Effect of different doses of group-2 chromosomes on homoeologous pairing in intergeneric wheat hybrids

1986 ◽  
Vol 28 (2) ◽  
pp. 240-246 ◽  
Author(s):  
C. Ceoloni ◽  
I. Strauss ◽  
M. Feldman
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
Intergeneric Hybrid ◽  
Homoeologous Pairing ◽  
Aegilops Variabilis ◽  
Group 2 ◽  
Wheat Hybrids ◽  
A Minor ◽  
Homoeologous Chromosomes ◽  
Different Doses

While an extra dose of chromosome 2A of common wheat, previously reported to carry a pairing promoter on its short arm, did not increase pairing between homoeologous chromosomes in F1 hybrids between common wheat cv. Chinese Spring (CS) and Aegilops variabilis, two doses of chromosome 2D or 2B caused a significant increase in homoeologous pairing. Evidently, chromosomes 2D and 2B carry a pairing promoter(s). Studies of F1 hybrids between aneuploids of CS, either deficient for chromosome 2D or having it in an extra dose, and Ae. variabilis, Ae. longissima, and Secale cereale supported the finding that this chromosome carries a pairing promoter. Using ditelosomic lines, the promoter was found to be located on the short arm of 2D (2DS). It was deduced that the promoter of 2B is also located on the homoeologous short arm, i.e., on 2BS. Evidence was obtained that the long arm of 2D may carry a suppressor(s) of pairing. Thus, the short arm of 2A, 2D, and 2B carries a pairing promoter(s), while the long arm of 2D and possibly of 2A and 2B carry a minor suppressor(s). The promoters are more potent than the suppressors and the overall effect of group-2 chromosomes is pairing promotion.Key words: wheat, homoeologous pairing, pairing promoter, pairing suppressor, intergeneric hybrid, meiosis.

CYTOGENETICS OF SOLID STEM IN COMMON WHEAT: III. CULM MEASUREMENTS AND THEIR RELATION TO STEM SOLIDNESS IN MONOSOMIC LINES OF THE VARIETY S-615

1959 ◽  
Vol 37 (3) ◽  
pp. 379-391 ◽  
Author(s):  
Ruby I. Larson ◽  
M. D. MacDonald
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
Monosomic Analysis ◽  
Secondary Effects ◽  
Stem Solidness ◽  
Solid Stem ◽  
Homoeologous Chromosomes

Most monosomics of the solid-stemmed variety of common wheat, S-61S, were shorter than normal. Many had thinner culms, but monosomics XIII and XVI had thicker culms. Although the effect of loss of homoeologous chromosomes on culm dimensions was generally similar in S-615 monosomics and Chinese Spring nullisomics, the most extreme member of each group was not always the same in the two varieties. The differences between solid stem in monosomics and normal lines of S-615 were due to loss of the chromosome affecting pith production and not to secondary effects caused by changes in culm dimensions. Nevertheless, within lines of genetically similar plants there was a small but consistent association between short culm and solidness, between thin culm at the tops of internodes I, III, and IV and hollowness, and between thin culm in the center and lower parts of internode I and solidness. This has a bearing on interpretation of data in monosomic analysis of solid stem.

scholarly journals Effect of a rye B chromosome and its segments on homoeologous pairing in hybrids between common wheat and Aegilops variabilis

2012 ◽  
Vol 87 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Ryota Kousaka ◽  
Takashi R. Endo
Keyword(s):  
Common Wheat ◽  
B Chromosome ◽  
Homoeologous Pairing ◽  
Aegilops Variabilis

Spindle sensitivity to isopropyl-N-phenyl-carbamate and griseofulvin of common wheat plants carrying different doses of the Ph1 gene

1984 ◽  
Vol 26 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Giampiero Gualandi ◽  
Carla Ceoloni ◽  
Moshe Feldman ◽  
Lydia Avivi
Keyword(s):  
Common Wheat ◽  
Chinese Spring ◽  
The Other ◽  
Microtubule Organization ◽  
Chromosome 5B ◽  
Ph1 Gene ◽  
Complete Disruption ◽  
Spindle Microtubules ◽  
Different Doses ◽  
Microtubule Structure

Lines of common wheat cv. 'Chinese Spring' carrying different doses of the Ph1 gene, located on the long arm of chromosome 5B were treated with the antimitotic agents griseofulvin and isopropyl-N-phenyl-carbamate (IPC). Treatments with low griseofulvin concentrations and IPC resulted mainly in the production of a high percentage of cells exhibiting spindle disorganization at metaphase and multipolar cells at anaphase–telophase. These treatments did not differentially affect the tested genotypes. On the other hand, higher griseofulvin concentrations induced the appearance of frequent C-metaphases and C-anaphases because of complete disruption of the spindle microtubules; in such cases, more pronounced sensitivity was observed in a line lacking the Ph1 gene than in lines disomic and tetrasomic for chromosome 5B. From this evidence it can be concluded that subcellular structures regulating microtubule organization and orientation, which are apparently the target of IPC and low griseofulvin concentrations, are not related to the action of the Ph1 gene. Rather, tubulin–microtubules equilibrium, which is affected by colchicine and high griseofulvin concentrations, is influenced by the action of this gene. Thus, the Ph1 gene product may correspond to a tubulin or a microtubule-associated protein which in turn stabilizes microtubule structure. In either case, the equilibrium tubulin–microtubules would be shifted towards microtubules in plants containing two doses of Ph1 and even more in plants containing an extra dose of this gene.Key words: spindle, Triticum, microtubules, antitubulins, griseofulvin.

Promotion of homoeologous chromosome pairing in hybrids of Triticum aestivum × Aegilops variabilis

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 825-828 ◽  
Author(s):  
S. Farooq ◽  
N. Iqbal ◽  
T. M. Shah
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Chiasma Frequency ◽  
Intergeneric Hybrids ◽  
Mutant Form ◽  
Homoeologous Pairing ◽  
Homoeologous Chromosome ◽  
Homoeologous Chromosome Pairing ◽  
Aegilops Variabilis

Intergeneric hybrids of Triticum aestivum variety Lu-26 and ph1b mutant of the cultivar Chinese Spring were produced with three accessions, A, B, and E, of Aegilops variabilis. Significant differences were found in the amount of homoeologous chromosome pairing at meiotic metaphase I. Hybrids between wheat variety Lu-26 and accessions A and B of Ae. variabilis showed very little pairing, as indicated by the chiasma frequency of 1.0 and 1.5 per cell, respectively. Hybrids between Lu-26 and accession E, on the other hand, showed significantly increased homoeologous pairing (mean chiasma frequency, 12.6/cell). The level of such pairing was essentially the same as that between the hybrids of ph1b 'Chinese Spring' × Ae. variabilis accessions A and B. However, when the ph1b mutant was hyridized with accession E, the level of chromosome pairing increased significantly (mean chiasma frequency, 17.52/cell). This is indicative of the presence of pairing promoter gene(s) in Ae. variabilis accession E, which are epistatic to the wheat Ph1 allele and positively interact with its mutant form to further increase the ph1b ceiling to homoeologous pairing in wheat.Key words: Triticum aestivum, ph1b mutant, Aegilops variabilis, intergeneric hybrids, homoeologous pairing.

Combining mutations for the two homoeologous pairing suppressor genes Ph1 and Ph2 in common wheat and in hybrids with alien Triticeae

Genome ◽  
1993 ◽  
Vol 36 (2) ◽  
pp. 377-386 ◽  
Author(s):  
Carla Ceoloni ◽  
Paolo Donini
Keyword(s):  
Common Wheat ◽  
Interspecific Hybrids ◽  
Double Mutant ◽  
Homoeologous Pairing ◽  
Suppressor Genes ◽  
Plant Variation ◽  
Significant Difference ◽  
Chromosome Arm ◽  
Aegilops Variabilis ◽  
Pairing Behaviour

Two lines of common wheat cv. Chinese Spring, carrying simultaneous mutations for the two major homoeologous pairing wheat suppressor genes Ph1 and Ph2 have been developed and their pairing behaviour compared with that of the ph1b mutant of the same cultivar. Besides carrying the ph1b mutation, the first double mutant line lacked the chromosome arm pair 3DS, containing Ph2, whereas the second had a euploid constitution and carried the ph1b allele on 3DS. Hybrids of Aegilops variabilis and Secale cereale with mono-5B (ph1b) and 3D/3DL plants have also been obtained, where the 3D versus 3DL presence marked the two pairing alternatives (ph1b only and ph1b + Ph2−, respectively). In the wheat × Ae. variabilis hybrids, an 8% increase in total chromosome pairing, almost entirely ascribable to an increment of multivalent associations, was observed in the 2n = 34 + t plants with respect to their 2n = 35 sibs. The number of bivalents showed no significant difference, but a tendency towards a decrease, which was significant for the rod types, was exhibited by the Ph2− plants. A weaker but similar effect was observed in wheat itself. The different mutants, in fact, showed a similar percentage of paired chromosomes but varied in their pairing pattern. A significant reduction in the number of bivalents, owing to a decrease of the rings, only partly compensated for by an increase of the rods, was observed in the double mutants. They also exhibited an increase in the multivalent fraction, which was significant for the most complex associations. In both common wheat and its hybrids with Ae. variabilis the addition of a ph2 mutation thus seems to reinforce the ph1b effect in promoting homoeologous pairing. On the other hand, such an effect was not noticed in the wheat × S. cereale hybrids. However, possible quantitative differences could have been masked by the considerable plant-to-plant variation and potential differences in relative incidence of wheat–wheat versus wheat–rye associations were undetectable in the Feulgen-stained materials analyzed.Key words: common wheat, interspecific hybrids, homoeologous pairing, Ph mutations.

PRODUCTION, MORPHOLOGY AND MEIOSIS OF RECIPROCAL BARLEY-WHEAT HYBRIDS

1980 ◽  
Vol 22 (1) ◽  
pp. 117-123 ◽  
Author(s):  
George Fedak
Keyword(s):  
Triticum Aestivum ◽  
Hordeum Vulgare ◽  
Chinese Spring ◽  
Reciprocal Cross ◽  
Triticum Aestivum L ◽  
Homoeologous Pairing ◽  
Hordeum Vulgare L ◽  
Barley Genome ◽  
Cytological Abnormalities ◽  
Wheat Hybrids

The intercrossing of wheat (Triticum aestivum L. cv. Chinese Spring) and barley (Hordeum vulgare L. cv. Betzes) yielded hybrids at a frequency of 0.80% of pollinated florets for the barley-wheat combinations and 0.23% for the reciprocal cross. An increase in homoeologous pairing of wheat chromosomes was observed in both hybrids compared with the pairing observed in wheat haploids indicating that the barley genome had pairing promoting properties. Cytological abnormalities such as hyperploid meiotic cells and isochromosomes were attributed to abnormalities at premeiotic mitosis.

The effect of different doses of Ph1 on chromosome pairing in hybrids between tetraploid Agropyron elongatum and common wheat

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 974-977 ◽  
Author(s):  
A. Charpentier ◽  
M. Feldman ◽  
Y. Cauderon
Keyword(s):  
Common Wheat ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Meiotic Metaphase ◽  
Polyploid Species ◽  
Agropyron Elongatum ◽  
Genomic Relationships ◽  
Wheat Lines ◽  
Tetraploid Cytotypes ◽  
Different Doses

Chromosome pairing at first meiotic metaphase was studied in F1 hybrids between tetraploid cytotypes of Agropyron elongatum and common wheat lines of the cultivar Chinese Spring, carrying zero, one, and two doses of Ph1. The bivalentization gene system of A. elongatum could not compensate for the absence of Ph1: hybrids deficient for this gene exhibited pairing between the Agropyron E1 and E2 chromosomes, between the wheat A, B, and D chromosomes, and between the Agropyron and the wheat chromosomes. In hybrids with one or two doses of Ph1, pairing was restricted to the Agropyron E1 and E2 chromosomes. It was concluded that E1 and E2 are distant homologues, thus further supporting the autoploidy nature of tetraploid A. elongatum. The genomic relationships in other polyploid species of the genus Agropyron is discussed in the light of this evidence.Key words: chromosome pairing, Triticum, common wheat, Agropyron.

The effect of different Agropyron elongatum chromosomes on pairing in Agropyron – common wheat hybrids

Genome ◽  
1988 ◽  
Vol 30 (6) ◽  
pp. 978-983 ◽  
Author(s):  
A. Charpentier ◽  
M. Feldman ◽  
Y. Cauderon
Keyword(s):  
Common Wheat ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Chromosomal Location ◽  
Wheat Cultivar ◽  
Agropyron Elongatum ◽  
The Common ◽  
Disomic Addition Lines ◽  
Wheat Hybrids ◽  
Tetraploid Cytotypes

Chromosome pairing at first meiotic metaphase was studied in hybrids between the common wheat cultivar Chinese Spring (CS) and an induced autotetraploid line derived from diploid Agropyron elongatum. The latter was found to carry genes for homoeologous pairing. To determine the chromosomal location of these and other genes that control pairing, disomic addition lines of A. elongatum in the cv. Chinese Spring were crossed with tetraploid cytotypes of A. elongatum, and pairing was then compared in the resulting hybrids and in hybrids between cv. Chinese Spring and tetraploid A. elongatum. The elongatum chromosomes were classified into those that suppress (6E), promote (5E, 3E, and possibly 1E), or have no effect on pairing (4E). The effect of chromosomes 2E and 7E was not studied. Chromosomes 5E and 3E differed in their effect on the degree and pattern of chromosome pairing. These findings are compared with the available data on the control of pairing in A. elongatum and in other Triticinae species.Key words: chromosome pairing, pairing promoter, Triticum, common wheat, Agropyron.

Arm homoeology of wheat and rye chromosomes

Genome ◽  
1987 ◽  
Vol 29 (6) ◽  
pp. 873-882 ◽  
Author(s):  
T. Naranjo ◽  
A. Roca ◽  
P. G. Goicoechea ◽  
R. Giraldez
Keyword(s):  
Key Words ◽  
Common Wheat ◽  
Chinese Spring ◽  
Structural Changes ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Wheat Evolution ◽  
C Banding ◽  
Chromosome Arm ◽  
Homoeology Relationships

Meiotic pairing was studied at metaphase I in three different cv. Chinese Spring × rye hybrid combinations (5B deficient, 3D deficient, and normal ABDR) to establish the arm homoeology of wheat and rye chromosomes. The majority of individual wheat chromosomes and their arms, as well as the arms of chromosomes 1R and 5R, were identified by means of C-banding. The results on pairing relationships support the genome reallocation of chromosomes 4A and 4B. The short arms of wheat chromosomes belonging to homoeologous groups 1, 3, 5, and 6 and of chromosome pairs 4A–4D and 7A–7D showed full pairing homoeology as well as the long arms of wheat chromosomes of groups 1, 3, 6, and 7 and of chromosome pairs 4A–4D and 5B–5D. Chromosomes 2A, 2B, and 2D were homoeologous, but the homoeologies of their arms were not identified. Reduced homoeologies of the 4BL arm to 7AS and 7DS, of the 5AL arm to 4AL and 4DL, and of the 7BS arm to 5BL and 5DL were identified. Arms 4BL, 5AL, and 7BS are involved in a double translocation that arose during the evolution of common wheat. The homoeology relationships of chromosome arm 4BS were not identified since this arm seldom paired. The homoeologous pairing pattern between wheat chromosomes was characterized by a remarkable predominance of A–D associations, altered only by structural changes in groups 4 and 5. Chromosome arm 1RL showed full pairing homoeology to 1AL, 1BL, and 1DL, while 5RL was homoeologous to 5AL and partially homoeologous to 4AL and 4DL. It is concluded that 5RL carries a translocated segment from 4RL. Key words: homoeologous pairing, translocations, wheat evolution, C-banding.

NONSTRUCTURAL CHROMOSOME DIFFERENTIATION AMONG WHEAT CULTIVARS, WITH SPECIAL REFERENCE TO DIFFERENTIATION OF CHROMOSOMES IN RELATED SPECIES

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 391-414
Author(s):  
Jan Dvořák ◽  
Patrick E McGuire
Keyword(s):  
Chinese Spring ◽  
Structural Changes ◽  
Wheat Cultivar ◽  
Chromosome Complement ◽  
Triticum Aestivum L ◽  
Substitution Lines ◽  
Structural Differentiation ◽  
Chromosome Differentiation ◽  
Mother Cells ◽  
Homoeologous Chromosomes

ABSTRACT Wheat cultivar Chinese Spring (Triticum aestivum L. em. Thell.) was crossed with cultivars Hope, Cheyenne and Timstein. In all three hybrids, the frequencies of pollen mother cells (PMCs) with univalents at metaphase I (MI) were higher than those in the parental cultivars. No multivalents were observed in the hybrids, indicating that the cultivars do not differ by translocations. Thirty-one Chinese Spring telosomic lines were then crossed with substitution lines in which single chromosomes of the three cultivars were substituted for their Chinese Spring homologues. The telosomic lines were also crossed with Chinese Spring. Data were collected on the frequencies (% of PMCs) of pairing of the telesomes with their homologues at MI and the regularity of pairing of the remaining 20 pairs of Chinese Spring chromosomes in the monotelodisomics obtained from these crosses. The reduced MI pairing in the intercultivar hybrids was caused primarily by chromosome differentiation, rather than by specific genes. Because the differentiation involved a large part of the chromosome complement in each hybrid, it was concluded that it could not be caused by structural changes such as inversions or translocations. In each case, the differentiation appeared to be unevenly distributed among the three wheat genomes. It is proposed that the same kind of differentiation, although of greater magnitude, differentiates homoeologous chromosomes and is responsible, together with structural differentiation, for poor chromosome pairing in interspecific hybrids.

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