Meiotic pairing of the amphiploid Hordeum chilense X Triticum turgidum conv. durum studied by means of Giemsa C-banding technique

1985 ◽  
Vol 70 (1) ◽  
pp. 85-91 ◽  
Author(s):  
J. A. Fernandez ◽  
J. M. Gonzalez ◽  
N. Jouve
Keyword(s):  
Triticum Turgidum ◽  
Hordeum Chilense ◽  
Banding Technique ◽  
Meiotic Pairing ◽  
C Banding

Image analysis of C-banded chromosomes and pairing regionalization in wheat

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 1062-1067 ◽  
Author(s):  
Angeles Bernardo ◽  
Martin Montero ◽  
Angeles Cuadrado ◽  
Nicolás Jouve
Keyword(s):  
Image Analysis ◽  
Chinese Spring ◽  
Genetic Factors ◽  
Triticum Turgidum ◽  
Chromosome Region ◽  
Chromosome Length ◽  
Physical Parameters ◽  
Meiotic Pairing ◽  
C Banding ◽  
Mutant Lines

C-banding and image analysis are used to characterize nine somatic chromosomes of wheat and to quantify a series of physical parameters (arm length, heterochromatic band intensity and position) in tetraploid Triticum turgidum and hexaploid T. aestivum wheat. The arm-by-arm meiotic association of the chromosomes at first meiotic metaphase is evaluated with respect to these parameters and genetic pairing regulators. The effect of the genetic factors is analyzed comparatively in homozygous lines or both normal and mutant lines (Ph1/Ph1, ph1a/ph1a, ph1b/ph1b, and ph1c/ph1c) and in aneuploids (ditelo-5BL and nulli-5B–tetra-5D). The pairing values were progressively reduced as follows: 'Chinese Spring' Ph1/Ph1 > 'Chinese Spring' dt-5BL > 'Chinese Spring' ph1a/ph1a > 'Chinese Spring' nulli-5B–tetra-5D > 'Chinese Spring' ph1b/ph1b > 'Cappelli' ph1c/ph1c. The results indicate that although a different contribution to overall pairing exists for each specific chromosome region, the differences in the genetic systems regulating pairing from line to line indiscriminately affected chiasma levels and did not lead to specific deviations in any line. The results seem to show that maintenance of chiasmata at first metaphase of meiosis depends on chromosome length and correlation is strong for the chance of double chiasmata. Moreover, there are indications that some C-bands, particularly in intercalary positions in chromosome arms 4AL, 2BL, 5BS, and 7BL, increase the frequency of chiasma at first metaphase. The pairing intensity in each specific chromosomal segment may be the product of an integrated action of chromosome length, the presence or absence of heterochromatin, and genetic factors.Key words: image analysis, heterochromatin, Triticum, C-banding, meiotic pairing.

Pairing affinities of the B- and G-genome chromosomes of polyploid wheats with those of Aegilops speltoides

Genome ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 814-819 ◽  
Author(s):  
S Rodríguez ◽  
B Maestra ◽  
E Perera ◽  
M Díez ◽  
T Naranjo
Keyword(s):  
Chromosome Pairing ◽  
Interspecific Hybrids ◽  
Triticum Turgidum ◽  
Aegilops Speltoides ◽  
Meiotic Pairing ◽  
Triticum Timopheevii ◽  
C Banding ◽  
Tetraploid Wheats ◽  
B Genome ◽  
Metaphase I

Chromosome pairing at metaphase I was studied in different interspecific hybrids involving Aegilops speltoides (SS) and polyploid wheats Triticum timopheevii (AtAtGG), T. turgidum (AABB), and T. aestivum (AABBDD) to study the relationships between the S, G, and B genomes. Individual chromosomes and their arms were identified by means of C-banding. Pairing between chromosomes of the G and S genomes in T. timopheevii × Ae. speltoides (AtGS) hybrids reached a frequency much higher than pairing between chromosomes of the B and S genomes in T. turgidum × Ae. speltoides (ABS) hybrids and T. aestivum × Ae. speltoides (ABDS) hybrids, and pairing between B- and G-genome chromosomes in T. turgidum × T. timopheevii (AAtBG) hybrids or T. aestivum × T. timopheevii (AAtBGD) hybrids. These results support a higher degree of closeness of the G and S genomes to each other than to the B genome. Such relationships are consistent with independent origins of tetraploid wheats T. turgidum and T. timopheevii and with a more recent formation of the timopheevi lineage.Key words: Triticum turgidum, Triticum timopheevii, Aegilops speltoides, meiotic pairing, evolution, C-banding.

scholarly journals Wheat, Rye, and Barley Genomes Can Associate during Meiosis in Newly Synthesized Trigeneric Hybrids

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 113
Author(s):  
María-Dolores Rey ◽  
Carmen Ramírez ◽  
Azahara C. Martín
Keyword(s):  
Chromosome Segregation ◽  
Genome Duplication ◽  
Triticum Turgidum ◽  
Aegilops Tauschii ◽  
Genomic In Situ Hybridization ◽  
Hordeum Chilense ◽  
Genomic Constitution ◽  
Chromosome Associations ◽  
High Level

Polyploidization, or whole genome duplication (WGD), has an important role in evolution and speciation. One of the biggest challenges faced by a new polyploid is meiosis, in particular, discriminating between multiple related chromosomes so that only homologs recombine to ensure regular chromosome segregation and fertility. Here, we report the production of two new hybrids formed by the genomes of species from three different genera: a hybrid between Aegilops tauschii (DD), Hordeum chilense (HchHch), and Secale cereale (RR) with the haploid genomic constitution HchDR (n = 7× = 21); and a hybrid between Triticum turgidum spp. durum (AABB), H. chilense, and S. cereale with the constitution ABHchR (n = 7× = 28). We used genomic in situ hybridization and immunolocalization of key meiotic proteins to establish the chromosome composition of the new hybrids and to study their meiotic behavior. Interestingly, there were multiple chromosome associations at metaphase I in both hybrids. A high level of crossover (CO) formation was observed in HchDR, which shows the possibility of meiotic recombination between the different genomes. We succeeded in the duplication of the ABHchR genome, and several amphiploids, AABBHchHchRR, were obtained and characterized. These results indicate that recombination between the genera of three economically important crops is possible.

Cytology and morphology of the amphiploid Hordeum chilense � triticum turgidum conv. Durum

Euphytica ◽  
1982 ◽  
Vol 31 (1) ◽  
pp. 261-267 ◽  
Author(s):  
A. Martin ◽  
E. Sanchez-Mongelaguna
Keyword(s):  
Triticum Turgidum ◽  
Hordeum Chilense

Characterization of Thinopyrum distichum chromosomes using double fluorescence in situ hybridization, RFLP analysis of 5S and 26S rRNA, and C-banding of parents and addition lines

Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 689-696 ◽  
Author(s):  
A Fominaya ◽  
S. Molnar ◽  
G. Fedak ◽  
K. C. Armstrong ◽  
N.-S. Kim ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Chromosome Pair ◽  
Triticum Turgidum ◽  
5S Rrna ◽  
Polymorphism Analysis ◽  
Addition Lines ◽  
C Banding ◽  
26S Rrna

Diagnostic markers for eight Thinopyrum distichum addition chromosomes in Triticum turgidum were established using C-banding, in situ hybridization, and restriction fragment length polymorphism analysis. The C-band karyotype conclusively identified individual Th. distichum chromosomes and distinguished them from chromosomes of T. turgidum. Also, TaqI and BamHI restriction fragments containing 5S and 18S–5.8S–26S rRNA sequences were identified as positive markers specific to Th. distichum chromosomes. Simultaneous fluorescence in situ hybridization showed both 5S and 18S–5.8S–26S ribosomal RNA genes to be located on chromosome IV. Thinopyrum distichum chromosome VII carried only a 18S–5.8S–26S rRNA locus and chromosome pair II carried only a 5S rRNA locus. The arrangement of these loci on Th. distichum chromosome IV was different from that on wheat chromosome pair 1B. Two other unidentified Th. distichum chromosome pairs also carried 5S rRNA loci. The homoeologous relationship between Th. distichum chromosomes IV and VII and chromosomes of other members of the Triticeae was discussed by comparing results obtained using these physical and molecular markers.Key words: Triticum turgidum, homoeologous relationship, Triticeae, addition lines, NOR.

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