1. Aegilops speltoides Ph1 suppressors Practical utility for wheat

2. Chromosome 5B is responsible for diploid-like meiotic chromosome pairing in hexaploid T. aestivum
Euploid
Nullisomic 5B
R. Riley, Heredity 15: , 1960

3. (extant relative of the B genome)
Triticum urartu
(AA genomes)
Wild emmer wheat
(AABB genomes )
Aegilops speltoides
SS genomes
(extant relative of the B genome)

4. Aegilops speltoides
Surprisingly, Ae. speltoides was found to not have Ph1 but to promote homoeologous pairing in wheat.

5. T. aestivum x Ae. speltoides
Ph1 suppression is controlled by two unlinked duplicated major genes and several minor genes
K.C. Chen and J. Dvorak, Can. J. Genet. Cytol. 26: , 1983

6. Mean numbers of chiasmata per cell in hybrids involving low- and high-pairing Ae. speltoides inbred lines
low-pairing
high pairing
Ae. speltoides x Ae. tauschii
Ae. speltoides x Ae. caudata
No. chismata

7. The average chiasma number per cell in hybrids T
The average chiasma number per cell in hybrids T. aestivum backcrosses x Ae. variabilis
Chen et al. TAG 88:97-101, 1994 16 14 12 10
Mean chiasma number 8 6 4 2
low int. PhI

8. Comparison of Ae. speltoides chromosome 1S and T
Comparison of Ae. speltoides chromosome 1S and T. monococcum chromosome 1Am genetic maps

9. Comparison of Ae. speltoides chromosome 3S and T
Comparison of Ae. speltoides chromosome 3S and T. monococcum chromosome 3Am genetic maps

11. 590 hybrids were produced, no
590 hybrids were produced, no. chiasmata per cell was estimated, DNA were isolated, and Southern blots were hybridized with informative markers
The population of 590 hybrids was partitioned by marker allele
ANOVAs were computed to determine marker effect on pairing

12. Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)10 9 8 7 6 5
Mean no. chiasmata per cell 4 3 2 1 5S

13. Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)10 9 8 7 6 5
Mean no. chiasmata per cell 4 3 2 1 5S 7S 3S
3S+7S
3S+7S+5S

14. Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)10 9 8 7 6 5
Mean no. chiasmata per cell 4 3 2 1 5S 7S 3S
3S+7S
3S+7S+5S

15. Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)10 9 8 7 6 5
Mean no. chiasmata per cell 4 3 2 1 5S 7S 3S
3S+7S
3S+7S+5S

16. Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)10 9 8 7 6 5
Mean no. chiasmata per cell 4 3 2 1 5S 7S 3S
3S+7S
3S+7S+5S

17. Segregation of Su1-Ph1 in T. aestivum x Ae. speltoides hybrids

18. Effect of segregation for Su1-Ph1 on meiotic pairing in T
Effect of segregation for Su1-Ph1 on meiotic pairing in T. aestivum x Ae. speltoides hybrids - +

19. Genetic maps of the Su1-Ph1 region in Ae. speltoides

20. PCR assay for marker PSR1205 using Ae
PCR assay for marker PSR1205 using Ae. speltoides genome specific primers
Chinese Spring
BC4 wheat segregant without Ph1-Su1
Ae. speltoides
BC4 wheat segregant with Ph1-Su1

21. The average chiasma number per cell in hybrids T
The average chiasma number per cell in hybrids T. aestivum backcrosses x Ae. variabilis
Chen et al. TAG 88:97-101, 1994 16 14 12 10
Mean chiasma number 8 6 4 2
low int. PhI

22. The average chiasma number per cell in hybrids T
The average chiasma number per cell in hybrids T. aestivum backrosses x Ae. variabilis
Chen et al. TAG 88:97-101
Su1-Ph1 data
Mean chiasma number
Su1-Ph1 -
low int PhI
Su1-Ph1 +

23. select recombinants without Ph1-Su1 using molecular markes
The use of Ph1-Su1 in alien gene transfer in wheat
Alien DS line x Ph1-Su1 line F1
targeted recombination between the alien chromosome and wheat homoeologue
BC1
select recombinants without Ph1-Su1 using molecular markes

24. Acknowledgements
Kuey-Chu Chen
Ming-Cheng Luo
Karin R. Deal