Meiotic pairing in wheat–rye addition and substitution lines

1984 ◽  
Vol 26 (1) ◽  
pp. 25-33 ◽  
Author(s):  
J. Orellana ◽  
M. C. Cermeño ◽  
J. R. Lacadena
Keyword(s):  
Chromosome Pairing ◽  
Chinese Spring ◽  
Constitutive Heterochromatin ◽  
Banding Technique ◽  
Addition Line ◽  
Meiotic Pairing ◽  
Addition Lines ◽  
Substitution Lines ◽  
Homologous Chromosomes ◽  
Complex Process

Chromosome pairing was examined in wheat–rye addition and substitution lines using the C-banding technique. It was found that both rye and wheat chromosomes affect each other's homologous pairing. The strongest diminution of wheat pairing (measured as bound arms per cell) was produced by chromosome 5R of rye (7.5 and 7.2% in 'Chinese Spring' – 'Imperial' and 'Holdfast' – 'King II' addition lines, respectively). The weakest diminution of wheat pairing was produced by chromosome 3R in the 'Chinese Spring' – 'Imperial' addition line (1.1%). The diminution of rye chromosome pairing produced by wheat chromosomes ranges from 6.9 to 48.4% ('Chinese Spring' – 'Imperial' and 'Holdfast' – 'King II' addition lines, respectively). When put into a wheat background, the rye chromosomes suffer a worse fate than the wheat chromosomes. For example, chromosome 6R reduces the wheat complement pairing in the 'Holdfast' – 'King II' addition line by 3.8% but its own pairing is reduced by 41.4%. The decrease in pairing of both wheat and rye homologous chromosomes in addition and substitution lines is a complex process in which factors such as genes controlling meiotic pairing, constitutive heterochromatin, and cryptic wheat–rye interactions can play important roles.

Molecular Cytogenetic Analysis and Meiotic Pairing Behavior of Progenies Originating from a Hexaploid Triticale (×Triticosecale, Wittmack) and Bread Wheat (Triticum aestivum, L.) Cross

2020 ◽  
Vol 160 (1) ◽  
pp. 47-56
Author(s):  
Aybeniz J. Aliyeva ◽  
András Farkas ◽  
Naib Kh. Aminov ◽  
Klaudia Kruppa ◽  
Márta Molnár-Láng ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Chromosome Pairing ◽  
Addition Line ◽  
Meiotic Pairing ◽  
Hexaploid Triticale ◽  
Substitution Lines ◽  
Molecular Cytogenetic ◽  
Triticale Line ◽  
Pairing Behavior

The chromosomal constitution of 9 dwarf (D) and 8 semidwarf (SD) lines derived by crossing hexaploid Triticale line NA-75 (AABBRR, 2n = 6x = 42) with Triticumaestivum (AABBDD, 2n = 6x = 42) cv. Chinese Spring was investigated using molecular cytogenetic techniques: fluorescence in situ hybridization and genomic in situ hybridization. A wheat-rye translocation (T4DS.7RL), 8 substitution lines, and a ditelosomic addition line (7RSdt) were identified. In the substitution lines, 1, 2, or 4 pairs of wheat chromosomes, belonging to the A, B, or D genome, were replaced by rye chromosomes. Substitutions between chromosomes belonging to different wheat genomes [5B(5A), 1D(1B)] also occurred. The lines were genetically stable, each carrying 42 chromosomes, except the wheat-rye ditelosomic addition line, which carried 21 pairs of wheat chromosomes and 1 pair of rye telocentric chromosomes (7RS). The chromosome pairing behavior of the lines was studied during metaphase I of meiosis. The chromosome pairing level and the number of ring bivalents were different for each line. Besides rod bivalents, univalent and multivalent associations (tri- and quadrivalents) were also detected. The main goal of the experiment was to develop genetically stable wheat/Triticale recombinant lines carrying chromosomes/chromatin fragments originating from the R genome of Triticale line NA-75. Introgression of rye genes into hexaploid wheat can broaden its genetic diversity, and the newly developed lines can be used in wheat breeding programs.

EFFECTS OF ADDITIONS AND SUBSTITUTIONS OFAGROPYRON ELONGATUMCHROMOSOMES ON QUANTITATIVE CHARACTERS IN WHEAT

1974 ◽  
Vol 16 (3) ◽  
pp. 627-637 ◽  
Author(s):  
J. Dvořák ◽  
F. W. Sosulski
Keyword(s):  
Protein Content ◽  
Chinese Spring ◽  
Seed Protein ◽  
Addition Line ◽  
Addition Lines ◽  
Seed Protein Content ◽  
Substitution Lines ◽  
Quantitative Characters ◽  
Disomic Addition Lines ◽  
Chromosome Ii

Alien disomic and ditelosomic addition lines and disomic substitution lines involving the recipient wheat cultivar Chinese Spring and each of the seven chromosomes of diploid Agropyron elongatum were used to study the distribution of genes affecting date of heading, maturity, tillering, plant height and weight, seed protein content and components of seed yield in the Agropyron genome. Four Agropyron chromosomes, III, IV, V, and VI, affected days to heading and maturity but only chromosome VI conditioned early heading date. Complementary genes on opposite arms of the alien chromosome were responsible for late maturity in disomic addition line V. Tillering was affected by chromosome II which reduced the number of tillers per plant and by chromosome IV which increased the number. Plant height was increased by chromosome II and decreased in the presence of chromosomes III, IV, V and VI. Seed weight was increased in disomic addition lines II, III and VI while it was decreased in dosomic addition line V. Seed shrivelling, which was apparent in the amphiploid, Ag. elongatum × Chinese Spring, is controlled by Agropyron chromosome II. The number of seeds per spike was affected by six and seed yield by seven Agropyron chromosomes. Except for one line, the disomic addition lines and one substitution line showed significantly higher seed protein content than Chinese Spring. However, it was shown that yield depression accounted for a large portion of the increase in protein content. To remove this factor, the actual protein content in each line was compared with the adjusted protein content obtained from the regression of protein content on yield. Then it appeared that five of the seven Agropyron chromosomes are implicated in the control of seed protein. The amino acid compositions of proteins in the Agropyron-wheat derivatives were uniform and did not differ from Chinese Spring. It was shown that genes on Agropyron and wheat homoeologous chromosomes frequently have related effects on the characters studied. Because of genetic similarity among Agropyron and wheat homoeologues, the alien substitution lines tend to be superior to the alien addition lines in which the deleterious characters are largely caused by gene dosage effects. It is suggested that interlocus gene interactions play a significant role in the control of quantitative characters in this Agropyron genotype.

scholarly journals LATENT NONSTRUCTURAL DIFFERENTIATION AMONG HOMOLOGOUS CHROMOSOMES AT THE DIPLOID LEVEL: CHROMOSOME 6Be OF AEGILOPS LONGISSIMA

Genetics ◽  
1986 ◽  
Vol 114 (2) ◽  
pp. 579-592
Author(s):  
Rama S Kota ◽  
Patrick E McGuire ◽  
Jan Dvořák
Keyword(s):  
Chromosome Pairing ◽  
Chinese Spring ◽  
Constitutive Heterochromatin ◽  
Diploid Species ◽  
Triticum Aestivum L ◽  
Homologous Chromosomes ◽  
B Genome ◽  
Aegilops Longissima ◽  
Chinese Spring Wheat ◽  
Diploid Level

ABSTRACT Previous work has shown that chromosome pairing at metaphase I (MI) of wheat homologous chromosomes from different inbred lines (heterohomologous chromosomes) is reduced relative to that between homologous chromosomes within an inbred line (euhomologous chromosomes). In order to determine if a potential for this phenomenon exists in diploid species closely related to the wheat B genome, MI chromosome pairing was investigated between euhomologous and heterohomologous 6Be (=6Se) chromosomes, each from a different population of Aegilops longissima Schweinf. et Muschl. (2n = 2x = 14) substituted for chromosome 6B of Chinese Spring wheat (Triticum aestivum L., 2n = 6x = 42). Euhomologous and heterohomologous monotelodisomics, i.e., plants with one complete chromosome 6Be and a telosome of either 6Bep or 6Beq, were constructed in the isogenic background of Chinese Spring. Pairing at MI of the Ae. longissima chromosomes was reduced in heterohomologous monotelodisomics compared to that in the corresponding euhomologous monotelodisomics. The remaining 20 pairs of Chinese Spring chromosomes paired equally well in the euhomologous and heterohomologous monotelodisomics. Thus, the cause of the reduced pairing must reside specifically in the Ae. longissima heterohomologues. In the hybrids between the Ae. longissima lines that contributed the substituted chromosomes, pairing between the heterohomologous chromosomes was normal and did not differ from that of the euhomologous chromosomes. These data provide evidence that a potential for reduced pairing between the heterohomologues is present in the diploid species, but is expressed only in the polyploid wheat genetic background. The reduction in heterohomologous chromosome pairing was greater in the p arm than in the q arm, exactly as in chromosome 6B of wheat. It is concluded that the reduced pairing between Ae. longissima heterohomologues has little to do with constitutive heterochromatin. The value of chromosome pairing as an unequivocal means of determining the origin of genomes in polyploid plants is questioned.

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.

Isolation and characterization of wheat–Elytrigia elongata chromosome 3E and 5E addition and substitution lines

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 519-524 ◽  
Author(s):  
N. A. Tuleen ◽  
G. E. Hart
Keyword(s):  
Chinese Spring ◽  
Addition Lines ◽  
Homoeologous Group ◽  
Substitution Lines ◽  
Agropyron Elongatum ◽  
Chromosome Addition ◽  
Isolation And Characterization ◽  
Chromosome Addition Lines ◽  
Group 3 ◽  
Group 5

Isozyme markers were used to develop Triticum aestivum cv. Chinese Spring–Elytrigia elongata (= Agropyron elongatum, 2n = 14, genome E) disomic 3E and 5E addition lines. Subsequently, all possible lines containing 3E and 5E substituted for wheat homoeologues and several 3E and 5E ditelosomic addition and substitution lines were developed. Plants containing chromosome 3E substituted for wheat chromosomes of homoeologous group 3 are similar to 'Chinese Spring' in vigor and fertility while plants containing 3EL substituted for chromosomes of group 3 are less fertile than 'Chinese Spring'. This indicates that both arms of 3E are involved in sporophytic compensation. Plants containing chromosome 5E substituted for wheat chromosomes of homoeologous group 5 are as vigorous but less fertile than 'Chinese Spring'. 5EL (5A) and 5EL (5B) plants are lower in fertility than 5E (5A) and 5E (5B) plants, indicating that both arms of 5E are involved in sporophytic compensation. 5E (5D) and 5EL (5D) plants are similar in fertility. Male gametophytes in which 3E or 5E replaces a wheat homoeologue function at a lower rate than normal gametes.Key words: wheat, Triticum, Elytrigia elongata, alien chromosome addition lines.

Complete meiotic pairing of crested newt chromosomes

Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1105-1111 ◽  
Author(s):  
H. Wallace ◽  
B. M. N. Wallace
Keyword(s):  
Synaptonemal Complex ◽  
Genome Size ◽  
Chromosome Pairing ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Direct Observations ◽  
Crested Newt ◽  
The Individual ◽  
Complex Length ◽  
Complex Genome

The longest chromosome (number 1) of Trituturus cristatus carries a heteromorphic segment, a heterozygosity perpetuated by a balanced lethal system. The heteromorphic segment is regarded as achiasmate and has been claimed to be asynaptic. Direct observations of chromosome pairing in spermatocytes and oocytes yield some cases where all homologous chromosomes appear to be completely paired, but the individual bivalents could not be identified as pachytene is not particularly clear in this species. The long arms of bivalent 1 usually remain attached by a terminal chiasma in spermatocytes of T. c. cristatus but the corresponding chiasma is only rarely present in T. c. carnifex spermatocytes. Synaptonemal complexes have been measured in both spermatocytes and oocytes of T. c. cristatus. A karyotype constructed from these measurements matches the main features of somatic and lampbrush chromosome karyotypes, indicating that all chromosomes must be completely paired and proportionately represented as synaptonemal complex. The total length of synaptonemal complex is much the same in spermatocytes and oocytes and is similar to the length in spermatocytes of Xenopus laevis. These two amphibian examples supplement a recent survey of other vertebrate classes to reinforce its conclusion that synaptonemal complex length is not related to genome size in vertebrates.Key words: chromosome pairing, synaptonemal complex, genome size, amphibia.

Salt tolerance of two wheat – Agropyron junceum disomic addition lines

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 559-564 ◽  
Author(s):  
B. P. Forster ◽  
T. E. Miller ◽  
C. N. Law
Keyword(s):  
Salt Tolerance ◽  
Chinese Spring ◽  
Major Gene ◽  
Addition Line ◽  
Similar Response ◽  
Addition Lines ◽  
Disomic Addition Line ◽  
Wheat Group ◽  
Group 2 ◽  
Disomic Addition Lines

Two wheat – Agropyron junceum disomic addition lines homoeologous to groups 2 and 5 were tested for tolerance to salt. The experiments included germination and growth to maturity at various concentrations of sodium chloride (NaCl). The results were compared with those of wheat lines tetrasomic for chromosomes 2A, 2B, 2D, 5A, 5B, and 5D and also with the wheat parent 'Chinese Spring', and the salt-tolerant 'Chinese Spring' – A. junceum amphiploid. The addition of homoeologous group 2 chromosomes reduced the tolerance to salt relative to 'Chinese Spring' in every case. The order of tolerance was ranked as 'Chinese Spring' > 2J disomic addition line > tetra 2A = tetra 2D > tetra 2B. The addition of wheat group 5 chromosomes was either equal to 'Chinese Spring' or worse with respect to tolerance to salt. However, the disomic addition line for 5J showed considerable tolerance to salt and at 200 mol m−3 NaCl produced a similar response to that of the amphiploid in producing fertile tillers. Both produced viable grain, but the grain produced by the 5J addition line at 200 mol−3 NaCl was small and shrivelled, unlike the plump grain produced by the amphiploid. The order of tolerance was ranked as amphiploid > 5J addition line > 'Chinese Spring' = tetra 5A > tetra 5B = tetra 5D. It is concluded that there are genes on the group 2 chromosomes that confer susceptibility to salt and that chromosome 5J of A. junceum carries a major gene(s) for tolerance to salt. The potential for transferring this character into wheat is discussed. A hypothesis is also proposed to explain the function of the salt-tolerance gene(s) at critical stages in the life cycle of wheat.Key words: salt tolerance, wheat, Agropyron junceum, disomic addition lines.

DISOMIC AND DITELOSOMIC ADDITIONS OF DIPLOID AGROPYRON ELONGATUM CHROMOSOMES TO TRITICUM AESTIVUM

1974 ◽  
Vol 16 (2) ◽  
pp. 399-417 ◽  
Author(s):  
J. Dvorak ◽  
D. R. Knott
Keyword(s):  
Triticum Aestivum ◽  
Chinese Spring ◽  
Gene Dosage ◽  
Plant Morphology ◽  
Addition Line ◽  
Addition Lines ◽  
Agropyron Elongatum ◽  
Monosomic Addition ◽  
Monosomic Addition Lines ◽  
Disomic Addition Lines

A set of disomic addition lines was produced in which each chromosome of Agropyron elongatum (2n = 14) was added to the chromosome complement of Triticum aestivum cv. Chinese Spring. In addition a complete set of ditelosomic addition lines involving Agropyron chromosome arms IS, IIα, IIIα, IVS, IVL, VS, VL, VIS and VIIα, was developed. Except for disomic addition line VII which is similar to Chinese Spring, each added alien chromosome pair was found to have a specific effect on plant morphology. Five disomic addition lines had reduced fertility. Agropyron chromosome arms carrying genes for anthocyanin production, waxless foliage, tenacious glumes, and several other traits were identified. The single Agropyron chromosomes in the monosomic addition lines usually have either minor effects or no effect on plant morphology and fertility.The disomic addition lines are similar in many characters to tetrasomics of the corresponding homoeologous wheat chromosomes and show characters that are not present in either Ag. elongatum or the amphiploid, T. aestivum × Ag. elongatum. Thus many of the effects are due to gene dosage. If individual disomic addition lines are compared with the amphiploid a significant role of interchromosomal gene interactions is apparent.In combination with knowledge of the homoeologous relationships among wheat and alien chromosomes, sets of disomic addition lines can provide valuable information on the evolutionary past of genomes in Triticinae. In monosomic addition lines only Agropyron chromosome IV paired with a wheat chromosome and it is concluded that it is improbable that Agropyron genomes played any role in the evolution of the polyploid series of Aegilops and Triticum.

THE EFFECT OF GENES CONTROLLING DIFFERENT DEGREES OF HOMOEOLOGOUS PAIRING ON QUADRIVALENT FREQUENCY IN INDUCED AUTOTETRAPLOID LINES OF TRITICUM LONGISSIMUM

1976 ◽  
Vol 18 (2) ◽  
pp. 357-364 ◽  
Author(s):  
Lydia Avivi
Keyword(s):  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Spatial Separation ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Homologous Pairing ◽  
Homologous Chromosomes ◽  
Chromosomal Pairing ◽  
Per Se ◽  
Quadrivalent Frequency

Different genotypes of Triticum longissimum are known to either promote or suppress chromosome pairing in crosses with polyploid wheats. Lines that promote homoeologous pairing are here designated as intermediate pairing lines, while those which have no such effect or suppress pairing are known as low pairing lines. To determine a possible effect of these genotypes on homologous pairing, tetraploidy was induced in both lines and chromosomal pairing was studied at first metaphase of meiosis. While the two induced autotetraploids did not differ in chiasma frequency or in the number of paired chromosomal arms, they differed significantly in multivalent frequency; the intermediate-pairing autotetraploid exhibited the same multivalent frequency as that expected on the basis of two telomeric initiation sites, while the low pairing autotetraploid exhibited a significantly lower frequency. It is assumed that in the autotetraploid the low pairing genotype does not affect meiotic pairing per se, but modifies the pattern of homologous association in a similar manner to that known in polyploids and caused by diploidization genes. It is speculated that the tendency for bivalent pairing in the low pairing autotetraploid is due to spatial separation of the four homologous chromosomes in somatic and premeiotic cells into two groups of two.

The initiation of meiotic chromosome pairing: the cytological view

Genome ◽  
1990 ◽  
Vol 33 (6) ◽  
pp. 759-778 ◽  
Author(s):  
Josef Loidl
Keyword(s):  
Synaptonemal Complex ◽  
Chromosome Pairing ◽  
Meiotic Chromosome ◽  
Meiotic Pairing ◽  
Cytological Evidence ◽  
Homologous Chromosomes ◽  
Synaptonemal Complex Formation ◽  
Meiotic Synapsis ◽  
The One ◽  
First Contact

Opposing views are held with respect to the time when and the mechanisms whereby homologous chromosomes find each other for meiotic synapsis. On the one hand, some evidence has been presented for somatic homologous associations or some other kind of relationship between chromosomes in somatic cells as a preliminary to meiotic pairing. On the other hand, it is argued by many that homologous contacts are first established at meiotic prophase prior to, or in the course of, synaptonemal complex formation. The present paper reviews the controversial cytological evidence, hypotheses, and ideas on how the first contact between homologous chromosomes comes about.Key words: synapsis, meiosis, presynaptic alignment, homologous recognition, synaptonemal complex, chromosome pairing.

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