutions. A disadvantage of rye translocations is insufficient heterozygote semisterility. Series of otherwise rearranged chromosomes have not been reported. Sets of lines with chromosomes conspicuously differing from the standard C-banding pattern have been obtained. Molecular markers are available for most rye chromosome, but lack of heterozygosity, necessary for classification afterin situ hybridization is a restriction for use as cytological testers. In the cases of most translocations, C-banding andin situ molecular markers, each separate plant in a segregating population must be screened cytologically, whereas with aneuploid markers or with translocations having sufficient heterozygote semisterility, analyzing segregations is sufficient. 相似文献
15.
Summary C-banding andin situ hybridization were used to determine the chromosomal constitution of the greenbug-resistant germplasm GRS 1204. The results showed that this line had the radiation-induced non-homoeologous wheat-rye translocation chromosomes T2AS-1RS·1RL and T2AL·2AS-1RS. C-banding analysis further revealed the presence of a wheat-Agropyron elongatum translocation chromosome T1BL·1BS-3Ae#1L in line GRS 1204, that was derived from Teewon. The greenbug resistance of line GRS 1204 is similar to that of line GRS 1201 that was earlier shown to have the greenbug resistance geneGb6 located on the 1RS arm of the wheat-rye translocation chromosome T1AL·1RS. BecauseGb6 in line GRS 1204 is present on one of the non-homoeologous translocation chromosomes, agronomically line GRS 1201 should be the better adapted source ofGb6 resistance and be used in cultivar improvement. 相似文献
16.
C-banded karyotypes and meiotic abnormalities in germplasm derived from interploidy crosses in Avena
C-banded karyotypes of somatic chromosomes and meiotic abnormalities were investigated in four crown rust resistant lines
derived from interploidy crosses in Avena.C-banding revealed that line N770-165-2-1 contained a 6C/21translocation while line DCS1789 contained a pair of A. strigosa chromosomes substituted for A. sativachromosome 12. Line JR2-3-3-B contained both the 6C/21 translocation and the pair of substituted A. strigosachromosomes, but line MAM17-4 contained neither. Although meiotic irregularities, including mispositioned bivalents, occurred
in all four lines and in their F1 hybrids with A. sativa, the percentages of normal meiosis ranged from 75.4 to 88.6%. This allowed for stability of line performance and for their
use as breeding stocks.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
An interspecific cross was made to transfer leaf rust and stripe rust resistance from an accession of Aegilops ovata (UUMM) to susceptible Triticum aestivum (AABBDD) cv. WL711. The F1was backcrossed to the recurrent wheat parent, and after two to three backcrosses and selfing, rust resistant progenies were
selected. The C-banding study in a uniformly leaf rust and stripe rust resistant derivative showed a substitution of the 5M
chromosome of Ae. ovata for 5D of wheat. Analysis of rust resistant derivatives with mapped wheat microsatellite makers confirmed the substitution
of 5M for 5D. Some of these derivatives also possessed one or more of the three alien translocations involving 1BL, 2AL and
5BS wheat chromosomes which could not be detected through C-banding. A translocation involving 5DSof wheat and the substituted
chromosome 5M of Ae. ovata was also observed in one of the derivatives. Susceptibility of this derivative to leaf rust showed that the leaf rust resistance
gene(s) is/are located on short arm of 5M chromosome of Ae. ovata. Though the Ae. ovatasegment translocated to 1BL and 2AL did not seem to possess any rust resistance gene, the alien segment translocated to 5BS
may also possess gene(s) for rust resistance. The study demonstrated the usefulness of microsatellite markers in characterisation
of interspecific derivatives.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
Crosses between octoploid and hexaploid triticales have been made m breeding programs for several years, From an analysis of the progeny of such crosses where selections for an octoploid-like phenotype had been made, it was established that 149 out of 150 lines were hexaploid in chromosome number, C-banding and in situ hybridization demonstrated that all but five of the 62 lines analyzed in detail contained visible chromosomes or segments from the D genome. Only four lines had D-genome chromosome replacing rye chromosomes. All of the remaining 53 D-genome substitutions involved the replacing of wheat chromosomes from either the A or B genomes. This establishes the ease with which D-genome genes can be placed into triticale without the loss of rye chromosomes. 相似文献
19.
A disease (powdery mildew, leaf rust) resistant line was selected from the progenies of a Triticum aestivum × Triticum timopheevii amphiploid produced at Martonvásár. This line was previously identified with C-banding as a 6G(6B) substitution. In order
to detect the 6G chromosome in a wheat background, fluorescence in situ hybridization (FISH) and microsatellite marker analysis
were used. Ten microsatellite markers of the 43 tested generated PCR products that were polymorphic between chromosomes 6B
and 6G, and four showed length-polymorphism. The FISH hybridization pattern of 6G from T. timopheevii was identified using a combination of four repetitive DNA probes (Afa-family, pSc119.2, pTa71, (GAA)7). Genomic in situ hybridization (GISH) technique, capable of labelling the At and G genomes separately, was used on the same slides to differentiate the At and G genomes in T. timopheevii. The At and G genomes of T. timopheevii were grouped on the basis of the GISH patterns and a cyclic intergenomic translocation involving 6At-1G-4G was detected in T. timopheevii accession TRI667. The presence of 6G in the substitution line was demonstrated using FISH with the four repetitive DNA probes.
Chromosome 6G was clearly identified and its FISH pattern was different from that of 6B in the parental wheat cultivar Fleischmann-481.
According to field tests, the 6G(6B) substitution line has resistance to leaf rust. 相似文献
20.
Previous studies showed that a T. aestivum-H. villosa disomic substitution line DS4V(4D) showed a high level of resistance to wheat spindle streak mosaic virus (WSSMV). By crossing
DS4V(4D) with the common wheat variety Yangmai #5, plants were obtained that were double monosomic for chromosomes 4V and
4D. Univalents are prone to misdivision at the centromere, and fusion of the derived telocentric chromosomes leads to the
production of Robertsonian whole-arm translocations. We screened the progenies of such double monosomic plants by C-banding
and genomic in situ hybridization and identified one compensating translocation where the short arm of 4V was translocated to the long arm of
4D of wheat, T4VS⋅4DL. RFLP analysis using the group-4 specific probe BCD110 was used to confirm the translocation. The T4VS⋅4DL
translocation stock, accessioned as NAU413, is highly resistant to WSSMV and is also of good agronomic type. The WSSMV resistance
gene located on 4VS was designated Wss1. 相似文献