Introduction of the D-genome chromosomes from bread wheat into hexaploid triticale with a complete rye genome

Genome ◽  
1987 ◽  
Vol 29 (3) ◽  
pp. 425-430 ◽  
Author(s):  
A. J. Lukaszewski ◽  
B. Apolinarska ◽  
J. P. Gustafson

Hexaploid triticale (× Triticosecale Wittmack) lines selected from the progeny of octoploid × tetraploid triticale hybrids were karyotyped using C-banding. The number of D-genome chromosome pairs substituted for A- and (or) B-genome chromosomes ranged from 0 to 4, averaging 2.1 substitutions per line. Every D-genome chromosome was present in at least 1 of the 70 lines analyzed. The most frequent were chromosomes 3D and 6D, followed by 1D. Of the 14 possible substitutions, 12 were present in the homozygous condition, 1 (4D/4B) was still segregating, and 6D/6B was absent. With the exception of one 1D/1R substitution and one 7RS/4DS translocation, all lines had a complete rye genome. Key words: triticale, chromosome substitutions, D genome.

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 2007-2023 ◽  
Author(s):  
Marion S Röder ◽  
Victor Korzun ◽  
Katja Wendehake ◽  
Jens Plaschke ◽  
Marie-Hélène Tixier ◽  
...  

Abstract Hexaploid bread wheat (Triticum aestivum L. em. Thell) is one of the world's most important crop plants and displays a very low level of intraspecific polymorphism. We report the development of highly polymorphic microsatellite markers using procedures optimized for the large wheat genome. The isolation of microsatellite-containing clones from hypomethylated regions of the wheat genome increased the proportion of useful markers almost twofold. The majority (80%) of primer sets developed are genome-specific and detect only a single locus in one of the three genomes of bread wheat (A, B, or D). Only 20% of the markers detect more than one locus. A total of 279 loci amplified by 230 primer sets were placed onto a genetic framework map composed of RFLPs previously mapped in the reference population of the International Triticeae Mapping Initiative (ITMI) Opata 85 × W7984. Sixty-five microsatellites were mapped at a LOD >2.5, and 214 microsatellites were assigned to the most likely intervals. Ninety-three loci were mapped to the A genome, 115 to the B genome, and 71 to the D genome. The markers are randomly distributed along the linkage map, with clustering in several centromeric regions.


Genome ◽  
2006 ◽  
Vol 49 (12) ◽  
pp. 1545-1554 ◽  
Author(s):  
J. Li ◽  
D.L. Klindworth ◽  
F. Shireen ◽  
X. Cai ◽  
J. Hu ◽  
...  

The aneuploid stocks of durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husnot) and common wheat ( T. aestivum L.) have been developed mainly in ‘Langdon’ (LDN) and ‘Chinese Spring’ (CS) cultivars, respectively. The LDN-CS D-genome chromosome disomic substitution (LDN-DS) lines, where a pair of CS D-genome chromosomes substitute for a corresponding homoeologous A- or B-genome chromosome pair of LDN, have been widely used to determine the chromosomal locations of genes in tetraploid wheat. The LDN-DS lines were originally developed by crossing CS nulli-tetrasomics with LDN, followed by 6 backcrosses with LDN. They have subsequently been improved with 5 additional backcrosses with LDN. The objectives of this study were to characterize a set of the 14 most recent LDN-DS lines and to develop chromosome-specific markers, using the newly developed TRAP (target region amplification polymorphism)-marker technique. A total of 307 polymorphic DNA fragments were amplified from LDN and CS, and 302 of them were assigned to individual chromosomes. Most of the markers (95.5%) were present on a single chromosome as chromosome-specific markers, but 4.5% of the markers mapped to 2 or more chromosomes. The number of markers per chromosome varied, from a low of 10 (chromosomes 1A and 6D) to a high of 24 (chromosome 3A). There was an average of 16.6, 16.6, and 15.9 markers per chromosome assigned to the A-, B-, and D-genome chromosomes, respectively, suggesting that TRAP markers were detected at a nearly equal frequency on the 3 genomes. A comparison of the source of the expressed sequence tags (ESTs), used to derive the fixed primers, with the chromosomal location of markers revealed that 15.5% of the TRAP markers were located on the same chromosomes as the ESTs used to generate the fixed primers. A fixed primer designed from an EST mapped on a chromosome or a homoeologous group amplified at least 1 fragment specific to that chromosome or group, suggesting that the fixed primers might generate markers from target regions. TRAP-marker analysis verified the retention of at least 13 pairs of A- or B-genome chromosomes from LDN and 1 pair of D-genome chromosomes from CS in each of the LDN-DS lines. The chromosome-specific markers developed in this study provide an identity for each of the chromosomes, and they will facilitate molecular and genetic characterization of the individual chromosomes, including genetic mapping and gene identification.


1985 ◽  
Vol 65 (3) ◽  
pp. 487-490 ◽  
Author(s):  
A. E. LIMIN ◽  
J. DVORAK ◽  
D. B. FOWLER

The excellent cold hardiness of rye (Secale cereale L.) makes it a potential source of genetic variability for the improvement of this character in related species. However, when rye is combined with common wheat (Triticum aestivum L.) to produce octaploid triticale (X Triticosecale Wittmack, ABDR genomes), the superior rye cold hardiness is not expressed. To determine if the D genome of hexaploid wheat might be responsible for this lack of expression, hexaploid triticales (ABR genomes) were produced and evaluated for cold hardiness. All hexaploid triticales had cold hardiness levels similar to their tetraploid wheat parents. Small gains in cold hardiness of less than 2 °C were found when very non-hardy wheats were used as parents. This similarity in expression of cold hardiness in both octaploid and hexaploid triticales indicates that the D genome of wheat is not solely, if at all, responsible for the suppression of rye cold hardiness genes. There appears to be either a suppressor(s) of the rye cold hardiness genes on the AB genomes of wheat, or the expression of diploid rye genes is reduced to a uniform level by polyploidy in triticale. The suppression, or lack of expression, of rye cold hardiness genes in a wheat background make it imperative that cold-hardy wheats be selected as parents for the production of hardy triticales.Key words: Triticale, Secale, winter wheat, cold hardiness, gene expression


1976 ◽  
Vol 18 (4) ◽  
pp. 687-700 ◽  
Author(s):  
J. B. Thomas ◽  
P. J. Kaltsikes

Differential staining of telomeric rye heterochromatin and telocentric chromosomes were used to identify chromosomes which were unpaired at first meiotic metaphase of hexaploid triticale (× Triticosecale Wittmack). Both approaches showed that it was the rye chromosomes which were seen as univalents. Differences in the rate of pairing from triticale to triticale were mostly explained by variation in the pairing of the rye genome. Within the rye genome, chromosome arms with telomeric heterochromatin showed pairing rates much lower than chromosome arms lacking heterochromatin. Wheat telocentrics and heterochromatin-free rye telocentrics which showed intermediate levels of pairing failure (65-90%), had mostly terminal chiasmata. On the other hand rye telocentrics with large heterochromatin bands on the telomeres had mostly nonterminal chiasmata and very low pairing (5-35%). It is concluded that the presence of heterochromatin on certain telomeres of rye chromosomes blocks the formation of terminal chiasmata and this results in desynapsis and univalents at MI.


1997 ◽  
Vol 116 (4) ◽  
pp. 387-389 ◽  
Author(s):  
M. N. Inagaki ◽  
W. H. Pfeiffer ◽  
M. Mergoum ◽  
A. Mujeeb-Kazi ◽  
A. J. Lukaszewski

Genome ◽  
2007 ◽  
Vol 50 (10) ◽  
pp. 907-926 ◽  
Author(s):  
E. D. Badaeva ◽  
O. S. Dedkova ◽  
G. Gay ◽  
V. A. Pukhalskyi ◽  
A. V. Zelenin ◽  
...  

Four hundred and sixty polyploid wheat accessions and 39 triticale forms from 37 countries of Europe, Asia, and USA were scored by C-banding for the presence of translocations. Chromosomal rearrangements were detected in 70 of 208 accessions of tetraploid wheat, 69 of 252 accessions of hexaploid wheat, and 3 of 39 triticale forms. Altogether, 58 types of major chromosomal rearrangements were identified in the studied material; they are discussed relative to 11 additional translocation types described by other authors. Six chromosome modifications of unknown origin were also observed. Among all chromosomal aberrations identified in wheat, single translocations were the most frequent type (39), followed by multiple rearrangements (9 types), pericentric inversions (9 types), and paracentric inversions (3 types). According to C-banding analyses, the breakpoints were located at or near the centromere in 60 rearranged chromosomes, while in 52 cases they were in interstitial chromosome regions. In the latter case, translocation breakpoints were often located at the border of C-bands and the euchromatin region or between two adjacent C-bands; some of these regions seem to be translocation “hotspots”. Our results and data published by other authors indicate that the B-genome chromosomes are involved in translocations most frequently, followed by the A- and D-genome chromosomes; individual chromosomes also differ in the frequencies of translocations. Most translocations were detected in 1 or 2 accessions, and only 11 variants showed relatively high frequencies or were detected in wheat varieties of different origins or from different species. High frequencies of some translocations with a very restricted distribution could be due to a “bottleneck effect”. Other types seem to occur independently and their broad distribution can result from selective advantages of rearranged genotypes in diverse environmental conditions. We found significant geographic variation in the spectra and frequencies of translocation in wheat: the highest proportions of rearranged genotypes were found in Central Asia, the Middle East, Northern Africa, and France. A low proportion of aberrant genotypes was characteristic of tetraploid wheat from Transcaucasia and hexaploid wheat from Middle Asia and Eastern Europe.


2004 ◽  
Vol 55 (5) ◽  
pp. 577 ◽  
Author(s):  
M-J. Vawser ◽  
G. B. Cornish

In Canada in 1993, a special market class of wheat, Canada Western Extra Strong (CWES), was established to segregate wheat varieties known to produce very strong and extensible doughs. These exceptional dough properties enable CWES cultivars to be blended with wheats of lesser quality as well as being suited to the manufacture of frozen dough products. The high molecular weight (HMW) glutenin allele (Glu-B1al) that confers these properties, particularly dough strength, has now been identified. Typically, the presence of the Glu-B1al (7+8*) allele is associated with the overexpression of HMW-GS 1Bx 7. RP-HPLC was used to quantify the proportion (% area) of individual HMW-GS relative to total HMW-GS in wheat varieties of different origin. The B genome contributed the highest percentage of HMW-GS, with the exception of Glu-B1d (6+8*) where the D genome contributed the most. Cultivars that possessed the Glu-B1al allele contained a significantly higher (P < 0.001) proportion of HMW-GS (56.80 ± 3.25%) encoded by the B genome. This suggests that the proportion of Glu-B1 subunits, relative to the total amount of HMW-GS expressed, has a major effect on dough strength. We also identified germplasm, of different origin, that contains the Glu-B1al allele and overexpresses subunit 7, including the most likely source of this allele in bread wheat cultivars. The Glu-B1al allele in the varieties identified in this paper could be traced, at least through one parent, to the Argentinean bread wheat cultivar Klein Universal II. RP-HPLC elution and expression profiles of various common HMW-GS are also discussed.


1985 ◽  
Vol 27 (1) ◽  
pp. 17-22 ◽  
Author(s):  
N. Jouve ◽  
J. M. Gonzalez ◽  
A. Fominaya ◽  
E. Ferrer

Two intervarietal hybrids of common wheat, Triticum aestivum L., are meiotically analyzed using the C-banding staining method. The C-banding pattern of nine meiotic chromosomes (4A, 7A, and the seven of the B genome) permitted their unequivocal recognition at first metaphase plates. The pairing frequency of each B-genome chromosome arm was scored. Data on the pairing frequency of the arms, separately considered, are applied to calculate expected pairing of whole chromosomes and whole genomes. The application of mathematical models to predict the genome pairing using either equal or different frequencies per chromosome arm is discussed.Key words: meiotic analysis, Triticum aestivum L., C-banding.


2013 ◽  
Vol 12 (1) ◽  
pp. 151-155
Author(s):  
Zeratsion Abera Desta ◽  
Jihad Orabi ◽  
Ahmed Jahoor ◽  
Gunter Backes

Genetic diversity and structure plays a key role in the selection of parents for crosses in plant breeding programmes. The aim of the present study was to analyse the genetic diversity and structure of Eritrean bread wheat accessions. We analysed 284 wheat accessions from Eritrea using 30 simple sequence repeat markers. A total of 539 alleles were detected. The allele number per locus ranged from 2 to 21, with a mean allele number of 9.2. The average genetic diversity index was 0.66, with values ranging from 0.01 to 0.89. Comparing the three genomes of wheat, the B genome had the highest genetic diversity (0.66) and the D genome the lowest diversity (0.61). A STRUCTURE analysis based on the Bayesian model-based cluster analysis followed by a graphical representation of the distances by non-parametric multidimensional scaling revealed a distinct partition of the Eritrean wheat accessions into two major groups. This is the first report of the genetic diversity and structure of Eritrean bread wheat.


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