Genomic Instability in Wheat Induced by Chromosome 6b(s) of Triticum Speltoides.

Abstract A massive restructuring of chromosomes was observed during the production of a substitution of chromosome 6B(s) from Triticum speltoides (Tausch) Gren. ex Richter for chromosome 6B of Chinese Spring wheat (Triticum aestivum L.). Deletions, translocations, ring chromosomes, dicentric chromosomes and a paracentric inversion were observed. Chromosome rearrangements occurred in both euchromatic and heterochromatic regions. Chromosome rearrangements were not observed either in the amphiploid between Chinese Spring and T. speltoides or in Chinese Spring. No chromosome rearrangements were observed in the backcross derivatives; however, after self-pollination of a monosomic substitution (2n = 41) of chromosome 6B(s) for wheat chromosome 6B, 49 of the 138 plants carried chromosome aberrations. Chromosome rearrangements were observed in both wheat and T. speltoides chromosomes. The frequency of chromosome rearrangements was high among the B-genome chromosomes, moderate among the A-genome chromosomes, and low among the D-genome chromosomes. In the B genome, the rearrangements were nonrandom, occurring most frequently in chromosomes 1B and 5B. Chromosome rearrangements were also frequent for the 6B(s) chromosome of T. speltoides. An intriguing aspect of these observations is that they indicate that wheat genomes can be subject to uneven rates of structural chromosome differentiation in spite of being in the same nucleus.

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Control of alien gene expression for aluminum tolerance in wheat

Genome ◽

10.1139/g90-002 ◽

1990 ◽

Vol 33 (1) ◽

pp. 9-12 ◽

Cited By ~ 18

Author(s):

J. P. Gustafson ◽

K. Ross

Keyword(s):

Gene Expression ◽

Triticum Aestivum ◽

Chinese Spring ◽

Aluminum Tolerance ◽

Wheat Chromosome ◽

Triticum Aestivum L ◽

D Genome ◽

Chinese Spring Wheat ◽

Secale Cereale L ◽

Alien Gene

The expression of aluminum tolerance from rye (Secale cereale L.) when present in a wheat (Triticum aestivum L. em. Thell.) background has been observed to be much lower than that in rye itself. By crossing each of the ditelocentric lines of 'Chinese Spring' wheat with a tolerant rye, the effects of the presence or absence of each arm of wheat on the expression of rye aluminum tolerance could be established. Of 42 wheat chromosome arms, 18 affected the expression of rye aluminum tolerance. Tolerance was increased over that observed in the euploid wheat–rye hybrid when arms 4AL, 5AL, 6AL, 7BS, 7BL, and 3DS were absent. Tolerance was reduced when arms 2AL, 5AS, 6BS, 1DS, 1DL, 2DL, 4DL, 5DS, 5DL, 6DL, 7DS, and 7DL were absent. Thus, the control of aluminum tolerance expression from rye in a wheat background was evidently under the influence of genes located on a number of wheat chromosome arms, with a few arms tending to enhance expression and many others tending to reduce it. In fact, 5AS of 'Chinese Spring' enhances expression, while 5AL suppresses it. The D genome of bread wheat appears to have the most pronounced effect on the expression of rye aluminum tolerance.Key words: rye, activator genes, suppressor genes, alien manipulation.

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A Microsatellite Map of Wheat

Genetics ◽

10.1093/genetics/149.4.2007 ◽

1998 ◽

Vol 149 (4) ◽

pp. 2007-2023 ◽

Cited By ~ 8

Author(s):

Marion S Röder ◽

Victor Korzun ◽

Katja Wendehake ◽

Jens Plaschke ◽

Marie-Hélène Tixier ◽

...

Keyword(s):

Bread Wheat ◽

Reference Population ◽

Triticum Aestivum L ◽

Wheat Genome ◽

D Genome ◽

B Genome ◽

Microsatellite Map ◽

A Genome ◽

Polymorphic Microsatellite ◽

Primer Sets

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.

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GENETIC REGULATION OF HETEROGENETIC CHROMOSOME PAIRING IN POLYPLOID SPECIES OF THE GENUS TRITICUM sensu lato

Canadian Journal of Genetics and Cytology ◽

10.1139/g82-007 ◽

1982 ◽

Vol 24 (1) ◽

pp. 57-82 ◽

Cited By ~ 24

Author(s):

Patrick E. McGuire ◽

Jan Dvořák

Keyword(s):

Triticum Aestivum ◽

Chromosome Pairing ◽

Chinese Spring ◽

Genetic Regulation ◽

Triticum Aestivum L ◽

Polyploid Species ◽

D Genome ◽

Chromosome 5B ◽

A Genome

Polyploid species of Triticum sensu lato were crossed with Triticum aestivum L. em. Thell. cv. Chinese Spring monotelodisomics or ditelosomics that were monosomic for chromosome 5B. Progeny from these crosses were either euploid, nullisomic for 5B, monotelosomic for a given Chinese Spring chromosome, or nullisomic for 5B and monotelosomic simultaneously. The Chinese Spring telosome in the hybrids permitted the evaluation of autosyndesis of chromosomes of the tested species. In addition, several Chinese Spring eu- and aneuhaploids were produced. Genotypes of T. cylindricum Ces., T. juvenale Thell., T. triunciale (L.) Raspail, T. ovatum (L.) Raspail, T. columnare (Zhuk.) Morris et Sears, T. triaristatum (Willd.) Godr. et Gren., and T. rectum (Zhuk.) comb. nov. were all shown to have suppressive effects on heterogenetic pairing in hybrids lacking 5B or 3AS, whereas T. kotschyi (Boiss.) Bowden had no effect. It was concluded that diploid-like meiosis in these species is due to genetic regulation. A number of these genotypes promoted heterogenetic pairing in the presence of 5B. A model is presented to explain this dichotomous behavior of the tested genotypes. Monotelosomic-3AL haploids had a greater amount of pairing than did euhaploid Chinese Spring, which substantiated the presence of a pairing suppressor(s) on the 3AS arm. Evidence is presented that shows that T. juvenale does not have a genome homologous with the D genome of T. aestivum.

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Novel fluorescent sequence-related amplified polymorphism(FSRAP) markers for the construction of a genetic linkage map of wheat(Triticum aestivum L.)

Genetika ◽

10.2298/gensr1703081z ◽

2017 ◽

Vol 49 (3) ◽

pp. 1081-1093 ◽

Cited By ~ 1

Author(s):

Lingbo Zhao ◽

Zhang Li ◽

Jipeng Qu ◽

Yan Yu ◽

Lu Lu ◽

...

Keyword(s):

Genetic Linkage Map ◽

Average Distance ◽

Triticum Aestivum L ◽

Genetic Maps ◽

The Novel ◽

Linkage Groups ◽

D Genome ◽

Wheat Varieties ◽

B Genome ◽

A Genome

Novel fluorescent sequence-related amplified polymorphism (FSRAP) markers were developed based on the SRAP molecular marker. Then, the FSRAP markers were used to construct the genetic map of a wheat (Triticum aestivumL.) recombinant inbred line population derived from a Chuanmai 42?Chuannong 16 cross. Reproducibility and polymorphism tests indicated that the FSRAP markers have repeatability and better reflect the polymorphism of wheat varieties compared with SRAP markers. A total of 430 polymorphic loci between Chuanmai 42 and Chuannong 16 were detected with 189 FSRAP primer combinations. A total of 281 FSARP markers and 39 SSR markers re classified into 20 linkage groups. The maps spanned a total length of 2499.3cM with an average distance of 7.81cM between markers. A total of 201 markers were mapped on the B genome and covered a distance of 1013cM. On the A genome, 84 markers were mapped and covered a distance of 849.6cM. On the D genome, however, only 35 markers were mapped and covered a distance of 636.7cM. No FSRAP markers were distributed on the 7D chromosome. The results of the present study revealed that the novel FSRAP markers can be used to generate dense, uniform genetic maps of wheat.

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SOME CHARACTERISTICS OF HEXAPLOID TRITICALE SUBSTITUTION LINES INVOLVING THE A-, B-, AND D-GENOME CHROMOSOMES OF WHEAT

Canadian Journal of Genetics and Cytology ◽

10.1139/g81-074 ◽

1981 ◽

Vol 23 (4) ◽

pp. 679-689 ◽

Cited By ~ 6

Author(s):

E. N. Larter ◽

K. Noda

Keyword(s):

Polyacrylamide Gel Electrophoresis ◽

Triticum Aestivum L ◽

Low Fertility ◽

Specific Chromosome ◽

Substitution Lines ◽

D Genome ◽

Seed Supply ◽

B Genome ◽

A Genome ◽

Definitive Method

Three hexaploid (2n = 6x = 42) triticale lines (× Triticosecale Wittmack) were synthesized in which a specific chromosome of either the A or B genomes was replaced by a homoelogous chromosome of the D genome of wheat (Triticum aestivum L. em Thell.). Two of the substitutions involved the B genome [substitution lines 1D(1B)R-4 and 6D (6B)R-5] and the third involved the A genome [4D(4A)R-1]. Polyacrylamide gel electrophoresis of gliadin proteins produced distinct differences in banding patterns between the three substitutions and provided a definitive method for the identification of specific chromosome substitutions in triticale. Plant and spike characteristics of the substitution triticales were similar to those of the control (unsubstituted) triticale. Substitution 6D(6B)R-5 exhibited extremely low fertility and was difficult to maintain. The substitution 4D(4A), on the other hand, appeared to have no effect on fertility, while substitution 1D(1B) reduced fertility by almost one-half of that of the control triticale. Chromosome pairing in substitution 4D(4A)R-1 was regular whereas 1D(1B)R-4 exhibited an average of five univalents/cell at MI. Limited seed supply prevented a meiotic study of 6D(6B)R-5. Flour proteins of the three substitution triticales ranged from 15.8% for 4D(4A)R-1 to 18.0% for 6D(6B)R-5. A comparison of the three substitutions for amino acid composition indicated that line 6D(6B)R-5 was 25% higher in methionine than the control, while in substitution 4D(4A)R-1 methionine content was reduced by 53%.

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

Genetics ◽

10.1093/genetics/114.2.579 ◽

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.

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The genomic inheritance of aluminum tolerance in 'Atlas 66' wheat

Genome ◽

10.1139/g92-104 ◽

1992 ◽

Vol 35 (4) ◽

pp. 689-693 ◽

Cited By ~ 47

Author(s):

William A. Berzonsky

Keyword(s):

Root Growth ◽

Aluminum Tolerance ◽

Triticum Aestivum L ◽

Nuclear Genes ◽

D Genome ◽

Hard Red Spring Wheat ◽

Al Stress ◽

Soft Red Winter Wheat ◽

B Genome ◽

Segregation Ratios

Toxicity to aluminum (Al) limits wheat (Triticum aestivum L. em. Thell.) yields. 'Atlas 66', a soft red winter wheat classified as tolerant (root growth ≥ 0.5 cm after Al stress) to 0.44 mM Al, was hybridized with tetraploid (4x) and hexaploid (6x) 'Canthatch', a hard red spring wheat classified as sensitive (root growth < 0.5 cm after Al stress) to 0.44 mM Al. Progenies produced from these hybridizations were tested for tolerance to 0.44 mM Al in solution to ascertain the number of genes and the genomes of 'Atlas 66', which determine tolerance to aluminum. Tests of 'Atlas 66', 6x-'Canthatch', and the F1's resulting from hybridizations between the parents indicated that dominant, nuclear genes carried by 'Atlas 66' determine tolerance to 0.44 mM Al. Segregation ratios for the F2 significantly differed from ratios expected for a dominant, duplicate genetic mechanism. F1 backcross segregation ratios did not significantly differ from ratios expected for dominant, duplicate nuclear genes for tolerance to aluminum. The expression of genes for tolerance to 0.44 mM Al for 'Atlas 66' appears to be more complex than is predicted by the existence of two dominant genes. A crossing scheme, which involved hybridizing 4x-'Canthatch' with 'Atlas 66', was executed to produce 42-chromosome plants having recombinant A- and B-genome chromosomes and D-genome chromosomes derived exclusively from 'Atlas 66'. Eleven F6 and F7 lines, developed from these plants, were selfed and plants in the F6 generation were backcrossed to 'Atlas 66' and 6x-'Canthatch'. The F6 and F7 lines were subjected to 0.44 mM Al in solution as were the backcrosses. While none of the lines had more than 50% of their seedlings classified as sensitive to Al in the F6 generation, four lines exhibited such a response in the F7 generation. In general, backcrossing the F6 lines to 6x-'Canthatch' increased sensitivity to Al, while backcrossing to 'Atlas 66' increased tolerance. Results suggest that genes for tolerance to Al in 'Atlas 66' wheat are not all located on D-genome chromosomes.Key words: aluminum tolerance, genomic inheritance, Triticum.

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A ‘Chinese Spring’ wheat (Triticum aestivum L.) bacterial artificial chromosome library and its use in the isolation of SSR markers for targeted genome regions

Theoretical and Applied Genetics ◽

10.1007/s00122-005-0077-1 ◽

2005 ◽

Vol 111 (8) ◽

pp. 1489-1494 ◽

Cited By ~ 15

Author(s):

B. Shen ◽

D.M. Wang ◽

C.L. McIntyre ◽

C.J. Liu

Keyword(s):

Triticum Aestivum ◽

Bacterial Artificial Chromosome ◽

Ssr Markers ◽

Spring Wheat ◽

Bacterial Artificial Chromosome Library ◽

Chinese Spring ◽

Artificial Chromosome ◽

Triticum Aestivum L ◽

Chinese Spring Wheat

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Chromosome location of genes controlling aluminum tolerance in wheat, rye, and triticale

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-111 ◽

1984 ◽

Vol 26 (6) ◽

pp. 701-705 ◽

Cited By ~ 161

Author(s):

A. Aniol ◽

J. P. Gustafson

Keyword(s):

Chinese Spring ◽

Wheat Variety ◽

Aluminum Tolerance ◽

Triticum Aestivum L ◽

Additive Effects ◽

Chromosome Location ◽

Irreversible Damage ◽

Wheat Varieties ◽

Chinese Spring Wheat ◽

Secale Cereale L

'Chinese Spring' wheat nullisomic–tetrasomic and ditelosomic lines were used for the identification of Aluminum-tolerance genes in wheat (Triticum aestivum L. em Thell.). Rye additions and substitutions in different wheat varieties were used for the identification of aluminum-tolerance genes in rye (Secale cereale L.). The point where concentrations of aluminum caused irreversible damage to the root apical meristems on exposure for 24 h at 25 °C was the measure of aluminum tolerance. Genes for aluminum tolerance in the medium-tolerant wheat variety 'Chinese Spring' were found to be localized in chromosome arms 6AL, 7AS, 2DL, 3DL, 4DL, and 4BL, and on chromosome 7D. Major genes for tolerance in rye seem to be located on 3R and 6RS, with other genes on 4R. The expression of aluminum-tolerance genes located on rye chromosomes incorporated into sensitive wheat was often suppressed by the action of unknown genes in the wheat background.Key words: Triticum, Secale, aluminum tolerance, additive effects, polygenes.

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