Enhanced meiotic chromosome pairing in intergeneric hybrids between Triticum aestivum and diploid Inner Mongolian Agropyron

Genome ◽  
1992 ◽  
Vol 35 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Qin Chen ◽  
Joseph Jahier ◽  
Yvonne Cauderon
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Inner Mongolia ◽  
Meiotic Chromosome ◽  
Embryo Rescue ◽  
Genetic System ◽  
Intergeneric Hybrids ◽  
B Chromosomes ◽  
Meiotic Pairing ◽  
Reciprocal Hybrids

Triticum aestivum cv. Chinese Spring (2n = 6x = 42, ABD genomes) was crossed with diploid Inner Mongolian Agropyron Gaertn. species A. cristatum and A. mongolicum and reciprocal hybrids between them (2n = 2x = 14, P genome, with or without B chromosomes). Intergeneric hybrids with 2n = 27, 28, 32, and 33 chromosomes were produced by the aid of embryo rescue. The extra chromosomes in two hybrids were assumed to be B chromosomes transmitted by the male Agropyron parent. Average meiotic pairing in the euploid hybrid with 28 chromosomes was 14.38 univalents + 4.92 bivalents + 1.26 trivalents. This level of pairing higher than expected was likely due to homeologous associations between wheat chromosomes. This data indicates that the P genome of diploid as well as tetraploid Agropyron originating from Inner Mongolia possess a genetic system interfering with 5B homoeologous restricting system of wheat.Key words: intergeneric hybrids, Triticum aestivum, diploid Agropyron species, chromosome pairing.

scholarly journals Wheat mutants permitting homoeologous meiotic chromosome pairing

1971 ◽  
Vol 18 (3) ◽  
pp. 311-328 ◽  
Author(s):  
A. M. Wall ◽  
Ralph Riley ◽  
Victor Chapman
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Secale Cereale ◽  
Meiotic Chromosome ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Homozygous Condition ◽  
Meiotic Chromosome Pairing ◽  
Homoeologous Chromosomes

SUMMARYPlants of Triticum aestivum (2n = 6x = 42) ditelocentric 5BL were treated with EMS in order to produce mutations in the 5B system by which meiotic pairing between homoeologous chromosomes is normally prevented. To check for the occurrence of mutation T. aestivum ditelo-5BL plants were pollinated with rye (Secale cereale 2n = 14) and meiosis was examined in the resulting hybrids.Wheat-rye hybrids were scored for the presence of mutants when the wheat parents were either the EMS-treated wheat plants, or their selfed derivatives, or their progenies obtained after pollination with untreated euploid individuals.Mutants were detected by each of these procedures and mutant gametes were produced by the treated ditelocentric plants with frequencies between 1·5 and 2·5%, but there were differences between the mutants in the extent to which homoeologous pairing occurred in the derived wheat-rye hybrids. The differences may have resulted from the occurrence of mutation at different loci or to different extents at the same locus.Two mutants, Mutant 10/13 and Mutant 61, were fixed in the homozygous condition. Mutant 10/13 was made homozygous both in the 5BL ditelocentric and in the euploid conditions but these genotypes regularly formed 21 bivalents at meiosis, and there was no indication of homoeologous pairing although the mutant 10/13 gave rise to homoeologous pairing in wheat-rye hybrids.

Nonhomologous Chromosome Pairing in Aegilops-Secale Hybrids

2015 ◽  
Vol 147 (4) ◽  
pp. 268-273 ◽  
Author(s):  
Yarui Su ◽  
Dale Zhang ◽  
Yuge Li ◽  
Suoping Li
Keyword(s):  
Chromosome Pairing ◽  
Secale Cereale ◽  
Embryo Rescue ◽  
Intergeneric Hybrids ◽  
Meiotic Pairing ◽  
Chromosome Homology ◽  
R And D ◽  
Young Embryo ◽  
Nonhomologous Chromosome

Intergeneric hybrids and amphidiploid hybrids from crosses of Aegilopstauschii and Secale cereale were produced using young embryo rescue. The hybrids showed complete sets of both parental chromosomes. The dihaploid plants showed an average meiotic pairing configuration of 10.84 I + 1.57 II + 0.01 III. Genomic in situ staining revealed 3 types of bivalent associations, i.e. D-D, R-R and D-R at frequencies of 8.6, 8.2 and 83.3%, respectively. Trivalents consisted of D-R-D or R-D-R associations. These results suggested that both intra- and intergenomic chromosome homology were contributed to chromosome pairing. Derived amphidiploids with 2n = 28 paired at metaphase I of meiosis as 4.51 I + 11.70 II + 0.03 III. Chromosome pairing of amphidiploids appeared more or less regular, i.e. bivalent-like with some trivalent configurations.

Meiotic pairing control in wheat–rye hybrids. II. Effect of rye genome and rye B-chromosomes and interaction with the wheat genetic system

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 76-80 ◽  
Author(s):  
C. Cuadrado ◽  
C. Romero ◽  
J. R. Lacadena
Keyword(s):  
Triticum Aestivum ◽  
Genetic System ◽  
B Chromosomes ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Homoeologous Group ◽  
Wheat Genotype ◽  
Main Determinant ◽  
Group 3 ◽  
Wheat Parent

Several hybrid combinations between rye and wheat ditelosomic for homoeologous group 3 or 5 chromosomes or mutant ph2b were used to analyze the effects of the rye genome and rye B-chromosomes on meiotic pairing. The results indicated that the rye Bs have an effect on bound-arm frequency, which varies with the wheat genotype. If wheat suppressors are absent, pairing decreases when Bs are added; whereas if wheat promoters are lacking, a pairing increase is observed in some hybrids with two rye Bs. There was thus an interaction between the genetic systems of the two parents, with the wheat parent being the main determinant of the pairing level in the hybrids. The rye genome tends to decrease pairing in the absence of wheat suppressors and increase it when wheat promoters are lacking, and the rye Bs tend to reinforce this primary rye action.Key words: Triticum aestivum, Secale cereale, homoeologous pairing, B-chromosomes, promoter–suppressor interaction.

Intergeneric hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x)

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 245-249 ◽  
Author(s):  
A. Comeau ◽  
G. Fedak ◽  
C. A. St-Pierre ◽  
R. Cazeault
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Meiotic Chromosome ◽  
Plant Morphology ◽  
Intergeneric Hybrids ◽  
Hybrid Vigor ◽  
Brittle Rachis ◽  
Hordeum Jubatum

Twelve embryos of interspecific hybrids between Hordeum jubatum (4x) and Triticum aestivum (6x) cv. Fukuho were produced out of 280 pollinated florets. Embryos were minute and globular and only one of them was successfully grown in vitro. Plant morphology of the hybrid was intermediate between the two parents and hybrid vigor was observed. Several traits of the hybrid were characteristic of the Hordeum parent such as brittle rachis, long awn, outerglume characteristics, and foliage waxiness being the most prominent. Average meiotic chromosome pairing in the hybrid was 28.6 univalents + 3.2 bivalents + 0.007 trivalents, which is not above what would be expected in a common wheat haploid.Key words: intergeneric hybrids, Critesion, Hordeum, Triticum, meiosis.

Intergeneric hybrids between Triticum aestivum and three crested wheatgrasses: Agropyron mongolicum, A. michnoi, and A. desertorum

Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 663-667 ◽  
Author(s):  
Qin Chen ◽  
Joseph Jahier ◽  
Yvonne Cauderon
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Adult Stage ◽  
Meiotic Chromosome ◽  
Intergeneric Hybrids ◽  
Species Hybrid ◽  
Hybrid Necrosis ◽  
Hybrid Plants ◽  
High Degree ◽  
First Time

Three hybridizations of Triticum aestivum cv. Chinese Spring (CS) (2n = 42) with Agropyron mongolicum (2n = 14), A. michnoi (2n = 28), and A. desertorum (2n = 28) are reported for the first time. Hybrid embryos were obtained at frequencies of 0.24, 1.13, and 2.05%, respectively. The hybrid plants obtained from pollinating CS by A. mongolicum had the expected chromosome number of 2n = 4x = 28, but as a result of hybrid necrosis, none could be raised to the adult stage. Hybrids CS × A. michnoi and CS × A. desertorum both had 2n = 5x = 35 chromosomes. The average meiotic chromosome pairing per cell was 7.04 I + 12.14 II + 1.06 III + 0.07 IV + 0.02 V + 0.02 VI and 9.29 I + 11.05 II + 1.14 III + 0.05 IV, respectively. Their analysis leads to the conclusions that (i) the two Agropyron genomes in the hybrids share a high degree of homology, thus revealing that tetraploid Agropyron species are true autoploids (genome constitution PPPP) and (ii) gene(s) in the Agropyron species suppress the activity of the homoeologous pairing control system of wheat. The possibility of gene transfer from Agropyron to wheat is discussed.Key words: intergeneric hybrids, Triticum aestivum, Agropyron species, hybrid necrosis, chromosome pairing.

Inferences from genetical evidence on the course of meiotic chromosome pairing in plants

1977 ◽  
Vol 277 (955) ◽  
pp. 313-326 ◽  
Keyword(s):  
Chromosome Pairing ◽  
Developmental Stages ◽  
Meiotic Chromosome ◽  
Critical Assessment ◽  
Gene Control ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Meiotic Chromosome Pairing ◽  
Combined Use ◽  
Or Gene

Meiotic chromosome pairing is a process that is amenable to genetic and experimental analysis. The combined use of these two approaches allows for the process to be dissected into several finite periods of time in which the developmental stages of pairing can be precisely located. Evidence is now available, in particular in plants, that shows that the pairing of homologous chromosomes, as observed at metaphase I, is affected by events occurring as early as the last premeiotic mitosis; and that the maintenance of this early determined state is subsequently maintained by constituents (presumably proteins) that are sensitive to either colchicine, temperature or gene control. A critical assessment of this evidence in wheat and a comparison of the process of pairing in wheat with the course of meiotic pairing in other plants and animals is presented.

Intergeneric hybrids of Hordeum vulgare with Agropyron caninum and A. dasystachyum

1985 ◽  
Vol 27 (4) ◽  
pp. 387-392 ◽  
Author(s):  
George Fedak
Keyword(s):  
Hordeum Vulgare ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Intergeneric Hybrids ◽  
Spindle Fibre ◽  
Chromosome Behavior ◽  
Paternal Parent ◽  
Agropyron Caninum

Hybrids were obtained by pollinating Hordeum vulgare cv. Betzes with Agropyron caninum (4x) and A. dasystachyum (4x) at frequencies of 1.4 and 6.1% of pollinated florets, respectively. The hybrids were sterile and phenotypically resembled the paternal parent, except for floret structure which was intermediate between the parental types. Chromosome pairing at meiosis was very low and thus provided no indication of homoeology between parental genomes. Abnormal meiotic chromosome behavior in meiocytes that occurred in sectors on the 'Betzes' × A. dasystachyum hybrid was attributed to abnormal spindle fibre function.Key words: intergeneric hybrids, Hordeum vulgare, Agropyron caninum, Agropyron dasystachyum.

Chromosome pairing in Oryza sativa L. × O. latifolia Desv. hybrids

1986 ◽  
Vol 28 (2) ◽  
pp. 278-281 ◽  
Author(s):  
E. M. Nowick
Keyword(s):  
Oryza Sativa ◽  
Chromosome Pairing ◽  
Embryo Culture ◽  
Oryza Sativa L ◽  
Meiotic Chromosome ◽  
Genetic System ◽  
Meiotic Chromosome Pairing

Meiotic chromosome pairing was examined in F1 hybrid regenerants from Oryza sativa (AA) × O. latifolia (CCDD) and O. glumaepatula (AcuAcu) × O. latifolia (CCDD) crosses produced through embryo culture. The average number of chromosome pairs in the O. sativa × O. latifolia regenerants ranged from 13.79 to 14.79. Ten to 18 bivalents were observed per cell. The average number of bivalents in the O. glumaepatula × O. latifolia regenerants ranged from 12.44 to 13.87, with 10–17 bivalents per cell. Some desynapsis occurred but 10 to 12 true bivalents remained at late metaphase in most cells. The high number of bivalents observed in the hybrids from these divergent parents indicates that a genetic system for pairing control similar to that in Triticum may be present in the Oryza genus.Key words: Oryza, embryo culture, meiosis.

Cytogenetic studies of progenies from crosses between 'Centurk' wheat and its doubled haploids derived from anther culture

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 622-628 ◽  
Author(s):  
Sawsan S. Youssef ◽  
R. Morris ◽  
P. S. Baenziger ◽  
C. M. Papa
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Doubled Haploid ◽  
Structural Changes ◽  
Meiotic Chromosome ◽  
Doubled Haploids ◽  
Triticum Aestivum L ◽  
Root Tips ◽  
Doubled Haploid Lines ◽  
A Minor

Karyotype stability, which is essential when using wheat (Triticum aestivum L.) doubled haploids in a breeding program, was evaluated in 14 anther-derived doubled-haploid lines after at least three generations of selfing, by crossing them as females with the parent cultivar 'Centurk' and doing cytological studies on the progenies. There were no deviations from the hexaploid chromosome number (2n = 42) in root tips. Meiotic chromosome pairing was as stable as that in the control ('Centurk' × 'Centurk') in most progenies. Chromosomal structural changes and (or) behavioral deviations were detected at the metaphase I, anaphase I, telophase I, and quartet stages of meiosis in a minor proportion of the cells. The frequencies of multivalents, lagging bivalents and univalents, bridges, and micronuclei were higher in some progenies than in the control. Chromosomal fragments were infrequent. The ranges in percentages of normal cells were 72.4–90.0 at anaphase I, 76.4–92.6 at telophase I, and 82.6–93.2 at quartet stages in the doubled-haploid progenies, compared with 95–100, 92–100, and 94–96, respectively, in the control. On the basis of these results, the doubled-haploid lines should produce enough normal gametes to provide adequate seed supplies when they are used as parents in wheat cultivar and population improvement.Key words: Triticum aestivum, chromosome pairing, chromosome aberrations, gametoclonal variation.

Cytological and molecular characterization of a Triticum aestivum × Lophopyrum ponticum backcross derivative resistant to barley yellow dwarf

Genome ◽  
1994 ◽  
Vol 37 (5) ◽  
pp. 876-881 ◽  
Author(s):  
Gan-Yuan Zhong ◽  
Patrick E. Mcguire ◽  
Calvin O. Qualset ◽  
Jan Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Barley Yellow Dwarf Virus ◽  
Virus Disease ◽  
Meiotic Chromosome ◽  
Yellow Dwarf ◽  
Homoeologous Chromosome ◽  
Barley Yellow Dwarf ◽  
Homoeologous Chromosome Pairing ◽  
Lophopyrum Ponticum

Barley yellow dwarf is the most damaging virus-caused disease in bread wheat (Triticum aestivum L.). A resistant line, SW335.1.2-13-11-1-5 (2n = 47), derived from a cross of T. aestivum × Lophopyrum ponticum was characterized by meiotic chromosome pairing, by in situ DNA hybridization and by expression of molecular markers to determine its chromosome constitution. All progeny of this line had three pairs of L. ponticum chromosomes from homoeologous chromosome groups 3, 5, and 6 and the 2n = 47 progeny had an additional L. ponticum monosome. The pairs from groups 3 and 6 were in the added state, while the group 5 pair was substituted for wheat chromosome 5D. Several wheat–wheat translocations with respect to the parental wheat genotype occurred in this line, presumably owing to the promotion of homoeologous chromosome pairing by L. ponticum chromosomes. It was hypothesized that homoeologous recombination results in homoeologous duplication–deletions in wheat chromosomes. An aberrant 3:1 disjunction creates the potential at each meiosis for replacement of these wheat chromosomes by homoeologous L. ponticum chromosomes. Wheat chromosomes 3A and 6A appeared to be in intermediate stages of this substitution process.Key words: wheat, wheatgrass, Lophopyrum, barley yellow dwarf virus, disease resistance, homoeologous chromosome recombination, homoeologous pairing, alien chromosome substitution.

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