Population genetics of the wheat leaf rust fungus, Puccinia triticina in Central Asia

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Population genetics of the wheat leaf rust
fungus, Puccinia triticinain Central Asia

• J. A. Kolmer
• M. E. Ordonez
• USDA-ARS
• Cereal Disease Laboratory
• University of Minnesota -St. Paul

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Leaf Rust Collections

• Collections from 2002, 2004, 2005
• A. Morgounov - CIMMYT, Almaty Kazakhstan
• 137 isolates tested for virulence - 99 for SSR
• Caucasus - (Azb.,Geo. Arm.) 13 Uzbekistan - 7
• Tajikistan-Kyrgyzstan -15
• S. Kazakhstan - 39
• N. Kazakhstan- 25
• N. America-16
• Durum - 2
• Clone corrected within populations
• (race/SSR genotype)
• 20 differentials - 23 SSR loci

Super highway - Kazakhstan
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Virulence and SSR Diversity
Cauc. N. Kaz. S. Kaz Tjk-Kyg Uzbek N. Am.
No. isolates 13 25 39 15 7 16
No. races 12 21 37 15 7 16
No. SSR genotype 11 21 34 9 5 14
Shannon/ Ln(N) 0.92 0.93 0.94 0.70 0.76 0.93

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Tjk-Kyg-Uzb.-Caucasus not sig. differentiated
S. Kaz - N. Kaz.not sig. differentiated
Differentiation Statistics (Phi) of Pair-wise
Populations - Virulence phenotypes
Neighbor joining
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Differentiation (Fst) Statistics of Pair-wise
Populations SSR Genotypes

• Tjk-Kyg-Uzb - Caucasus not signif.
  differentiated
• S. Kaz - N. Kaz.
• not signif. differentiated
• 0.82 correlation with virulence tree

Neighbor joining
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Individual Isolates SSR Allele Variation

• -Central Asia
• 1 Avir Lr2a Vir Lr2c
• 2
• 4
• Most from Cauc-Tjk-Kry-Uzb.
• 3 Vir Lr2a Vir Lr2c
• Most from S. N.Kazakhstan
• -North America
• Avir Lr2a Vir Lr2c
• Vir Lr2a Lr2c
• Avir Lr2a Lr2c
• -Durum
• 6 Avir. to almost all Lr genes

Neighbor joining
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Central AsiaP. triticina populations
Come to Kazakhstan!!!

• Two distinct regional populations - mountain
  barrier
• Limited migration between regions - very few
  SSR-virulence genotypes in common
• Strong relationship between virulence and SSR
  genotypes

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Population Genetics of P. triticina - Future
Goals

• Describe world-wide populations
• 20 Tc line differentials
• 23 SSR loci
• North America, Central Asia, Middle East,
• South America, Europe
• Determine genetic relationships between
  populations -
• (MCDS - USA- S. America)