Characterization of wheat-Thinopyrum partial amphiploids by meiotic analysis and genomic in situ hybridization

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 ◽  
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 ◽  
2003 ◽  
Vol 46 (1) ◽  
pp. 164-169 ◽  
Author(s):  
Pernilla Ellneskog-Staam ◽  
Björn Salomon ◽  
Roland von Bothmer ◽  
Kesara Anamthawat-Jónsson

The genomic constitution of two species in the genus Psammopyrum, i.e., Ps. athericum (2n = 6x = 42) and Ps. pungens (2n = 8x = 56), was studied by genomic in situ hybridization (GISH). In Ps. athericum, one diploid chromosome set hybridized to a genomic probe from Pseudoroegneria ferganensis (St genome), one diploid set to a probe from Agropyron cristatum (P genome), and one diploid set to a probe from Thinopyrum junceiforme (EbEe genomes) or Th. bessarabicum (Eb genome). Substituting the St-genome probe with an L-genome probe from Festucopsis serpentinii resulted in exactly the same hybridization pattern, suggesting a genomic constitution of EStP or ELP for Ps. athericum. The same probes used on Ps. pungens showed two diploid sets of chromosomes hybridizing to the St-genome probe, one diploid set hybridizing to the P-genome probe, and one diploid set hybridizing to the EbEe-genome probe. The L-genome probe hybridized to approximately 14 of the chromosomes that were labeled by the St-genome probe. Hence the genomic constitution for Ps. pungens is proposed to be EStStP or EStLP.Key Words: Psammopyrum athericum, Psammopyrum pungens, in situ hybridization, Elytrigia pycnantha, Elytrigia pungens, genome analysis.


Genome ◽  
1999 ◽  
Vol 42 (5) ◽  
pp. 987-992 ◽  
Author(s):  
F Dong ◽  
R G Novy ◽  
J P Helgeson ◽  
J Jiang

Four somatic hybrids derived from a diploid wild species Solanum etuberosum and a diploid tuber-bearing Solanum clone 463-4, together with five BC1 and three BC2 plants, were analyzed by genomic in situ hybridization (GISH). None of the four somatic hybrids had the expected chromosome constitutions, i.e., 24 chromosomes from each fusion parent. Either one chromosome from S. etuberosum or one from the potato parent 463-4 was lost in the hybrids. Three BC1 plants had exactly one set of S. etuberosum chromosomes. The other two BC1 plants either had one extra or one fewer S. etuberosum chromosome, possibly because their somatic hybrid parents had an extra or had lost one S. etuberosum chromosome. The presence of one set, or close to one set, of S. etuberosum chromosomes in all BC1 plants suggests a preferential pairing and segregation of the S. etuberosum chromosomes in the somatic hybrids. Two of the three BC2 plants had 52 chromosomes, deviating significantly from the expected chromosome number of 48. These results suggest poor pairing between S. etuberosum and S. tuberosum chromosomes in the BC1 plants. The present study demonstrates the importance of combining GISH and DNA marker analysis for a thorough characterization of potato germplasm containing chromosomes from different species.Key words: potato germplasm, Solanum etuberosum, molecular cytogenetics.


Genome ◽  
2000 ◽  
Vol 43 (2) ◽  
pp. 398-403 ◽  
Author(s):  
Mingshu Cao ◽  
David A Sleper ◽  
Fenggao Dong ◽  
Jiming Jiang

Intergeneric hybridizations have been made between species of Lolium and Festuca. It has been demonstrated, largely through conventional cytogenetic analysis, that the genomes of the two genera are related, however, much information is lacking on exactly how closely related the genomes are between the two species. We applied genomic in situ hybridization (GISH) techniques to the F1 hybrids of tetraploid Festuca mairei with a genomic constitution of M1M1M2M2 and diploid Lolium perenne with a genomic constitution of LL. It was shown in the triploid hybrids (LM1M2) that the chromosomes of M1 and M2 from F. mairei could pair with each other, and it was further discovered that L chromosomes of L. perenne paired with M1 and M2 chromosomes. Our results showed that meiocytes of Lolium-Festuca are amenable to GISH analysis, and provided direct evidence for the hypothesis that the chromosomes of Lolium and Festuca may be genetically equivalent and that reciprocal mixing of the genomes may be possible. Key words: Lolium, Festuca, in situ hybridization, meiosis.


Sign in / Sign up

Export Citation Format

Share Document