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 ◽  
...  

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.

Genome ◽  
2011 ◽  
Vol 54 (10) ◽  
pp. 836-844 ◽  
Author(s):  
Cheng Liu ◽  
Lili Qi ◽  
Wenxuan Liu ◽  
Wanchun Zhao ◽  
Jamie Wilson ◽  
...  

Dasypyrum villosum (L.) Candargy, a wild relative of bread wheat ( Triticum aestivum L.), is the source of many agronomically important genes for wheat improvement. Production of compensating Robertsonian translocations (cRobTs), consisting of D. villosum chromosome arms translocated to homoeologous wheat chromosome arms, is one of the initial steps in exploiting this variation. The cRobTs for D. villosum chromosomes 1V, 4V, and 6V have been reported previously. Here we report attempted cRobTs for wheat – D. villosum chromosome combinations 2D/2V, 3D/3V, 5D/5V, and 7D/7V. The cRobTs for all D. villosum chromosomes were recovered except for the 2VS and 5VL arms. As was the case with the 6D/6V combination, no cRobTs involving 2D/2V chromosomes were recovered; instead, cRobT T2BS·2VL involving a nontargeted chromosome was recovered. All cRobTs are fertile, although the level of spike fertility and hundred kernel weight (HKW) varied among the lines. The set of cRobTs involving 12 of the 14 D. villosum chromosomes will be useful in wheat improvement programs. In fact, among the already reported cRobTs, T6AL·6VS carrying the Pm21 gene is deployed in agriculture and many useful genes have been reported on other cRobTs including resistance to stem rust race UG99 on T6AS·6VL.


Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 56-62 ◽  
Author(s):  
Xiwen Cai ◽  
Stephen S. Jones ◽  
Timothy D. Murray

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.


Genome ◽  
2009 ◽  
Vol 52 (2) ◽  
pp. 156-165 ◽  
Author(s):  
István Molnár ◽  
Elena Benavente ◽  
Márta Molnár-Láng

The frequency and pattern of irradiation-induced intergenomic chromosome rearrangements were analysed in the mutagenized (M0) and the first selfed (M1) generations of Triticum aestivum  L. – Aegilops biuncialis Vis. amphiploids (2n = 70, AABBDDUbUbMbMb) by multicolour genomic in situ hybridization (mcGISH). mcGISH allowed the simultaneous discrimination of individual Ae. biuncialis genomes and wheat chromosomes. Dicentric chromosomes, fragments, and terminal translocations were most frequently induced by γ-irradiation, but centric fusions and internal exchanges were also more abundant in the treated plants than in control amphiploids. Rearrangements involving the Ub genome (Ub-type aberrations) were more frequent than those involving the Mb genome (Mb-type aberrations). This irradiation sensitivity of the Ub chromosomes was attributed to their centromeric or near-centromeric regions, since Ub-type centric fusions were significantly more abundant than Mb-type centric fusions at all irradiation doses. Dicentrics completely disappeared, but centric fusions and translocations were well transmitted from M0 to M1. Identification of specific chromosomes involved in some rearrangements was attempted by sequential fluorescence in situ hybridization with a mix of repeated DNA probes and GISH on the same slide. The irradiated amphiploids formed fewer seeds than untreated plants, but normal levels of fertility were recovered in their offspring. The irradiation-induced wheat – Ae. biuncialis intergenomic translocations will facilitate the successful introgression of drought tolerance and other alien traits into bread wheat.


2019 ◽  
Vol 20 (8) ◽  
pp. 2031 ◽  
Author(s):  
Wei Xi ◽  
Zongxiang Tang ◽  
Shuyao Tang ◽  
Zujun Yang ◽  
Jie Luo ◽  
...  

Thinopyrum has been widely used to improve wheat (Triticum aestivum L.) cultivars. Non-denaturing fluorescence in situ hybridization (ND-FISH) technology using oligonucleotides (oligo) as probes provides a convenient and efficient way to identify alien chromosomes in wheat backgrounds. However, suitable ND-FISH-positive oligo probes for distinguishing Thinopyrum chromosomes from wheat are lacking. Two oligo probes, Oligo-B11 and Oligo-pThp3.93, were designed according to the published Thinopyrum ponticum (Th. ponticum)-specific repetitive sequences. Both Oligo-B11 and Oligo-pThp3.93 can be used for ND-FISH analysis and can replace conventional GISH and FISH to discriminate some chromosomes of Th. elongatum, Th. intermedium, and Th. ponticum in wheat backgrounds. The two oligo probes provide a convenient way for the utilization of Thinopyrum germplasms in future wheat breeding programs.


Genome ◽  
2013 ◽  
Vol 56 (3) ◽  
pp. 131-137 ◽  
Author(s):  
Shirabe Komuro ◽  
Ryota Endo ◽  
Kaori Shikata ◽  
Akio Kato

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.


Genome ◽  
2016 ◽  
Vol 59 (4) ◽  
pp. 277-288 ◽  
Author(s):  
Wujuan Yang ◽  
Changyou Wang ◽  
Chunhuan Chen ◽  
Yajuan Wang ◽  
Hong Zhang ◽  
...  

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.


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