scholarly journals Quantification of genetic relationships among A genomes of wheats

Genome ◽  
2006 ◽  
Vol 49 (4) ◽  
pp. 297-305 ◽  
Author(s):  
A Brandolini ◽  
P Vaccino ◽  
G Boggini ◽  
H Özkan ◽  
B Kilian ◽  
...  
Keyword(s):  
Phylogenetic Tree ◽  
Triticum Turgidum ◽  
Genetic Relationships ◽  
Triticum Monococcum ◽  
Aflp Fingerprinting ◽  
Triticum Urartu ◽  
D Genome ◽  
Genome Donor ◽  
A Genome

The genetic relationships of A genomes of Triticum urartu (Au) and Triticum monococcum (Am) in polyploid wheats are explored and quantified by AFLP fingerprinting. Forty-one accessions of A-genome diploid wheats, 3 of AG-genome wheats, 19 of AB-genome wheats, 15 of ABD-genome wheats, and 1 of the D-genome donor Ae. tauschii have been analysed. Based on 7 AFLP primer combinations, 423 bands were identified as potentially A genome specific. The bands were reduced to 239 by eliminating those present in autoradiograms of Ae. tauschii, bands interpreted as common to all wheat genomes. Neighbour-joining analysis separates T. urartu from T. monococcum. Triticum urartu has the closest relationship to polyploid wheats. Triticum turgidum subsp. dicoccum and T. turgidum subsp. durum lines are included in tightly linked clusters. The hexaploid spelts occupy positions in the phylogenetic tree intermediate between bread wheats and T. turgidum. The AG-genome accessions cluster in a position quite distant from both diploid and other polyploid wheats. The estimates of similarity between A genomes of diploid and polyploid wheats indicate that, compared with Am, Au has around 20% higher similarity to the genomes of polyploid wheats. Triticum timo pheevii AG genome is molecularly equidistant from those of Au and Am wheats.Key words: A genome, Triticum, genetic relationships, AFLP.

Biochemical data bearing on the relationship between the genome of Triticum urartu and the A and B genomes of the polyploid wheats

Genome ◽  
1988 ◽  
Vol 30 (4) ◽  
pp. 576-581 ◽  
Author(s):  
K. Kerby ◽  
J. Kuspira ◽  
B. L. Jones
Keyword(s):  
Amino Acid ◽  
Triticum Turgidum ◽  
Amino Acid Sequences ◽  
Triticum Monococcum ◽  
Triticum Urartu ◽  
B Genome ◽  
Genome Donor ◽  
A Genome ◽  
The Relationship ◽  
Donor Species

To determine whether the Triticum urartu genome is more closely related to the A or B genome of the polyploid wheats, the amino acid sequence of its purothionin was compared to the amino acid sequences of the purothionins in Triticum monococcum, Triticum turgidum, and Triticum aestivum. The residue sequence of the purothionin from T. urartu differs by five and six amino acid substitutions respectively from the α1 and α2 forms coded for by genes in the B and D genomes, and is identical to the β form specified by a gene in the A genome. Therefore, the T. urartu purothionin is either coded by a gene in the A genome or a chromosome set highly homologous to it. The results demonstrate that at least a portion of the T. urartu and T. monococcum genomes is homologous and probably identical. A variety of other studies have also shown that T. urartu is very closely related to T. monococcum and, in all likelihood, also possesses the A genome. Therefore, it could be argued that either T. urartu and T. monococcum are the same species or that T. urartu rather than T. monococcum is the source of the A genome in T. turgidum and T. aestivum. Except for Johnson's results, our data and that of others suggest a revised origin of polyploid wheats. Specifically, the list of six putative B genome donor species is reduced to five, all members of the Sitopsis section of the genus Aegilops.Key words: Triticum monococcum, Triticum urartu, polyploid wheats, genomes A and B, purothionins.

The phylogeny of the polyploid wheats Triticum aestivum (bread wheat) and Triticum turgidum (macaroni wheat)

Genome ◽  
1987 ◽  
Vol 29 (5) ◽  
pp. 722-737 ◽  
Author(s):  
K. Kerby ◽  
J. Kuspira
Keyword(s):  
Triticum Aestivum ◽  
Triticum Turgidum ◽  
Diploid Species ◽  
Triticum Monococcum ◽  
Aegilops Speltoides ◽  
Triticum Urartu ◽  
B Genome ◽  
Aegilops Longissima ◽  
A Genome ◽  
Genome Donors

The phylogeny of the polyploid wheats has been the subject of intense research and speculation during the past 70 years. Various experimental approaches have been employed to ascertain the diploid progenitors of these wheats. The species having donated the D genome to Triticum aestivum has been unequivocally identified as Aegilops squarrosa. On the basis of evidence from many studies, Triticum monococcum has been implicated as the source of the A genome in both Triticum turgidum and Triticum aestivum. However, numerous studies since 1968 have shown that Triticum urartu is very closely related to Triticum monococcum and that it also carries the A genome. These studies have prompted the speculation that Triticum urartu may be the donor of this chromosome set to the polyploid wheats. The donor of the B genome to Triticum turgidum and Triticum aestivum remains equivocal and controversial. Six different diploid species have been implicated as putative B genome donors: Aegilops bicornis, Aegilops longissima, Aegilops searsii, Aegilops sharonensis, Aegilops speltoides, and Triticum urartu. Until recently, evidence presented by different researchers had not permitted an unequivocal identification of the progenitor of the B genome in polyploid wheats. Recent studies, involving all diploid and polyploid wheats and putative B genome donors, lead to the conclusion that Aegilops speltoides and Triticum urartu can be excluded as B genome donors and that Aegilops searsii is the most likely source of this chromosome set. The possibility of the B genome having arisen from an AAAA autotetraploid or having a polyphyletic origin is discussed. Key words: phylogeny; Triticum aestivum; Triticum turgidum; A, B, and D genomes.

scholarly journals Applicability of chromosome-specific SSR wheat markers for the introgression of Triticum urartu in durum wheat breeding programmes

2011 ◽  
Vol 9 (3) ◽  
pp. 439-444 ◽  
Author(s):  
C. Rodríguez-Suárez ◽  
M. C. Ramírez ◽  
A. Martín ◽  
S. G. Atienza
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Crop Improvement ◽  
Wheat Chromosome ◽  
Wheat Breeding ◽  
Triticum Urartu ◽  
Founder Line ◽  
A Genome ◽  
Breeding Programmes ◽  
Novel Alleles

Triticum urartu, the A-genome donor of tetraploid and hexaploid wheats, is a potential source of novel alleles for crop improvement. A fertile amphiploid between T. urartu (2n = 2x = 14; AuAu) and durum wheat cv ‘Yavaros’ (Triticum turgidum ssp. durum; 2n = 4x = 28, AABB) was obtained as a first step to making the genetic variability of the wild ancestor available to durum wheat breeding. The amphiploid was backcrossed with ‘Yavaros’ and the offspring from this cross was selfed. A plant from this progeny (founder line) with 28 chromosomes and active x and y subunits of the Glu-A1 locus of T. urartu was selfed, which resulted in the obtaining of 98 pre-introgression lines (pre-ILs). In this work, a set of 78 wheat chromosome-specific microsatellite markers (simple sequence repeats, SSR), uniformly distributed over the A genome, was used for marker-assisted selection of T. urartu in a durum wheat background. A total of 57 SSRs allowed a clear discrimination between T. urartu and ‘Yavaros’. This set of markers was further used for characterizing the pre-ILs, identifying and defining the T. urartu introgressed regions. The applicability of these markers is discussed.

ANALYSIS OF SPECIES RELATIONSHIPS IN AVENAE BY THIN-LAYER CHROMATOGRAPHY AND DISC ELECTROPHORESIS

1972 ◽  
Vol 14 (2) ◽  
pp. 305-316 ◽  
Author(s):  
H. C. Dass
Keyword(s):  
Thin Layer ◽  
Diploid Species ◽  
Disc Electrophoresis ◽  
Tetraploid Species ◽  
Species Relationships ◽  
D Genome ◽  
Genome Donor ◽  
A Genome ◽  
Layer Chromatography ◽  
Esterase Patterns

Thin-layer chromatographic studies on flavonoids, and disc electrophoretic studies on proteins and esterase isoenzymes were conducted with Avena to determine species relationships and genome homologies. Distinctness of Avena ventricosa and A. pilosa was observed in comparison to other diploid species. Closeness of the diploid species of the A. strigosa group (including hirtula and wiestii) was evident from the similarity of their protein and esterase spectra. The tetraploid species, A. barbata and A. abyssinica, were found to be very close to A. hirtula and A. strigosa, respectively, by TLC studies. Proteins and esterases also showed that the tetraploid species are very close to the A. strigosa group of diploid species. The contribution of a genome by the A. strigosa group to the tetraploids and hexaploids was confirmed. The hexaploids showed different protein and esterase patterns. The involvement of A. ventricosa as the C genome donor to the hexaploids was shown by the protein and esterase spectra. A few extra protein bands observed may have been from the D genome.

scholarly journals Identification of Resistance to Pseudocercosporella herpotrichoides in Triticum monococcum

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1181-1186 ◽  
Author(s):  
M. M. Cadle ◽  
T. D. Murray ◽  
S. S. Jones
Keyword(s):  
Pacific Northwest ◽  
Hexaploid Wheat ◽  
The United States ◽  
Triticum Monococcum ◽  
Close Relative ◽  
Pseudocercosporella Herpotrichoides ◽  
Eyespot Resistance ◽  
Genome Donor ◽  
A Genome ◽  
Important Disease

Eyespot is an important disease of wheat in the United States Pacific Northwest. Genes Pch1, located on chromosome 7D, and Pch2, located on chromosome 7A, are the only known sources of eyespot resistance in hexaploid wheat. A core collection of Triticum monococcum, a close relative of the A-genome donor of bread wheat, consisting of 118 accessions from 26 countries was screened for resistance using a β-glucuronidase-transformed strain of the pathogen. Fifty-two (44%) accessions from 15 different countries were resistant. More than half of the accessions collected in Turkey (26 of 42) were resistant. Two accessions were more resistant than resistant cultivars Cappelle Desprez (Pch2) and Madsen (Pch1). Screening these accessions for the isozyme marker Ep-A1b, which is linked with Pch2 in hexaploid wheat, revealed variation but no association with resistance. These results indicate T. monococcum is a new source of resistance to Pseudocercosporella herpotrichoides that potentially contains more effective resistance to P. herpotrichoides than that conferred by either Pch1 or Pch2.

A direct repeat sequence associated with the centromeric retrotransposons in wheat

Genome ◽  
2004 ◽  
Vol 47 (4) ◽  
pp. 747-756 ◽  
Author(s):  
Hidetaka Ito ◽  
Shuhei Nasuda ◽  
Takashi R Endo
Keyword(s):  
Genomic Dna ◽  
Direct Repeat ◽  
Repeat Sequence ◽  
Triticum Monococcum ◽  
Fish Analysis ◽  
Long Terminal Repeats ◽  
D Genome ◽  
B Genome ◽  
Cereal Species ◽  
A Genome

A high-density BAC filter of Triticum monococcum was screened for the presence of a centromeric retrotransposon using the integrase region as a probe. Southern hybridization to the BAC digests using total genomic DNA probes of Triticum monococcum, Triticum aestivum, and Hordeum vulgare detected differentially hybridizing restriction fragments between wheat and barley. The fragments that hybridized to genomic DNA of wheat but not to that of barley were subcloned. Fluorescence in situ hybridization (FISH) analysis indicated that the clone pHind258 hybridized strongly to centromeric regions in wheat and rye and weakly to those in barley. The sequence of pHind258 was homologous to integrase and long terminal repeats of centromeric Ty3-gypsy retrotransposons of cereal species. Additionally, pHind258 has a pair of 192-bp direct repeats. FISH analysis indicated that the 192-bp repeat probe hybridized to centromeres of wheat and rye but not to those of barley. We found differential FISH signal intensities among wheat chromosomes using the 192-bp probe. In general, the A-genome chromosomes possess strong FISH signals, the B-genome chromosomes possess moderate signals, and the D-genome chromosomes possess weak signals. This was consistent with the estimated copy numbers of the 192-bp repeats in the ancestral species of hexaploid wheat.Key words: centromere, Ty3-gypsy retrotransposon, FISH, wheat, repetitive element.

scholarly journals Systematic Comparisons of Orthologous Selenocysteine Methyltransferase and Homocysteine Methyltransferase Genes from Seven Monocots Species

2015 ◽  
Vol 7 (2) ◽  
pp. 210-216 ◽  
Author(s):  
De-yong ZHAO ◽  
Fu-lai SUN ◽  
Bo ZHANG ◽  
Zhi-qiang ZHANG ◽  
Long-quan YIN
Keyword(s):  
Common Wheat ◽  
Brachypodium Distachyon ◽  
Aegilops Tauschii ◽  
Selenium Deficiency ◽  
D Genome ◽  
Genome Donor ◽  
A Genome ◽  
Selenocysteine Methyltransferase ◽  
Homocysteine Methyltransferase ◽  
Plant Arabidopsis Thaliana

Identifying and manipulating genes underlying selenium metabolism could be helpful for increasing selenium content in crop grain, which is an important way to overcome diseases resulted from selenium deficiency. A reciprocal smallest distance algorithm (RSD) approach was applied using two experimentally confirmed Homocysteine S-Methyltransferases genes (HMT1 and HMT2) and a putative Selenocysteine Methyltransferase (SMT) from dicots plant Arabidopsis thaliana, to explore their orthologs in seven sequenced diploid monocot species: Oryza sativa, Zea mays, Sorghum bicolor, Brachypodium distachyon, Hordeum vulgare, Aegilops tauschii (the D-genome donor of common wheat) and Triticum urartu (the A-genome donor of common wheat). HMT1 was apparently diverged from HMT2 and most of SMT orthologs were the same with that of HMT2 in this study, leading to the hypothesis that SMT and HMT originate from one common ancestor gene. Identifying orthologs provide candidates for further experimental confirmation; also it could be helpful in designing primers to clone SMT or HMT orthologs in other crops.

Production of durum wheat substitution haploids from durum × maize crosses and their cytological characterization

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M Dogramac1-Altuntepe ◽  
P P Jauhar
Keyword(s):  
In Situ Hybridization ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Genomic In Situ Hybridization ◽  
Substitution Lines ◽  
Genome Chromosome ◽  
D Genome ◽  
Maize Pollen ◽  
A Genome

The objective of this study was to investigate the effect of individual durum wheat (Triticum turgidum L.) chromosomes on crossability with maize (Zea mays L.) and to cytologically characterize the haploids recovered. Fourteen 'Langdon' (LDN) D-genome disomic substitution lines, a LDN Ph mutant (Ph1b ph1b), and normal 'Langdon' were pollinated with maize pollen. After pollination, hormonal treatment was given daily for up to 14 days. Haploid embryos were obtained from all lines and were aseptically cultured. From a total of 55 358 pollinated florets, 895 embryos were obtained. Only 14 of the embryos germinated and developed into healthy plants. Different substitution lines showed varying degrees of success. The most successful was the substitution 5D(5B) for both embryo formation and haploid plantlet production. These results indicate that the substitution of 5D for 5B confers on durum wheat a greater ability to produce haploids. Fluorescent genomic in situ hybridization (GISH) showed that the substitution haploids consisted of 7 A-genome chromosomes, 6 B-genome chromosomes, and 1 D-genome chromosome. Triticum urartu Tum. genomic DNA was efficient in probing the 7 A-genome chromosomes, although the D-genome chromosome also showed intermediate hybridization. This shows a close affinity between the A genome and D genome. We also elucidated the evolutionary translocation involving the chromosomes 4A and 7B that occurred at the time of evolution of durum wheat. We found that the distal segment translocated from chromosome 7B constitutes about 24% of the long arm of 4A.Key words: cyclic translocation 4A·5A·7B, crossability, disomic substitution, fluorescent genomic in situ hybridization (GISH), Triticum turgidum.

Molecular characterization of the Glu-Ay gene from Triticum urartu for its potential use in quality wheat breeding

2011 ◽  
Vol 9 (2) ◽  
pp. 334-337 ◽  
Author(s):  
M. V. Gutiérrez ◽  
C. Guzmán ◽  
L. M. Martín ◽  
J. B. Alvarez
Keyword(s):  
Storage Proteins ◽  
Pcr Amplification ◽  
Wheat Breeding ◽  
Triticum Urartu ◽  
Bread Making ◽  
Genome Donor ◽  
A Genome ◽  
Pcr Products ◽  
Modern Wheat ◽  
Genetic Pool

Triticum urartu Thum. ex Gandil. is a wild species identified as A-genome donor for polyploid wheats, which could be used as gene source for wheat breeding. The high-molecular weight glutenin subunits are endosperm storage proteins that are associated with bread-making quality. In T. urartu, these proteins are encoded by the Ax and Ay genes at the Glu-Au1 locus. The Ay gene of 17 Glu-Au1 allelic variants previously detected in this species has been analysed using PCR amplification and digestion of the PCR products with two endonucleases (DdeI and PstI). The combination of two restriction patterns has revealed variations between the active and inactive alleles, and within each type. This variation, especially that detected among the active alleles, could enlarge the high-quality genetic pool of modern wheat and be used for bread-making quality improvement in durum and common wheat.

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