Genome-specific control of meiotic pairing evidenced in mutant Aegilops ventricosa-Secale cereale amphidiploids

1985 ◽  
Vol 71 (3) ◽  
pp. 532-535 ◽  
Author(s):  
J. Orellana ◽  
N. Cuñado ◽  
M. C. Cermeño
Keyword(s):  
Secale Cereale ◽  
Meiotic Pairing ◽  
Aegilops Ventricosa ◽  
Specific Control

Evidence of nonchiasmate bonds at metaphase I in inbred rye

1984 ◽  
Vol 26 (4) ◽  
pp. 409-414 ◽  
Author(s):  
M. C. Cermeño ◽  
J. Orellana ◽  
J. R. Lacadena
Keyword(s):  
Secale Cereale ◽  
Chiasma Frequency ◽  
Meiotic Pairing ◽  
Secale Cereale L ◽  
Chromosome 1R ◽  
Metaphase I

The loss of bound chromosome arms through early, middle, and late metaphase I has been analyzed in a plant of inbred rye (Secale cereale L.) heterozygous for a terminal heterochromatic C-band of the long arm of chromosome 1R. From the increase in the number of univalent pairs due to bound arm loss, and from the comparison between the frequencies of bound arms at metaphase I and recombinant chromosomes at anaphase I, it is concluded that some of the chromosome bonds appearing at metaphase I are actually nonchiasmate associations that can be considered as remnants of prophase pairing. Conclusions concerning recombination obtained solely from the analysis of chiasma frequency measured as bound arms may be invalid.Key words: inbred rye, C-heterochromatin, meiotic pairing, nonchiasmate bonds.

scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN AUTOTETRAPLOID RYE. I. SUBMETACENTRIC CHROMOSOMES

Genetics ◽  
1985 ◽  
Vol 111 (4) ◽  
pp. 933-944
Author(s):  
J Orellana ◽  
J L Santos
Keyword(s):  
Genetic Control ◽  
Secale Cereale ◽  
Inbred Lines ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Partner Exchange ◽  
Pairing Behavior ◽  
Chromosome 1R ◽  
Heterochromatin Content

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in ten induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heerochromatin C-bands in both arms of chromosome 1R. These plants were the progeny of two crosses between only one plant of cv. Petkus, used as male, and two plants of the inbred lines E and R, respectively. Different pairing preferences for chromosome 1R were found: (1) between plants, (2) between chromosome arms within the same plant and (3) between bivalents and multivalents within the same plant. The possible influence in the preferences of several factors such as differences in C-heterochromatin content in the chromosomes analyzed, specific genetic control and independence in pairing behavior between both arms and partner exchange is discussed.

scholarly journals PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN RYE AND GRASSHOPPERS

Genetics ◽  
1983 ◽  
Vol 104 (4) ◽  
pp. 677-684
Author(s):  
J L Santos ◽  
J Orellana ◽  
R Giraldez
Keyword(s):  
Secale Cereale ◽  
Banding Pattern ◽  
Chromosome Pair ◽  
Meiotic Pairing ◽  
Homologous Pairing ◽  
Eyprepocnemis Plorans ◽  
Homologous Chromosomes ◽  
Random Pairing ◽  
Structural Differences ◽  
Telomeric Heterochromatin

ABSTRACT Meiotic pairing preferences between identical and homologous but not identical chromosomes were analyzed in spontaneous tetraploid/diploid chimeras of three male grasshoppers (Eyprepocnemis plorans) whose chromosome pair 11 were heterozygous for C-banding pattern and in four induced tetraploid/diploid chimaeral rye plants (Secale cereale) heterozygous for telomeric heterochromatin C-bands in chromosomes 1R and 2R. In the grasshoppers, a preference for identical over homologous pairing was observed, whereas in rye both a preference for homologous rather than identical pairing and random pairing between the four chromosomes of the set was found. From the results in rye, it can be deduced that pairing preferences do not depend exclusively on the similarities between chromosomes involved. It is suggested that genotypic or cryptic structural differences between the homologous chromosomes of each pair analyzed might be responsible for the pairing preferences found. This hypothesis can also explain the results obtained in grasshoppers, although the possibility of premeiotic association cannot be excluded in this material.

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.

Nucleolar competition analysis in Aegilops ventricosa and its amphiploids with tetraploid wheats and diploid rye by the silver-staining procedure

1984 ◽  
Vol 26 (1) ◽  
pp. 34-39 ◽  
Author(s):  
J. Orellana ◽  
J. L. Santos ◽  
J. R. Lacadena ◽  
M. C. Cermeño
Keyword(s):  
Secale Cereale ◽  
Silver Staining ◽  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Nucleolar Organizer ◽  
Triticum Dicoccoides ◽  
Staining Procedure ◽  
Nucleolar Organizer Regions ◽  
Aegilops Ventricosa ◽  
Tetraploid Wheats

The nucleolar organizer activity of Aegilops ventricosa and its amphiploids with tetraploid wheats (Triticum turgidum, Triticum dicoccum, and Triticum aethiopicum) and diploid rye (Secale cereale) was analyzed by the silver-staining procedure. Triticum turgidum and Triticum dicoccoides show four Ag-NORs (silver-stained nucleolar organizer regions), in agreement with previous data. Only two Ag-NORs are detected in Ae. ventricosa (genome constitution DDMM) indicating that natural amphiplasty occurs in this allotetraploid species. No amphiplasty was observed in the Ae. ventricosa – tetraploid wheat amphiploids since six Ag-NORs were visible in all of them. On the contrary, only two Ag-NORs were detected in the Ae. ventricosa – Secale cereale amphiploid, the rye NORs being suppressed by the presence of ventricosa chromosomes. The ventricosa NORs therefore are codominant with those of tetraploid wheat (chromosomes 1B and 6B) and dominant to chromosome 1R of rye. Eleven T. aestivum – Ae. ventricosa addition lines have been also analyzed. All of them showed four Ag-NORs. Clear-cut conclusions were not reached since the added ventricosa chromosomes were not identified.

Different genetic systems in rye affecting homoeologous pairing in wheat – rye combinations

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 793-796 ◽  
Author(s):  
M. C. Cuadrado ◽  
C. Romero
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Chinese Spring ◽  
Genetic System ◽  
The Other ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Major Genes ◽  
Genetic Systems ◽  
Polygenic System

The present study analyzed meiotic pairing in wheat – rye hybrids obtained by crossing of Triticum aestivum cv. Chinese Spring with allogamous ryes, two cultivars of Secale cereale ('Don Enrique' and 'Selectión') and Secale cereale ssp. segetale. The results indicate that each rye type has different behaviour on hybrid meiotic pairing because they contain distinct genetic systems affecting meiotic pairing. In the case of 'Don Enrique' and 'Selección,' a polygenic system could be present, but not identical in both cultivars. On the other hand, Secale cereale ssp. segetale contained genes that strongly affect the genetic system controlling homoeologous pairing in wheat.Key words: homoeologous pairing, wheat – rye hybrids, polygenic system, major genes.

Meiotic pairing control in wheat–rye hybrids. I. Effect of different wheat chromosome arms of homoeologous groups 3 and 5

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 72-75 ◽  
Author(s):  
C. Cuadrado ◽  
C. Romero ◽  
J. R. Lacadena
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Wheat Chromosome ◽  
Suppressive Effect ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Promoting Effect ◽  
Promotive Effect ◽  
Chromosome Arm ◽  
Homoeologous Chromosomes

Wheat–rye hybrids were analyzed to study how the homoeologous-pairing control of wheat is altered when specific regulators of groups 3 and 5 are lacking or mutated. Lack of the 3DS chromosome arm and the ph2b mutation showed the most significant effect, due to a deficiency or inactivity of the Ph2 suppressor. The 3DL, 5AS, and 5BS chromosome arms have a promoting effect, 5BS being the most effective. A weak suppressive effect of 3AS and 3AL is proposed, and a promotive effect of 5DS was not ruled out. The suppressive effect of 3BS is discussed.Key words: Triticum aestivum, Secale cereale, homoeologous chromosomes, genetic pairing regulation.

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