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)