Genomic relationships of N-genome Triticum species

Genome ◽  
1992 ◽  
Vol 35 (6) ◽  
pp. 962-966 ◽  
Author(s):  
Yang Yen ◽  
Gordon Kimber
Keyword(s):  
Genome Analysis ◽  
Polyploid Species ◽  
D Genome ◽  
The Third ◽  
Triticum Species ◽  
Genomic Relationships ◽  
M Genome

Induced autotetraploids of Triticum uniaristatum, T. tauschii, and T. umbellulatum were used to study the genomes of the polyploid species T. ventricosum, T. neglecta, and T. recta. The N genome in T. ventricosum is homologous to the N genome in the putative diploid donor T. uniaristatum and has undergone little modification. The D genome in T. ventricosum is also essentially unmodified. The U genome of T. neglecta appears to be unchanged from the U genome of T. umbellulatum. Two of the genomes of T. recta are the same as the genomes in T. neglecta (U and a presumed modified M genome). The presence of a U genome in T. recta has also been independently confirmed. The origin of the third genome in T. recta has not been confirmed.Key words: chromosomes, meiosis, genome analysis, wheat.

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

1982 ◽  
Vol 24 (1) ◽  
pp. 57-82 ◽  
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.

The interspecific and evolutionary relationships of Triticum ovatum

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 218-221 ◽  
Author(s):  
Gordon Kimber ◽  
P. J. Sallee ◽  
M. M. Feiner
Keyword(s):  
Genome Analysis ◽  
Evolutionary Relationships ◽  
New Combinations ◽  
Diploid Progenitor ◽  
Meiotic Analysis ◽  
Theory Of Evolution ◽  
Substantial Modification ◽  
Wheat Group ◽  
M Genome

Meiotic analysis of 13 hybrids, 3 of which are new combinations, shows that the M genome of Triticum ovatum has undergone substantial modification. The pivotal U genome is much closer to its diploid progenitor, Triticum umbellulatum. However, the possibility exists that it too has been somewhat modified. If this is substantiated, then some reconsideration of the pivotal–differential theory of evolution in the wheat group may be required.Key words: genome analysis, meiosis, Aegilops, wheat.

Genomic relationships of Triticum searsii to other S-genome diploid Triticum species

Genome ◽  
1990 ◽  
Vol 33 (3) ◽  
pp. 369-373 ◽  
Author(s):  
Yang Yen ◽  
Gordon Kimber
Keyword(s):  
Biological Species ◽  
Phylogenetic Distance ◽  
Natural Logarithm ◽  
Triticum Species ◽  
Relative Affinity ◽  
Genomic Relationships

Interspecific triploid hybrids of Triticum searsii (2x) (= Aegilops searsii) with T. longissimum (4x), T. speltoides (4x), and T. bicorne (4x) were made and cytologically studied. Optimization analyses of the meiotic configurations allow the calculation of a numerical measure (the natural logarithm of the ratio of the relative affinity of the most closely related chromosomes to the most distantly) of phylogenetic distance and showed that T. searsii was almost equally but distantly related to the three other species. The validity of T. searsii being a biological species is therefore confirmed.Key words: triploid, wheat, meiosis, phylogenesis, hybrid.

Genomic in situ hybridization (GISH) discriminates between the A and the B genomes in diploid and tetraploid Setaria species

Genome ◽  
2001 ◽  
Vol 44 (4) ◽  
pp. 685-690 ◽  
Author(s):  
A Benabdelmouna ◽  
Y Shi ◽  
M Abirached-Darmency ◽  
H Darmency
Keyword(s):  
In Situ Hybridization ◽  
Foxtail Millet ◽  
Diploid Species ◽  
Genomic In Situ Hybridization ◽  
The Other ◽  
Polyploid Species ◽  
Nucleolar Organizing Regions ◽  
Genomic Relationships ◽  
Clear Differentiation

Genomic in situ hybridization (GISH) was used to investigate genomic relationships between different Setaria species of the foxtail millet gene pool (S. italica) and one interspecific F1 hybrid. The GISH patterns obtained on the two diploid species S. viridis (genome A) and S. adhaerans (genome B), and on their F1 hybrid showed clear differentiation between these two genomes except at the nucleolar organizing regions. Similar GISH patterns allowed differentiation of S. italica from S. adhaerans. However, GISH patterns did not distinguish between the genomes of S. italica and its putative wild ancestor S. viridis. GISH was also applied to polyploid Setaria species and enabled confirmation of the assumed allotetraploid nature of S. faberii and demonstration that both S. verticillata and S. verticillata var. ambigua were also allotetraploids. All these tetraploid species contained two sets of 18 chromosomes each, one from genome A and the other from genome B. Only one polyploid species, S. pumila, was shown to bear an unknown genomic composition that is not closely related either to genome A or to genome B.Key words: Setaria, genomic in situ hybridization, genome analysis.

Repetitive DNA variation and pivotal–differential evolution of wild wheats

Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 14-20 ◽  
Author(s):  
L. E. Talbert ◽  
G. Kimber ◽  
G. M. Magyar ◽  
C. B. Buchanan
Keyword(s):  
Repetitive Dna ◽  
Dna Sequences ◽  
Sympatric Species ◽  
Repetitive Dna Sequences ◽  
Large Set ◽  
Polyploid Species ◽  
Genome Species ◽  
Dna Variation ◽  
Cytogenetic Evidence ◽  
M Genome

Several polyploid species in the genus Triticum contain a U genome derived from the diploid T. umbellulatum. In these species, the U genome is considered to be unmodified from the diploid based on chromosome pairing analysis, and it is referred to as pivotal. The additional genome(s) are considered to be modified, and they are thus referred to as differential genomes. The M genome derived from the diploid T. comosum is found in many U genome polyploids. In this study, we cloned three repetitive DNA sequences found primarily in the U genome and two repetitive DNA sequences found primarily in the M genome. We used these to monitor variation for these sequences in a large set of species containing U and M genomes. Investigation of sympatric and allopatric accessions of polyploid species did not show repetitive DNA similarities among sympatric species. This result does not support the idea that the polyploid species are continually exchanging genetic information through introgression. However, it is also possible that repetitive DNA is not a suitable means of addressing the question of introgression. The U genomes of both diploid and polyploid U genome species were similar regarding hybridization patterns observed with U genome probes. Much more variation was found both among diploid T. comosum accessions and polyploids containing M genomes. The observed variation supports the cytogenetic evidence that the M genome is more variable than the U genome. It also raises the possibility that the differential nature of the M genome may be due to variation within the diploid T. comosum, as well as among polyploid M genome species and accessions.Key words: wheat, molecular, evolution, introgression.

A thin-layer chromatographic study of the phenolics of the genus Aegilops. II. Numerical chemotaxonomy of the polyploid species

1970 ◽  
Vol 48 (10) ◽  
pp. 1781-1786 ◽  
Author(s):  
P. J. Kaltsikes ◽  
W. Dedio
Keyword(s):  
Thin Layer ◽  
Genetic Material ◽  
Natural Hybridization ◽  
Chromatographic Study ◽  
Aegilops Species ◽  
Polyploid Species ◽  
D Genome ◽  
Young Leaves ◽  
New Compounds ◽  
Hybridization And Introgression

Based upon a thin-layer chromatographic study of the phenolics of young leaves of the species of the genus Aegilops, in which affinities both within and among diploid and polyploid groups were compared, the following conclusions were drawn. No new compounds were found in the polyploid Aegilops species. A. ovata must have arisen from A. umbellulata and A. comosa. A. columnaris probably contains genetic material derived from members of the Sitopsis section. A. biuncialis contains parts of the genome of A. comosa and parts from some member of the Sitopsis section. A. variabilis contains an S or modified S genome. A. triuncialis contains the C and Cu genomes. A. cylindrica contains the genomes C and D. A. crassa(4x) has an S genome in its constitution. A. ventricosa seems to contain parts of the A. caudata genome. A. crassa (6x) contains one D genome, probably from A. squarrosa, one from A. bicornis, and the third genome appears to contain parts from the M and S genomes. A. juvenalis and A. triaristata (6x) contain a modified S genome.The present study supports the hypothesis that extensive natural hybridization and introgression has taken place during the evolution of the polyploid species.

The genome origin and evolution of hexaploid Triticum crassum and Triticum syriacum determined from variation in repeated nucleotide sequences

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 806-814 ◽  
Author(s):  
Hong-Bin Zhang ◽  
Jan Dvořák
Keyword(s):  
Nucleotide Sequences ◽  
The Other ◽  
5S Rrna ◽  
D Genome ◽  
Extinct Species ◽  
Origin And Evolution ◽  
The Third ◽  
Hexaploid Species ◽  
A Genome ◽  
Aegilops Crassa

Hexaploid Triticum crassum Aitch &Hemsl. (syn. Aegilops crassa Boiss.) and Triticum syriacum Bowden [syn. Aegilops crassa Boiss. var. palaestina Eig, Aegilops vavilovii (Zhuk.) Chen.] are members of the T. crassum complex. Previous studies suggested that they have the D genomes of T. tauschii (Coss.) Schmalh., but the sources of the other genomes of these species remain uncertain. In the present investigation, variation in 27 repeated nucleotide sequences and the 5S rRNA loci was used to determine the genome origin of these hexaploid species. This study indicated that the two hexaploid species share two pairs of genomes that were contributed by a common ancestral tetraploid with a genome formula DcDcXX. It was concluded that the Dc genome was contributed by ancient T. tauschii and the X genome by an extinct species, possibly a species that was ancestral to the entire genus Triticum L. sensu Bowden except for T. tauschii. The third genome of hexaploid T. crassum is virtually identical to the D genome of extant T. tauschii and that of T. syriacum is identical to the Sse genome of T. searsii (syn. Aegilops searsii Feldman et Kislev). The genome formula of hexaploid T. crassum was proposed to be DcDcXXDD and that of T. syriacum DcDcXXSseSse to reflect the results reported here. The present study suggested that the apparent modification of the Dc and X genomes of the hexaploids resulted from evolutionary divergence.Key words: Triticum, Aegilops, Aegilops crassa, Aegilops vavilovii, phylogeny.

St2-80: a new FISH marker for St genome and genome analysis in Triticeae

Genome ◽  
2017 ◽  
Vol 60 (7) ◽  
pp. 553-563 ◽  
Author(s):  
Long Wang ◽  
Qinghua Shi ◽  
Handong Su ◽  
Yi Wang ◽  
Lina Sha ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Genome Analysis ◽  
Centromeric Region ◽  
Repetitive Sequences ◽  
Terminal Region ◽  
Oligonucleotide Primer ◽  
Dot Blot ◽  
D Genome ◽  
Ploidy Levels

The St genome is one of the most fundamental genomes in Triticeae. Repetitive sequences are widely used to distinguish different genomes or species. The primary objectives of this study were to (i) screen a new sequence that could easily distinguish the chromosome of the St genome from those of other genomes by fluorescence in situ hybridization (FISH) and (ii) investigate the genome constitution of some species that remain uncertain and controversial. We used degenerated oligonucleotide primer PCR (Dop-PCR), Dot-blot, and FISH to screen for a new marker of the St genome and to test the efficiency of this marker in the detection of the St chromosome at different ploidy levels. Signals produced by a new FISH marker (denoted St2-80) were present on the entire arm of chromosomes of the St genome, except in the centromeric region. On the contrary, St2-80 signals were present in the terminal region of chromosomes of the E, H, P, and Y genomes. No signal was detected in the A and B genomes, and only weak signals were detected in the terminal region of chromosomes of the D genome. St2-80 signals were obvious and stable in chromosomes of different genomes, whether diploid or polyploid. Therefore, St2-80 is a potential and useful FISH marker that can be used to distinguish the St genome from those of other genomes in Triticeae.

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