02b rvi2, rvi4, rvi11 snp markers and surprises-m. jänsch-20130221
1. Rvi2, Rvi4, Rvi11: SNP markers and surprises
Melanie Jänsch, Juliane Weger, Giovanni Broggini, Vincent Bus, Sue Gardiner,
Heather Bassett and Andrea Patocchi
2. Objectives
1. Identification of 5 single nucleotide polymorphisms
(SNPs) within an interval of 1 cM
2. Check for level of polymorphism of SNPs in 8 founders
3. Focus of this talk: apple scab resistance genes Rvi 11
(Vbj), Rvi 2 (Vh2) and Rvi 4 (Vh4)
(Bus et al., 2011)
3. repeat
Method – SNP development
or reject region
BLAST
available flanking markers on GD sequence
Primer Design + PCR
SEQ and SNP analysis
SNP found
SNP confirmation of map position
with subset of resistant , susceptible and
recombinant individuals closest to the gene
SNP polymorphism
test with 8 founders
SNP identified and validated
ok
ok
ok
ok
reject region
reject region
9. Rvi4 vs. Rvi15
• Indication that Rvi4 and Rvi15 may
derive from the same region
• Allelic?
• Phenotype of the two genes is the
same (PPP)
• Rvi4 symptoms visible after 3-4
days, Rvi15 after 7 days
• Difference due to difference level of
enhancement of the resistance
cascade?
005
Hi22d06
SNP_region_TNL1(20)
SNP_region_3(2)
SNP_region_10(1)
SNP_region_Vr2_3(3)
Rvi4
SNP_region_ARGH37(1)
CH02c02a
Hi02a07
S22_SCAR
2.1
0.4
1.3
Rvi4
CH02f06
ARGH37
Rvi15
ARGH17
CH02c02a
2.9
1.2
0.3
1.7
Rvi15
(Bus et al., 2011)
10. Conclusion
• SNP markers for resistance genes most used in breeding
will be soon available.
• This will simplify marker assisted selection (MAS) and will
allow a reduction of its costs .
• The precise mapping of the genes increases the precision of
MAS and indicates the possible allelism of:
– Rvi2 and Rvi11
– Rvi4 and Rvi15