# Presentation: 764992

## Aegilops speltoides Ph1 suppressors

**Practical utility for wheat  **

## Chromosome 5B is responsible for diploid-like meiotic chromosome pairing in hexaploid T. aestivum 

**Chromosome 5B is responsible for diploid-like meiotic chromosome pairing in hexaploid *****T. aestivum****** ***

**R. Riley, Heredity 15:407-429, 1960****  **

**Euploid**

**Nullisomic 5B**

## Wild emmer wheat

**Wild emmer wheat**
**(AABB genomes )**

***Triticum urartu***** **
**(AA genomes)**

***Aegilops speltoides***** **
**SS genomes**
**(extant relative of the B genome)**

## Aegilops speltoides 

***Aegilops speltoides***** **

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

## T. aestivum x Ae. speltoides 

***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. 26:279-287, 1983**** **

## Mean numbers of chiasmata per cell in hybrids involving low- and high-pairing Ae. speltoides inbred lines 

**Mean numbers of chiasmata per cell in hybrids involving low- and high-pairing *****Ae. speltoides***** inbred lines **

**No. chismata**

**low-pairing **

**high pairing**

***Ae. speltoides***** x *****Ae. tauschii***

***Ae. speltoides x Ae. caudata***

## 	    low	     int.	    PhI

- 0

- 2

- 4

- 6

- 8

- 10

- 12

- 14

- 16

***	******    *****low*****	******     *****int.*****	******    Ph******I***

**Chen et al. TAG 88:97-101, 1994**

**The average chiasma number per cell in hybrids *****T. aestivum *****backcrosses x *****Ae. variabilis*****  **

**Mean chiasma number **

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

**Comparison of *****Ae. speltoides***** chromosome 1S and *****T. monococcum***** chromosome 1A****m**** genetic maps**** **

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

**Comparison of *****Ae. speltoides***** chromosome 3S and *****T. monococcum***** chromosome 3A****m**** genetic maps**** **

## Slide 10

## 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**

## 5S

**Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)**

**5S**

- 0

- 1

- 2

- 3

- 4

- 5

- 6

- 7

- 8

- 9

- 10

## 5S

**Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)**

**5S**

**7S**

**3S**

**3S+7S**

**3S+7S+5S**

- 0

- 1

- 2

- 3

- 4

- 5

- 6

- 7

- 8

- 9

- 10

## 5S

**Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)**

**5S**

**7S**

**3S**

**3S+7S**

**3S+7S+5S**

- 0

- 1

- 2

- 3

- 4

- 5

- 6

- 7

- 8

- 9

- 10

## 5S

**Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)**

**5S**

**7S**

**3S**

**3S+7S**

**3S+7S+5S**

- 0

- 1

- 2

- 3

- 4

- 5

- 6

- 7

- 8

- 9

- 10

## 5S

**Increase in the mean number of chiasmata per cell over background (= 7 chiasmata per cell)**

**5S**

**7S**

**3S**

**3S+7S**

**3S+7S+5S**

- 0

- 1

- 2

- 3

- 4

- 5

- 6

- 7

- 8

- 9

- 10

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

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

## -

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

**-**

**+**

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

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

## PCR assay for marker PSR1205 using Ae. speltoides genome specific primers 

**Chinese Spring**** **

**Ae. speltoides**** **

**BC****4 ****wheat segregant without *****Ph1-Su1***

**BC****4 ****wheat segregant with *****Ph1-Su1***

**PCR assay for marker PSR1205 using *****Ae. speltoides***** genome specific primers **

## 	    low	     int.	    PhI

- 0

- 2

- 4

- 6

- 8

- 10

- 12

- 14

- 16

***	******    *****low*****	******     *****int.*****	******    Ph******I***

**Chen et al. TAG 88:97-101, 1994**

**The average chiasma number per cell in hybrids *****T. aestivum *****backcrosses x *****Ae. variabilis*****  **

**Mean chiasma number **

## -

**Chen et al. TAG 88:97-101**

***Su1-Ph1***** data**

**low*****	*****int      *****   Ph******I***

**The average chiasma number per cell in hybrids *****T. aestivum***** backrosses x *****Ae. variabilis*****  **

**Mean chiasma number **

***Su1-Ph1***
**-**

***Su1-Ph1***
**+**

## 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**

**BC****1**
**select recombinants without *****Ph1-Su1 *****using molecular markes **

## Acknowledgements

**Kuey-Chu Chen**
**Ming-Cheng Luo**
**Karin R. Deal **

## Slide 25

## Slide 26

## Slide 27