Exploiting Hybrid Potato Breeding for Accelerating Introgression and Stacking of

New Resistance Sources against Phytophthora infestans

Asmaa Youssef

EuroBlight Workshop

14-05-2019

Content

The state-of-the-art in resistance to late blight

Utilizing hybrid potato breeding for developing resistance to late

blight

Packing up all of the Solanum weapons against late blight

The cellular interaction between host plants and P. infestans

NB-LRRs/NLRs (also called Rpi genes )

Resistance

PRRs + NB-LRRs/NLRs Stable resistance

Source: http://www.apsnet.org/edcenter/intropp/lessons/fungi/oomycetes/pages/lateblight.aspx Dodds and Rathjen (2010)

and apoplastic effectors

563 cytoplasmic

Haverkort et al. (2016)

• Up to date, there are about 70 mapped and/or clonedresistance to P. infestans (Rpi)genes from potato and its wild relatives, and are located on chromosome IV, V, VI, VII, VIII, IX, X and XI.

• Two PRRs were mapped on Scr74-response receptor on chromosome IX and ELR chromosome XII.

Rpi-sto2Scr74-response receptor

The phytotoxin-like 74-amino acid secreted cysteine-rich (scr74) protein is an apoplastic effectors of P. infestans.

Stable Resistance

PRRs

NLRs

NRCs

(-)veregulators

(+)veregulators

S genesBreeding potato for a

stable resistance against Phytophthora infestansBreeding potato for a stable

resistance against the late blight

The traditional tetraploid breeding of potato cv. Bionica

took about 46 years to introduced the Rpi-blb2 gene from Solanum bulbocastanum

Haverkort et al. (2009)

Content

The state-of-the-art in resistance to late blight

Utilizing hybrid potato breeding for developing resistance to late

blight

Packing up all of the Solanum weapons against late blight

Stable resistance

Hybrid potato

breeding

Mapping-by-

sequencing

marker-assistedbreeding

Rpi genes from

Solanumspecies

Effectoromics

14-05-2019

Hybrid potato breeding for accelerating introgression and

stacking of Rpi genes

• Introgression and stacking of new traits can be achieved within few to some years (Lindhout et al., 2011, 2018; Ying et al., 2019).

14-05-2019

Hybrid Potato Breeding Scheme

Ying et al. (2019)

F2

x

Trait introduction and stacking via marker-assisted backcross breeding EU H2020 Project

vStep 2: Back cross

Step 3: Selfing

Step 1:Cross

Result

Donor parent(resistant but commercially unattractive)

Resistance gene on chromosome 11

Existing variety(not resistant but commercially attractive)

1st backcross 2nd backcross

Existing variety but resistant

With recurrent parent

Rpi1

Rpi1+Rpi2

R-gene

01 02 03 04 05 06 07 08 09 10 11 1205

2.6

11.4

30.1

52.3

60.0

71.2

86.4

4.8

25.5

33.3

40.445.148.2

2.9

35.6

45.9

54.658.2

5.2

14.7

50.2

60.2

69.7

1.4

7.7

12.7

20.3

40.5

51.7

5.98.7

32.1

40.9

58.0

4.9

31.6

51.555.9

3.2

8.5

36.1

43.4

56.8

5.5

10.5

21.2

44.0

58.7

33.7

54.1

3.8

14.8

20.1

46.1

54.2

36.2

47.150.8

52.255.7

58.6

14.2

41.245.2

6.1

11.7

60.0

Rpi2x

Content

The state-of-the-art in resistance to late blight

Utilizing hybrid potato breeding for developing resistance to late

blight

Packing up all of the Solanum weapons against late blight

Rpi genes-donor Solanum species used for gene pyramiding

14-05-2019

S. tarijense 852-5Rpi-tar1, Chr10

position ~53 Mb

S. avilesii 478-2Rpi-avl1, Chr11

position ~1.8 Mb

S. venturii 283-1Rpi-vnt1, Chr9

position ~51 Mb

S. chacoense 543-5Rpi-chc1, Chr10 position ~53 Mb

14

2015: susceptible hybrid x resistant source2016: marker assisted backcrossings2017: field trial with double stack resistant hybrid

DEMONSTRATION TRIAL IN 2017

Rpi1SusceptibleRpi1+Rpi2Rpi2

2017 field trial: Diploid potato with double Rpi gene stack exhibited higher level of resistance to the P. infestans isolate IPO-C over three locations in NL

14-05-2019

0

1

2

3

4

5

6

7

8

9

10

No genes avl1 chc1 tar1 vnt1 avl1+chc1 avl1+tar1 avl1+vnt1 tar1+vnt1 chc1+vnt1

Resi

stan

ce le

vel

Rpi gene composition

Haarweg 33 dpi Haarweg 62 dpi

Ying et al. (2019)

2017 field trial: Diploid potato with double Rpi gene stack exhibited higher level of resistance to the P. infestans isolate IPO-C over three locations in NL

14-05-2019

0

1

2

3

4

5

6

7

8

9

10

No genes avl1 chc1 tar1 vnt1 avl1+chc1 avl1+tar1 avl1+vnt1 tar1+vnt1 chc1+vnt1

Resi

stan

ce le

vel

Rpi gene composition

Wijster 31 dpi Hoge Born 32 dpi Haarweg 33 dpi

Ying et al. (2019)

2018 field trial: Diploid potato with double Rpi gene stack exhibited higher level of resistance to the P. infestans isolate Blue-13

14-05-2019

0

1

2

3

4

5

6

7

8

9

10

Avl1 Vnt1 Chc1 + Avl1 Tar1 + Avl1 Vnt1 + Avl1 Chc1 + Vnt1 Tar1 + Vnt1 Chc1 + Vnt1 +Avl1

Tar1 + Vnt1 +Avl1

Bionica (Scontrl.)

Sarpo Mira (Rcontrl.)

Fontane (Scontrl.)

Resi

stan

ce le

vel

Rpi gene composition

Conclusions

• There is an increased level of resistance.• Variation of resistance conferred by different Rpi genes and their

combinations, which may differ according to time and location.• Additional trials over more years and locations are needed to manage

resistance genes.

Future research

19

1. More genetic backgrounds2. More stacks of Rpi gene combinations3. Repeat field trials over multiple geographic locations

Acknowledgments

Selected ReferencesAguilera-Galvez, C. et al.(2018) ‘Two different R gene loci co-evolved with Avr2 of Phytophthora infestans and confer

distinct resistance specificities in potato’, Studies in Mycology, 89, pp. 105–115.

Chen, X. et al. (2018) ‘Identification and rapid mapping of a gene conferring broad-spectrum late blight resistance in the diploid potato species Solanum verrucosum through DNA capture technologies’, Theoretical and Applied Genetics, 131, pp. 1287–1297.

Du, J. et al. (2015) ‘Elicitin recognition confers enhanced resistance to Phytophthora infestans in potato’, Nature Plants, 1, pp. 1–5. doi: 10.1038/nplants.2015.34.

Haverkort, A. J. et al.(2016) ‘Durable Late Blight Resistance in Potato Through Dynamic Varieties Obtained by Cisgenesis: Scientific and Societal Advances in the DuRPh Project’, Potato Research. Potato Research, 59, pp. 35–66.

Rietman, H. (2011). Putting the Phytophthora infestans genome sequence at work; multiple novel avirulence and potato resistance gene candidates revealed, Wagningen PhD thesis.

Verzaux, E. et al. (2011) ‘High Resolution Mapping of a Novel Late Blight Resistance Gene Rpi-avl1, from the Wild Bolivian Species Solanum avilesii’, American Journal of Potato Research, 88, pp. 511–519.

Vleeshouwers, V. G. A. A. et al.(2011) ‘Understanding and Exploiting Late Blight Resistance in the Age of Effectors’, Annual Review of Phytopathology, 49, pp. 507–531.

Ying S., Viquez-Zamora M., den Uil D., Sinnige J., Kruyt H., Lindhout P. and van Heusden S. (2019). High Speed Potato Breeding (HiSPoB). American Journal of Potato Research (submitted).