THE EVOLUTION OF CHROMOSOME-ARM RATIO IN WHEAT

1971 ◽  
Vol 13 (3) ◽  
pp. 404-409 ◽  
Author(s):  
Gordon Kimber
Keyword(s):  
Artificial Selection ◽  
Hexaploid Wheat ◽  
Homoeologous Group ◽  
Evolutionary Patterns ◽  
Selection Pressures ◽  
Ratio Measurement ◽  
Chromosome Arm ◽  
Coefficient Of Concordance

The coefficient of concordance between arm-ratio measurement and homoeologous group in two varieties of hexaploid wheat was found to be highly significant. This is taken to indicate considerable cytological stability in the evolution of the wheats. This stability in the evolution of the cultivated forms of the subtribe Triticinae differs from the evolutionary patterns found in other species of the subtribe. It is possible that this difference is related to the artificial selection pressures imposed by cultivation.

The chromosomal location of genes encoding NADH dehydrogenase isozymes in hexaploid wheat and related species

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 44-51 ◽  
Author(s):  
C. J. Liu ◽  
M. D. Gale
Keyword(s):  
Hexaploid Wheat ◽  
Nadh Dehydrogenase ◽  
Genetic System ◽  
Hordeum Chilense ◽  
Homoeologous Group ◽  
Agropyron Elongatum ◽  
Aegilops Sharonensis ◽  
Chromosome Arm ◽  
Genes Encoding ◽  
Group 3

Analysis of NADH dehydrogenase isozymes in hexaploid wheat (Triticum aestivum) by flat-bed isoelectric focusing revealed a genetic system involving four sets of Ndh loci. The Ndh-A1 locus, previously identified on chromosome arm 4AL, was confirmed. Homoeoloci Ndh-R1 in rye, Ndh-H1 in barley, Ndh-Hch1 in Hordeum chilense, Ndh-Sl1 in Aegilops sharonensis, and Ndh-V1 in Dasypyrum villosum were also identified. The Ndh-2 loci, encoding monomeric isozymes, were found in the short arms of homoeologous group 7 chromosomes. Homoeoloci Ndh-A2, Ndh-D2, and Ndh-R2 are described. The Ndh-3 set, encoding multimeric isozymes, were found on each of the homoeologous group 3 chromosome long arms. An Ndh-B3b variant and homoeoloci Ndh-R3 (on chromosome arm 6RL), Ndh-H3, and Ndh-Sl3 are described. The Ndh-4 set, encoding monomeric isozymes for which no varietal variation was found, were identified on the short arms of group 3 chromosomes. Ndh-A4, Ndh-B4, Ndh-H4, Ndh-R4, and Ndh-E4 (Agropyron elongatum) homoeoloci are described.Key words: NADH dehydrogenase, isozymes, wheat, Triticeae.

scholarly journals Reduced chromatin accessibility underlies gene expression differences in homologous chromosome arms of diploid Aegilops tauschii and hexaploid wheat

GigaScience ◽  
2020 ◽  
Vol 9 (6) ◽  
Author(s):  
Fu-Hao Lu ◽  
Neil McKenzie ◽  
Laura-Jayne Gardiner ◽  
Ming-Cheng Luo ◽  
Anthony Hall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hexaploid Wheat ◽  
Aegilops Tauschii ◽  
Wheat Chromosome ◽  
Pilot Scale ◽  
Chromatin Accessibility ◽  
Diploid Progenitor ◽  
Genomic Changes ◽  
Chromosome Arm ◽  
Elevated Expression

Abstract Background Polyploidy is centrally important in the evolution and domestication of plants because it leads to major genomic changes, such as altered patterns of gene expression, which are thought to underlie the emergence of new traits. Despite the common occurrence of these globally altered patterns of gene expression in polyploids, the mechanisms involved are not well understood. Results Using a precisely defined framework of highly conserved syntenic genes on hexaploid wheat chromosome 3DL and its progenitor 3 L chromosome arm of diploid Aegilops tauschii, we show that 70% of these gene pairs exhibited proportionately reduced gene expression, in which expression in the hexaploid context of the 3DL genes was ∼40% of the levels observed in diploid Ae tauschii. Several genes showed elevated expression during the later stages of grain development in wheat compared with Ae tauschii. Gene sequence and methylation differences probably accounted for only a few cases of differences in gene expression. In contrast, chromosome-wide patterns of reduced chromatin accessibility of genes in the hexaploid chromosome arm compared with its diploid progenitor were correlated with both reduced gene expression and the imposition of new patterns of gene expression. Conclusions Our pilot-scale analyses show that chromatin compaction may orchestrate reduced gene expression levels in the hexaploid chromosome arm of wheat compared to its diploid progenitor chromosome arm.

Synthetic Taxonomy of Rosa Races Using ACT-STATIS

2000 ◽  
Vol 55 (5-6) ◽  
pp. 399-409 ◽  
Author(s):  
Olivier Raymond ◽  
Jean-Louis Fiasson ◽  
Maurice Jay
Keyword(s):  
Artificial Selection ◽  
Contingency Tables ◽  
Principal Component ◽  
Data Sets ◽  
Independent Data ◽  
Selection Pressures ◽  
Principal Component Analyses ◽  
History Of ◽  
Rv Coefficient ◽  
Good Agreement

Fifteen Rosa cultivated races were described by means of phenotypic frequencies (11 tables). Two groups of correlated contingency tables were identified by ACT-STATIS (Analyse Conjointe de Tableaux - Structuration de Tableaux à Trois Indices de la Statistique) interstructure analysis. Three data sets appeared to be independent from the others. Typologies of races were obtained after ACT-STATIS compromise analyses for the two groups of correlated tables, and after Principal Component Analyses for the independent data sets. Each typology was original and variously influenced by genealogical structure, mutation or artificial selection pressures. A weighted synthesis was attempted in order to build a taxonomy of races taking into account these diversity factors. The good agreement between the resulting classification and the assumptions about the history of Rosa domestication advocated for a wider utilization of ACT-STATIS and RV coefficient when the relationships between individuals or populations have to be studied on the basis of their similarities.

scholarly journals LINKAGE STUDIES INVOLVING TWO CHROMOSOMAL MALE-STERILITY MUTANTS IN HEXAPLOID WHEAT

Genetics ◽  
1981 ◽  
Vol 98 (4) ◽  
pp. 791-799
Author(s):  
K K Barlow ◽  
C J Driscoll
Keyword(s):  
Male Sterility ◽  
Hexaploid Wheat ◽  
Linkage Studies ◽  
Chromosome Arm

ABSTRACT The factors for Cornerstone and Probus male sterility are allelic on chromosome arm 4Aα. They map independently of the centromere, but show linkage with a rye segment located 1 crossover unit from the centromere on the β arm. The alien segment causes asynapsis and some precocious terminalization of chiasmata when in repulsion with the mutants. The mutants, presumed to be terminal deletions, cause some desynapsis, but not asynapsis.

scholarly journals Preferential elimination of chromosome 1D from homoeologous group-1 alien addition lines in hexaploid wheat

2007 ◽  
Vol 82 (5) ◽  
pp. 403-408 ◽  
Author(s):  
Monika Garg ◽  
Hala M. M. Elamein ◽  
Hiroyuki Tanaka ◽  
Hisashi Tsujimoto
Keyword(s):  
Hexaploid Wheat ◽  
Addition Lines ◽  
Homoeologous Group ◽  
Alien Addition Lines ◽  
Group 1

GENETIC SUPPRESSION OF HOMOEOLOGOUS CHROMOSOME PAIRING IN HEXAPLOID WHEAT

1972 ◽  
Vol 14 (1) ◽  
pp. 39-42 ◽  
Author(s):  
C. J. Driscoll
Keyword(s):  
Chromosome Pairing ◽  
Hexaploid Wheat ◽  
Homoeologous Pairing ◽  
Homoeologous Group ◽  
Homoeologous Chromosome ◽  
Chromosome 5B ◽  
Homoeologous Chromosome Pairing ◽  
Genetic Complexity ◽  
Genetic Suppression ◽  
Group 3

Greater genetic complexity has been revealed for the control of bivalency in hexaploid wheat. A suppressor of homoeologous pairing has been detected on chromosome 3A. Thus, there are two suppressors in homoeologous group 3. The 3A suppressor may be homoeoallelic to either the suppressor on 3Dβ or the promoter, detected in this study, on 3Dα. Individually these two suppressors are less effective than the suppressor on the long arm of chromosome 5B; however, their combined effect is yet to be studied. This greater complexity suggests that hexaploid wheat may not be too dissimilar to other polyploids as regards genetic control of bivalency. The mode of action of these suppressors appears to be consistent with a heteromultimeric hypothesis.

Molecular genetic maps of the group 6 chromosomes of hexaploid wheat (Triticum aestivum L. em. Thell.)

Genome ◽  
1996 ◽  
Vol 39 (2) ◽  
pp. 359-366 ◽  
Author(s):  
Celso L. Marino ◽  
Neal A. Tuleen ◽  
Gary E. Hart ◽  
James C. Nelson ◽  
Mark E. Sorrells ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Genetic Maps ◽  
Wheat Bread ◽  
Linkage Maps ◽  
Homoeologous Group ◽  
Group 6 ◽  
Orthologous Loci

Restriction fragment length polymorphism (RFLP) maps of chromosomes 6A, 6B, and 6D of hexaploid wheat (Triticum aestivum L. em. Thell.) have been produced. They were constructed using a population of F7–8 recombinant inbred lines derived from a synthetic wheat × bread wheat cross. The maps consist of 74 markers assigned to map positions at a LOD ≥ 3 (29 markers assigned to 6A, 24 to 6B, and 21 to 6D) and 2 markers assigned to 6D ordered at a LOD of 2.7. Another 78 markers were assigned to intervals on the maps. The maps of 6A, 6B, and 6D span 178, 132, and 206 cM, respectively. Twenty-one clones detected orthologous loci in two homoeologues and 3 detected an orthologous locus in each chromosome. Orthologous loci are located at intervals of from 1.5 to 26 cM throughout 70% of the length of the linkage maps. Within this portion of the maps, colinearity (homosequentiality) among the three homoeologues is strongly indicated. The remainder of the linkage maps consists of three segments ranging in length from 47 to 60 cM. Colinearity among these chromosomes and other Triticeae homoeologous group 6 chromosomes is indicated and a consensus RFLP map derived from maps of the homoeologous group 6 chromosomes of hexaploid wheat, tetraploid wheat, Triticum tauschii, and barley is presented. Key words : RFLP, wheat, linkage maps, molecular markers.

scholarly journals Chromosome Bin Map of Expressed Sequence Tags in Homoeologous Group 1 of Hexaploid Wheat and Homoeology With Rice and Arabidopsis

Genetics ◽  
2004 ◽  
Vol 168 (2) ◽  
pp. 609-623 ◽  
Author(s):  
J. H. Peng ◽  
H. Zadeh ◽  
G. R. Lazo ◽  
J. P. Gustafson ◽  
S. Chao ◽  
...  
Keyword(s):  
Expressed Sequence Tags ◽  
Hexaploid Wheat ◽  
Homoeologous Group ◽  
Expressed Sequence ◽  
Bin Map ◽  
Group 1

scholarly journals CHROMOSOMAL LOCATION OF GENES CONTROLLING FLAVONOID PRODUCTION IN HEXAPLOID WHEAT

Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 313-321
Author(s):  
Paula R Neuman ◽  
J G Waines ◽  
K W Hilu ◽  
D Barnhart
Keyword(s):  
Triticum Aestivum ◽  
Hexaploid Wheat ◽  
Chinese Spring ◽  
Chromosomal Location ◽  
Triticum Aestivum L ◽  
Phenolic Glycoside ◽  
Two Dimensional ◽  
Chromosome Arm ◽  
The Individual ◽  
Homoeologous Chromosomes

ABSTRACT Two-dimensional paper chromatography was performed on methanol extracts of leaves of hexaploid bread wheat, Triticum aestivum L. em. Thell. cultivar Chinese Spring, and of the available nullisomic-tetrasomic compensating lines, the tetrasomic lines and the ditelocentric lines. The chromatograms had 27 spots identified as flavonoids and six representing phenolic acids. Some of the areas were complex and contained more than one compound. Four flavonoids were identified as under the control of gene(s) on chromosome arms 1DS, 4DL, 5AS and 6BS. A phenolic glycoside was concluded to be controlled by a gene(s) on chromosome arm 7BL. Gene(s) on chromosome arm 4DL affected the amount of compounds in two other spots, and gene(s) on chromosome arm 4BS reduced the level of all flavonoid compounds. The individual compounds in some of the complex spots may be under the control of gene(s) on homoeologous chromosomes.

scholarly journals Reduced chromatin accessibility underlies gene expression differences in homologous chromosome arms of hexaploid wheat and diploidAegilops tauschii

2019 ◽  
Author(s):  
Fu-Hao Lu ◽  
Neil McKenzie ◽  
Laura-Jayne Gardiner ◽  
Ming-Cheng Luo ◽  
Anthony Hall ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hexaploid Wheat ◽  
Large Scale ◽  
Aegilops Tauschii ◽  
Wheat Chromosome ◽  
Chromatin Accessibility ◽  
Chromosome Arm ◽  
Elevated Expression ◽  
Differential Gene ◽  
Altered Gene

AbstractPolyploidy has been centrally important in driving the evolution of plants, and leads to alterations in gene expression that are thought to underlie the emergence of new traits. Despite the common occurrence of these global patterns of altered gene expression in polyploids, the mechanisms involved are not well understood. Using a precise framework of highly conserved syntenic genes on hexaploid wheat chromosome 3DL and its progenitor 3L chromosome arm of diploidAegilops tauschii, we show that 70% of these genes exhibited proportionally reduced gene expression, in which expression in the hexaploid context of the 3DL genes was approximately 40% of the levels observed in diploidAe. tauschii.Many genes showing elevated expression during later stages of grain development in wheat compared toAe. tauschii.Gene sequence and methylation differences accounted for only a few cases of differences in gene expression. In contrast, large scale patterns of reduced chromatin accessibility of genes in the hexaploid chromosome arm compared to its diploid progenitor were correlated with observed overall reduction in gene expression and differential gene expression. Therefore, that an overall reduction in accessible chromatin underlies the major differences in gene expression that results from polyploidization.

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