Characterization of genomes and chromosomes in partial amphiploids of the hybrid Triticum aestivum × Thinopyrum ponticum by in situ hybridization, isozyme analysis, and RAPD

Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1062-1071 ◽  
Author(s):  
Xueyong Zhang ◽  
Yushen Dong ◽  
Richard R.-C. Wang

Genomic in situ hybridization (GISH) and Southern hybridization of genome-specific RAPD markers were used to demonstrate that the E genome (including Ee and Eb from Thinopyrum elongatum and Thinopyrum bessarabicum, respectively) and the St genome (from Pseudoroegneria species) were the two basic genomes in Thinopyrum ponticum. GISH also revealed that the centromeric region may be the critical area that discriminates the St genome from the E genome in Th. ponticum. Of the seven partial amphiploids isolated from backcrossed progenies of Triticum aestivum × Thinopyrum ponticum hybrids, two (lines 693 and 7631) have eight pairs of chromosomes from the Ee and (or) Eb genomes. Four partial amphiploids (lines 784, 68, 7430, and 40767-1) have an incomplete St genome, i.e., six pairs of chromosomes of St and one pair of chromosomes from Ee or Eb. In a heptaploid individual of the partial amphiploid 40767-2, there were four pairs of St chromosomes, one pair of St/1B Robertsonian translocation chromosomes, one pair of St/E translocation chromosomes, and one pair of Ee or Eb chromosomes. The isoelectric focusing of Est-5, Est-4, β-Amy-1, α-Amy-1, and α-Amy-2 and the RAPD data generated with 24 decamer primers on five partial amphiploids (lines 784, 693, 7631, 68, and 7430) indicated that lines 693 and 7631 had identical genomes from Th. ponticum. The partial amphiploid 784 probably had a set of chromosomes completely different from those of 693 and 7631. These results indicate that genome recombination usually occurred during the formation of new polyploid lines. Key words : Thinopyrum ponticum, wheat, partial amphiploid, GISH, isozyme, RAPD.

Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 712-719 ◽  
Author(s):  
George Fedak ◽  
Qin Chen ◽  
Robert L Conner ◽  
André Laroche ◽  
René Petroski ◽  
...  

A combination of genomic in situ hybridization (GISH) and meiotic pairing analysis of wheat-Thinopyrum partial amphiploids was employed to identify the genomic constitution and relationships between partial amphiploids derived from wheat and wheatgrass crosses. On the basis of similarities in the meiotic behavior and GISH patterns, the alien chromosomes of two of eight partial amphiploids, TAF46 and 'Otrastayuskaya 38', were judged to originate from Th. intermedium, whereas Th. ponticum was one of the parents of the other six partial amphiploids; PWM706, PWM206, PWM209, PWMIII, OK7211542, and Ag-wheat hybrid. Each of these partial amphiploids was found to contain a synthetic alien genome composed of different combinations of St-, J-, or Js-genome chromosomes. For relatedness of partial amphiploid lines, meiotic analysis of F1 hybrids and GISH results were generally complementary, but the latter offered greater precision in identifying constituent genomes.Key words: wheat, Thinopyrum, partial amphiploids, GISH, meiotic analysis.


Genome ◽  
2000 ◽  
Vol 43 (4) ◽  
pp. 712-719 ◽  
Author(s):  
George Fedak ◽  
Qin Chen ◽  
Robert L. Conner ◽  
André Laroche ◽  
René Petroski ◽  
...  

Genome ◽  
1998 ◽  
Vol 41 (4) ◽  
pp. 580-586 ◽  
Author(s):  
Qin Chen ◽  
R L Conner ◽  
A Laroche ◽  
J B Thomas

Genomic in situ hybridization (GISH) using genomic DNA probes from Thinopyrum elongatum (Host) D.R. Dewey (genome E, 2n = 14), Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (genome J, 2n = 14), and Pseudoroegneria strigosa (M. Bieb.) Á. Löve (genome S, 2n = 14), was used to examine the genomic constitution of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey (2n = 6x = 42) and Thinopyrum ponticum (Podp.) Barkworth & D.R. Dewey (2n = 10x = 70). Evidence from GISH indicated that hexaploid Th. intermedium contained the J, Js, and S genomes, in which the J genome was related to the E genome of Th. elongatum and the J genome of Th. bessarabicum. The S genome was homologous to the S genome of Ps. strigosa, while the Js genome referred to modified J- or E-type chromosomes distinguished by the presence of S genome specific sequences close to the centromere. Decaploid Th. ponticum had only the two basic genomes J and Js. The Js genome present in Th. intermedium and Th. ponticum was homologous with E or J genomes, but was quite distinct at centromeric regions, which can strongly hybridize with the S genome DNA probe. Based on GISH results, the genomic formula of Th. intermedium was redesignated JJsS and that of Th. ponticum was redesignated JJJJsJs. The finding of a close relationship among S, J, and Js genomes provides valuable markers for molecular cytogenetic analyses using S genome DNA probes to monitor the transfer of useful traits from Th. intermedium and Th. ponticum to wheat.Key words: genomic in situ hybridization, GISH, Thinopyrum intermedium, Thinopyrum ponticum, genomic analysis, Js genome.


Genome ◽  
2009 ◽  
Vol 52 (9) ◽  
pp. 748-754 ◽  
Author(s):  
A. Sepsi ◽  
I. Molnár ◽  
M. Molnár-Láng

The absence of chromosome 7D in the wheat–Thinopyrum ponticum partial amphiploid BE-1 was detected previously by multicolour genomic in situ hybridization, sequential FISH (fluorescence in situ hybridization) using repetitive DNA probes, and SSR marker analysis. In the present study the previous cytogenetic and SSR marker analyses were expanded to include 25 other SSR markers assigned to wheat chromosomes 7A and 7D to confirm the presence of a 7A.7D translocation and to specify its composition. An almost complete chromosome 7A and a short chromosome segment derived from the terminal region of 7DL were detected, confirming the presence of a terminal translocation involving the distal regions of 7AL and 7DL. In both cases the position of the translocation breakpoint was different from that of known deletion lines. The identification of the 7AL.7DL translocation and its breakpoint position provides a new physical landmark for future physical mapping studies, opening up the possibility of more precise localization of genes or molecular markers within the terminal regions of 7DL and 7AL.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Cui ◽  
Piyi Xing ◽  
Xiaolei Qi ◽  
Yinguang Bao ◽  
Honggang Wang ◽  
...  

Abstract Background Thinopyrum intermedium (2n = 6x = 42) is an important wild perennial Triticeae species exhibiting many potentially favorable traits for wheat improvement. Wheat-Th. intermedium partial amphiploids serve as a bridge to transfer desirable genes from Th. intermedium into common wheat. Results Three octoploid Trititrigia accessions (TE261–1, TE266–1, and TE346–1) with good resistances to stripe rust, powdery mildew and aphids were selected from hybrid progenies between Th. intermedium and the common wheat variety ‘Yannong 15’ (YN15). Genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH) and multicolor GISH (McGISH) analyses demonstrated that the three octoploid Trititrigia possess 42 wheat chromosomes and 14 Th. intermedium chromosomes. The 14 alien (Th. intermedium) chromosomes belong to a mixed genome consisting of J-, JS- and St-genome chromosomes rather than a single J, JS or St genome. Different types of chromosomal structural variation were also detected in the 1A, 6A, 6B, 2D and 7D chromosomes via FISH, McGISH and molecular marker analysis. The identity of the alien chromosomes and the variationes in the wheat chromosomes in the three Trititrigia octoploids were also different. Conclusions The wheat-Th. intermedium partial amphiploids possess 14 alien chromosomes which belong to a mixed genome consisting of J-, JS- and St- chromosomes, and 42 wheat chromosomes with different structural variations. These accessions could be used as genetic resources in wheat breeding for the transfer of disease and pest resistance genes from Th. intermedium to common wheat.


Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 906-913 ◽  
Author(s):  
Hongjie Li ◽  
Qin Chen ◽  
Robert L Conner ◽  
Beihai Guo ◽  
Yanmin Zhang ◽  
...  

Leaf rust (caused by Puccinia triticina Eriks.) occurs annually in most wheat-growing areas of the world. Thinopyrum ponticum (Podp.) Z.-W. Liu & R.-C. Wang has provided several leaf rust resistance genes to protect wheat from this fungal disease. Three chromosome substitution lines, Ji806, Ji807, and Ji859, and two chromosome addition lines, Ji791 and Ji924, with a winter growing habit were developed from crosses between wheat (Triticum aestivum L. em Thell.) and the wheat – Th. ponticum partial amphiploid line 693. These lines were resistant to leaf rust isolates from China. Sequence-tagged site (STS) analysis with the J09-STS marker, which is linked to the gene Lr24, revealed that the partial amphiploid line 693 and all of the substitution and addition lines carried gene Lr24. Genomic in situ hybridization (GISH) analysis was carried out on chromosome preparations using total genomic DNA from Pseudoroegneria strigosa (M. Bieb) A. Löve (St genome, 2n = 14) as a probe in the presence of total genomic DNA from T. aestivum 'Chinese Spring' wheat (ABD genomes, 2n = 42). The GISH analysis demonstrated that these lines had a pair of chromosomes displaying the typical pattern of a Js genome chromosome. This indicates that the chromosome that carries gene Lr24 belonged to the Js genome of Th. ponticum. In addition to 40 wheat chromosomes, eight Js and eight J genome chromosomes were also differentiated by GISH in the partial amphiploid line 693. Since most sources of Lr24 have a red grain color, the white-colored seeds in all of these substitution and addition lines, together with high protein content in some of the lines, make them very useful as a donor source for winter wheat breeding programs.Key words: Lr24, genomic in situ hybridization, sequence-tagged site, random amplified polymorphic DNA.


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