Characterization of an Agropyron elongatum chromosome conferring resistance to cephalosporium stripe in common wheat

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Xiwen Cai ◽  
Stephen S. Jones ◽  
Timothy D. Murray
Keyword(s):  
In Situ Hybridization ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
Chromosome Substitution ◽  
Agropyron Elongatum ◽  
Breeding Lines ◽  
C Banding ◽  
Small Band ◽  
Cephalosporium Gramineum

Related wheat (Triticum aestivum L.) breeding lines, PI 561033, REA 9232, REA 9257, and CI 13113 were analyzed cytogenetically to characterize the association of resistance to cephalosporium stripe (caused by Cephalosporium gramineum Nis. & Ika.) with Agropyron elongatum chromatin. One pair of A. elongatum chromosomes was detected in PI 561033, REA 9232, and CI 13113 by genomic in situ hybridization. The sib line of PI 561033 and REA 9232, REA 9257, which is not resistant to this disease, lacked this pair of A. elongatum chromosomes. PI 561033 was characterized as a disomic T. aestivum – A. elongatum 6Ae#2(6A) chromosome substitution line using test crosses and C-banding. In situ hybridization and test crosses showed that the donor parent, CI 13113, also had chromosome 6A substituted by A. elongatum chromosome 6Ae#2. The C-banding pattern of 6Ae#2 showed two subterminal bands on the long arm and one small band proximal to the centromere on the short arm. Based on chromosome pairing and compensation, chromosome 6Ae#2 shows a close homoeologous relationship with wheat chromosome 6A. Key words : Cephalosporium gramineum, Agropyron elongatum, in situ hybridization, C-banding, chromosome substitution.

Molecular cytogenetic analysis of intergeneric chromosomal translocations between wheat (Triticum aestivum L.) and Dasypyrum villosum arising from tissue culture

Genome ◽  
2000 ◽  
Vol 43 (5) ◽  
pp. 756-762 ◽  
Author(s):  
Hong-Jie Li ◽  
Bei-Hai Guo ◽  
Yi-Wen Li ◽  
Li-Qun Du ◽  
Xu Jia ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Tissue Culture ◽  
In Situ Hybridization ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
Average Frequency ◽  
Dasypyrum Villosum ◽  
Chromosome Translocations ◽  
Chromosome Arm

Fluorescence in situ hybridization (FISH) was applied with total genomic DNA extracted from Dasypyrum villosum (L.) Candargy as a probe to characterize chromosome translocations arising from tissue culture in hybrids of Triticum aestivum × (T. durum - D. villosum, amphiploid). Chromosome translocations between wheat and D. villosum occurred in callus cells at an average frequency of 1.9%. Translocations existed not only in callus cells but also in regenerants. Three plants with translocation chromosomes were characterized among 66 regenerants of T. aestivum 'Chinese Spring' × 'TH1W' and 'NPFP' × 'TH1'. One of them proved to be a reciprocal translocation with an exchange of about one third of a wheat chromosome arm with about one half of a chromosome arm of D. villosum. The breakpoints of the other two translocations were located at, or near centromeres. The results are similar for both callus cells and regenerants and provide further evidence that translocations take place in tissue culture. Other structural chromosomal changes, for example, fragments, telocentrics, dicentromeres, and deletions, as well as numerical alterations including aneuploidy and polyploidy were recorded both in callus cells and regenerants.Key words: wheat, Dasypyrum villosum, translocation, genomic in situ hybridization, tissue culture.

Genomic and chromosomal distribution patterns of various repeated DNA sequences in wheat revealed by a fluorescence in situ hybridization procedure

Genome ◽  
2013 ◽  
Vol 56 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Shirabe Komuro ◽  
Ryota Endo ◽  
Kaori Shikata ◽  
Akio Kato
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Dna Sequences ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
Fluorescent Labeling ◽  
Homologous Sequence ◽  
Chromosomal Distribution ◽  
Discrete Signals

Wheat (Triticum aestivum L.) is an allohexaploid, in which each of the three genomes has a high 1C content. This indicates the presence of multiple tandemly repeated sequences, which should be detectable using in situ hybridization. Some repeats have already been described, but others remain to be recognized. To discover others, 2000 plasmid wheat clones were examined for signal presence after fluorescence in situ hybridization and microscopic signal observation. Among them, 47 clones produced strong discrete signals on wheat chromosomes. Two of the newly identified clones (pTa-535 and pTa-713) were determined to have especially valuable sequences for chromosome identification. In combination with pTa-86 (the pSc119 homologous sequence), these probes enable unambiguous discrimination of all wheat chromosomes including orientation. Four newly identified sequences (pTa-465, pTa-k566, pTa-s120, and pTa-s126) were useful in that they produced discrete signals on various wheat chromosome arms. Two other clones (pTa-k288 and pTa-k229) produced GISH-like (genomic in situ hybridization) signals because they allowed the A, B, and D genomes to be distinguished simultaneously. In addition, centromere, centromere-related, and ribosomal DNA clones were identified. Also described are improvements on slide preparation and reprobing procedures. To enhance discrete signal detection, a new direct fluorescent-labeling procedure, namely the VentR (exo-) terminal extension method, was employed.

A rapid technique for substituting alien chromosomes into Triticum aestivum and determining their homoeology

1985 ◽  
Vol 27 (5) ◽  
pp. 549-558 ◽  
Author(s):  
Rama S. Kota ◽  
Jan Dvořák
Keyword(s):  
In Situ Hybridization ◽  
Chinese Spring ◽  
Wheat Chromosome ◽  
Rrna Genes ◽  
Gene Probe ◽  
Rapid Technique ◽  
C Banding ◽  
Aegilops Longissima ◽  
26S Rrna

A rapid technique is described for the production of a disomic substitution of an alien chromosome for a selected wheat chromosome directly from the amphiploid. Determination of homoeology between the chromosomes involved is a by-product of this technique. The technique involves the production of a nullisomic amphiploid from a cross between a wheat mono-telosomic and a diploid species and recurrently backcrossing it as a male twice to the monotelosomic. Disomic and ditelosomic substitutions are then selected upon self-pollination. The utility of this technique is shown by producing a large number of disomic and ditelosomic substitutions of an Aegilops longissima chromosome homoeologous to wheat chromosome 6B from two populations of Ae. longissima. The incorporated Ae. longissima chromosome was characterized by C-banding and in situ hybridization of an 18S–26S rRNA gene probe. The chromosome differs in C-band pattern from chromosome 6B of 'Chinese Spring' and does not pair with the 6Bp telosome at metaphase I. It also differs from 'Chinese Spring' chromosome 6B by having the 18S–26S rRNA compound locus in the long arm.Key words: disomic substitution, homoeology, C-banding, in-situ hybridization, rRNA genes, gene synteny, Triticum, Aegilops longissima.

Isolation of a new species-specific repetitive sequence from Thinopyrum elongatum and its use in the studies of alien translocations

Genome ◽  
1994 ◽  
Vol 37 (1) ◽  
pp. 97-104 ◽  
Author(s):  
B. Bournival ◽  
M. Obanni ◽  
A. Abad ◽  
H. Ohm ◽  
S. Mackenzie
Keyword(s):  
In Situ Hybridization ◽  
Repetitive Sequence ◽  
Triticum Aestivum L ◽  
Deletion Mapping ◽  
Agropyron Elongatum ◽  
Low Copy Number ◽  
Species Specific ◽  
Thinopyrum Elongatum

A new repetitive sequence that is extremely abundant and well dispersed in the Thinopyrum elongatum genome but present in low-copy number in wheat (Triticum aestivum L.) has been isolated. This repeat and a Th. elongatum repeat isolated in another laboratory were used to identify cosmid genomic clones containing the repeats and, thus, putatively located on a Th. elongatum/T. aestivum translocation arm. Most of the selected cosmids contained single-or low-copy sequences, making them potentially useful in mapping studies. The repeats were used in deletion mapping to deduce gene order of three genes located on the Th. elongatum translocation arm. In situ hybridization studies suggested that this newly identified Th. elongatum repeat is well dispersed throughout the Thinopyrum genome but present at only one location in wheat. This raises some interesting questions about the role of such repetitive elements in the evolution of grass species.Key words: species-specific repeats, wheat, wheatgrass, Agropyron elongatum, in situ hybridization.

scholarly journals Molecular cytogenetic identification of a wheat–rye 1R addition line with multiple spikelets and resistance to powdery mildew

Genome ◽  
2016 ◽  
Vol 59 (4) ◽  
pp. 277-288 ◽  
Author(s):  
Wujuan Yang ◽  
Changyou Wang ◽  
Chunhuan Chen ◽  
Yajuan Wang ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Disease Resistance ◽  
In Situ Hybridization ◽  
Powdery Mildew ◽  
Common Wheat ◽  
Wheat Chromosome ◽  
Triticum Aestivum L ◽  
Addition Line ◽  
Disease Resistance Screening ◽  
High Level

Alien addition lines are important for transferring useful genes from alien species into common wheat. Rye is an important and valuable gene resource for improving wheat disease resistance, yield, and environment adaptation. A new wheat–rye addition line, N9436B, was developed from the progeny of the cross of common wheat (Triticum aestivum L., 2n = 6x = 42, AABBDD) cultivar Shaanmai 611 and rye (Secale cereal L., 2n = 2x = 14, RR) accession Austrian rye. We characterized this new line by cytology, genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), molecular markers, and disease resistance screening. N9436B was stable in morphology and cytology, with a chromosome composition of 2n = 42 + 2t = 22II. GISH investigations showed that this line contained two rye chromosomes. GISH, FISH, and molecular maker identification suggested that the introduced R chromosome and the missing wheat chromosome arms were 1R chromosome and 2DL chromosome arm, respectively. N9436B exhibited 30–37 spikelets per spike and a high level of resistance to powdery mildew (Blumeria graminis f. sp. tritici, Bgt) isolate E09 at the seedling stage. N9436B was cytologically stable, had the trait of multiple spikelets, and was resistant to powdery mildew; this line should thus be useful in wheat improvement.

C-banding and fluorescence in situ hybridization studies of the wheat–alien hybrid 'Agrotana'

Genome ◽  
1994 ◽  
Vol 37 (3) ◽  
pp. 477-481 ◽  
Author(s):  
Jie Xu ◽  
R. L. Conner ◽  
A. Laroche
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Genomic Dna ◽  
Chromosome Engineering ◽  
C Banding ◽  
Chinese Spring Wheat ◽  
Mother Cells ◽  
Alien Chromatin ◽  
Chromosome Segments

'Agrotana', a wheat-alien hybrid (2n = 56), is a potential source of resistance to common root rot, stem rust, wheat streak mosaic virus, and the wheat curl mite. However, the origin of 'Agrotana', reported to be durum wheat × Agropyron trichophorum (pubescent wheatgrass), is uncertain. The objective of this investigation was to determine the chromosome constitution of 'Agrotana' using C-banding and fluorescence in situ hybridization techniques. The F1 hybrid of 'Agrotana' × 'Chinese Spring' wheat showed 7 I + 21 II in 14.9% of the pollen mother cells, evidence of the presence of the A, B, and D genomes in 'Agrotana'. The hybrid had 16 heavily C-banded chromosomes, namely 4A, and 1-7B of wheat, and a translocation that probably involved wheat chromosomes 2A and 2D. In situ hybridization using biotinylated genomic DNA of Ag. trichophorum cv. Greenleaf blocked with CS DNA failed to identify the alien chromosomes in 'Agrotana', indicating that the alien chromosomes were not likely derived from pubescent wheatgrass. In situ hybridization using labelled wheat genomic DNA blocked with 'Agrotana' DNA revealed that 'Agrotana' had 40 wheat, 14 alien, and 2 (a pair) wheat–alien translocated chromosomes. There was no homology between wheat and the alien chromosomes or chromosome segments involved in the wheat–alien recombinant. Two of the seven pairs of alien chromosomes were homoeologous to each other. The ability to identify alien chromatin in wheat using labelled wheat DNA instead of labelled alien DNA will be particularly useful in chromosome engineering of wheat germplasms having alien chromatin of unknown origin.Key words: wheat–alien hybrid, C-banding, fluorescence in situ hybridization, labelled wheat DNA as probe.

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