FruitBreedomics – Technical SessionPyramiding scab and mildew resistance in the Agroscope breeding programI. Baumgartner (Agroscope)

San Giuseppe di Comacchio (Italy), June 19th 2015

Overview

• Objective: pyramiding resistance genes two or more genes against the same pathogen

• Crosses: parent selection (traits? pedigree?)

• SNP markers• Polymorphism in parents• Interpretaion of results: demonstration in

Excel

Mother (Resistances)

Father (Resistances)

Flowers

Fruits Seeds

ACW 11303 (Rvi6=Vf)

ACW 18522 (Rvi6=Vf, Rvi2=Vh2)

2246 352 2227

ACW 13652 (Rvi6=Vf, Pl2)

ACW 11567 (Rvi2=Vh2)

1370 323 2793

Progeny 1

Progeny 2

Pilot studies crosses at Agroscope

• Phenotypic symptoms (single resistance genes)?• Pedigree?

Be sure about the resistances

LG1

Rvi6 resistance to apple

scab

Scab and mildew resistances located on different chromosomes

LG2 LG3 LG4 LG5 LG6 LG7 LG8

LG9 LG10 LG11 LG12 LG13 LG14

LG15

LG16 LG17

Rvi2 resistance to apple

scab

Pl2 resistance

to powdery mildew

Apple genetic linkage map (17 chromosomes)

Trait / Locus Marker

Scab resistance Rvi6=Vf (LG1) Rvi6_42M10SP6_Y124 (SNP)

Scab resistance Rvi2=Vh2 (LG2) Rvi2_region53_M417 (SNP)

Mildew resistance Pl2 (LG11) Pl2_3_Y211 (SNP)

Fruit texture Md-PG1 (LG10) PG_FEM_LC_19 (SNP)

Shelf life Md-ACO1 (LG10) ACO_FEM_cg_4 (SNP)

Shelf life Md-ACS1 (LG15) ACS_FEM_cg_5 (SNP)

Crispness (LG16) Crispness_SNP1 (ss475881704; SNP1 from RosBREED)

Acidity (LG16) Acidity_SNP2 (ss475876558; SNP2 from RosBREED)

Markers used

Literature on SNPs for scab and mildew resistance

Code SNP

M A/C R A/G W A/T S C/G Y C/T K G/T H A/C/TV A/C/GD A/G/TB C/G/T

Jänsch et al. 2015

Polymorphism in parents

 Cross 1206

Rvi6_42M10SP6_Y124

Rvi2_region53_M417

Pl2_3_Y211

ACW13652 CT CC CTACW11567 CC CA CC

T = Rvi6 resisanceA = Rvi2 resistance

T = Pl2 resistance

 Cross 1205

Rvi6_42M10SP6_Y124

Rvi2_region53_M417

ACW11303 CT CCACW18522 CT CA

T = Vf resisanceA = Rvi2 resistance

Demonstration in Excel

Thank you for your attention

powdery mildew

Agroscope good food, healthy environment