Jim Kolmer
Maria Ordoñez
USDA-ARS Cereal Disease Laboratory St. Paul MN
Genetic differentiation of molecular genotypes and virulence phenotypes of
Puccinia triticina in Europe and world-wide.
Thanks to Kun Xiao
European P. triticina isolates Czech Rep. Slovakia - 20Germany - 2 Spain - 3France - 8England - 35Hungary - 6Italy - 15Romania - 2Turkey - 39Ukraine - 2
133 isolates - 122 after clone correction
• 23 SSR primer pairs
(18 CDL-5 Fr)
77 SSR genotypes• 20 Tc lines
89 virulence phenotypes
SSR Genotype Grouping
SSR Group No. isolates
Origin
EU1 19 CZ,GB,FR
EU2 29 CZ, TK,UK
EU3 10 ES, ITDurum types
EU4 15 CZ, FR, TK,GB
EU5 11 CZ, FR, GB, IT, TK
EU6 6 DL, FR, ES, GB, IT, TK
EU7 14 TK
EU8 18 CZ, FR, GB, HG, TK
Instruct – Bayesian methodology (no assumption of HW equilibrium)
K means clustering – maximize sum of distance2 between groups – minimize within groups
Consensus tree – bootstrapping
All methods indicate 8 SSR groups – identical grouping of isolates
Most groups cosmopolitan
(except EU7)
EU SSR Groups RST
RST = 0.50
EU2-EU7 ns
EU2-EU8 ns
EU7-EU8 ns
All other pairs significantly different
Stepwise mutation model – alleles close in mw more related
Reflect long term evolutionary relationships?
Homoplasy?
EU SSR Groups FST
FST = 0.32
All pairs significantly different
Assumes infinite alleles model
All alleles equally related
Genetic drift is source of variation
Detect recent immigrants better?
EU SSR GroupsVirulence phenotypesPHI = 0.46
EU3-EU5 ns
All other SSR groups significantly different for virulence
SSR genotype – virulence phenotype correlation = 0.55
World-wide P. triticina SSR groupsNorth America
South America
Central Asia
Middle East
Europe
New Zealand
South Africa
Durum isolates
(EU, SA, ME, NA)
Aegilops speltoides
587 isolates
FST = 0.331
Some geographical relationship
SA, NA vs. EU, ME, CA, NZ, SAF
Except ME1 with NA and SA
Durum groups distinct from common wheat groups
World-wide P. triticina SSR groupsRST = 0.561
Little geographic relationship
SSR groups from different continents closely related
many pairs ns different
Two major groups from common wheat – distinct from durum groups
Intercontinental migration of P. triticina?
SSR Group Virulence phenotypes
NA3 MCDSS, MBDSS MFPSS, MLDSSTBDSS, TCPSS
SA3 MCDSS, MBDSSMFPSS, MFDSSMDPSS, MBPNS
EU8 MCDSS, MBDSSMFPSS, MHPSSMCPSS, MNPSS
ME2 MCDSQ, MBDSQTCDSQ, PBDSSTHDSQ, PBGSL
EU2 PCPPQ, FHPSQPGPSS, PBPSNFHPPQ, FCPSQ
CA4 FHPSQ, FCPSLFHNSJ, FHNSGFGNSJ, FCNSS
EU7 FCMLQ, FBMSQFHPTQ, FGPSQFBFSQ, FCMSS
RST grouping
Highly related SSR groups have identical or similar virulence phenotypes
MBDSS-MCDSS
Mexico – early 1990s
North America -1996 (NA3)
South America- 1999 (SA3)
France – early 2000s (EU8)
Turkey- 2009 (EU8)
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