A Genomic Study in Octoploide Triticale (8x) and their Genitors (Wheat and Rye) by C-banding, N-Banding and In Situ Hybridization: The Translocation Identification 2BL/7RS

Author(s):  
Dounia Hammouda ◽  
Nadra Khalfallah ◽  
Houda Badri Mohammed
Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Jie Xu ◽  
R. L. Conner ◽  
A. Laroche

'Agrotana', a wheat-alien hybrid (2n = 56), is a potential source of resistance to common root rot, stem rust, wheat streak mosaic virus, and the wheat curl mite. However, the origin of 'Agrotana', reported to be durum wheat × Agropyron trichophorum (pubescent wheatgrass), is uncertain. The objective of this investigation was to determine the chromosome constitution of 'Agrotana' using C-banding and fluorescence in situ hybridization techniques. The F1 hybrid of 'Agrotana' × 'Chinese Spring' wheat showed 7 I + 21 II in 14.9% of the pollen mother cells, evidence of the presence of the A, B, and D genomes in 'Agrotana'. The hybrid had 16 heavily C-banded chromosomes, namely 4A, and 1-7B of wheat, and a translocation that probably involved wheat chromosomes 2A and 2D. In situ hybridization using biotinylated genomic DNA of Ag. trichophorum cv. Greenleaf blocked with CS DNA failed to identify the alien chromosomes in 'Agrotana', indicating that the alien chromosomes were not likely derived from pubescent wheatgrass. In situ hybridization using labelled wheat genomic DNA blocked with 'Agrotana' DNA revealed that 'Agrotana' had 40 wheat, 14 alien, and 2 (a pair) wheat–alien translocated chromosomes. There was no homology between wheat and the alien chromosomes or chromosome segments involved in the wheat–alien recombinant. Two of the seven pairs of alien chromosomes were homoeologous to each other. The ability to identify alien chromatin in wheat using labelled wheat DNA instead of labelled alien DNA will be particularly useful in chromosome engineering of wheat germplasms having alien chromatin of unknown origin.Key words: wheat–alien hybrid, C-banding, fluorescence in situ hybridization, labelled wheat DNA as probe.


Genome ◽  
1997 ◽  
Vol 40 (5) ◽  
pp. 689-696 ◽  
Author(s):  
A Fominaya ◽  
S. Molnar ◽  
G. Fedak ◽  
K. C. Armstrong ◽  
N.-S. Kim ◽  
...  

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.


Genome ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 742-746 ◽  
Author(s):  
Francesco Fontana ◽  
Ronald M Bruch ◽  
Fred P Binkowski ◽  
Massimo Lanfredi ◽  
Milvia Chicca ◽  
...  

A karyotype analysis using several staining techniques was carried out on the North American lake sturgeon, Acipenser fulvescens. The chromosome number was found to be 2n = 262 ± 6. A representative karyotype of 264 chromosomes was composed of 134 meta- and submetacentrics, 70 telo- and acrocentrics, and 60 microchromosomes. The constitutive heterochromatin, revealed by C banding, was localized in various positions on several chromosomes, including microchromosomes. The signals of fluorescent in situ hybridization (FISH) with a HindIII satellite DNA probe were visible as centromeric heterochromatin blocks on 48 chromosomes. The telomeric repeat (TTAGGG)n detected by FISH was localized at both ends of all chromosomes and two chromosomes were entirely marked. Fluorescent staining with GC-specific chromomycin A3 showed recognizable fluorescent regions, whereas a more uniform base composition was revealed by the AT-specific 4',6-diamidino-2-phenylindole (DAPI). After silver staining, the active nucleolar organizer regions (NORs) were detected on 12 chromosomes. FISH with the 5S probe showed four signals on four small chromosomes. Our data suggest that A. fulvescens is a tetraploid species.Key words: karyotype, C banding, telomeric sequence, fluorochrome staining, satellite DNA, 5S rDNA.


CYTOLOGIA ◽  
1994 ◽  
Vol 59 (4) ◽  
pp. 405-417 ◽  
Author(s):  
M. Wagenvoort ◽  
G. J. A. Rouwendal ◽  
G. Kuiper-Groenwold ◽  
H. P. J. de Vries van Hulten

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Xiwen Cai ◽  
Stephen S. Jones ◽  
Timothy D. Murray

Related wheat (Triticum aestivum L.) breeding lines, PI 561033, REA 9232, REA 9257, and CI 13113 were analyzed cytogenetically to characterize the association of resistance to cephalosporium stripe (caused by Cephalosporium gramineum Nis. & Ika.) with Agropyron elongatum chromatin. One pair of A. elongatum chromosomes was detected in PI 561033, REA 9232, and CI 13113 by genomic in situ hybridization. The sib line of PI 561033 and REA 9232, REA 9257, which is not resistant to this disease, lacked this pair of A. elongatum chromosomes. PI 561033 was characterized as a disomic T. aestivum – A. elongatum 6Ae#2(6A) chromosome substitution line using test crosses and C-banding. In situ hybridization and test crosses showed that the donor parent, CI 13113, also had chromosome 6A substituted by A. elongatum chromosome 6Ae#2. The C-banding pattern of 6Ae#2 showed two subterminal bands on the long arm and one small band proximal to the centromere on the short arm. Based on chromosome pairing and compensation, chromosome 6Ae#2 shows a close homoeologous relationship with wheat chromosome 6A. Key words : Cephalosporium gramineum, Agropyron elongatum, in situ hybridization, C-banding, chromosome substitution.


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