Durable Powdery mildew resistance in grapevines: myth or reality - - PowerPoint PPT Presentation

▶

Sep 26, 2023 273 likes •429 views

Durable Powdery mildew resistance in grapevines: myth or reality Summaira Riaz University of California, Davis Photo: NMSU Photo: Peter Magare Integrative approach Identification of resistance and marker development Durable Pathogen

SLIDE 1

Durable Powdery mildew resistance in grapevines: myth or reality

Photo: Peter Magare Photo: NMSU

Summaira Riaz University of California, Davis

SLIDE 2

Pathogen biology Identification

f resistance

and marker development Mechanisms

resistance Breeding (MAS)

Integrative approach

Durable field resistance

SLIDE 3

PM resistance loci in breeding program

Ren1
V. sylvestris/vinifera

chr13 Ren1

Run1, Run2
M. rotundifolia

chr12

Run1

Ren6
Ren7
V. piasezkii
Ren4
V. romanetii

chr9 chr19

Ren6 Ren7

chr18

Ren4 Run2

Other loci: Ren2 (V. cinerea B9) Ren3 and Ren9 (American spp hybrid, Regent) Ren8 (Villard blanc) Ren10 (Seyval blanc)

SLIDE 4

PM Breeding program at UC Davis

SLIDE 5

09314-102 09338-016 09331-047 07355-075 09356-235

PdR1 locus from b43-17
Chr14, MAS breeding
Field trials and wine tasting
Nursery release in 2017
Public release in 2020

Summary

SLIDE 6

Constant field evaluations

Isolate collection -- Summer 2016

13352-57-A = BC1 population with Ren6 locus

(infected leaves)

14370-37-C = Pyramid cross with 3 loci (infected

berries and rachis)

Carignane= C- isolate (infected leaves)
In vitro leaf assay
Greenhouse grown plants
Categorical scoring (1 – 5 scale)

SLIDE 7

11373 population retesting

SLIDE 8

2014 2017

A B

QTL analysis comparisons

SLIDE 9

SLIDE 10

Does combining loci with similar mechanisms of resistance improve overall resistance?

a b c c

SLIDE 11

What we have learned, what we don’t know?

Multiple loci to breed
Isolate specificity of different loci
Understanding of pathogen biology
How quickly do virulent isolates originate or

evolve?

Monitoring the spread of virulent isolates
Resistant loci are not surety for complete

eradication of PM

SLIDE 12

Conclusions

Preventive sprays in the beginning and end of season
Worth testing superior parental selections with wide

range of isolates

Understanding of mechanisms of resistance and how

underlying genes function is important – core set of effectors

SLIDE 13

Team Powdery mildew

SLIDE 14

Durable Powdery mildew resistance in grapevines: myth or reality - - PowerPoint PPT Presentation

Durable Powdery mildew resistance in grapevines: myth or reality

Summaira Riaz University of California, Davis

Integrative approach

PM resistance loci in breeding program

Other loci: Ren2 (V. cinerea B9) Ren3 and Ren9 (American spp hybrid, Regent) Ren8 (Villard blanc) Ren10 (Seyval blanc)

PM Breeding program at UC Davis

Summary

Constant field evaluations

Isolate collection -- Summer 2016

(infected leaves)

berries and rachis)

11373 population retesting

QTL analysis comparisons

Does combining loci with similar mechanisms of resistance improve overall resistance?

What we have learned, what we don’t know?

evolve?

eradication of PM

Conclusions

range of isolates

underlying genes function is important – core set of effectors

Team Powdery mildew

Thanks!

Funding Sources: American Vineyard Foundation,

Louise Rossi Endowed Chair in Viticulture