Genome analysis of Thinopyrum intermedium and Thinopyrum ponticum using genomic in situ hybridization

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 ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Hongjie Li ◽  
Robert L Conner ◽  
Qin Chen ◽  
Haiyan Li ◽  
André Laroche ◽  
...  

Common root rot, caused by Cochliobolus sativus (Ito and Kurib) Drechs. ex Dastur, is a major soil-borne disease of spring and winter wheat (Triticum aestivum L. em Thell.) on the Canadian prairies. Resistance to common root rot from Thinopyrum ponticum (Podp.) Liu and Wang was transferred into wheat via crossing with Agrotana, a resistant wheat – Th. ponticum partial amphiploid line. Evaluation of common root rot reactions showed that selected advanced lines with blue kernel color derived from a wheat × Agrotana cross expressed more resistance than the susceptible T. aestivum 'Chinese Spring' parent and other susceptible wheat check cultivars. Cytological examination revealed 41 to 44 chromosomes in the advanced lines. Genomic in situ hybridization, using total genomic DNA from Pseudoroegneria strigosa (M. Bieb) A. Löve (St genome) as a probe, demonstrated that the blue kernel plants had two pairs of spontaneously translocated J–Js and Js–J chromosomes derived from the J and Js genome of Th. ponticum. The presence of these translocated chromosomes was associated with increased resistance of wheat to common root rot. The lines with blue aleurone color always had a subcentromeric Js–J translocated chromosome. The subtelocentric J–Js translocated chromosome was not responsible for the blue kernel color. The genomic in situ hybridization analysis on meiosis revealed that the two spontaneous translocations were not reciprocal translocations.Key words: Cochliobolus sativus, genomic in situ hybridization, blue kernel color.


Genome ◽  
1997 ◽  
Vol 40 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Shunxue Tang ◽  
Jiajun Zhuang ◽  
Yuxiang Wen ◽  
Shanjiang Abydylla Ai ◽  
Hongjie Li ◽  
...  

Using genomic in situ hybridization to chromosomes, we identified introgressed segments in a tetrageneric hybrid of Triticum, Avena, Thinopyrum, and Secale, which conferred high resistance to leaf rust, stem rust, stripe rust, powdery mildew, and root rot to wheat. The disease-resistance traits of the hybrid originated from three wild related genera of Triticum, namely Avena, Thinopyrum, and Secale. The new breeding system that combined traditional wide hybridization with anther culture was efficient and rapid in creating wheat germplasms resistant to major diseases.Key words: Triticum aestivum, Avena fatua, Thinopyrum intermedium, Secale cereale, wide hybridization, anther culture, genomic in situ hybridization, GISH.


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.


Genome ◽  
2010 ◽  
Vol 53 (10) ◽  
pp. 824-831 ◽  
Author(s):  
Gisèle Yvonne Perthuy ◽  
Susana Martínez ◽  
Eduardo José Greizerstein ◽  
Lidia Poggio

Eryngium L. (Umbelliferae) is a large genus including more than 250 species worldwide. The large morphological variability in this genus makes it difficult to delimit the species or to establish phylogenetic relationships. The occurrence of different ploidy levels within the genus might indicate a hybrid origin of the polyploid species. In the present study, the chromosome number and karyotype of E. regnellii are reported for the first time and the ploidy level of a population of E. paniculatum is confirmed. We compare the genomes of the diploids E. horridum and E. eburneum , the tetraploids E. megapotamicum and E. regnellii , and the hexaploids E. pandanifolium (as a representative of the whole pandanifolium complex) and E. paniculatum using genomic in situ hybridization (GISH). Although it was not possible to identify the parental species of the polyploid taxa analyzed, the GISH technique allowed us to postulate some hypotheses about their origin. Eryngium horridum and E. eburneum do not seem to be the direct progenitors of the polyploids analyzed. On the other hand, it seems that other diploid species unrelated to E. horridum and E. eburneum are involved in their origin. Our results are consistent with morphological and phylogenetic studies, indicating a close relationship between the species of the series Latifolia.


Genome ◽  
1999 ◽  
Vol 42 (6) ◽  
pp. 1217-1223 ◽  
Author(s):  
Qin Chen ◽  
R L Conner ◽  
A Laroche ◽  
W Q Ji ◽  
K C Armstrong ◽  
...  

The genomic origin of alien chromosomes present in a wheat - Thinopyrum intermedium partial amphiploid TAF46 (2n = 8x = 56) and six derived chromosome addition lines were analyzed by genomic in situ hybridization (GISH) using S genomic DNA from Pseudoroegneria strigosa (2n = 2x = 14, SS) as a probe. The GISH analysis clearly showed that the chromosome complement of the partial amphiploid TAF46 consists of an entire wheat genome plus one synthetic genome consisting of a mixture of six S genome chromosomes and eight J (=E) genome chromosomes derived from Th. intermedium (2n = 6x = 42, JJJsJsSS). There were no Js genome chromosomes present in TAF46. The J genome chromosomes present in TAF46 displayed a unique GISH hybridization pattern with the S genomic DNA probe, in which S genome DNA strongly hybridized at the terminal regions and weakly hybridized over the remaining parts of the chromosomes. This provides a diagnostic marker for distinguishing J genome chromosomes from Js or S genome or wheat ABD genome chromosomes. The genomic origin of the alien chromosomes present in the six derived chromosome addition lines were identified by their characteristic GISH hybridization patterns with S genomic DNA probe. GISH analysis showed that addition lines L1, L2, L3, and L5 carried one pair of J genome chromosomes, while addition lines L4 and L7 each carried one pair of S genome chromosomes. GISH patterns detected by the S genome probe on addition line of L1 were identical to those of the J genome chromosomes present in the partial amphiploid TAF46, suggesting that these chromosomes were not structurally altered when they were transferred from TAF46 to addition lines.Key words: GISH, genomic composition, addition lines, Thinopyrum intermedium, partial amphiploid.


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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