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Population genetics of Puccinia triticina in North America. Maria E. Ordoñ ez James A. Kolmer. USDA-ARS-Cereal Disease Laboratory University of Minnesota St. Paul, MN. P. triticina collections. 89 isolates from U.S. 2004-2005 37 isolates from the U.S. 1980’s 1990’s
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Population genetics of Puccinia triticina in North America Maria E. Ordoñez James A. Kolmer USDA-ARS-Cereal Disease Laboratory University of Minnesota St. Paul, MN
P. triticina collections • 89 isolates from U.S. 2004-2005 • 37 isolates from the U.S. 1980’s 1990’s • 20 isolates from Canada mid 1990’s • 5 isolates from durum wheat from Mexico 2003 Total = 151
Virulence phenotypes on 20 Thatcher near-isogenic lines • Molecular genotypes with 23 simple sequence repeat markers (SSR) 89 virulence phenotypes 73 SSR genotypes
B C NJ tree of clone corrected virulence phenotypes M FPN DL TM- 17 P-17 S Groups based on Vir/Avir to Lr1, Lr2a, Lr2c, Lr3, Lr3bg, Lr17 and Lr28 TK T’
Durum NJ tree of clone corrected SSR genetic distances FPND B P-17 S L T’ TKM 9 groups based on SSR and virulence to Lr1, Lr2a, Lr2c, Lr3, Lr3bg, Lr17 and Lr28 TM-17
Distribution of SSR allelic variation, diversity index, heterozygosity FSTRST Among pop. 21% 41% Within pop. 79% 59% I = 0.7577 Ho = 0.6508 He = 0.4507
Unrooted NJ dendrogram based on pair-wise FST values for SSR genotypes Significant difference (p<0.05) FPND - P-17 TKM - TM-17 T’ - all S - all Durum - all
Summary • Several groups of P. triticina found in NA based on virulence phenotype and SSR genotype • Difference in virulence and SSR genotypes suggest introduction or migration of a new race: • TM-17 and other T, K, M • T’ and other T races • Similar virulence and SSR genotype suggest mutation and selection: • T low on Lr14a and Lr20, and T high on Lr14a and Lr20 • T, M, K races • P, F races • P-17 and other P races different groups • Durum isolates genetically different from common wheat isolates